local lastStatus = 0
local status = 0 -- 0Clueless-1Starting-2Harvesting-3Returning-4onRail
local n = 0

--todo: if no fuel in fuelslot, return immediatly.

-- refuel the turtle with slot 1, coal
function Refuel()
	turtle.select(1)
	if not turtle.refuel(3) then
		status = 3
	end
end

--grabs fuel from coal chest
function GrabFuel()
	turtle.turnLeft()
	turtle.select(1)
	turtle.suck()
	turtle.turnRight()
end

-- This function checks where the turtle is located on the rail, it's needed in case the program boots while the
-- turtle is not at the dropoff location
function UpdateStatus()
	local s, under = turtle.inspectDown()
	local s2, front = turtle.inspect()


	lastStatus = status
	if s then
		if under.name == "minecraft:cobblestone" then
			status = 1
		end
		if under.name == "minecraft:torch" then
			status = 4
		end
		if under.name == "minecraft:dirt" then
			turtle.back()
			turtle.turnLeft()
		end
		if under.name == "minecraft:leaves" then
			turtle.digDown()
			turtle.down()
		end
	else
		turtle.down()
	end

	if s2 then
		if front.name == "minecraft:chest" then
			turtle.turnLeft()
			turtle.turnLeft()
			status = 1
		end
		if front.name == "minecraft:log" or front.name == "minecraft:sapling" then
			turtle.turnLeft()
			UpdateStatus()
		end
		if front.name == "minecraft:gravel" then
			turtle.turnLeft()
			turtle.turnLeft()
		end
	elseif status == 4 then
		turtle.forward()
	end

	print("Updated Status: " .. lastStatus .. " to " .. status)

end

function CheckTree(side)
	if side == 1 then
		turtle.turnLeft()
		turtle.suck()
	elseif side == 2 then
		turtle.turnRight()
		turtle.suck()
	end
	local s, d = turtle.inspect()
	if s and d.name == "minecraft:log" then
		return true
	elseif s and d.name == "minecraft:sapling" then
		return false
	else
		Replant()
		return false
	end
end

function ChopTree(side)
	if CheckTree(side) then
		turtle.dig()
		for i = 1, 4 do
			print("Chopping up: " .. i)
			if not turtle.up() then
				turtle.digUp()
				turtle.up()
			end
			turtle.dig()
		end
		while true do
			sleep(0.1)
			local s, d = turtle.inspectDown()
			if s and d.name ~= "minecraft:torch" then
				print("Going down but leaves in way?")
				turtle.digDown()
				turtle.down()
			end
			if s and d.name == "minecraft:torch" then
				print("I'm back down now")
				break
			end
			turtle.down()
			print("Moving down..")
		end
		Replant()
	end

	if side == 1 then
		turtle.turnRight()
	elseif side == 2 then
		turtle.turnLeft()
	end
end

function Replant()
	turtle.select(2)
	if turtle.getItemCount(2) > 0 then
		if turtle.getItemDetail(2).name == "minecraft:sapling" then
			turtle.place()
		end
	end
end

function Forward()
	turtle.forward()
end

function RefuelIfNeeded()
	if turtle.getFuelLevel() < 10 then
		print("Refueling..")
		Refuel()
	end
end

-- main loop
-- reset -> refuel -> pickup fuel -> chop -> deposit
while true do
	-- first get the turtle back to start
	if status == 0 or status == 4 then
		print("Updating status..")
		UpdateStatus()
	end

	--todo, put item in right chest
	if turtle.getItemCount(1) > 0 then
		if turtle.getItemDetail(1).name ~= "minecraft:coal" then
			turtle.select(1)
			turtle.dropDown()
		end
	end

	--grab fuel if at start
	if turtle.getItemCount(1) < 16 and status == 1 then
		print("Grabbing Fuel..")
		GrabFuel()
	end

	--refuel if needed
	RefuelIfNeeded()
	-- Ready to begin harvesting, dump inventory and load saplings first
	if status == 1 then
		turtle.turnRight()
		print("Now dumping saplings")
		for i = 1,16 do
			if turtle.getItemCount(i) > 0 and turtle.getItemDetail(i).name == "minecraft:sapling" then
				turtle.select(i)
				turtle.drop()
			end
		end
		turtle.turnRight()
		print("Now dumping logs")
		for i = 1,16 do
			if turtle.getItemCount(i) > 0 and turtle.getItemDetail(i).name == "minecraft:log" then
				turtle.select(i)
				turtle.drop()
			end
		end
		print("Now dumping apples")
		for i = 1,16 do
			if turtle.getItemCount(i) > 0 and turtle.getItemDetail(i).name == "minecraft:apple" then
				turtle.select(i)
				turtle.dropUp()
			end
		end
		status = 2
		turtle.turnLeft()
		turtle.select(2)
		turtle.suck()
		turtle.turnLeft()
	end

	if n == 2 then
		n = 0
		sleep(30)
	end

	--Move forward Once, check for trees on left then right, chop them if it finds any.
	if status == 2 then
		turtle.forward()
		RefuelIfNeeded()
		local s, d = turtle.inspect()
		if s and d.name == "minecraft:gravel" then
			n = n + 1
			status = 4
		end
		turtle.suckDown()
		ChopTree(1)
		ChopTree(2)
	end

end