local refuel = require("modules.refuel")
local inv_utils = require("modules.inv_utils")
local str_utils = require("modules.str_utils")
local nav = require("modules.nav")

local DATA_PATH = "/data/sorter_data.txt" 
local CAT_PATH = "/data/sorter_cat.txt" 


local function runDiagnostics()
	local canStart = true

	print("Running diagnostics...")
	print(string.format("Fuel level: %s", turtle.getFuelLevel()))
	local fuelStorage = peripheral.wrap("front")
	local hasInStorage = refuel.hasFuelInStorage(fuelStorage) and "yes" or "no"
	print(string.format("Fuel in storage: %s", hasInStorage))
	
	local dataExists = fs.exists(DATA_PATH)

	if not dataExists then
		canStart = false
	end

	print(string.format("Data path exists: %s", dataExists and "yes" or "no"))
	
	print(string.format("Category path exists: %s", fs.exists(CAT_PATH) and "yes" or "no"))

	local hasItemsInUnsorted = inv_utils.hasItemsInStorage(peripheral.wrap("top"))

	if not hasItemsInUnsorted then
		canStart = false
	end

	print(string.format("Items in unsorted storage: %s", hasItemsInUnsorted and "yes" or "no"))

	local hasItemsInLeftover = inv_utils.hasItemsInStorage(peripheral.wrap("bottom"))

	if hasItemsInLeftover then
		canStart = false
	end

	print(string.format("Items in leftover storage: %s", hasItemsInLeftover and "yes" or "no"))
	
	local hasItemsInTurtle = inv_utils.hasItemsInTurtle()

	if hasItemsInTurtle then
		canStart = false
	end

	print(string.format("Items in turtle: %s", hasItemsInTurtle and "yes" or "no"))

	if canStart then
		print("Ready to start sorting.")
	else
		print("Can not start sorting.")
	end

	return canStart
end

local function getState()
	local state = {}
	
	local file = fs.open(DATA_PATH, "r")
	local content = file.readAll()
	file.close()

	state.coords = {}
	local coord_count = 0
	for idx, elem in pairs(str_utils.split(content)) do
		if idx == 1 then
			state.safe_y = tonumber(elem)
		else
			local modulo = (idx - 2) % 4
			if modulo == 0 then
				table.insert(state.coords, { 0, 0, 0, 0 })
				coord_count = coord_count + 1
			end

			state.coords[coord_count][modulo + 1] = tonumber(elem)
		end
	end

	state.park_pos = state.coords[1]
	state.start_pos = state.coords[2]
	state.sort_pos = state.coords[3]
	state.leftover_pos = state.coords[4]

	for ii = 1, 4 do
		table.remove(state.coords, 1)
	end

	state.categories = { }
	if fs.exists(CAT_PATH) then	
		local file2 = fs.open(CAT_PATH, "r")
		local cat_content = file2.readAll()
		file2.close()

		for _, cat in pairs(str_utils.split(cat_content, "---")) do
			local categ = {}
			for _, entry in pairs(str_utils.split(cat)) do
				table.insert(categ, entry)
			end
			table.insert(state.categories, categ)
		end
	end

	return state
end

local function move(a, b, safe_y, unsafe)
	nav.travel(a[1], a[2], a[3], a[4], b[1], b[2], b[3], b[4], safe_y, unsafe)
end

local function debugPrintPos(a)
	print(a[1], a[2], a[3], a[4])
end

local function runErrands()
	local state = getState()

	move(state.park_pos, state.start_pos, state.safe_y, true)
	move(state.start_pos, state.sort_pos, state.safe_y)

	inv_utils.fillTurtle()
	local oneMoreRound = inv_utils.hasItemsInTurtle()
	while (oneMoreRound) do
		local current_pos = state.sort_pos
		for _, next_pos in pairs(state.coords) do
			move(current_pos, next_pos, state.safe_y)
			current_pos = next_pos
			inv_utils.storeIdenticalItemsInStorage(state)

			if not inv_utils.hasItemsInTurtle() then
				break
			end
		end

		if inv_utils.hasItemsInTurtle() then
			move(current_pos, state.leftover_pos, state.safe_y)
			inv_utils.emptyTurtle()
			move(state.leftover_pos, state.sort_pos, state.safe_y)
		else
			move(current_pos, state.sort_pos, state.safe_y)
		end


		inv_utils.fillTurtle()
		oneMoreRound = inv_utils.hasItemsInTurtle()
	end

	move(state.sort_pos, state.start_pos, state.safe_y)
	move(state.start_pos, state.park_pos, state.safe_y, true)
end

local function run()
	local result = runDiagnostics()
	if not result then
		return nil
	end

	write("Start? (y/N) ")
	local response = read()
	local firstChar = string.sub(response, 1, 1)
	if firstChar == "y" or firstChar == "Y" then
		print("Started sorting.")
		refuel.refuel()
		runErrands()
	else
		print("Aborted.")
		return nil
	end

	os.shutdown()
end

return { run = run }