os.loadAPI('/fuel')

local args = { ... }
if #args < 2 or #args > 3 then
  print( "Usage: quarry <toTheRight> <toTheFront>[ <toTheDown>]" )
  error()
end

function checkFuel()
	while (turtle.getFuelLevel() < 100) do
		if (fuel.canRefuel()) then
			fuel.fuelUp()
		else
			return false
		end
	end
	return true
end

function fullInventory()
	local full = true
	local current = 1
	while (current < 16) do
		if (turtle.getItemCount(current) == 0) then
			full = false
		end
		current = current + 1
	end
	return full
end

function dropEverything()
	local current = 1
	while (current < 16) do
		turtle.dropDown()
		current = current + 1
	end
end

function digLength()
	local forward = 0
	while (forward < tonumber(args[2])) do
		if (not checkFuel()) then
			return false
		end
		if (turtle.detect()) then
			turtle.dig()
		end
		turtle.forward()
		forward = forward + 1
		if (fullInventory()) then
			dropEverything()
		end
	end
	return true
end

local canRefuel = true
local depth = 0
while (true) do
	if (not digLength()) then
		return
	end
	local right = 0
	while (right < tonumber(args[1])) do
		turtle.turnRight()
		if (turtle.detect()) then
			turtle.dig()
		end
		turtle.forward()
		turtle.turnRight()
		if (not digLength()) then
			return
		end
		turtle.turnLeft()
		if (turtle.detect()) then
			turtle.dig()
		end
		turtle.forward()
		turtle.turnLeft()
		if (not digLength()) then
			return
		end
		right = right + 2
	end

	if (#args > 2) then
		if (depth >= tonumber(args[3])) then
			print('Mining Complete')
			return
		end
	end

	turtle.turnRight()
	turtle.turnRight()
	if (turtle.detectDown()) then
		if (not turtle.digDown()) then
			print ('Reached the bottom')
			return
		end
	end
	turtle.down()
	depth = depth + 1

	print('Dug ' .. depth .. ' layers')
end