function GpsPos()
	local x, y, z = gps.locate()
	return {x, y, z}
end

local args = { ... }

if (#args ~= 2) then
	print("Gib depth then gib width plsss")
	error()
end

nb_blocks = 2
movement = 1
base_forward_movement = tonumber(args[1])
forward_movement_left = base_forward_movement
lateral_movement_left = tonumber(args[2])

function StrafeRight()
	turtle.turnRight()
	turtle.forward()
	turtle.turnLeft()
end

function StrafeLeft()
	turtle.turnLeft()
	turtle.forward()
	turtle.turnRight()
end

function Sign(p_int)
	if (p_int < 0) then
		return -1
	end
	return 1
end

function Abs(p_int)
	return p_int * Sign(p_int)
end

function UpdateMovement()
	forward_movement_left = forward_movement_left - 1

	--[[ Determine if we have gone far enough --]]
	if (forward_movement_left == 0) then
		print("Bounds detected")
		forward_movement_left = base_forward_movement

		lateral_movement_left = lateral_movement_left - 1

		if (lateral_movement_left == 0) then
			return
		end

		--[[ Lateral movement --]]
		if (movement == 1) then
			StrafeRight()
		else
			StrafeLeft()
		end

		UpdateBlocks(GpsPos())

		--[[ Reverse current direction --]]
		movement = -movement
		turtle.turnRight()
		turtle.turnRight()
	end

	turtle.forward()
end

function Distance(xA, zA, xB, zB)
	return Abs(xB - xA) + Abs(zB - zA)
end

function GetBlockId(p_pos)
	if (Distance(0, 0, p_pos[1], p_pos[3]) == 10) then
		return 1
	end
	if (Distance(10, 10, p_pos[1], p_pos[3]) == 5) then
		return 1
	end
	if (Distance(-10, 10, p_pos[1], p_pos[3]) == 5) then
		return 1
	end
	if (Distance(10, -10, p_pos[1], p_pos[3]) == 5) then
		return 1
	end
	if (Distance(-10, -10, p_pos[1], p_pos[3]) == 5) then
		return 1
	end
	return 2
end

function UpdateBlocks(p_pos)
	--[[ Destroy block below --]]
	if (turtle.detectDown()) then
		turtle.digDown()
	end
	--[[ Determine what to place below --]]
	print("Position is " .. p_pos[1] .. " " .. p_pos[3])

	turtle.select(GetBlockId(p_pos))
	turtle.placeDown()
end

function GetBlockFromNextSlot(slot_id)
	local slot_to_take_from = slot_id + nb_blocks

	--[[ If the slot we want to take blocks from doesn't have them, ask them to fetch them --]]
	if (turtle.getItemCount(slot_to_take_from) < 16) then
		GetBlockFromNextSlot(slot_to_take_from)
	end

	turtle.transferTo(slot_id + nb_blocks, 16)
end

function Reload()
	local i = 1
	while (i < nb_blocks + 1) do
		if (turtle.getItemCount == 0) then
			GetBlockFromNextSlot(i)
		end
		i = i - 1
	end
end

function Update()
	Reload()
	UpdateBlocks(GpsPos())
	UpdateMovement()
end

while(lateral_movement_left > 0) do
	Update()
end

print("Let's go back home")

turtle.turnRight()

local i = tonumber(args[2])

while (i > 0) do
	i = i - 1
	turtle.forward()
end

print("Job's done!")