local ENDER_CHEST_SLOT = 2
local DIG_SLOT = 3

--save movments
function move(move, detect, dig, attack)
	if needsPitstop() then
		doPitstop()
	end

	local first = true
	while not move() do
		if detect() then
			turtle.select(DIG_SLOT)
			dig()
		else
			attack()
		end

		if not first then
			sleep(0.5)
		end
		first = false
	end
end

function moveForward()
	move(turtle.forward, turtle.detect, turtle.dig, turtle.attack)
end

function moveBack()
	turn180()
	moveForward()
	turn180()
end

function moveUp()
	move(turtle.up, turtle.detectUp, turtle.digUp, turtle.attackUp)
end

function moveDown()
	move(turtle.down, turtle.detectDown, turtle.digDown, turtle.attackDown)
end

function turn180()
	turtle.turnLeft()
	turtle.turnLeft()
end

--pitstop
function doPitstop()
	if turtle.detectUp() then
		turtle.select(DIG_SLOT)
		turtle.digUp()
	end

	turtle.select(ENDER_CHEST_SLOT)
	turtle.placeUp()

	local enderChest = peripherals.wrap()

	if not hasSpace() then
		for i = 3, 16, 1 do
			while turtle.getItemCount(i) > 0 do
				local moved = false
				for j = 2, enderChest.getInventorySize(), 1 do
					if enderChest.pullItem("down", i, 64, j) ~= 0 then
						moved = true
					end
				end

				if not moved then
					sleep(2)
				end
			end
		end
	end

	--TODO: add support for normal fuel
	while turtle.getFuelLevel() < 5 do
		local lavaBucket = enderChest.getStackInSlot(1)
		if lavaBucket ~= nil and lavaBucket["id"] == "minecraft:lava_bucket" then
			enderChest.pushItem("down", 1, 64, 1)
			turtle.select(1)
			turtle.refuel()
			enderChest.pullItem("down", 1, 64, 1)
		end

		if turtle.getFuelLevel() < 5 then
			sleep(1)
		end
	end

	turtle.select(ENDER_CHEST_SLOT)
	turtle.digUp()
end

function needsPitstop()
	return (not hasSpace()) or turtle.getFuelLevel() < 5
end

function hasSpace()
	local count = 0
	for i = 3, 16, 1 do
		if turtle.getItemCount(i) == 0 then
			count = count + 1
		end
	end
	return count > 1
end

function readNumber()
	local num = -1
	repeat
		if num ~= -1 then
			print("Text is not a number.")
		end
		num = tonumber(read())
	until num ~= nil
	return num
end

--ore stuff
function isOre()
	local success, data = turtle.inspect()
	return checkOre(success, data)
end

function isOreUp()
	local success, data = turtle.inspectUp()
	return checkOre(success, data)
end

function isOreDown()
	local success, data = turtle.inspectDown()
	return checkOre(success, data)
end

function checkOre(success, data)
	if success then
		local name = data["name"]
		if name ~= nil then
			--Alternative name bypass
			if name == "Forestry:resources" or name == "TConstruct:SearedBrick"
					or name == "denseores:block0" or name == "rftools:dimensionalShardBlock"
					or name == "harvestcraft:salt" then
				return true
			end

			local index = string.find(name, ":")
			if index ~= nil then
				local part = string.lower(string.sub(name, index))
				local isOre = string.find(part, "ore")
				return isOre ~= nil
			end
		end
	end
	return false
end

--vein stuff
function mineVein()
	while true do
		if isOre() then
			veinMoveForward()
		elseif isOreUp() then
			veinMoveUp()
		elseif isOreDown() then
			veinMoveDown()
		else
			local success = false
			for i = 1, 3, 1 do
				veinMoveLeft()
				if isOre() then
					veinMoveForward()
					success = true
					break
				end
			end

			if not success then
				if not popVeinMovment() then
					return
				end
			end
		end
		sleep(0.5)
	end
end

function veinMoveForward()
	moveForward()
	pushToVeinStack(1)
end

function veinMoveUp()
	moveUp()
	pushToVeinStack(2)
end

function veinMoveDown()
	moveDown()
	pushToVeinStack(3)
end

function veinMoveLeft()
	turtle.turnLeft()
	pushToVeinStack(4)
end

function veinMoveRight()
	turtle.turnRight()
	pushToVeinStack(5)
end

function veinMoveBack()
	moveBack()
	pushToVeinStack(6)
end

function popVeinMovment()
	local direction = getFromVeinStack()

	if direction == nil then
		return false
	end

	if direction == 1 then
		moveBack()
	elseif direction == 2 then
		moveDown()
	elseif direction == 3 then
		moveUp()
	elseif direction == 4 then
		turtle.turnRight()
		removeLastVeinStack()
		return popVeinMovment()
	elseif direction == 5 then
		turtle.turnLeft()
		removeLastVeinStack()
		return popVeinMovment()
	elseif direction == 6 then
		moveForward()
	elseif direction == 0 then
		removeLastVeinStack()
		return popVeinMovment()
	end

	removeLastVeinStack()

	return true;
end

function pushToVeinStack(direction)
	local handle = fs.open("VeinStack.dat", "a")
	handle.writeLine(tostring(direction))
	handle.close()
end

function getFromVeinStack()
	local data = getVeinStack()

	if data ~= nil then
		return tonumber(data[#data])
	end
	return nil
end

function getVeinStack()
	--optimize vein stack
	local handle = fs.open("VeinStack.dat", "r")

	if handle ~= nil then
		local data = {}
		local index = 0
		repeat
			index = index + 1
			data[index] = handle.readLine()
		until data[index] == nil
		handle.close()

		if #data > 0 then
			data = optimizeVeinStack(data)
			if #data > 0 then
				return data
			end
		end
	end
	return nil
end

function optimizeVeinStack(data)
	local lastAction = 0
	local actionCount = 0

	for i = 1, #data, 1 do
		--turn right and then left is somewhat useless
		if data[i] == 4 and lastAction == 5 or
			data[i] == 5 and lastAction == 4 then
			data = moveArrayContent(data, i + 2, 2)

			if #data < 1 then
				break
			end
		end

		if data[i] ~= lastAction then
			lastAction = 0
			actionCount = 0
		end

		if data[i] == 4 then
			lastAction = 4
			actionCount = actionCount + 1
		elseif data[i] == 5 then
			lastAction = 5
			actionCount = actionCount + 1
		end

		if actionCount == 3 then
			local newAction = 4
			if lastAction == 4 then
				newAction = 5
			end

			data = moveArrayContent(data, i + 1, 2)
			data[i - 2] = newAction

			i = i - 1
		end
	end
	return data
end

function moveArrayContent(array, startIndex, amount)
	local size = #array
	for i = startIndex, size, 1 do
		array[i - amount] = array[i]
		array[i] = nil
	end
	return array
end

function removeLastVeinStack()
	local data = getVeinStack()

	if data ~= nil then
		handle = fs.open("VeinStack.dat", "w")
		for i = 1, #data - 1, 1 do
			handle.writeLine(data[i])
		end
		handle.close()
	end
end


mineVein()
--print("Enter the max depth of the mine.")
--local depth = readNumber()

--print("Enter the max width of the mine.")
--local width = readNumber()