local trees = 23
local currentPos = 0
local lastStatus = 0
local status = 0 -- 0Clueless-1Starting-2Harvesting-3Returning-4onRail

--todo: if no fuel in fuelslot, return immediatly.
--todo: fix status updating to work with y-level
--todo:

-- refuel the turtle with slot 1, coal
function Refuel()
	turtle.select(1)
	turtle.refuel(3)
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 start of 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
	end --todo: check if on right y level, should be if s is false

	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()
	elseif side == 2 then
		turtle.turnRight()
	end
	local s, d = turtle.inspect()
	if s and d.name == "minecraft:log" then
		return true
	else
		return false
	end
end

function ChopTree(side)
	if CheckTree(side) then
		turtle.dig()
		for i = 1, 5 do
			if not turtle.up() then
				turtle.digUp()
				turtle.up()
			end
			turtle.dig()
		end
		while true do
			local s, d = turtle.inspectDown()
			if s and d.name ~= "minecraft:torch" then
				turtle.digDown()
				turtle.down()
			end
			if s and d.name == "minecraft:torch" then
				break
			end
			turtle.down()
		end
		Replant()
	end

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

function Replant()
	turtle.select(2)
	turtle.place()
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

	--refuel if needed
	if turtle.getFuelLevel() < 5 then
		print("Refueling..")
		Refuel()
	end

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

	-- Ready to begin harvesting
	if status == 1 then
		status = 2
	end

	--Move forward Once, check for trees on left then right, chop them if it finds any.
	if status == 2 then
		turtle.forward()
		ChopTree(1)
		ChopTree(2)
	end

end