farmer 1.10

local arg1, arg2 = ...
limX = tonumber(arg1)
limZ = tonumber(arg2)
area = limX * limZ
relX = 0
relZ = 0
facing = 0

function plant()
	if turtle.detectDown()
	then
		return false
	end
	turtle.down()
	seeds = selectSeeds()
	if not seeds
	then
		return false
	end
	turtle.placeDown()
	return true
end

function selectSeeds()
	for i = 1, 16, 1
	do
		turtle.select(i)
		name = turtle.getItemDetail().name
		if name == "minecraft:seeds"
		then
			return true
		end
	end
	return false
end

function harvest()
	if turtle.detectDown()
	then
		local success, data = turtle.inspectDown()
		if data.name == "minecraft:wheat"
		then
			if data.metadata == 7
			then
				turtle.digDown()
			end
		end
	end
end

function turnTo(dir)
	if facing > dir
	then
		turtle.turnRight()
		dir = dir - 1
		turnTo(dir)
	end
	if facing < dir
	then
		turtle.turnLeft()
		dir = dir + 1
		turnTo(dir)
	end
	if facing == dir
	then
		return
	end
end

function goUp()
	turnTo(0)
	turtle.forward()
	relZ = relZ + 1
end

function goDown()
	turnTo(2)
	turtle.forward()
	relZ = relZ - 1
end

function goLeft()
	turnTo(1)
	turtle.forward()
	relX = relX - 1
end

function goRight()
	turnTo(3)
	turtle.forward()
	relX = relX + 1
end

function walkField()
	while relZ <= limZ
	do
		goUp()
		while relX <= limX
		do
			goRight()
			harvest()
			plant()
		end
		goUp()
		while relX > 1
		do
			goLeft()
			harvest()
			plant()
		end
	end
end

function returnToOrigin()
	while relX > 0
	do
		goLeft()
	end
	while relY > 0
	do
		goDown()
	end
end

function depositItems()
	for i = 1, 16, 1
	do
		turtle.drop()
	end
end

function grabSeeds()
	i = 1
	remaining = area
	while remaining > 64
	do
		turtle.select(i)
		turtle.suckDown(64)
		i = i + 1
		remaining = remaining - 64
	end
	turtle.suckDown(remaining)
end

function feedFuel()
	turnTo(3)
	while (getFuelLevel() < 2000)
	do
		turtle.suck(4)
		turtle.refuel(4)
	end
end

function execute()
	feedFuel()
	grabSeeds()
	walkField()
	returnToOrigin()
	depositItems()
	turnTo(0)
end

function main()
	while (true)
	do
		if redstone.getInput("left")
		then
			execute()
		end
	end
end

main()