-- Live GPS Tracker for Pocket Computer
-- Shows your current location in real-time

local Channels  = require('platform.channels')
local WebBridge = require('platform.webbridge')

local STATUS_CHANNEL = Channels.get('remoteturtle.status')

-- Setup modem
local modem = peripheral.find("modem")
if not modem then
    error("No wireless modem found!")
end

-- Equip modem if on pocket computer
if pocket then
    pocket.equipBack()
    modem = peripheral.find("modem")
end

WebBridge.openChannels(modem, { 'remoteturtle.status' })

local w, h = term.getSize()
local myID = os.getComputerID()
local currentPos = {x = 0, y = 0, z = 0}
local lastUpdate = 0
local turtles = {}

-- Get GPS position
local function updateGPS()
    local x, y, z = gps.locate(5)
    if x then
        currentPos = {x = math.floor(x), y = math.floor(y), z = math.floor(z)}
        lastUpdate = os.clock()
        return true
    end
    return false
end

-- Draw header
local function drawHeader()
    term.setCursorPos(1, 1)
    term.setBackgroundColor(colors.blue)
    term.setTextColor(colors.white)
    term.clearLine()
    term.setCursorPos(math.floor((w - 14) / 2), 1)
    term.write(" GPS TRACKER ")
end

-- Draw position info
local function drawPosition()
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.white)
    
    -- Computer ID
    term.setCursorPos(2, 3)
    term.write("Computer ID: ")
    term.setTextColor(colors.yellow)
    term.write(tostring(myID))
    
    -- Current coordinates
    term.setTextColor(colors.white)
    term.setCursorPos(2, 5)
    term.write("Current Position:")
    
    term.setCursorPos(4, 6)
    term.setTextColor(colors.red)
    term.write("X: ")
    term.setTextColor(colors.white)
    term.write(string.format("%d", currentPos.x))
    
    term.setCursorPos(4, 7)
    term.setTextColor(colors.green)
    term.write("Y: ")
    term.setTextColor(colors.white)
    term.write(string.format("%d", currentPos.y))
    
    term.setCursorPos(4, 8)
    term.setTextColor(colors.blue)
    term.write("Z: ")
    term.setTextColor(colors.white)
    term.write(string.format("%d", currentPos.z))
    
    -- Time since last update
    local timeSince = os.clock() - lastUpdate
    term.setCursorPos(2, 10)
    term.setTextColor(colors.gray)
    if lastUpdate > 0 then
        term.write(string.format("Updated %.1fs ago", timeSince))
    else
        term.write("No GPS fix yet...")
    end
end

-- Draw nearby turtles
local function drawTurtles()
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.white)
    
    term.setCursorPos(2, 12)
    term.write("Nearby Turtles:")
    
    local line = 13
    local count = 0
    
    -- Sort turtles by distance
    local sortedTurtles = {}
    for id, data in pairs(turtles) do
        if data.position then
            local dx = data.position.x - currentPos.x
            local dy = data.position.y - currentPos.y
            local dz = data.position.z - currentPos.z
            local distance = math.sqrt(dx*dx + dy*dy + dz*dz)
            table.insert(sortedTurtles, {id = id, data = data, distance = distance})
        end
    end
    
    table.sort(sortedTurtles, function(a, b) return a.distance < b.distance end)
    
    -- Display up to 5 closest turtles
    for i = 1, math.min(5, #sortedTurtles) do
        local turtle = sortedTurtles[i]
        term.setCursorPos(4, line)
        term.setTextColor(colors.yellow)
        term.write(string.format("#%d", turtle.id))
        term.setTextColor(colors.white)
        term.write(string.format(" [%.1fm]", turtle.distance))
        
        term.setCursorPos(6, line + 1)
        term.setTextColor(colors.gray)
        term.write(string.format("(%d, %d, %d)", 
            turtle.data.position.x,
            turtle.data.position.y,
            turtle.data.position.z))
        
        line = line + 2
        count = count + 1
        if line >= h - 2 then break end
    end
    
    if count == 0 then
        term.setCursorPos(4, line)
        term.setTextColor(colors.gray)
        term.write("None detected")
    end
end

-- Draw footer
local function drawFooter()
    term.setCursorPos(1, h)
    term.setBackgroundColor(colors.gray)
    term.setTextColor(colors.white)
    term.clearLine()
    term.setCursorPos(2, h)
    term.write("[Q] Quit  [R] Refresh")
end

-- Full screen refresh
local function draw()
    term.setBackgroundColor(colors.black)
    term.clear()
    drawHeader()
    drawPosition()
    drawTurtles()
    drawFooter()
end

-- Handle turtle status broadcasts
local function handleStatus(message)
    if message.id and message.id ~= myID then
        if not turtles[message.id] then
            turtles[message.id] = {}
        end
        
        -- Update turtle data
        if message.position then
            turtles[message.id].position = message.position
        end
        if message.status then
            turtles[message.id].status = message.status
        end
        if message.fuel then
            turtles[message.id].fuel = message.fuel
        end
        
        turtles[message.id].lastSeen = os.clock()
    end
end

-- Clean up old turtles (not seen in 30 seconds)
local function cleanupTurtles()
    local now = os.clock()
    for id, data in pairs(turtles) do
        if data.lastSeen and (now - data.lastSeen) > 30 then
            turtles[id] = nil
        end
    end
end

-- Main loop
local function main()
    print("GPS Tracker starting...")
    print("Getting initial GPS fix...")
    
    -- Get initial GPS position
    updateGPS()
    
    draw()
    
    local gpsTimer = os.startTimer(2) -- Update GPS every 2 seconds
    local cleanupTimer = os.startTimer(10) -- Cleanup every 10 seconds
    local drawTimer = os.startTimer(0.5) -- Redraw every 0.5 seconds
    
    while true do
        local event, param1, param2, param3, param4, param5 = os.pullEvent()
        
        if event == "timer" then
            if param1 == gpsTimer then
                updateGPS()
                gpsTimer = os.startTimer(2)
            elseif param1 == cleanupTimer then
                cleanupTurtles()
                cleanupTimer = os.startTimer(10)
            elseif param1 == drawTimer then
                draw()
                drawTimer = os.startTimer(0.5)
            end
            
        elseif event == "modem_message" then
            local channel = param2
            local replyChannel = param3
            local message = param4
            
            -- Uses Channels.match() for dual-mode safety: accepts messages on
            -- both legacy (102) and target (4212) channels during migration.
            if Channels.match('remoteturtle.status', channel) and type(message) == "table" then
                handleStatus(message)
            end
            
        elseif event == "char" then
            if param1 == "q" or param1 == "Q" then
                term.setBackgroundColor(colors.black)
                term.setTextColor(colors.white)
                term.clear()
                term.setCursorPos(1, 1)
                print("GPS Tracker stopped.")
                return
            elseif param1 == "r" or param1 == "R" then
                updateGPS()
                draw()
            end
            
        elseif event == "mouse_click" then
            -- Check if quit button clicked (bottom bar)
            if param3 == h then
                term.setBackgroundColor(colors.black)
                term.setTextColor(colors.white)
                term.clear()
                term.setCursorPos(1, 1)
                print("GPS Tracker stopped.")
                return
            end
        end
    end
end

-- Run the tracker
local success, err = pcall(main)
if not success then
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.white)
    term.clear()
    term.setCursorPos(1, 1)
    print("Error: " .. tostring(err))
end