local class      = require('opus.class')
local Util       = require('opus.util')
local itemDB     = require('core.itemDB')
local Peripheral = require('opus.peripheral')

local ChestAdapter = class()

function ChestAdapter:init(args)
	local defaults = {
		name = 'chest',
		adapter = 'ChestAdapter18'
	}
	Util.merge(self, defaults)
	Util.merge(self, args)

	local chest
	if not self.side then
		chest = Peripheral.getByMethod('list') or
						Peripheral.getByMethod('listAvailableItems')
	else
		chest = Peripheral.getBySide(self.side)
		if chest and not chest.list and not chest.listAvailableItems then
			chest = nil
		end
	end

	if chest then
		Util.merge(self, chest)

		if chest.listAvailableItems then
			self.list = chest.listAvailableItems
		end
	end
end

function ChestAdapter:isValid()
	return not not self.list
end

-- handle both AE/RS and generic inventory
function ChestAdapter:getItemDetails(index, item)
	if self.getItemMeta then
		local s, detail = pcall(self.getItemMeta, index)
		if not s or not detail or detail.name ~= item.name then
			return
		end
		return detail
	else
		local detail = self.findItems(item)
		if detail and #detail > 0 then
			return detail[1].getMetadata()
		end
	end
end

function ChestAdapter:getCachedItemDetails(item, k)
	local cached = itemDB:get(item)
	if cached then
		return cached
	end

	local detail = self:getItemDetails(k, item)
	if detail then
		return itemDB:add(detail)
	end
end

function ChestAdapter:refresh(throttle)
	return self:listItems(throttle)
end

-- provide a consolidated list of items
function ChestAdapter:listItems(throttle)
	for _ = 1, 5 do
		local list = self:listItemsInternal(throttle)
		if list then
			return list
		end
	end
	error('Error accessing inventory: ' .. self.direction)
end

function ChestAdapter:listItemsInternal(throttle)
	local cache = { }
	local items = { }
	throttle = throttle or Util.throttle()

	for k,v in pairs(self.list()) do
		if v.count > 0 then
			local key = table.concat({ v.name, v.damage, v.nbtHash }, ':')

			local entry = cache[key]
			if not entry then
				entry = self:getCachedItemDetails(v, k)
				if not entry then
					return -- Inventory has changed
				end
				entry = Util.shallowCopy(entry)
				entry.count = 0
				cache[key] = entry
				table.insert(items, entry)
			end

			if entry then
				entry.count = entry.count + v.count
			end
			throttle()
		end
	end
	itemDB:flush()

	self.cache = cache
	return items
end

function ChestAdapter:getItemInfo(item)
	if not self.cache then
		self:listItems()
	end
	local key = table.concat({ item.name, item.damage, item.nbtHash }, ':')
	local items = self.cache or { }
	return items[key]
end

function ChestAdapter:getPercentUsed()
	if self.cache and self.getDrawerCount then
		return math.floor(Util.size(self.cache) / self.getDrawerCount() * 100)
	end
	return 0
end

function ChestAdapter:provide(item, qty, slot, direction)
	local total = 0

	local _, m = pcall(function()
		local stacks = self.list()
		for key,stack in Util.rpairs(stacks) do
			if stack.name == item.name and
				 stack.damage == item.damage and
				 stack.nbtHash == item.nbtHash then
				local amount = math.min(qty, stack.count)
				if amount > 0 then
					amount = self.pushItems(direction or self.direction, key, amount, slot)
				end
				qty = qty - amount
				total = total + amount
				if qty <= 0 then
					break
				end
			end
		end
	end)
	return total, m
end

function ChestAdapter:extract(slot, qty, toSlot, direction)
	return self.pushItems(direction or self.direction, slot, qty, toSlot)
end

function ChestAdapter:insert(slot, qty, toSlot, direction)
	return self.pullItems(direction or self.direction, slot, qty, toSlot)
end

return ChestAdapter