-- Inventory Manager: Touch UI on monitor
-- Main computer (networked). Computer 1 sits next to dropper_0 and auto-dispenses.

-------------------------------------------------
-- Default configuration (overridden by .manager_config)
-------------------------------------------------

local DROPPER_NAME  = "minecraft:dropper_9"
local BARREL_NAME   = "minecraft:barrel_0"
local POLL_INTERVAL = 2    -- seconds between barrel checks
local MONITOR_SIDE  = "left"
local SCAN_INTERVAL = 120  -- seconds between full background scans
local SMELT_INTERVAL = 3   -- seconds between furnace checks
local SMELT_RESERVE  = 128 -- keep at least 2 stacks of each raw material
local DEFRAG_INTERVAL = 600 -- seconds between defrag passes (10 min)
local COMPOST_INTERVAL = 3  -- seconds between composter checks
local ALERT_INTERVAL  = 15 -- seconds between alert re-checks
local CACHE_FILE     = ".inventory_cache"  -- persistent cache file
local SMELTER_MONITOR_SIDE = "top"
local DISABLED_RECIPES_FILE = ".disabled_recipes"

-- Network sync (for client displays)
local BROADCAST_CHANNEL  = 4200
local ORDER_CHANNEL      = 4201
local BROADCAST_INTERVAL = 1   -- seconds between state broadcasts

-- Crafting turtle
local CRAFT_CHANNEL       = 4203
local CRAFT_REPLY_CHANNEL = 4204

-- Remote reboot system channel (all devices listen on this)
local SYSTEM_CHANNEL      = 4205

-------------------------------------------------
-- Idempotent command tracking
-------------------------------------------------

local processedCmdIds = {}   -- commandId -> os.epoch("utc") ms
local CMD_TTL_MS      = 300000  -- 5 minutes

local function isCommandDuplicate(commandId)
    if not commandId then return false end
    local entry = processedCmdIds[commandId]
    if entry and (os.epoch("utc") - entry) < CMD_TTL_MS then
        return true
    end
    return false
end

local function recordCommandId(commandId)
    if not commandId then return end
    processedCmdIds[commandId] = os.epoch("utc")
end

local function cleanupCommandIds()
    local cutoff = os.epoch("utc") - CMD_TTL_MS
    for id, ts in pairs(processedCmdIds) do
        if ts < cutoff then processedCmdIds[id] = nil end
    end
end

-------------------------------------------------
-- Load config from file if present
-------------------------------------------------

local CONFIG_FILE = ".manager_config"
local _loadedConfig = nil  -- stored for deferred overrides (compost settings declared later)

-------------------------------------------------
-- Structured logging
-------------------------------------------------

local log = dofile("lib/log.lua")

local function loadConfig()
    if not fs.exists(CONFIG_FILE) then return end
    local f = fs.open(CONFIG_FILE, "r")
    local data = f.readAll()
    f.close()
    local ok, cfg = pcall(textutils.unserialiseJSON, data)
    if not ok or not cfg then
        log.warn("CONFIG", "Failed to parse %s", CONFIG_FILE)
        return
    end
    _loadedConfig = cfg
    -- Peripheral names
    if cfg.dropperName      then DROPPER_NAME      = cfg.dropperName      end
    if cfg.barrelName       then BARREL_NAME        = cfg.barrelName       end
    if cfg.monitorSide      then MONITOR_SIDE       = cfg.monitorSide      end
    if cfg.smelterMonitorSide then SMELTER_MONITOR_SIDE = cfg.smelterMonitorSide end
    -- Timing intervals
    if cfg.pollInterval     then POLL_INTERVAL      = cfg.pollInterval     end
    if cfg.scanInterval     then SCAN_INTERVAL      = cfg.scanInterval     end
    if cfg.smeltInterval    then SMELT_INTERVAL     = cfg.smeltInterval    end
    if cfg.defragInterval   then DEFRAG_INTERVAL    = cfg.defragInterval   end
    if cfg.compostInterval  then COMPOST_INTERVAL   = cfg.compostInterval  end
    if cfg.alertInterval    then ALERT_INTERVAL     = cfg.alertInterval    end
    if cfg.broadcastInterval then BROADCAST_INTERVAL = cfg.broadcastInterval end
    -- Reserves
    if cfg.smeltReserve     then SMELT_RESERVE      = cfg.smeltReserve     end
    -- Modem channels
    if cfg.broadcastChannel then BROADCAST_CHANNEL  = cfg.broadcastChannel end
    if cfg.orderChannel     then ORDER_CHANNEL      = cfg.orderChannel     end
    if cfg.craftChannel     then CRAFT_CHANNEL      = cfg.craftChannel     end
    if cfg.craftReplyChannel then CRAFT_REPLY_CHANNEL = cfg.craftReplyChannel end
    -- Log level
    if cfg.logLevel         then log.setLevel(cfg.logLevel)                end
    log.info("CONFIG", "Loaded from %s", CONFIG_FILE)
end

loadConfig()

-------------------------------------------------
-- Furnace types to manage
-------------------------------------------------

local FURNACE_TYPES = {
    "minecraft:furnace",
    "minecraft:smoker",
    "minecraft:blast_furnace",
}

-- Furnace slots: 1 = input, 2 = fuel, 3 = output (standard Minecraft)
local SLOT_INPUT  = 1
local SLOT_FUEL   = 2
local SLOT_OUTPUT = 3

-------------------------------------------------
-- Load data tables from external files (data/)
-------------------------------------------------

local SMELTABLE        = dofile("data/smeltable.lua")
local FUEL_LIST        = dofile("data/fuel.lua")
local _compostData     = dofile("data/compostable.lua")
local COMPOSTABLE      = _compostData.items
local COMPOST_TRASH    = _compostData.trash
local CRAFTABLE        = dofile("data/craftable.lua")
local LOW_STOCK_ALERTS = dofile("data/alerts.lua")

-- Pre-build furnace compatibility sets for O(1) lookup
for _, recipe in pairs(SMELTABLE) do
    recipe.furnaceSet = {}
    for _, ft in ipairs(recipe.furnaces) do
        recipe.furnaceSet[ft] = true
    end
end

-- Pre-built smelt candidate lists per furnace type (sorted: food first, then alpha)
local smeltCandidatesByType = {}
do
    for _, ftype in ipairs(FURNACE_TYPES) do
        smeltCandidatesByType[ftype] = {}
    end
    for itemName, recipe in pairs(SMELTABLE) do
        local isFood = recipe.furnaceSet["minecraft:smoker"] or false
        for ft, _ in pairs(recipe.furnaceSet) do
            table.insert(smeltCandidatesByType[ft], { name = itemName, recipe = recipe, food = isFood })
        end
    end
    for _, list in pairs(smeltCandidatesByType) do
        table.sort(list, function(a, b)
            if a.food ~= b.food then return a.food end
            return a.name < b.name
        end)
    end
end

-- Build fuel set for quick lookup
local FUEL_SET = {}
for _, f in ipairs(FUEL_LIST) do FUEL_SET[f.name] = true end

-- Build compostable set for quick lookup
local COMPOSTABLE_SET = {}
for _, name in ipairs(COMPOSTABLE) do COMPOSTABLE_SET[name] = true end

-- Compost settings (overridable via config)
local COMPOST_RESERVE = 128 -- 2 stacks
local COMPOST_DROPPER = "minecraft:dropper_10"
local COMPOST_HOPPER  = "minecraft:hopper_0"

if _loadedConfig then
    if _loadedConfig.compostReserve then COMPOST_RESERVE = _loadedConfig.compostReserve end
    if _loadedConfig.compostDropper then COMPOST_DROPPER = _loadedConfig.compostDropper end
    if _loadedConfig.compostHopper  then COMPOST_HOPPER  = _loadedConfig.compostHopper  end
end

-- Crafting grid-to-slot mapping
local GRID_TO_SLOT = {1, 2, 3, 5, 6, 7, 9, 10, 11}

-------------------------------------------------
-- Shared UI helpers (drawing, zones, craft math)
-------------------------------------------------

local ui = dofile("lib/ui.lua")

-- Active alerts (populated by checkAlerts)
local activeAlerts = {}

-------------------------------------------------
-- State version tracking (for delta broadcasting)
-------------------------------------------------

local stateVersion = 0
local lastBroadcastVersion = -1
local configDirty = true

local function bumpStateVersion()
    stateVersion = stateVersion + 1
end

-------------------------------------------------
-- Cached data (updated by background scanner)
-------------------------------------------------

local cache = {
    catalogue  = {},    -- itemName -> { {chest=name, total=N}, ... }
    itemList   = {},    -- sorted list of { name, total }
    itemListDirty = false, -- lazy rebuild flag for itemList
    grandTotal = 0,
    chestCount = 0,
    totalSlots = 0,
    usedSlots  = 0,
    freeSlots  = 0,
    usedRatio  = 0,
    dropperOk  = false,
    barrelOk   = false,
    furnaceCount  = 0,
    furnaceStatus = {},   -- per-furnace { name, type, input, fuel, output, active }
    droppers      = {},   -- list of available dropper peripherals for dispensing
}

-- Client-registered droppers, keyed by clientId
local clientDroppers = {}

-------------------------------------------------
-- Activity state (shown on monitor)
-------------------------------------------------

local activity = {
    sorting    = false,   -- barrel sort in progress
    dispensing = false,   -- order in progress
    scanning   = false,   -- background scan in progress
    smelting   = false,   -- auto-smelt in progress
    defragging = false,   -- defrag in progress
    composting = false,   -- auto-compost in progress
    crafting   = false,   -- crafting in progress
}

-------------------------------------------------
-- Instant cache adjustment (no scan needed)
-------------------------------------------------

--- Adjust cached counts for a single item move.
-- delta > 0 means items arrived in chestName;
-- delta < 0 means items left chestName.
local function adjustCache(itemName, chestName, delta)
    if delta == 0 then return end

    -- 1) catalogue: per-chest totals
    local cat = cache.catalogue
    if delta > 0 then
        -- Items added to a chest
        if not cat[itemName] then cat[itemName] = {} end
        local found = false
        for _, entry in ipairs(cat[itemName]) do
            if entry.chest == chestName then
                entry.total = entry.total + delta
                found = true
                break
            end
        end
        if not found then
            table.insert(cat[itemName], { chest = chestName, total = delta })
        end
    else
        -- Items removed from a chest
        if cat[itemName] then
            for idx, entry in ipairs(cat[itemName]) do
                if entry.chest == chestName then
                    entry.total = entry.total + delta  -- delta is negative
                    if entry.total <= 0 then
                        table.remove(cat[itemName], idx)
                    end
                    break
                end
            end
            -- Remove item from catalogue entirely if no sources left
            if #cat[itemName] == 0 then
                cat[itemName] = nil
            end
        end
    end

    -- 2) Mark itemList as needing rebuild (deferred until actually read)
    cache.itemListDirty = true

    -- 3) Update grandTotal incrementally
    cache.grandTotal = cache.grandTotal + delta

    -- 4) Bump state version for delta broadcasting
    bumpStateVersion()
end

--- Rebuild itemList from catalogue if dirty (lazy rebuild)
local function ensureItemList()
    if not cache.itemListDirty then return end
    local itemList = {}
    local grandTotal = 0
    for name, sources in pairs(cache.catalogue) do
        local total = 0
        for _, s in ipairs(sources) do total = total + s.total end
        grandTotal = grandTotal + total
        table.insert(itemList, { name = name, total = total })
    end
    table.sort(itemList, function(a, b) return a.total > b.total end)
    cache.itemList   = itemList
    cache.grandTotal = grandTotal
    cache.itemListDirty = false
end

-------------------------------------------------
-- Inventory helpers (cached peripheral lists)
-------------------------------------------------

local PERIPHERAL_CACHE_TTL = 5  -- seconds
local cachedChests = nil
local cachedChestsTime = 0
local cachedFurnaces = nil
local cachedFurnacesTime = 0

local function invalidatePeripheralCaches()
    cachedChests = nil
    cachedFurnaces = nil
end

-- Peripheral handle cache (avoids re-creating proxy tables on every call)
-- Handles are cleared on peripheral_detach events and during full scans.
local wrapCache = {}

local function wrapCached(name)
    local handle = wrapCache[name]
    if handle then return handle end
    handle = peripheral.wrap(name)
    if handle then
        wrapCache[name] = handle
    end
    return handle
end

local function invalidateWrapCache(name)
    if name then
        wrapCache[name] = nil
    else
        wrapCache = {}
    end
end

local function getChests()
    local now = os.clock()
    if cachedChests and (now - cachedChestsTime) < PERIPHERAL_CACHE_TTL then
        return cachedChests
    end
    local chests = {}
    for _, name in ipairs(peripheral.getNames()) do
        if peripheral.getType(name) == "minecraft:chest" then
            table.insert(chests, name)
        end
    end
    cachedChests = chests
    cachedChestsTime = now
    return chests
end

local function getFurnaces()
    local now = os.clock()
    if cachedFurnaces and (now - cachedFurnacesTime) < PERIPHERAL_CACHE_TTL then
        return cachedFurnaces
    end
    local furnaces = {}
    for _, ftype in ipairs(FURNACE_TYPES) do
        for _, name in ipairs(peripheral.getNames()) do
            if peripheral.getType(name) == ftype then
                table.insert(furnaces, name)
            end
        end
    end
    cachedFurnaces = furnaces
    cachedFurnacesTime = now
    return furnaces
end

local function refreshFurnaceStatus()
    local furnaces = getFurnaces()
    local status = {}
    for _, fname in ipairs(furnaces) do
        local furnace = wrapCached(fname)
        if furnace then
            local contents = furnace.list()
            local entry = {
                name   = fname,
                type   = peripheral.getType(fname),
                input  = contents[SLOT_INPUT] or nil,
                fuel   = contents[SLOT_FUEL] or nil,
                output = contents[SLOT_OUTPUT] or nil,
                active = (contents[SLOT_INPUT] ~= nil and contents[SLOT_FUEL] ~= nil),
            }
            table.insert(status, entry)
        end
    end
    cache.furnaceStatus = status
    bumpStateVersion()
end

local function scanInventory(deviceName)
    local inv = wrapCached(deviceName)
    if not inv then return {} end
    local result = {}
    for slot, item in pairs(inv.list()) do
        if not result[item.name] then
            result[item.name] = { total = 0, slots = {} }
        end
        result[item.name].total = result[item.name].total + item.count
        result[item.name].slots[slot] = { name = item.name, count = item.count }
    end
    return result
end

-- Full scan: updates the global cache
-- onProgress(current, total, chestName) is called per chest if provided
local function refreshCache(onProgress)
    activity.scanning = true

    -- Clear handle cache so we pick up any changes
    invalidateWrapCache()

    -- Single pass over peripherals: classify into chests and furnaces
    local chests = {}
    local furnaces = {}
    local furnaceTypeSet = {}
    for _, ft in ipairs(FURNACE_TYPES) do furnaceTypeSet[ft] = true end

    for _, name in ipairs(peripheral.getNames()) do
        local ptype = peripheral.getType(name)
        if ptype == "minecraft:chest" then
            table.insert(chests, name)
        elseif furnaceTypeSet[ptype] then
            table.insert(furnaces, name)
        end
    end

    -- Update peripheral caches so getChests()/getFurnaces() stay fresh
    local now = os.clock()
    cachedChests = chests
    cachedChestsTime = now
    cachedFurnaces = furnaces
    cachedFurnacesTime = now

    local catalogue = {}
    local totalSlots = 0
    local usedSlots = 0

    for ci, chest in ipairs(chests) do
        if onProgress then onProgress(ci, #chests, chest) end
        local inv = wrapCached(chest)
        if inv then
            totalSlots = totalSlots + inv.size()
            local contents = inv.list()
            for slot, item in pairs(contents) do
                usedSlots = usedSlots + 1
                if not catalogue[item.name] then
                    catalogue[item.name] = {}
                end
                -- Accumulate per-chest totals
                local found = false
                for _, entry in ipairs(catalogue[item.name]) do
                    if entry.chest == chest then
                        entry.total = entry.total + item.count
                        found = true
                        break
                    end
                end
                if not found then
                    table.insert(catalogue[item.name], { chest = chest, total = item.count })
                end
            end
        end
    end

    -- Build sorted item list
    local itemList = {}
    local grandTotal = 0
    for itemName, sources in pairs(catalogue) do
        local total = 0
        for _, s in ipairs(sources) do total = total + s.total end
        grandTotal = grandTotal + total
        table.insert(itemList, { name = itemName, total = total })
    end
    table.sort(itemList, function(a, b) return a.total > b.total end)

    -- Update cache atomically
    cache.catalogue  = catalogue
    cache.itemList   = itemList
    cache.grandTotal = grandTotal
    cache.chestCount = #chests
    cache.totalSlots = totalSlots
    cache.usedSlots  = usedSlots
    cache.freeSlots  = totalSlots - usedSlots
    cache.usedRatio  = totalSlots > 0 and (usedSlots / totalSlots) or 0
    cache.dropperOk  = peripheral.isPresent(DROPPER_NAME)
    cache.barrelOk   = peripheral.isPresent(BARREL_NAME)

    -- Discover all droppers on the network (for location-based dispensing)
    -- Use name-based matching as peripheral.getType() may return "inventory"
    -- as the primary type in some CC:Tweaked versions (1.99+)
    local droppers = {}
    for _, name in ipairs(peripheral.getNames()) do
        local isDropper = name:match("^minecraft:dropper_")
        if not isDropper and peripheral.hasType then
            isDropper = peripheral.hasType(name, "minecraft:dropper")
        end
        if not isDropper then
            isDropper = peripheral.getType(name) == "minecraft:dropper"
        end
        if isDropper and name ~= COMPOST_DROPPER then
            local isDefault = (name == DROPPER_NAME)
            table.insert(droppers, { name = name, isDefault = isDefault })
        end
    end
    -- Sort so default dropper comes first
    table.sort(droppers, function(a, b)
        if a.isDefault ~= b.isDefault then return a.isDefault end
        return a.name < b.name
    end)

    -- Merge in droppers registered by remote clients
    local seenNames = {}
    for _, d in ipairs(droppers) do seenNames[d.name] = true end
    for clientId, clientList in pairs(clientDroppers) do
        for _, d in ipairs(clientList) do
            if not seenNames[d.name] then
                table.insert(droppers, { name = d.name, isDefault = false, clientId = clientId })
                seenNames[d.name] = true
            end
        end
    end

    cache.droppers = droppers

    -- Furnace count already computed from single-pass above
    cache.furnaceCount = #furnaces

    -- Scan furnace contents for smelter dashboard
    refreshFurnaceStatus()

    activity.scanning = false
    bumpStateVersion()

    -- Persist cache to disk
    pcall(function()
        local data = {
            catalogue  = cache.catalogue,
            itemList   = cache.itemList,
            grandTotal = cache.grandTotal,
            chestCount = cache.chestCount,
            totalSlots = cache.totalSlots,
            usedSlots  = cache.usedSlots,
            freeSlots  = cache.freeSlots,
            usedRatio  = cache.usedRatio,
            dropperOk  = cache.dropperOk,
            barrelOk   = cache.barrelOk,
            furnaceCount = cache.furnaceCount,
            furnaceStatus = cache.furnaceStatus,
            droppers   = cache.droppers,
            savedAt    = os.epoch("utc"),
        }
        local f = fs.open(CACHE_FILE, "w")
        f.write(textutils.serialise(data))
        f.close()
    end)
end

-- Load cache from disk (returns true if loaded)
local function loadCacheFromDisk()
    if not fs.exists(CACHE_FILE) then return false end
    local ok, err = pcall(function()
        local f = fs.open(CACHE_FILE, "r")
        local raw = f.readAll()
        f.close()
        local data = textutils.unserialise(raw)
        if data and data.catalogue and data.itemList then
            cache.catalogue    = data.catalogue
            cache.itemList     = data.itemList
            cache.grandTotal   = data.grandTotal   or 0
            cache.chestCount   = data.chestCount   or 0
            cache.totalSlots   = data.totalSlots   or 0
            cache.usedSlots    = data.usedSlots    or 0
            cache.freeSlots    = data.freeSlots    or 0
            cache.usedRatio    = data.usedRatio    or 0
            cache.dropperOk    = data.dropperOk    or false
            cache.barrelOk     = data.barrelOk     or false
            cache.furnaceCount = data.furnaceCount or 0
            cache.furnaceStatus = data.furnaceStatus or {}
            cache.droppers     = data.droppers     or {}
        else
            error("invalid cache data")
        end
    end)
    if not ok then
        log.warn("INIT", "Could not load cache: %s", tostring(err))
        return false
    end
    return true
end

-------------------------------------------------
-- Monitor setup
-------------------------------------------------

local mon = nil
local monName = nil
local smelterMon = nil
local smelterMonName = nil
local networkModem = nil
local networkModemName = nil
local craftTurtleName = nil

local function setupMonitor()
    mon, monName = ui.setupMonitor(MONITOR_SIDE, SMELTER_MONITOR_SIDE)
    return mon ~= nil
end

local function setupSmelterMonitor()
    smelterMon, smelterMonName = ui.setupSmelterMonitor(SMELTER_MONITOR_SIDE, monName)
    return smelterMon ~= nil
end

-------------------------------------------------
-- UI State
-------------------------------------------------

local selectedAmount = 1
local amountOptions = {1, 4, 8, 16, 32, 64}
local statusMessage = ""
local statusColor = colors.white
local statusTimer = 0

local touchZones = {}
local pendingZones = {}
local needsRedraw = true

local currentPage = 1
local totalPages = 1
local searchQuery = ""
local showKeyboard = false

-- Keyboard layout
local kbRows = {
    {"Q","W","E","R","T","Y","U","I","O","P"},
    {"A","S","D","F","G","H","J","K","L"},
    {"Z","X","C","V","B","N","M"},
}

-------------------------------------------------
-- Smelter dashboard state
-------------------------------------------------

local smelterView = "status"    -- "status" or "recipes"
local smelterPage = 1
local smelterTotalPages = 1
local smelterTouchZones = {}
local smelterPendingZones = {}
local smelterNeedsRedraw = true
local smeltingPaused = false
local disabledRecipes = {}      -- { ["minecraft:raw_iron"] = true }

local function loadDisabledRecipes()
    if not fs.exists(DISABLED_RECIPES_FILE) then return end
    pcall(function()
        local f = fs.open(DISABLED_RECIPES_FILE, "r")
        local raw = f.readAll()
        f.close()
        local data = textutils.unserialise(raw)
        if type(data) == "table" then
            if data.disabled then disabledRecipes = data.disabled end
            if data.paused ~= nil then smeltingPaused = data.paused end
        end
    end)
end

local function saveDisabledRecipes()
    pcall(function()
        local f = fs.open(DISABLED_RECIPES_FILE, "w")
        f.write(textutils.serialise({ disabled = disabledRecipes, paused = smeltingPaused }))
        f.close()
    end)
end

-- Get items filtered by search query
local function getFilteredItems()
    ensureItemList()
    return ui.getFilteredItems(cache.itemList, searchQuery)
end

local function addZone(x1, y1, x2, y2, action, data)
    ui.addZone(pendingZones, x1, y1, x2, y2, action, data)
end

local function hitTest(x, y)
    return ui.hitTest(touchZones, x, y)
end

local function addSmelterZone(x1, y1, x2, y2, action, data)
    ui.addZone(smelterPendingZones, x1, y1, x2, y2, action, data)
end

local function smelterHitTest(x, y)
    return ui.hitTest(smelterTouchZones, x, y)
end

-------------------------------------------------
-- Drawing helpers (delegated to shared ui module)
-------------------------------------------------

local draw = nil   -- set to window target before each draw cycle

local function setDrawTarget(target)
    draw = target
    ui.draw = target
end

local function monWrite(x, y, text, fg, bg)   ui.monWrite(x, y, text, fg, bg) end
local function monFill(y, color)               ui.monFill(y, color) end
local function monCenter(y, text, fg, bg)      ui.monCenter(y, text, fg, bg) end
local function monBar(x, y, w, r, bc, bgc)     ui.monBar(x, y, w, r, bc, bgc) end
local function drawButton(x, y, t, fg, bg, pl, pr) return ui.drawButton(x, y, t, fg, bg, pl, pr) end

-------------------------------------------------
-- Dashboard (reads ONLY from cache — no peripheral calls — instant)
-------------------------------------------------

local function drawDashboard()
    if not mon then return end

    local w, h = mon.getSize()
    pendingZones = {}

    -- Offscreen buffer
    setDrawTarget(window.create(mon, 1, 1, w, h, false))
    draw.setBackgroundColor(colors.black)
    draw.clear()

    -- ===== Title bar =====
    monFill(1, colors.blue)
    monCenter(1, " ** INVENTORY MANAGER ** ", colors.white, colors.blue)

    -- ===== Status bar =====
    monFill(2, colors.gray)
    local statusParts = {}
    table.insert(statusParts, string.format(" Chests: %d", cache.chestCount))
    table.insert(statusParts, cache.dropperOk and "Dropper: OK" or "Dropper: --")
    table.insert(statusParts, cache.barrelOk  and "Barrel: OK"  or "Barrel: --")
    if cache.furnaceCount and cache.furnaceCount > 0 then
        table.insert(statusParts, string.format("Furnaces: %d", cache.furnaceCount))
    end

    -- Activity indicators
    local actParts = {}
    if activity.sorting    then table.insert(actParts, "SORTING")    end
    if activity.dispensing then table.insert(actParts, "DISPENSING") end
    if activity.smelting   then table.insert(actParts, "SMELTING")   end
    if activity.scanning   then table.insert(actParts, "SCANNING")   end
    if activity.defragging then table.insert(actParts, "DEFRAG")     end
    if activity.composting then table.insert(actParts, "COMPOST")    end

    monWrite(2, 2, table.concat(statusParts, "  |  "), colors.white, colors.gray)

    if #actParts > 0 then
        local actStr = " " .. table.concat(actParts, " | ") .. " "
        monWrite(w - #actStr, 2, actStr, colors.white, colors.orange)
    end

    -- ===== Divider =====
    monFill(3, colors.lightBlue)
    monCenter(3, string.rep("-", math.min(w - 4, 60)), colors.cyan, colors.lightBlue)

    -- ===== Storage capacity =====
    monFill(4, colors.black)
    local capLabel = string.format(" Storage: %d/%d slots (%d free)",
        cache.usedSlots, cache.totalSlots, cache.freeSlots)
    monWrite(2, 4, capLabel, colors.lightGray, colors.black)

    local barStart = #capLabel + 4
    local barWidth = w - barStart - 2
    if barWidth > 4 then
        local barColor = colors.lime
        if cache.usedRatio > 0.9 then barColor = colors.red
        elseif cache.usedRatio > 0.7 then barColor = colors.orange
        elseif cache.usedRatio > 0.5 then barColor = colors.yellow
        end
        monBar(barStart, 4, barWidth, cache.usedRatio, barColor, colors.gray)
        local pctStr = string.format(" %d%% ", math.floor(cache.usedRatio * 100))
        local pctX = barStart + math.floor(barWidth / 2) - math.floor(#pctStr / 2)
        monWrite(pctX, 4, pctStr, colors.white, barColor)
    end

    -- ===== Amount selector (row 5) =====
    monFill(5, colors.black)
    monWrite(2, 5, "Qty:", colors.lightGray, colors.black)
    local btnX = 7
    for _, amt in ipairs(amountOptions) do
        local label = tostring(amt)
        local bg = (amt == selectedAmount) and colors.cyan or colors.gray
        local fg = (amt == selectedAmount) and colors.white or colors.lightGray
        local x1, y1, x2, y2 = drawButton(btnX, 5, label, fg, bg)
        addZone(x1, y1, x2, y2, "amount", amt)
        btnX = x2 + 2
    end

    -- Refresh button
    local refreshBg = activity.scanning and colors.yellow or colors.green
    local refreshFg = activity.scanning and colors.black or colors.white
    local refreshTxt = activity.scanning and "Scanning" or "Refresh"
    local scanX = w - #refreshTxt - 3
    local sx1, sy1, sx2, sy2 = drawButton(scanX, 5, refreshTxt, refreshFg, refreshBg, 1, 1)
    addZone(sx1, sy1, sx2, sy2, "scan", nil)

    -- ===== Search bar + Pagination (row 6) =====
    monFill(6, colors.black)

    -- Keyboard toggle button
    local kbLabel = showKeyboard and " X " or " ? "
    local kbBg = showKeyboard and colors.red or colors.purple
    monWrite(2, 6, kbLabel, colors.white, kbBg)
    addZone(2, 6, 4, 6, "kb_toggle", nil)

    -- Search query display
    local queryDisplay = searchQuery
    if showKeyboard then
        queryDisplay = queryDisplay .. "|"
    elseif queryDisplay == "" then
        queryDisplay = "search..."
    end
    local fieldW = math.floor(w * 0.4)
    if fieldW < 10 then fieldW = 10 end
    local displayText = queryDisplay:sub(1, fieldW)
    displayText = displayText .. string.rep("_", math.max(0, fieldW - #displayText))
    monWrite(6, 6, displayText,
        (searchQuery == "" and not showKeyboard) and colors.gray or colors.white,
        colors.black)
    addZone(6, 6, 5 + fieldW, 6, "kb_toggle", nil)

    -- Filter items
    local filteredItems = getFilteredItems()

    -- Pagination
    local maxRows = h - 10
    if maxRows < 1 then maxRows = 1 end
    totalPages = math.max(1, math.ceil(#filteredItems / maxRows))
    if currentPage > totalPages then currentPage = totalPages end
    if currentPage < 1 then currentPage = 1 end

    -- Page controls (right side of row 6)
    local pageStr = string.format("Pg %d/%d", currentPage, totalPages)
    local navW = 3 + 1 + #pageStr + 1 + 3
    local navX = w - navW

    if currentPage > 1 then
        monWrite(navX, 6, " < ", colors.white, colors.gray)
        addZone(navX, 6, navX + 2, 6, "page_prev", nil)
    else
        monWrite(navX, 6, " < ", colors.lightGray, colors.black)
    end

    monWrite(navX + 4, 6, pageStr, colors.lightGray, colors.black)

    local nextX = navX + 4 + #pageStr + 1
    if currentPage < totalPages then
        monWrite(nextX, 6, " > ", colors.white, colors.gray)
        addZone(nextX, 6, nextX + 2, 6, "page_next", nil)
    else
        monWrite(nextX, 6, " > ", colors.lightGray, colors.black)
    end

    -- ===== Column headers (row 7) =====
    local row = 7
    monFill(row, colors.gray)
    monWrite(2,      row, "#",     colors.lightGray, colors.gray)
    monWrite(5,      row, "Item",  colors.lightGray, colors.gray)
    monWrite(w - 22, row, "Qty",   colors.lightGray, colors.gray)
    monWrite(w - 14, row, "Stock", colors.lightGray, colors.gray)
    monWrite(w - 1,  row, ">",     colors.lightGray, colors.gray)
    row = row + 1

    -- ===== Item rows (paginated + filtered) =====
    local maxCount = 0
    for _, item in ipairs(filteredItems) do
        if item.total > maxCount then maxCount = item.total end
    end
    if maxCount == 0 then maxCount = 1 end

    local startIdx = (currentPage - 1) * maxRows + 1
    local endIdx = math.min(startIdx + maxRows - 1, #filteredItems)

    if #filteredItems == 0 then
        monFill(8, colors.black)
        monFill(9, colors.black)
        if searchQuery ~= "" then
            monCenter(9, "No items match \"" .. searchQuery .. "\"", colors.gray, colors.black)
        else
            monCenter(9, "No items in storage", colors.gray, colors.black)
        end
        row = 10
    else
        for i = startIdx, endIdx do
            local item = filteredItems[i]
            local y = row
            local short = item.name:gsub("^minecraft:", ""):gsub("_", " ")
            short = short:sub(1,1):upper() .. short:sub(2)

            local maxNameLen = w - 30
            if #short > maxNameLen then
                short = short:sub(1, maxNameLen - 2) .. ".."
            end

            local rowBg = ((i - startIdx) % 2 == 0) and colors.black or colors.gray
            monFill(y, rowBg)

            monWrite(2, y, string.format("%2d", i), colors.lightBlue, rowBg)
            monWrite(5, y, short, colors.white, rowBg)
            monWrite(w - 22, y, tostring(item.total), colors.yellow, rowBg)

            local ratio = item.total / maxCount
            local barColor = colors.lime
            if ratio < 0.25 then barColor = colors.red
            elseif ratio < 0.5 then barColor = colors.orange
            end
            monBar(w - 14, y, 12, ratio, barColor, rowBg == colors.gray and colors.lightGray or colors.gray)

            monWrite(w - 1, y, ">", colors.orange, rowBg)
            addZone(1, y, w, y, "order", item.name)

            row = row + 1
        end
    end

    -- Fill remaining empty item rows
    local lastItemRow = h - 3
    while row <= lastItemRow do
        monFill(row, colors.black)
        row = row + 1
    end

    if showKeyboard then
        -- ===== Keyboard overlay (bottom 3 rows: h-2, h-1, h) =====
        local keyW = 3
        local keyGap = 1

        local kbDefs = {
            { keys = kbRows[1], specials = {{ label = " Bksp ", action = "kb_bksp", bg = colors.red }} },
            { keys = kbRows[2], specials = {{ label = " Done ", action = "kb_done", bg = colors.green }} },
            { keys = kbRows[3], specials = {
                { label = " Space ", action = "kb_space", bg = colors.lightGray },
                { label = " Clr ",   action = "kb_clear", bg = colors.orange },
            }},
        }

        for rowIdx, def in ipairs(kbDefs) do
            local y = h - 3 + rowIdx
            monFill(y, colors.black)

            -- Calculate total row width for centering
            local keysW = #def.keys * keyW + math.max(0, #def.keys - 1) * keyGap
            local specialsW = 0
            for _, sp in ipairs(def.specials) do
                specialsW = specialsW + keyGap + #sp.label
            end
            local rowW = keysW + specialsW
            local x = math.floor((w - rowW) / 2) + 1

            -- Draw letter keys
            for ki, key in ipairs(def.keys) do
                monWrite(x, y, " " .. key .. " ", colors.white, colors.gray)
                addZone(x, y, x + keyW - 1, y, "kb_key", key:lower())
                x = x + keyW
                if ki < #def.keys then x = x + keyGap end
            end

            -- Draw special keys
            for _, sp in ipairs(def.specials) do
                x = x + keyGap
                monWrite(x, y, sp.label, colors.white, sp.bg)
                addZone(x, y, x + #sp.label - 1, y, sp.action, nil)
                x = x + #sp.label
            end
        end
    else
        -- ===== Status message (h-2) =====
        monFill(h - 2, colors.black)
        if #activeAlerts > 0 then
            -- Show low-stock alerts scrolling through them
            local alertIdx = math.floor(os.epoch("utc") / 2000) % #activeAlerts + 1
            local a = activeAlerts[alertIdx]
            local alertMsg = string.format(" LOW STOCK: %s (%d/%d) ", a.label, a.current, a.min)
            monCenter(h - 2, alertMsg, colors.white, colors.red)
        elseif statusTimer > 0 and #statusMessage > 0 then
            monCenter(h - 2, statusMessage, statusColor, colors.black)
        end

        -- ===== Footer (h-1) =====
        ensureItemList()
        monFill(h - 1, colors.gray)
        local footerLeft = string.format(" Total: %d items | %d types ",
            cache.grandTotal, #cache.itemList)
        monWrite(2, h - 1, footerLeft, colors.white, colors.gray)

        if searchQuery ~= "" then
            local filterNote = string.format("| Showing %d ", #filteredItems)
            monWrite(2 + #footerLeft + 1, h - 1, filterNote, colors.yellow, colors.gray)
        end

        local timeStr = textutils.formatTime(os.time(), true)
        monWrite(w - #timeStr - 1, h - 1, timeStr, colors.lightGray, colors.gray)

        -- ===== Bottom accent (h) =====
        monFill(h, colors.blue)
        local bottomMsg = " Tap item to order "
        if activity.dispensing then
            bottomMsg = " DISPENSING... "
        elseif activity.smelting then
            bottomMsg = " SMELTING... "
        elseif activity.sorting then
            bottomMsg = " SORTING BARREL... "
        elseif activity.defragging then
            bottomMsg = " DEFRAGMENTING... "
        elseif activity.composting then
            bottomMsg = " COMPOSTING... "
        end
        monCenter(h, bottomMsg, colors.lightBlue, colors.blue)
    end

    -- Flush to monitor
    draw.setVisible(true)

    -- Swap zones
    touchZones = pendingZones
end

-------------------------------------------------
-- Crafting helpers (delegated to shared ui module)
-------------------------------------------------

--- Get stock total for an item from catalogue
local function getItemTotal(itemName)
    local have = 0
    if cache.catalogue[itemName] then
        for _, src in ipairs(cache.catalogue[itemName]) do
            have = have + src.total
        end
    end
    return have
end

local function getRecipeIngredients(recipe)
    return ui.getRecipeIngredients(recipe)
end

local function canCraftRecipe(recipe)
    return ui.canCraftRecipe(recipe, getItemTotal)
end

local function maxCraftBatches(recipe)
    return ui.maxCraftBatches(recipe, getItemTotal)
end

local function getMissingIngredients(recipe)
    return ui.getMissingIngredients(recipe, getItemTotal)
end

--- Execute a craft via the networked turtle.
-- Sends a craft_request message via modem with ingredient locations.
-- The turtle pulls items herself, crafts, pushes results back, and replies.
-- Requires the turtle to have a wired modem and run the updated craftingTurtle.lua.
local CRAFT_TIMEOUT = 15 -- seconds to wait for turtle reply

local function craftItem(recipeIdx)
    local recipe = CRAFTABLE[recipeIdx]
    if not recipe then
        log.error("CRAFT", "Invalid recipe index: %s", tostring(recipeIdx))
        return false, "Invalid recipe"
    end
    if not craftTurtleName then
        log.error("CRAFT", "No turtle detected on network")
        return false, "No turtle"
    end
    if not networkModem then
        log.error("CRAFT", "No modem available for craft commands")
        return false, "No modem"
    end

    -- Verify the turtle is still on the network
    if not peripheral.isPresent(craftTurtleName) then
        log.error("CRAFT", "Turtle offline: %s", craftTurtleName)
        return false, "Turtle offline"
    end

    log.info("CRAFT", "Starting craft: %s (turtle: %s)", recipe.output, craftTurtleName)

    activity.crafting = true
    needsRedraw = true
    smelterNeedsRedraw = true

    local chests = getChests()

    -- Build the slot map: for each grid position that needs an ingredient,
    -- find the exact chest and slot where the item is located.
    local slotMap = {} -- turtleSlot -> { chestName, chestSlot, itemName, count }
    local reservedSlots = {} -- "chestName:slot" -> true (prevent double-booking)

    for gridPos = 1, 9 do
        local itemName = recipe.grid[gridPos]
        if itemName then
            local turtleSlot = GRID_TO_SLOT[gridPos]
            local found = false

            if cache.catalogue[itemName] then
                for _, source in ipairs(cache.catalogue[itemName]) do
                    local chest = wrapCached(source.chest)
                    if chest then
                        for slot, slotItem in pairs(chest.list()) do
                            local key = source.chest .. ":" .. slot
                            if slotItem.name == itemName and not reservedSlots[key] then
                                slotMap[tostring(turtleSlot)] = {
                                    chestName = source.chest,
                                    chestSlot = slot,
                                    itemName  = itemName,
                                    count     = 1,
                                }
                                reservedSlots[key] = true
                                found = true
                                break
                            end
                        end
                    end
                    if found then break end
                end
            end

            if not found then
                log.error("CRAFT", "Cannot find %s in storage, aborting", itemName)
                activity.crafting = false
                needsRedraw = true
                smelterNeedsRedraw = true
                return false, "Missing ingredient: " .. itemName
            end
        end
    end

    -- Send craft request to turtle via modem
    local craftMessage = {
        type         = "craft_request",
        recipeIdx    = recipeIdx,
        output       = recipe.output,
        slots        = slotMap,
        returnChests = chests,
    }

    log.info("CRAFT", "Sending craft request to turtle on channel %d", CRAFT_CHANNEL)
    networkModem.transmit(CRAFT_CHANNEL, CRAFT_REPLY_CHANNEL, craftMessage)

    -- Adjust cache: mark ingredients as "in transit" (removed from chests)
    for _, info in pairs(slotMap) do
        adjustCache(info.itemName, info.chestName, -info.count)
    end

    -- Wait for reply from turtle with timeout
    log.info("CRAFT", "Waiting for turtle reply (timeout: %ds)...", CRAFT_TIMEOUT)
    local deadline = os.clock() + CRAFT_TIMEOUT
    local result = nil
    local bufferedMessages = {}  -- Buffer ORDER_CHANNEL messages to avoid re-queue bounce

    while os.clock() < deadline do
        local timerId = os.startTimer(math.max(0.1, deadline - os.clock()))
        local event, p1, p2, p3, p4, p5 = os.pullEvent()

        if event == "modem_message" then
            local channel = p2
            local message = p4
            if channel == CRAFT_REPLY_CHANNEL and type(message) == "table" and message.type == "craft_result" then
                result = message
                break
            elseif channel == ORDER_CHANNEL then
                -- Buffer for re-queue after loop exits (avoids bounce loop)
                table.insert(bufferedMessages, {event, p1, p2, p3, p4, p5})
            end
        elseif event == "timer" and p1 == timerId then
            -- Timeout tick, loop will check deadline
        end
    end

    -- Re-queue any buffered ORDER_CHANNEL messages so Task 12 processes them
    for _, msg in ipairs(bufferedMessages) do
        os.queueEvent(table.unpack(msg))
    end

    activity.crafting = false
    needsRedraw = true
    smelterNeedsRedraw = true

    if not result then
        -- Timeout — turtle didn't respond. Items may be stuck in turtle.
        -- We've already adjusted the cache as if ingredients were consumed.
        -- A manual scan will reconcile later.
        log.error("CRAFT", "TIMEOUT: No reply from turtle within %ds", CRAFT_TIMEOUT)
        log.error("CRAFT", "Items may be stuck in turtle. Run a manual scan to reconcile.")
        return false, "Turtle timeout"
    end

    if result.success then
        -- Craft succeeded. The turtle already pushed results back to chests.
        -- We need to credit the output items to the cache.
        -- The ingredients were already debited above.
        -- The turtle reports what it pushed; we credit the output item.
        local totalOutput = result.totalOutput or recipe.count
        -- Credit output across the chests (we don't know exactly which chest
        -- the turtle pushed to, so trigger a targeted rescan)
        -- For now, credit to the first available chest as an approximation.
        -- The next periodic scan will reconcile.
        if result.results then
            for _, r in ipairs(result.results) do
                -- Find which chest likely received it
                for _, ch in ipairs(chests) do
                    local chest = wrapCached(ch)
                    if chest then
                        for slot, slotItem in pairs(chest.list()) do
                            if slotItem.name == r.name then
                                -- Found the output in a chest, credit it
                                adjustCache(r.name, ch, r.count)
                                goto credited
                            end
                        end
                    end
                end
                -- If we can't find it, still credit to first chest for cache consistency
                if #chests > 0 then
                    adjustCache(r.name, chests[1], r.count)
                end
                ::credited::
            end
        else
            -- Fallback: credit the expected output
            if #chests > 0 then
                adjustCache(recipe.output, chests[1], totalOutput)
            end
        end

        local short = recipe.output:gsub("^minecraft:", ""):gsub("_", " ")
        log.info("CRAFT", "OK: %s x%d", short, totalOutput)
        return true
    else
        -- Craft failed. The turtle returned ingredients to chests.
        -- We already debited the cache; now credit them back.
        -- The returned items are back in the chests, so re-credit them.
        for turtleSlotStr, info in pairs(slotMap) do
            -- Re-credit the ingredient (it was returned)
            adjustCache(info.itemName, info.chestName, info.count)
        end

        local errMsg = result.error or "Craft failed"
        log.error("CRAFT", "Failed: %s", errMsg)
        return false, errMsg
    end
end

-------------------------------------------------
-- Smelter Dashboard
-------------------------------------------------

local function drawSmelterDashboard()
    if not smelterMon then return end

    local w, h = smelterMon.getSize()
    smelterPendingZones = {}

    -- Offscreen buffer
    setDrawTarget(window.create(smelterMon, 1, 1, w, h, false))
    draw.setBackgroundColor(colors.black)
    draw.clear()

    -- ===== Title bar =====
    monFill(1, colors.purple)
    monCenter(1, " ** SMELTER DASHBOARD ** ", colors.white, colors.purple)

    -- ===== Status bar =====
    monFill(2, colors.gray)
    local activeCount = 0
    for _, fs in ipairs(cache.furnaceStatus or {}) do
        if fs.active then activeCount = activeCount + 1 end
    end
    local statusStr = string.format(" Furnaces: %d  Active: %d",
        cache.furnaceCount or 0, activeCount)
    monWrite(2, 2, statusStr, colors.white, colors.gray)

    -- Pause/Resume button
    local pauseLabel = smeltingPaused and " PAUSED " or " ACTIVE "
    local pauseBg = smeltingPaused and colors.red or colors.lime
    local pauseFg = smeltingPaused and colors.white or colors.black
    monWrite(w - #pauseLabel, 2, pauseLabel, pauseFg, pauseBg)
    addSmelterZone(w - #pauseLabel, 2, w - 1, 2, "toggle_pause", nil)

    -- ===== Divider =====
    monFill(3, colors.magenta)
    monCenter(3, string.rep("-", math.min(w - 4, 60)), colors.pink, colors.magenta)

    -- ===== Tab row =====
    monFill(4, colors.black)
    local tabStatusBg  = smelterView == "status"  and colors.purple or colors.gray
    local tabSmeltBg   = smelterView == "smelt"   and colors.purple or colors.gray
    local tabCraftBg   = smelterView == "craft"   and colors.purple or colors.gray
    local tabMissingBg = smelterView == "missing"  and colors.purple or colors.gray
    local bx1, by1, bx2, by2
    bx1, by1, bx2, by2 = drawButton(2, 4, "Status", colors.white, tabStatusBg)
    addSmelterZone(bx1, by1, bx2, by2, "tab", "status")

    bx1, by1, bx2, by2 = drawButton(bx2 + 2, 4, "Smelt", colors.white, tabSmeltBg)
    addSmelterZone(bx1, by1, bx2, by2, "tab", "smelt")

    bx1, by1, bx2, by2 = drawButton(bx2 + 2, 4, "Craft", colors.white, tabCraftBg)
    addSmelterZone(bx1, by1, bx2, by2, "tab", "craft")

    bx1, by1, bx2, by2 = drawButton(bx2 + 2, 4, "Missing", colors.white, tabMissingBg)
    addSmelterZone(bx1, by1, bx2, by2, "tab", "missing")

    -- Hoisted counter: reused by bottom accent bar to avoid re-scanning recipes
    local craftAvailCount = nil

    if smelterView == "status" then
        -- ===== Furnace Status View =====
        -- Column headers
        monFill(5, colors.gray)
        local outCol = math.floor(w * 0.40)
        local fuelCol = math.floor(w * 0.65)
        local statCol = w - 6
        monWrite(2,  5, "#",      colors.lightGray, colors.gray)
        monWrite(4,  5, "T",      colors.lightGray, colors.gray)
        monWrite(6,  5, "Input",  colors.lightGray, colors.gray)
        monWrite(outCol, 5, "Output", colors.lightGray, colors.gray)
        monWrite(fuelCol, 5, "Fuel",   colors.lightGray, colors.gray)
        monWrite(statCol, 5, "State",  colors.lightGray, colors.gray)

        -- Furnace rows
        local furnaceList = cache.furnaceStatus or {}
        local maxRows = h - 8
        if maxRows < 1 then maxRows = 1 end
        smelterTotalPages = math.max(1, math.ceil(#furnaceList / maxRows))
        if smelterPage > smelterTotalPages then smelterPage = smelterTotalPages end
        if smelterPage < 1 then smelterPage = 1 end

        local startIdx = (smelterPage - 1) * maxRows + 1
        local endIdx = math.min(startIdx + maxRows - 1, #furnaceList)

        local row = 6
        if #furnaceList == 0 then
            monFill(7, colors.black)
            monCenter(7, "No furnaces found on network", colors.gray, colors.black)
            row = 8
        else
            for i = startIdx, endIdx do
                local fs = furnaceList[i]
                local y = row
                local rowBg = ((i - startIdx) % 2 == 0) and colors.black or colors.gray
                monFill(y, rowBg)

                -- Number
                monWrite(2, y, string.format("%d", i), colors.lightBlue, rowBg)

                -- Type abbreviation
                local typeAbbr = "F"
                local typeColor = colors.orange
                if fs.type == "minecraft:smoker" then
                    typeAbbr = "S"
                    typeColor = colors.green
                elseif fs.type == "minecraft:blast_furnace" then
                    typeAbbr = "B"
                    typeColor = colors.cyan
                end
                monWrite(4, y, typeAbbr, typeColor, rowBg)

                -- Input
                if fs.input then
                    local inName = fs.input.name:gsub("^minecraft:", ""):gsub("_", " ")
                    local maxIn = outCol - 8
                    if #inName > maxIn then inName = inName:sub(1, maxIn - 2) .. ".." end
                    monWrite(6, y, inName, colors.white, rowBg)
                    monWrite(outCol - 4, y, "x" .. fs.input.count, colors.yellow, rowBg)
                else
                    monWrite(6, y, "(empty)", colors.lightGray, rowBg)
                end

                -- Output
                if fs.output then
                    local outName = fs.output.name:gsub("^minecraft:", ""):gsub("_", " ")
                    local maxOut = fuelCol - outCol - 5
                    if #outName > maxOut then outName = outName:sub(1, maxOut - 2) .. ".." end
                    monWrite(outCol, y, outName, colors.white, rowBg)
                    monWrite(fuelCol - 4, y, "x" .. fs.output.count, colors.yellow, rowBg)
                else
                    monWrite(outCol, y, "-", colors.lightGray, rowBg)
                end

                -- Fuel
                if fs.fuel then
                    local fuelName = fs.fuel.name:gsub("^minecraft:", ""):gsub("_", " ")
                    local maxFuel = statCol - fuelCol - 4
                    if #fuelName > maxFuel then fuelName = fuelName:sub(1, maxFuel - 2) .. ".." end
                    monWrite(fuelCol, y, fuelName, colors.white, rowBg)
                    monWrite(statCol - 4, y, "x" .. fs.fuel.count, colors.yellow, rowBg)
                else
                    monWrite(fuelCol, y, "-", colors.lightGray, rowBg)
                end

                -- Status indicator
                if smeltingPaused then
                    monWrite(statCol, y, "PAUSE", colors.red, rowBg)
                elseif fs.active then
                    monWrite(statCol, y, " COOK", colors.lime, rowBg)
                elseif fs.input and not fs.fuel then
                    monWrite(statCol, y, "FUEL?", colors.orange, rowBg)
                else
                    monWrite(statCol, y, " IDLE", colors.lightGray, rowBg)
                end

                row = row + 1
            end
        end

        -- Fill remaining rows
        while row <= h - 2 do
            monFill(row, colors.black)
            row = row + 1
        end

    elseif smelterView == "smelt" then
        -- ===== Smelt Recipe Manager View =====

        -- Build sorted recipe list
        local recipeList = {}
        for inputName, recipe in pairs(SMELTABLE) do
            local short = inputName:gsub("^minecraft:", ""):gsub("_", " ")
            short = short:sub(1,1):upper() .. short:sub(2)
            local resultShort = recipe.result:gsub("^minecraft:", ""):gsub("_", " ")
            resultShort = resultShort:sub(1,1):upper() .. resultShort:sub(2)
            local types = ""
            if recipe.furnaceSet["minecraft:furnace"] then types = types .. "F" end
            if recipe.furnaceSet["minecraft:smoker"] then types = types .. "S" end
            if recipe.furnaceSet["minecraft:blast_furnace"] then types = types .. "B" end
            local enabled = not disabledRecipes[inputName]
            local inStorage = 0
            if cache.catalogue[inputName] then
                for _, s in ipairs(cache.catalogue[inputName]) do
                    inStorage = inStorage + s.total
                end
            end
            table.insert(recipeList, {
                inputName   = inputName,
                inputShort  = short,
                resultShort = resultShort,
                types       = types,
                enabled     = enabled,
                inStorage   = inStorage,
            })
        end
        table.sort(recipeList, function(a, b) return a.inputShort < b.inputShort end)

        -- Column positions
        local arrowCol  = math.floor(w * 0.30)
        local typeCol   = math.floor(w * 0.60)
        local stockCol  = math.floor(w * 0.72)
        local toggleCol = w - 5

        -- Column headers
        monFill(5, colors.gray)
        monWrite(2, 5, "Input", colors.lightGray, colors.gray)
        monWrite(arrowCol, 5, "Output", colors.lightGray, colors.gray)
        monWrite(typeCol, 5, "Type", colors.lightGray, colors.gray)
        monWrite(stockCol, 5, "Stock", colors.lightGray, colors.gray)
        monWrite(toggleCol, 5, "On?", colors.lightGray, colors.gray)

        -- Bulk action buttons on tab row
        local bulkX = w - 22
        bx1, by1, bx2, by2 = drawButton(bulkX, 4, "All On", colors.white, colors.green)
        addSmelterZone(bx1, by1, bx2, by2, "enable_all", nil)
        bx1, by1, bx2, by2 = drawButton(bx2 + 2, 4, "All Off", colors.white, colors.red)
        addSmelterZone(bx1, by1, bx2, by2, "disable_all", nil)

        -- Recipe rows
        local maxRows = h - 8
        if maxRows < 1 then maxRows = 1 end
        smelterTotalPages = math.max(1, math.ceil(#recipeList / maxRows))
        if smelterPage > smelterTotalPages then smelterPage = smelterTotalPages end
        if smelterPage < 1 then smelterPage = 1 end

        local startIdx = (smelterPage - 1) * maxRows + 1
        local endIdx = math.min(startIdx + maxRows - 1, #recipeList)

        local row = 6
        for i = startIdx, endIdx do
            local r = recipeList[i]
            local y = row
            local rowBg = ((i - startIdx) % 2 == 0) and colors.black or colors.gray
            monFill(y, rowBg)

            -- Input name
            local maxInputLen = arrowCol - 3
            local inputDisplay = r.inputShort
            if #inputDisplay > maxInputLen then
                inputDisplay = inputDisplay:sub(1, maxInputLen - 2) .. ".."
            end
            monWrite(2, y, inputDisplay, colors.white, rowBg)

            -- Output
            local maxOutLen = typeCol - arrowCol - 2
            local outDisplay = r.resultShort
            if #outDisplay > maxOutLen then
                outDisplay = outDisplay:sub(1, maxOutLen - 2) .. ".."
            end
            monWrite(arrowCol, y, outDisplay, colors.lightBlue, rowBg)

            -- Types
            monWrite(typeCol, y, r.types, colors.orange, rowBg)

            -- Stock
            monWrite(stockCol, y, tostring(r.inStorage), colors.yellow, rowBg)

            -- Toggle button
            if r.enabled then
                monWrite(toggleCol, y, " ON ", colors.white, colors.green)
            else
                monWrite(toggleCol, y, " OFF", colors.white, colors.red)
            end
            addSmelterZone(1, y, w, y, "toggle_recipe", r.inputName)

            row = row + 1
        end

        -- Fill remaining rows
        while row <= h - 2 do
            monFill(row, colors.black)
            row = row + 1
        end

    elseif smelterView == "craft" then
        -- ===== Available Crafting Recipes =====

        -- Turtle status on tab row
        local turtleOk = craftTurtleName and peripheral.isPresent(craftTurtleName)
        local tLabel = turtleOk and " Turtle OK " or " No Turtle "
        local tBg = turtleOk and colors.lime or colors.red
        local tFg = turtleOk and colors.black or colors.white
        monWrite(w - #tLabel, 4, tLabel, tFg, tBg)

        -- Build list of craftable recipes
        local availList = {}
        for idx, recipe in ipairs(CRAFTABLE) do
            if canCraftRecipe(recipe) then
                local short = recipe.output:gsub("^minecraft:", ""):gsub("_", " ")
                short = short:sub(1,1):upper() .. short:sub(2)
                local batches = maxCraftBatches(recipe)
                table.insert(availList, {
                    idx       = idx,
                    short     = short,
                    count     = recipe.count,
                    batches   = batches,
                })
            end
        end
        craftAvailCount = #availList

        -- Column headers
        monFill(5, colors.gray)
        local makeCol = w - 6
        monWrite(2, 5, "#", colors.lightGray, colors.gray)
        monWrite(4, 5, "Output", colors.lightGray, colors.gray)
        monWrite(math.floor(w * 0.45), 5, "Yield", colors.lightGray, colors.gray)
        monWrite(math.floor(w * 0.60), 5, "Can Make", colors.lightGray, colors.gray)
        monWrite(makeCol, 5, "Go", colors.lightGray, colors.gray)

        local maxRows = h - 8
        if maxRows < 1 then maxRows = 1 end
        smelterTotalPages = math.max(1, math.ceil(#availList / maxRows))
        if smelterPage > smelterTotalPages then smelterPage = smelterTotalPages end
        if smelterPage < 1 then smelterPage = 1 end

        local startIdx = (smelterPage - 1) * maxRows + 1
        local endIdx = math.min(startIdx + maxRows - 1, #availList)

        local row = 6
        if #availList == 0 then
            monFill(7, colors.black)
            monCenter(7, "No recipes available to craft", colors.gray, colors.black)
            row = 8
        else
            for i = startIdx, endIdx do
                local r = availList[i]
                local y = row
                local rowBg = ((i - startIdx) % 2 == 0) and colors.black or colors.gray
                monFill(y, rowBg)

                monWrite(2, y, string.format("%2d", i), colors.lightBlue, rowBg)

                local maxNameLen = math.floor(w * 0.40)
                local nameDisplay = r.short
                if #nameDisplay > maxNameLen then
                    nameDisplay = nameDisplay:sub(1, maxNameLen - 2) .. ".."
                end
                monWrite(4, y, nameDisplay, colors.white, rowBg)

                monWrite(math.floor(w * 0.45), y, "x" .. r.count, colors.yellow, rowBg)
                monWrite(math.floor(w * 0.60), y,
                    string.format("x%d", r.batches), colors.lime, rowBg)

                -- MAKE button
                if turtleOk then
                    monWrite(makeCol, y, " MAKE ", colors.white, colors.green)
                    addSmelterZone(makeCol, y, makeCol + 5, y, "craft", r.idx)
                else
                    monWrite(makeCol, y, " ---- ", colors.gray, colors.black)
                end

                row = row + 1
            end
        end

        while row <= h - 2 do
            monFill(row, colors.black)
            row = row + 1
        end

    elseif smelterView == "missing" then
        -- ===== Unavailable Crafting Recipes =====

        -- Build list of recipes that CANNOT be crafted
        local missList = {}
        for idx, recipe in ipairs(CRAFTABLE) do
            if not canCraftRecipe(recipe) then
                local short = recipe.output:gsub("^minecraft:", ""):gsub("_", " ")
                short = short:sub(1,1):upper() .. short:sub(2)
                local missing = getMissingIngredients(recipe)
                -- Build summary string
                local parts = {}
                for _, m in ipairs(missing) do
                    local mShort = m.name:gsub("^minecraft:", ""):gsub("_", " ")
                    table.insert(parts, string.format("%s %d/%d", mShort, m.have, m.need))
                end
                table.insert(missList, {
                    idx     = idx,
                    short   = short,
                    count   = recipe.count,
                    summary = table.concat(parts, ", "),
                })
            end
        end
        craftAvailCount = #CRAFTABLE - #missList

        -- Column headers
        monFill(5, colors.gray)
        monWrite(2, 5, "#", colors.lightGray, colors.gray)
        monWrite(4, 5, "Output", colors.lightGray, colors.gray)
        monWrite(math.floor(w * 0.35), 5, "Missing (have/need)", colors.lightGray, colors.gray)

        local maxRows = h - 8
        if maxRows < 1 then maxRows = 1 end
        smelterTotalPages = math.max(1, math.ceil(#missList / maxRows))
        if smelterPage > smelterTotalPages then smelterPage = smelterTotalPages end
        if smelterPage < 1 then smelterPage = 1 end

        local startIdx = (smelterPage - 1) * maxRows + 1
        local endIdx = math.min(startIdx + maxRows - 1, #missList)

        local row = 6
        if #missList == 0 then
            monFill(7, colors.black)
            monCenter(7, "All recipes can be crafted!", colors.lime, colors.black)
            row = 8
        else
            for i = startIdx, endIdx do
                local r = missList[i]
                local y = row
                local rowBg = ((i - startIdx) % 2 == 0) and colors.black or colors.gray
                monFill(y, rowBg)

                monWrite(2, y, string.format("%2d", i), colors.lightBlue, rowBg)

                local nameCol = math.floor(w * 0.35) - 5
                local nameDisplay = r.short .. " x" .. r.count
                if #nameDisplay > nameCol then
                    nameDisplay = nameDisplay:sub(1, nameCol - 2) .. ".."
                end
                monWrite(4, y, nameDisplay, colors.white, rowBg)

                -- Missing items summary
                local missCol = math.floor(w * 0.35)
                local missW = w - missCol - 1
                local summaryDisplay = r.summary
                if #summaryDisplay > missW then
                    summaryDisplay = summaryDisplay:sub(1, missW - 2) .. ".."
                end
                monWrite(missCol, y, summaryDisplay, colors.red, rowBg)

                row = row + 1
            end
        end

        while row <= h - 2 do
            monFill(row, colors.black)
            row = row + 1
        end
    end

    -- ===== Pagination (h - 1) =====
    monFill(h - 1, colors.gray)
    local pageStr = string.format("Pg %d/%d", smelterPage, smelterTotalPages)
    monCenter(h - 1, pageStr, colors.white, colors.gray)

    if smelterPage > 1 then
        monWrite(2, h - 1, " < ", colors.white, colors.lightGray)
        addSmelterZone(2, h - 1, 4, h - 1, "page_prev", nil)
    end
    if smelterPage < smelterTotalPages then
        monWrite(w - 3, h - 1, " > ", colors.white, colors.lightGray)
        addSmelterZone(w - 3, h - 1, w - 1, h - 1, "page_next", nil)
    end

    -- ===== Bottom accent =====
    monFill(h, colors.purple)
    local bottomMsg = ""
    if smelterView == "status" or smelterView == "smelt" then
        local enabledCount = 0
        local totalRecipes = 0
        for _ in pairs(SMELTABLE) do totalRecipes = totalRecipes + 1 end
        for inputName in pairs(SMELTABLE) do
            if not disabledRecipes[inputName] then enabledCount = enabledCount + 1 end
        end
        bottomMsg = string.format(" Smelt: %d/%d enabled ", enabledCount, totalRecipes)
        if activity.smelting then bottomMsg = " SMELTING... " end
    elseif smelterView == "craft" then
        bottomMsg = " Tap MAKE to craft "
        if activity.crafting then bottomMsg = " CRAFTING... " end
    elseif smelterView == "missing" then
        local availC = craftAvailCount or 0
        bottomMsg = string.format(" Available: %d/%d recipes ", availC, #CRAFTABLE)
    end
    monCenter(h, bottomMsg, colors.pink, colors.purple)

    -- Flush to monitor
    draw.setVisible(true)

    -- Swap zones
    smelterTouchZones = smelterPendingZones
end

-------------------------------------------------
-- Barrel auto-sort
-------------------------------------------------

local function sortBarrel(barrelOverride)
    local barrelTarget = (barrelOverride and barrelOverride ~= "") and barrelOverride or BARREL_NAME
    local barrel = wrapCached(barrelTarget)
    if not barrel then return end

    local contents = barrel.list()
    if not contents or not next(contents) then return end

    activity.sorting = true
    needsRedraw = true

    local catalogue = cache.catalogue
    local chests = getChests()

    for slot, item in pairs(contents) do
        local moved = 0
        local triedChests = {}  -- dedup: skip chests already tried via catalogue

        if catalogue[item.name] then
            for _, entry in ipairs(catalogue[item.name]) do
                triedChests[entry.chest] = true
                local n = barrel.pushItems(entry.chest, slot)
                if n and n > 0 then
                    moved = moved + n
                    adjustCache(item.name, entry.chest, n)
                    needsRedraw = true
                    smelterNeedsRedraw = true
                    log.info("SORT", "%s x%d -> %s", item.name, n, entry.chest)
                end
                if moved >= item.count then break end
            end
        end

        if moved < item.count then
            for _, chest in ipairs(chests) do
                if not triedChests[chest] then
                    local n = barrel.pushItems(chest, slot)
                    if n and n > 0 then
                        moved = moved + n
                        adjustCache(item.name, chest, n)
                        needsRedraw = true
                        smelterNeedsRedraw = true
                        log.info("SORT", "%s x%d -> %s", item.name, n, chest)
                    end
                    if moved >= item.count then break end
                end
            end
        end

        if moved < item.count then
            log.warn("SORT", "Could not sort %d remaining %s", item.count - moved, item.name)
        end
    end

    activity.sorting = false
    needsRedraw = true
end

-------------------------------------------------
-- Auto-smelt
-------------------------------------------------

local function autoSmelt()
    if smeltingPaused then return false end

    local furnaces = getFurnaces()
    if #furnaces == 0 then return false end

    local chests = getChests()
    local catalogue = cache.catalogue
    local didWork = false
    local emptyInputFurnaces = {}  -- collected during steps 1-3, filled in step 5

    for _, fname in ipairs(furnaces) do
        local furnace = wrapCached(fname)
        if furnace then
            local contents = furnace.list()

            -- 1) Pull finished output (slot 3) back to chests
            if contents[SLOT_OUTPUT] then
                local outputItem = contents[SLOT_OUTPUT]
                local remaining = outputItem.count
                for _, chest in ipairs(chests) do
                    local n = furnace.pushItems(chest, SLOT_OUTPUT)
                    if n and n > 0 then
                        adjustCache(outputItem.name, chest, n)
                        remaining = remaining - n
                        log.info("SMELT", "Output %s x%d -> %s",
                            outputItem.name, n, chest)
                        didWork = true
                        if remaining <= 0 then break end
                    end
                end
                if remaining > 0 then
                    log.warn("SMELT", "Could not move %d %s from %s output (chests full?)",
                        remaining, outputItem.name, fname)
                end
            end

            -- Also check all slots in case output ended up elsewhere
            -- Some modded furnaces or CC versions may use different slot indices
            for slot, item in pairs(contents) do
                if slot ~= SLOT_INPUT and slot ~= SLOT_FUEL and slot ~= SLOT_OUTPUT then
                    for _, chest in ipairs(chests) do
                        local n = furnace.pushItems(chest, slot)
                        if n and n > 0 then
                            adjustCache(item.name, chest, n)
                            log.info("SMELT", "Extra slot %d: %s x%d -> %s",
                                slot, item.name, n, chest)
                            didWork = true
                            break
                        end
                    end
                end
            end

            -- Re-read after output pull
            contents = furnace.list()

            -- 2) Check for incompatible items in input slot and remove them
            local furnaceType = peripheral.getType(fname)
            local inputItem = contents[SLOT_INPUT]
            if inputItem then
                local recipe = SMELTABLE[inputItem.name]
                local validHere = recipe and recipe.furnaceSet[furnaceType] or false
                if not validHere then
                    -- This item doesn't belong in this furnace type — pull it out
                    for _, chest in ipairs(chests) do
                        local n = furnace.pushItems(chest, SLOT_INPUT)
                        if n and n > 0 then
                            adjustCache(inputItem.name, chest, n)
                            log.info("SMELT", "Removed incompatible %s x%d from %s -> %s",
                                inputItem.name, n, fname, chest)
                            didWork = true
                            break
                        end
                    end
                    -- Re-read after removal
                    contents = furnace.list()
                end
            end

            -- 3) Refuel if fuel slot is empty or low
            local fuelItem = contents[SLOT_FUEL]
            local needFuel = not fuelItem or fuelItem.count < 8

            if needFuel then
                for _, fuel in ipairs(FUEL_LIST) do
                    if catalogue[fuel.name] then
                        for _, source in ipairs(catalogue[fuel.name]) do
                            local chest = wrapCached(source.chest)
                            if chest then
                                for slot, slotItem in pairs(chest.list()) do
                                    if slotItem.name == fuel.name then
                                        local toMove = math.min(16, slotItem.count)
                                        local n = chest.pushItems(fname, slot, toMove, SLOT_FUEL)
                                        if n and n > 0 then
                                            adjustCache(fuel.name, source.chest, -n)
                                            log.info("SMELT", "Fuel %s x%d -> %s",
                                                fuel.name, n, fname)
                                            didWork = true
                                            needFuel = false
                                            break
                                        end
                                    end
                                end
                            end
                            if not needFuel then break end
                        end
                    end
                    if not needFuel then break end
                end
            end

            -- 4) Collect furnaces with empty input for balanced loading below
            inputItem = contents[SLOT_INPUT]
            if not inputItem then
                table.insert(emptyInputFurnaces, { name = fname, type = furnaceType })
            end
        end
    end

    -- 5) Balanced distribution of smeltable items across all empty furnaces
    --    Instead of greedily filling one furnace at a time, we spread items
    --    evenly so all compatible furnaces work in parallel.
    if #emptyInputFurnaces > 0 then
        -- Build a unified, deduplicated candidate list across all empty furnace types
        local typesSeen = {}
        for _, ef in ipairs(emptyInputFurnaces) do typesSeen[ef.type] = true end

        local allCandidates = {}
        local candSeen = {}
        for ftype in pairs(typesSeen) do
            for _, cand in ipairs(smeltCandidatesByType[ftype] or {}) do
                if not candSeen[cand.name] then
                    candSeen[cand.name] = true
                    table.insert(allCandidates, cand)
                end
            end
        end
        -- Sort: food first, then alphabetical (same priority as before)
        table.sort(allCandidates, function(a, b)
            if a.food ~= b.food then return a.food end
            return a.name < b.name
        end)

        local usedFurnaces = {}  -- furnaces already assigned an item

        for _, cand in ipairs(allCandidates) do
            local itemName = cand.name
            if not disabledRecipes[itemName] and catalogue[itemName] then
                -- Find all compatible empty furnaces not yet used
                local compatFurnaces = {}
                for _, ef in ipairs(emptyInputFurnaces) do
                    if not usedFurnaces[ef.name] and cand.recipe.furnaceSet[ef.type] then
                        table.insert(compatFurnaces, ef)
                    end
                end

                if #compatFurnaces > 0 then
                    local totalInStorage = 0
                    for _, src in ipairs(catalogue[itemName]) do
                        totalInStorage = totalInStorage + src.total
                    end
                    local available = totalInStorage - SMELT_RESERVE
                    if available > 0 then
                        local perFurnace = math.min(64, math.ceil(available / #compatFurnaces))

                        for _, ef in ipairs(compatFurnaces) do
                            if available <= 0 then break end
                            local toLoad = math.min(perFurnace, available)
                            local remaining = toLoad
                            local loaded = false

                            -- Snapshot: adjustCache may remove entries during iteration
                            local srcSnapshot = { table.unpack(catalogue[itemName]) }
                            for _, source in ipairs(srcSnapshot) do
                                if source.total > 0 then
                                local chest = wrapCached(source.chest)
                                if chest then
                                    for slot, slotItem in pairs(chest.list()) do
                                        if slotItem.name == itemName then
                                            local toMove = math.min(slotItem.count, remaining)
                                            local n = chest.pushItems(ef.name, slot, toMove, SLOT_INPUT)
                                            if n and n > 0 then
                                                adjustCache(itemName, source.chest, -n)
                                                log.info("SMELT", "Input %s x%d -> %s (balanced %d/furnace)",
                                                    itemName, n, ef.name, perFurnace)
                                                didWork = true
                                                remaining = remaining - n
                                                available = available - n
                                                if remaining <= 0 then
                                                    loaded = true
                                                    break
                                                end
                                            end
                                        end
                                    end
                                end
                                end -- source.total > 0
                                if loaded then break end
                            end

                            if loaded or remaining < toLoad then
                                usedFurnaces[ef.name] = true
                            end
                        end
                    end
                end
            end
        end
    end

    return didWork
end

-------------------------------------------------
-- Defrag (consolidate partial stacks)
-------------------------------------------------

local function defragInventory()
    local chests = getChests()
    if #chests == 0 then return end

    activity.defragging = true
    needsRedraw = true

    -- Build a map: itemName -> list of { chest, slot, count, maxCount }
    local itemSlots = {}
    for _, chestName in ipairs(chests) do
        local inv = wrapCached(chestName)
        if inv then
            local contents = inv.list()
            for slot, item in pairs(contents) do
                if not itemSlots[item.name] then
                    itemSlots[item.name] = {}
                end
                -- CC:Tweaked: getItemDetail gives maxCount (stack size)
                local maxCount = 64
                local ok, detail = pcall(inv.getItemDetail, slot)
                if ok and detail and detail.maxCount then
                    maxCount = detail.maxCount
                end
                table.insert(itemSlots[item.name], {
                    chest = chestName,
                    slot  = slot,
                    count = item.count,
                    max   = maxCount,
                })
            end
        end
    end

    -- For each item, try to merge partial stacks
    local totalMerged = 0
    for itemName, slots in pairs(itemSlots) do
        -- Sort: smallest stacks first (donors), fullest last (receivers)
        table.sort(slots, function(a, b) return a.count < b.count end)

        local i = 1                      -- donor (smallest)
        local j = #slots                  -- receiver (largest, has room)

        while i < j do
            local donor = slots[i]
            local recv  = slots[j]

            -- Skip if same slot
            if donor.chest == recv.chest and donor.slot == recv.slot then
                i = i + 1
            elseif donor.count == 0 then
                i = i + 1
            elseif recv.count >= recv.max then
                j = j - 1
            else
                local space = recv.max - recv.count
                local toMove = math.min(donor.count, space)
                local donorInv = wrapCached(donor.chest)
                if donorInv then
                    local n = donorInv.pushItems(recv.chest, donor.slot, toMove, recv.slot)
                    if n and n > 0 then
                        donor.count = donor.count - n
                        recv.count  = recv.count + n
                        totalMerged = totalMerged + n
                        -- Update catalogue for cross-chest moves
                        if donor.chest ~= recv.chest then
                            adjustCache(itemName, donor.chest, -n)
                            adjustCache(itemName, recv.chest, n)
                        end
                    end
                end
                if donor.count <= 0 then i = i + 1 end
                if recv.count >= recv.max then j = j - 1 end
            end
        end
    end

    if totalMerged > 0 then
        log.info("DEFRAG", "Consolidated %d items", totalMerged)
    end

    activity.defragging = false
    needsRedraw = true
end

-------------------------------------------------
-- Auto-compost
-------------------------------------------------

local function autoCompost()
    local catalogue = cache.catalogue
    local chests = getChests()
    local didWork = false

    -- 1) Pull bone meal from hopper back to chests
    local hopper = wrapCached(COMPOST_HOPPER)
    if hopper then
        local contents = hopper.list()
        if contents then
            for slot, item in pairs(contents) do
                for _, chest in ipairs(chests) do
                    local n = hopper.pushItems(chest, slot)
                    if n and n > 0 then
                        adjustCache(item.name, chest, n)
                        log.info("COMPOST", "%s x%d -> %s", item.name, n, chest)
                        didWork = true
                        break
                    end
                end
            end
        end
    end

    -- 2) Feed compostable items into dropper
    local dropper = wrapCached(COMPOST_DROPPER)
    if not dropper then return didWork end

    -- Check how much item capacity the dropper has (slots * 64 - current items)
    local dropperContents = dropper.list()
    local dropperUsedSlots = 0
    local dropperUsedItems = 0
    if dropperContents then
        for _, item in pairs(dropperContents) do
            dropperUsedSlots = dropperUsedSlots + 1
            dropperUsedItems = dropperUsedItems + item.count
        end
    end
    local dropperSize = dropper.size()
    local dropperFreeItems = (dropperSize * 64) - dropperUsedItems

    if dropperFreeItems <= 0 then return didWork end

    for _, itemName in ipairs(COMPOSTABLE) do
        if dropperFreeItems <= 0 then break end
        if catalogue[itemName] then
            -- Count total in storage
            local totalInStorage = 0
            for _, src in ipairs(catalogue[itemName]) do
                totalInStorage = totalInStorage + src.total
            end

            local reserve = COMPOST_TRASH[itemName] and 0 or COMPOST_RESERVE
            local available = totalInStorage - reserve
            if available > 0 then
                local toFeed = math.min(available, dropperFreeItems)
                local fed = 0
                -- Snapshot: adjustCache may remove entries during iteration
                local srcSnapshot = { table.unpack(catalogue[itemName]) }
                for _, source in ipairs(srcSnapshot) do
                    if source.total > 0 then
                    local chest = wrapCached(source.chest)
                    if chest then
                        for slot, slotItem in pairs(chest.list()) do
                            if slotItem.name == itemName then
                                local batch = math.min(slotItem.count, toFeed - fed)
                                local n = chest.pushItems(COMPOST_DROPPER, slot, batch)
                                if n and n > 0 then
                                    adjustCache(itemName, source.chest, -n)
                                    fed = fed + n
                                    didWork = true
                                    log.info("COMPOST", "Fed %s x%d -> dropper",
                                        itemName, n)
                                    if fed >= toFeed then break end
                                end
                            end
                        end
                    end
                    end -- source.total > 0
                    if fed >= toFeed then break end
                end
                dropperFreeItems = dropperFreeItems - fed
            end
        end
    end

    return didWork
end

-------------------------------------------------
-- Low-stock alert checker
-------------------------------------------------

local function checkAlerts()
    local alerts = {}
    for _, alert in ipairs(LOW_STOCK_ALERTS) do
        local total = 0
        if cache.catalogue[alert.name] then
            for _, src in ipairs(cache.catalogue[alert.name]) do
                total = total + src.total
            end
        end
        if total < alert.min then
            table.insert(alerts, {
                label   = alert.label,
                current = total,
                min     = alert.min,
            })
        end
    end
    activeAlerts = alerts
    if #alerts > 0 then
        needsRedraw = true
        smelterNeedsRedraw = true
    end
end

-------------------------------------------------
-- Order
-------------------------------------------------

local function orderItem(itemName, amount, dropperOverride)
    activity.dispensing = true
    needsRedraw = true

    -- Use client-specified dropper if provided, otherwise master's default
    local dropperTarget = (dropperOverride and dropperOverride ~= "") and dropperOverride or DROPPER_NAME

    local catalogue = cache.catalogue

    if not catalogue[itemName] then
        statusMessage = "Not found: " .. itemName:gsub("^minecraft:", "")
        statusColor = colors.red
        statusTimer = 5
        activity.dispensing = false
        needsRedraw = true
        return false
    end

    local dropper = wrapCached(dropperTarget)
    if not dropper then
        statusMessage = "Dropper offline: " .. dropperTarget
        statusColor = colors.red
        statusTimer = 5
        activity.dispensing = false
        needsRedraw = true
        return false
    end

    local remaining = amount
    -- Snapshot: adjustCache may remove entries during iteration
    local srcSnapshot = { table.unpack(catalogue[itemName]) }
    for _, entry in ipairs(srcSnapshot) do
        if entry.total > 0 then
        local chest = wrapCached(entry.chest)
        if chest then
            for slot, slotItem in pairs(chest.list()) do
                if slotItem.name == itemName then
                    local toMove = math.min(remaining, slotItem.count)
                    local moved = chest.pushItems(dropperTarget, slot, toMove)
                    if moved and moved > 0 then
                        remaining = remaining - moved
                        adjustCache(itemName, entry.chest, -moved)
                        needsRedraw = true
                        smelterNeedsRedraw = true
                        log.info("ORDER", "%s x%d from %s", itemName, moved, entry.chest)
                    end
                    if remaining <= 0 then break end
                end
            end
        end
        end -- entry.total > 0
        if remaining <= 0 then break end
    end

    local sent = amount - remaining
    local short = itemName:gsub("^minecraft:", ""):gsub("_", " ")
    if sent > 0 then
        statusMessage = string.format("Dispensing %s x%d", short, sent)
        statusColor = colors.lime
        log.info("ORDER", "Ordered %s x%d", short, sent)
    else
        statusMessage = "Could not order " .. short
        statusColor = colors.red
    end
    statusTimer = 5

    activity.dispensing = false
    needsRedraw = true
    return sent > 0
end

-------------------------------------------------
-- Touch handler (no peripheral calls — instant)
-------------------------------------------------

local function handleTouch(x, y)
    local action, data = hitTest(x, y)
    if not action then
        log.debug("TOUCH", "No zone hit")
        return
    end

    if action == "amount" then
        selectedAmount = data
        log.debug("UI", "Amount set to %s", data)
        needsRedraw = true

    elseif action == "order" then
        local itemName = data
        if itemName then
            local short = itemName:gsub("^minecraft:", ""):gsub("_", " ")
            statusMessage = string.format("Ordering %s x%d...", short, selectedAmount)
            statusColor = colors.cyan
            statusTimer = 10
            activity.dispensing = true
            needsRedraw = true
            orderItem(itemName, selectedAmount)
        end

    elseif action == "scan" then
        statusMessage = "Refreshing..."
        statusColor = colors.cyan
        statusTimer = 3
        needsRedraw = true
        log.debug("UI", "Manual refresh")

    elseif action == "kb_toggle" then
        showKeyboard = not showKeyboard
        log.debug("UI", "Keyboard %s", showKeyboard and "open" or "closed")
        needsRedraw = true

    elseif action == "kb_key" then
        if #searchQuery < 30 then
            searchQuery = searchQuery .. data
        end
        currentPage = 1
        needsRedraw = true

    elseif action == "kb_bksp" then
        if #searchQuery > 0 then
            searchQuery = searchQuery:sub(1, -2)
        end
        currentPage = 1
        needsRedraw = true

    elseif action == "kb_space" then
        if #searchQuery < 30 then
            searchQuery = searchQuery .. " "
        end
        currentPage = 1
        needsRedraw = true

    elseif action == "kb_done" then
        showKeyboard = false
        log.debug("UI", "Keyboard closed")
        needsRedraw = true

    elseif action == "kb_clear" then
        searchQuery = ""
        currentPage = 1
        log.debug("UI", "Search cleared")
        needsRedraw = true

    elseif action == "page_prev" then
        if currentPage > 1 then
            currentPage = currentPage - 1
            log.debug("UI", "Page %d", currentPage)
        end
        needsRedraw = true

    elseif action == "page_next" then
        if currentPage < totalPages then
            currentPage = currentPage + 1
            log.debug("UI", "Page %d", currentPage)
        end
        needsRedraw = true
    end
end

-------------------------------------------------
-- Smelter touch handler
-------------------------------------------------

local function handleSmelterTouch(x, y)
    local action, data = smelterHitTest(x, y)
    if not action then return end

    if action == "tab" then
        smelterView = data
        smelterPage = 1
        log.debug("UI", "Tab: %s", data)
        smelterNeedsRedraw = true

    elseif action == "toggle_pause" then
        smeltingPaused = not smeltingPaused
        log.debug("UI", "Smelting %s", smeltingPaused and "PAUSED" or "RESUMED")
        saveDisabledRecipes()
        smelterNeedsRedraw = true
        needsRedraw = true

    elseif action == "toggle_recipe" then
        if disabledRecipes[data] then
            disabledRecipes[data] = nil
        else
            disabledRecipes[data] = true
        end
        local short = data:gsub("^minecraft:", ""):gsub("_", " ")
        log.debug("UI", "Recipe %s: %s", short, disabledRecipes[data] and "OFF" or "ON")
        saveDisabledRecipes()
        smelterNeedsRedraw = true

    elseif action == "enable_all" then
        disabledRecipes = {}
        log.debug("UI", "All recipes enabled")
        saveDisabledRecipes()
        smelterNeedsRedraw = true

    elseif action == "disable_all" then
        for inputName in pairs(SMELTABLE) do
            disabledRecipes[inputName] = true
        end
        log.debug("UI", "All recipes disabled")
        saveDisabledRecipes()
        smelterNeedsRedraw = true

    elseif action == "page_prev" then
        if smelterPage > 1 then
            smelterPage = smelterPage - 1
        end
        smelterNeedsRedraw = true

    elseif action == "page_next" then
        if smelterPage < smelterTotalPages then
            smelterPage = smelterPage + 1
        end
        smelterNeedsRedraw = true

    elseif action == "craft" then
        local recipeIdx = data
        local recipe = CRAFTABLE[recipeIdx]
        if recipe then
            local short = recipe.output:gsub("^minecraft:", ""):gsub("_", " ")
            log.info("CRAFT", "Craft request: %s (#%d)", short, recipeIdx)
            local ok, err = craftItem(recipeIdx)
            if ok then
                statusMessage = "Crafted " .. short .. " x" .. recipe.count
                statusColor = colors.lime
            else
                statusMessage = "Craft failed: " .. (err or "unknown")
                statusColor = colors.red
            end
            statusTimer = 5
            needsRedraw = true
            smelterNeedsRedraw = true
        end
    end
end

-------------------------------------------------
-- Network broadcast (sends state to client displays)
-------------------------------------------------

local function broadcastState()
    if not networkModem then return end
    ensureItemList()

    -- Build dynamic state (always included)
    local state = {
        type            = "state",
        stateVersion    = stateVersion,
        cache           = {
            itemList      = cache.itemList,
            grandTotal    = cache.grandTotal,
            chestCount    = cache.chestCount,
            totalSlots    = cache.totalSlots,
            usedSlots     = cache.usedSlots,
            freeSlots     = cache.freeSlots,
            usedRatio     = cache.usedRatio,
            dropperOk     = cache.dropperOk,
            barrelOk      = cache.barrelOk,
            furnaceCount  = cache.furnaceCount,
            furnaceStatus = cache.furnaceStatus,
            droppers      = cache.droppers,
        },
        activity        = activity,
        alerts          = activeAlerts,
        smeltingPaused  = smeltingPaused,
        disabledRecipes = disabledRecipes,
        craftTurtleOk   = craftTurtleName and peripheral.isPresent(craftTurtleName),
    }

    -- Include static config only when dirty (startup, scan, recipe toggles)
    if configDirty then
        state.smeltable = SMELTABLE
        state.craftable = CRAFTABLE
        configDirty = false
    end

    networkModem.transmit(BROADCAST_CHANNEL, ORDER_CHANNEL, state)
    lastBroadcastVersion = stateVersion
end

-------------------------------------------------
-- Main
-------------------------------------------------

local function main()
    print("=================================")
    print("  Inventory Manager v2 (Touch)")
    print("=================================")
    print("")

    if peripheral.isPresent(DROPPER_NAME) then
        log.info("INIT", "Dropper: %s", DROPPER_NAME)
    else
        log.warn("INIT", "Dropper not found: %s", DROPPER_NAME)
    end

    if peripheral.isPresent(BARREL_NAME) then
        log.info("INIT", "Barrel: %s", BARREL_NAME)
    else
        log.warn("INIT", "Barrel not found: %s", BARREL_NAME)
    end

    if setupMonitor() then
        log.info("INIT", "Monitor: %s", monName or MONITOR_SIDE)
    else
        log.warn("INIT", "No monitor on %s", MONITOR_SIDE)
    end

    if setupSmelterMonitor() then
        log.info("INIT", "Smelter monitor: %s", smelterMonName or SMELTER_MONITOR_SIDE)
    else
        log.warn("INIT", "No smelter monitor on %s", SMELTER_MONITOR_SIDE)
    end

    -- Find modem for client communication
    for _, name in ipairs(peripheral.getNames()) do
        if peripheral.getType(name) == "modem" then
            networkModem = peripheral.wrap(name)
            networkModemName = name
            networkModem.open(ORDER_CHANNEL)
            networkModem.open(CRAFT_REPLY_CHANNEL)
            networkModem.open(SYSTEM_CHANNEL)
            break
        end
    end
    if networkModem then
        log.info("INIT", "Network modem: %s", networkModemName)
    else
        log.warn("INIT", "No modem found for client sync")
    end

    -- Detect crafting turtle on network
    for _, name in ipairs(peripheral.getNames()) do
        if name:match("^turtle_") then
            craftTurtleName = name
            break
        end
    end
    if craftTurtleName then
        log.info("INIT", "Crafting turtle: %s", craftTurtleName)
    else
        log.warn("INIT", "No crafting turtle found")
    end

    -- Load recipe toggles from disk
    loadDisabledRecipes()
    if smeltingPaused then
        log.info("INIT", "Smelting is PAUSED (toggle on smelter monitor)")
    end
    local enabledCount = 0
    local totalRecipeCount = 0
    for _ in pairs(SMELTABLE) do totalRecipeCount = totalRecipeCount + 1 end
    for k in pairs(SMELTABLE) do
        if not disabledRecipes[k] then enabledCount = enabledCount + 1 end
    end
    log.info("INIT", "%d/%d recipes enabled", enabledCount, totalRecipeCount)

    -- Detect compost peripherals
    if peripheral.isPresent(COMPOST_DROPPER) then
        log.info("INIT", "Compost dropper: %s", COMPOST_DROPPER)
    else
        log.warn("INIT", "Compost dropper not found: %s", COMPOST_DROPPER)
    end
    if peripheral.isPresent(COMPOST_HOPPER) then
        log.info("INIT", "Compost hopper: %s", COMPOST_HOPPER)
    else
        log.warn("INIT", "Compost hopper not found: %s", COMPOST_HOPPER)
    end

    log.info("INIT", "Tracking %d low-stock alerts", #LOW_STOCK_ALERTS)

    print("")
    print("Console shows log. Use the monitors to interact.")
    print("")

    -- Try loading cached inventory from disk for instant startup
    local cacheLoaded = loadCacheFromDisk()
    if cacheLoaded then
        log.info("INIT", "Loaded cached inventory (%d types)", #cache.itemList)
        log.info("INIT", "Background refresh starting...")
    else
        -- No cache: do full scan with progress bar
        log.info("INIT", "No cache found. Scanning inventories...")
        if mon then
            local w, h = mon.getSize()
            local buf = window.create(mon, 1, 1, w, h, false)

            local function drawBoot(current, total, chestName)
                buf.setBackgroundColor(colors.black)
                buf.clear()

                -- Title
                buf.setBackgroundColor(colors.blue)
                buf.setCursorPos(1, 1)
                buf.write(string.rep(" ", w))
                local title = " INVENTORY MANAGER "
                buf.setCursorPos(math.floor((w - #title) / 2) + 1, 1)
                buf.setTextColor(colors.white)
                buf.write(title)

                -- Scanning label
                local midY = math.floor(h / 2)
                buf.setBackgroundColor(colors.black)
                buf.setTextColor(colors.lightGray)
                local label = "Scanning inventories..."
                buf.setCursorPos(math.floor((w - #label) / 2) + 1, midY - 2)
                buf.write(label)

                -- Chest name
                local short = chestName or ""
                if #short > w - 4 then short = ".." .. short:sub(-(w - 6)) end
                buf.setTextColor(colors.gray)
                buf.setCursorPos(math.floor((w - #short) / 2) + 1, midY - 1)
                buf.write(short)

                -- Progress bar
                local barW = math.min(w - 8, 40)
                local barX = math.floor((w - barW) / 2) + 1
                local ratio = total > 0 and (current / total) or 0
                local filled = math.floor(ratio * barW)

                buf.setCursorPos(barX, midY + 1)
                buf.setBackgroundColor(colors.lime)
                buf.write(string.rep(" ", filled))
                buf.setBackgroundColor(colors.gray)
                buf.write(string.rep(" ", barW - filled))

                -- Percentage + count
                buf.setBackgroundColor(colors.black)
                buf.setTextColor(colors.white)
                local pct = string.format("%d/%d  (%d%%)", current, total, math.floor(ratio * 100))
                buf.setCursorPos(math.floor((w - #pct) / 2) + 1, midY + 3)
                buf.write(pct)

                -- Bottom accent
                buf.setCursorPos(1, h)
                buf.setBackgroundColor(colors.blue)
                buf.write(string.rep(" ", w))

                buf.setVisible(true)
                buf.setVisible(false)
            end

            refreshCache(drawBoot)
        else
            refreshCache()
        end
        log.info("INIT", "Done. Found %d item types.", #cache.itemList)
    end
    print("")

    parallel.waitForAny(
        -- Task 1: Background inventory scanner
        function()
            -- If we loaded from disk cache, refresh immediately in background
            if cacheLoaded then
                pcall(refreshCache)
                pcall(checkAlerts)
                needsRedraw = true
                smelterNeedsRedraw = true
                log.info("INIT", "Background refresh complete. %d types.", #cache.itemList)
            end
            while true do
                sleep(SCAN_INTERVAL)
                pcall(refreshCache)
                pcall(checkAlerts)
                needsRedraw = true
                smelterNeedsRedraw = true
            end
        end,

        -- Task 2: Barrel auto-sort
        function()
            while true do
                pcall(sortBarrel)
                sleep(POLL_INTERVAL)
            end
        end,

        -- Task 3: Auto-smelt
        function()
            while true do
                local ok, didWork = pcall(autoSmelt)
                if ok and didWork then
                    activity.smelting = true
                    needsRedraw = true
                    smelterNeedsRedraw = true
                end
                activity.smelting = false
                -- Update furnace status quickly after smelt cycle
                pcall(refreshFurnaceStatus)
                needsRedraw = true
                smelterNeedsRedraw = true
                sleep(SMELT_INTERVAL)
            end
        end,

        -- Task 4: Defrag (consolidate partial stacks)
        function()
            sleep(10)  -- initial delay to let first scan finish
            while true do
                activity.defragging = true
                needsRedraw = true
                pcall(defragInventory)
                activity.defragging = false
                needsRedraw = true
                sleep(DEFRAG_INTERVAL)
            end
        end,

        -- Task 5: Auto-compost
        function()
            while true do
                activity.composting = true
                needsRedraw = true
                pcall(autoCompost)
                activity.composting = false
                needsRedraw = true
                pcall(checkAlerts)
                sleep(COMPOST_INTERVAL)
            end
        end,

        -- Task 6: Low-stock alert checker
        function()
            sleep(5)  -- initial delay
            pcall(checkAlerts)
            needsRedraw = true
            while true do
                sleep(ALERT_INTERVAL)
                pcall(checkAlerts)
                needsRedraw = true
            end
        end,

        -- Task 7: Inventory dashboard redraw (event-driven, checks every 0.1s)
        function()
            needsRedraw = true
            while true do
                if needsRedraw then
                    needsRedraw = false
                    pcall(drawDashboard)
                end
                -- Decrement status timer
                if statusTimer > 0 then
                    statusTimer = statusTimer - 0.1
                    if statusTimer <= 0 then
                        statusTimer = 0
                        needsRedraw = true
                    end
                end
                -- Redraw periodically for alert cycling
                if #activeAlerts > 0 then
                    needsRedraw = true
                end
                sleep(0.1)
            end
        end,

        -- Task 8: Smelter dashboard redraw
        function()
            smelterNeedsRedraw = true
            while true do
                if smelterNeedsRedraw then
                    smelterNeedsRedraw = false
                    pcall(drawSmelterDashboard)
                end
                sleep(0.1)
            end
        end,

        -- Task 9: Touch event listener (both monitors)
        function()
            while true do
                local event, side, x, y = os.pullEvent("monitor_touch")
                if smelterMonName and side == smelterMonName then
                    log.debug("TOUCH", "x=%d y=%d", x, y)
                    handleSmelterTouch(x, y)
                else
                    log.debug("TOUCH", "x=%d y=%d", x, y)
                    handleTouch(x, y)
                end
            end
        end,

        -- Task 10: Network state broadcast (skips if nothing changed)
        function()
            while true do
                if stateVersion ~= lastBroadcastVersion then
                    pcall(broadcastState)
                end
                sleep(BROADCAST_INTERVAL)
            end
        end,

        -- Task 11: Peripheral detach handler (invalidates cached handles)
        function()
            while true do
                local event, name = os.pullEvent("peripheral_detach")
                if name then
                    invalidateWrapCache(name)
                    invalidatePeripheralCaches()
                    log.info("DETACH", "%s", name)
                end
            end
        end,

        -- Task 12: Network order/command listener
        function()
            if not networkModem then return end
            while true do
                local event, side, channel, replyChannel, message, distance = os.pullEvent("modem_message")
                if channel == ORDER_CHANNEL and type(message) == "table" then
                    -- Idempotency: skip duplicate commands
                    if isCommandDuplicate(message.commandId) then
                        log.debug("NET", "Duplicate command skipped: %s", tostring(message.commandId))
                    else
                    recordCommandId(message.commandId)
                    cleanupCommandIds()
                    local handlerOk, handlerErr = pcall(function()
                    if message.type == "order" and message.itemName and message.amount then
                        log.info("NET", "Order: %s x%d", message.itemName, message.amount)
                        local pok, success = pcall(orderItem, message.itemName, message.amount, message.dropperName)
                        if not pok then
                            log.error("NET", "orderItem crashed: %s", tostring(success))
                            success = false
                            statusMessage = "Order error"
                            statusColor = colors.red
                            statusTimer = 5
                            needsRedraw = true
                        end
                        pcall(function()
                            networkModem.transmit(replyChannel, ORDER_CHANNEL, {
                                type      = "order_result",
                                commandId = message.commandId,
                                success   = success,
                                message   = statusMessage,
                                color     = statusColor,
                            })
                        end)
                        pcall(broadcastState)
                    elseif message.type == "scan" then
                        log.info("NET", "Scan request from client")
                        configDirty = true  -- resend full config after scan
                        pcall(refreshCache)
                        pcall(checkAlerts)
                        needsRedraw = true
                        smelterNeedsRedraw = true
                        pcall(broadcastState)
                    elseif message.type == "toggle_pause" then
                        smeltingPaused = not smeltingPaused
                        log.info("NET", "Smelting %s", smeltingPaused and "PAUSED" or "RESUMED")
                        saveDisabledRecipes()
                        bumpStateVersion()
                        smelterNeedsRedraw = true
                        needsRedraw = true
                        pcall(broadcastState)
                    elseif message.type == "toggle_recipe" and message.recipe then
                        if disabledRecipes[message.recipe] then
                            disabledRecipes[message.recipe] = nil
                        else
                            disabledRecipes[message.recipe] = true
                        end
                        log.info("NET", "Recipe toggle: %s", message.recipe)
                        saveDisabledRecipes()
                        configDirty = true
                        bumpStateVersion()
                        smelterNeedsRedraw = true
                        pcall(broadcastState)
                    elseif message.type == "enable_all" then
                        disabledRecipes = {}
                        log.info("NET", "All recipes enabled")
                        saveDisabledRecipes()
                        configDirty = true
                        bumpStateVersion()
                        smelterNeedsRedraw = true
                        pcall(broadcastState)
                    elseif message.type == "disable_all" then
                        for inputName in pairs(SMELTABLE) do
                            disabledRecipes[inputName] = true
                        end
                        log.info("NET", "All recipes disabled")
                        saveDisabledRecipes()
                        configDirty = true
                        bumpStateVersion()
                        smelterNeedsRedraw = true
                        pcall(broadcastState)
                    elseif message.type == "sort_barrel" and message.barrelName then
                        log.info("NET", "Sort barrel: %s", message.barrelName)
                        pcall(sortBarrel, message.barrelName)
                        pcall(broadcastState)
                    elseif message.type == "register_droppers" and message.clientId and message.droppers then
                        -- Client is announcing its locally-attached droppers
                        local cid = tostring(message.clientId)
                        clientDroppers[cid] = message.droppers
                        log.info("NET", "Client %s registered %d dropper(s)", cid, #message.droppers)
                        -- Rebuild the merged dropper list immediately
                        local seenNames = {}
                        local merged = {}
                        -- Master droppers first
                        for _, d in ipairs(cache.droppers or {}) do
                            if not d.clientId then
                                table.insert(merged, d)
                                seenNames[d.name] = true
                            end
                        end
                        -- Then all client droppers
                        for clientId, clientList in pairs(clientDroppers) do
                            for _, d in ipairs(clientList) do
                                if not seenNames[d.name] then
                                    table.insert(merged, { name = d.name, isDefault = false, clientId = clientId })
                                    seenNames[d.name] = true
                                end
                            end
                        end
                        cache.droppers = merged
                        bumpStateVersion()
                        pcall(broadcastState)
                    elseif message.type == "reboot" then
                        local target = message.target or "all"
                        log.info("NET", "Reboot command received, target: %s", target)
                        -- Broadcast reboot to all clients on system channel
                        networkModem.transmit(SYSTEM_CHANNEL, ORDER_CHANNEL, {
                            type   = "reboot",
                            target = target,
                        })
                        -- If manager itself is targeted, reboot after a short delay
                        if target == "all" or target == "manager" then
                            log.info("NET", "Manager rebooting in 1s...")
                            sleep(1)
                            os.reboot()
                        end
                    elseif message.type == "craft" and message.recipeIdx then
                        log.info("NET", "Craft request: recipe #%d", message.recipeIdx)
                        local pok, ok, err = pcall(craftItem, message.recipeIdx)
                        if not pok then
                            log.error("NET", "craftItem crashed: %s", tostring(ok))
                            err = tostring(ok)
                            ok = false
                        end
                        pcall(function()
                            networkModem.transmit(replyChannel, ORDER_CHANNEL, {
                                type      = "craft_result",
                                commandId = message.commandId,
                                success   = ok,
                                error     = err,
                            })
                        end)
                        smelterNeedsRedraw = true
                        needsRedraw = true
                        pcall(broadcastState)
                    end
                    end) -- end pcall handler
                    if not handlerOk then
                        log.error("NET", "Handler error: %s", tostring(handlerErr))
                    end
                    end -- end idempotency else
                end
            end
        end
    )
end

main()