-- luacheck: globals Character MyModGlobal Timer
local cursormacroer = require("Cyka.cursormacroer")
local dump = require("Cyka.dump")

---@class InventorySlot
---@field slot Barotrauma.ItemSlot
---@field inventory Barotrauma.ItemInventory
---@field slotIndex number

---@param inventory Barotrauma.ItemInventory
---@param predicate fun(slot: InventorySlot): boolean
---@return InventorySlot[], string?
local function findSlotsThat(inventory, predicate)
	local slots = {}
	for i, slot in ipairs(inventory.slots) do
		local inventorySlot = {
			slot = slot,
			inventory = inventory,
			slotIndex = i - 1
		}
		if predicate(inventorySlot) then
			slots[#slots + 1] = inventorySlot
		end
	end
	return slots
end

---@param slot InventorySlot
local function tryUnloadSlot(slot)
	---@type Barotrauma.Item
	local item = slot.slot.items[1]
	if not item then
		MyModGlobal.debugPrint("No item in slot")
		return
	end
	local inventory = item.OwnInventory
	if not inventory then
		MyModGlobal.debugPrint("Item has no own inventory")
		return
	end

	local toUnload = {}
	local toUnloadByPrefab = {}
	local inventorySlots = inventory.slots
	for _, inventorySlot in ipairs(inventorySlots) do
		for _, inventoryItem in ipairs(inventorySlot.items) do
			toUnload[#toUnload + 1] = inventoryItem
			-- This will only serve as O(1) lookup
			toUnloadByPrefab[inventoryItem.Prefab] = true
		end
	end

	-- Where can we put our toUnload items?
	local nearbySlots = findSlotsThat(slot.inventory, function(islot)
		local isEmpty = #islot.slot.items == 0
		if isEmpty then return true end

		for _, prefab in ipairs(toUnloadByPrefab) do
			local canAccept = islot.inventory.CanBePutInSlot(prefab, islot.slotIndex)
			if canAccept then return true end
		end
		return false
	end)
	-- print("Before sorting:")
	-- dump(nearbySlots)

	local slotsPerRow = slot.inventory.slotsPerRow or 1
	local getGridPos = function(slotIndex)
		local x = slotIndex % slotsPerRow
		local y = math.floor(slotIndex / slotsPerRow)
		return x, y
	end

	-- We are offsetting here by 1 because the backend uses 0-indexed slots
	-- And the lua uses 1-indexed slots
	-- We are trying to match the backend behavior for sorting
	local slotx, sloty = getGridPos(slot.slotIndex - 1)
	-- print(string.format("Slot position %d: %d, %d", slot.slotIndex, slotx, sloty))
	table.sort(nearbySlots, function(a, b)
		local ax, ay = getGridPos(a.slotIndex)
		local bx, by = getGridPos(b.slotIndex)

		local distA = math.max(math.abs(ax - slotx), math.abs(ay - sloty))
		local distB = math.max(math.abs(bx - slotx), math.abs(by - sloty))

		if distA == distB then
			return a.slotIndex < b.slotIndex
		end
		return distA < distB
	end)
	-- print(string.format("Current slot: %d at (%d, %d)", slot.slotIndex, slotx, sloty))

	for _, iitem in ipairs(toUnload) do
		for _, nearbySlot in ipairs(nearbySlots) do
			local canAccept = nearbySlot.inventory.CanBePutInSlot(iitem.Prefab, nearbySlot.slotIndex)
			if canAccept then
				local moved = nearbySlot.inventory.TryPutItem(iitem, nearbySlot.slotIndex, true, false, nil)
				-- print(string.format("Moved item %s to slot %d", iitem.Name, nearbySlot.slotIndex))
				if moved then break end
			end
		end
	end
end

local function tryUnloadCursorItem()
	local slots, err = cursormacroer.getInventorySlotsUnderCursor()
	if err then
		-- MyModGlobal.debugPrint(string.format("Error getting inventory slot: %s", err))
		return
	end

	if not slots or #slots == 0 then
		-- MyModGlobal.debugPrint("No items in slot")
		return
	end

	for _, slot in ipairs(slots) do
		tryUnloadSlot(slot)
	end

	-- local canAccept = inventorySlot.CanBePutInSlot(item, inventorySlot.slotIndex, item.Condition)
	-- if canAccept then
	-- 	toUnload[#toUnload + 1] = inventoryItem
	-- end
	-- local slots = findSlotsThat(inventory, function(slot)
	-- 	local canAccept
	-- end)

	-- local inventory = targetInventory
	-- -- MyModGlobal.debugPrint(string.format("Target inventory: %s", tostring(inventory)))
	-- if not inventory then
	-- 	local controlledCharacter = Character.Controlled
	-- 	if not controlledCharacter then
	-- 		-- MyModGlobal.debugPrint("No controlled character found")
	-- 		return
	-- 	end
	-- 	local cinventory = controlledCharacter.Inventory
	-- 	if not cinventory or not cinventory.slots then
	-- 		-- MyModGlobal.debugPrint("No inventory found")
	-- 		return
	-- 	end
	-- 	local bagSlot = cinventory.slots[MyModGlobal.BAG_SLOT]
	-- 	if not bagSlot or not bagSlot.items or not bagSlot.items[1] then
	-- 		-- MyModGlobal.debugPrint("No bag slot found")
	-- 		return
	-- 	end
	-- 	local bagItem = bagSlot.items[1]
	-- 	if not bagItem or not bagItem.OwnInventory then
	-- 		-- MyModGlobal.debugPrint("Bag item has no own inventory")
	-- 		return
	-- 	end
	-- 	local bagInventory = bagItem.OwnInventory
	-- 	if not bagInventory or not bagInventory.slots then
	-- 		-- MyModGlobal.debugPrint("Bag inventory has no slots")
	-- 		return
	-- 	end
	-- 	inventory = bagInventory
	-- end
	-- if not inventory then
	-- 	-- MyModGlobal.debugPrint("No inventory found")
	-- 	return
	-- end

	-- local itemTree
	-- itemTree, err = quickstack.buildItemTree(inventory)
	-- if err then
	-- 	-- MyModGlobal.debugPrint(string.format("Error building item tree: %s", err))
	-- 	return
	-- end
	-- itemTree = quickstack.sortItemTree(itemTree)

	-- local itemsToMove = {}
	-- local now = Timer.GetTime()
	-- for _, slot in ipairs(slots) do
	-- 	local runAfter = slotThrottle[slot] or 0
	-- 	if now < runAfter then
	-- 		goto continue
	-- 	end
	-- 	-- MyModGlobal.debugPrint(string.format("Enqueuing slot: %s, before: %d", tostring(slot), #itemsToMove))
	-- 	utils.enqueueSlot(slot.slot, itemsToMove)
	-- 	-- MyModGlobal.debugPrint(string.format("Enqueuing slot: %s, after: %d", tostring(slot), #itemsToMove))
	-- 	slotThrottle[slot] = now + 1
	-- 	::continue::
	-- end
	-- -- for _, item in ipairs(itemsToMove) do
	-- -- 	MyModGlobal.debugPrint(string.format("Enqueued item: %s", tostring(item)))
	-- -- end
	-- -- -- MyModGlobal.debugPrint(string.format("Enqueued %d items from the inventory slot", #itemsToMove))
	-- -- MyModGlobal.DumpTable(itemTree)

	-- quickstack.tryMoveItems(itemsToMove, itemTree, true)
	-- -- local errors = quickstack.tryMoveItems(itemsToMove, itemTree, true)
	-- -- for _, error in ipairs(errors) do
	-- -- 	MyModGlobal.debugPrint(string.format("Error moving item: %s", error))
	-- -- end
end

return {
	tryUnloadCursorItem = tryUnloadCursorItem,
}