tunnel2

local targs = { ... }

if #targs ~= 1 then
	print( "Usage: tunnel <distance>" )
	return
end

local digFor = tonumber( targs[1] )

if digFor < 1 then
	print("Excavate distance must be positive" )
end

local distance = 0;

local torchCount = turtle.getItemCount(1)
if torchCount == 0 then
	print("Please place torches in first slot")
end

local height = 0
local direction = 0

local function checkFuel()
	local fuelNeeded = (distance*2) + (digFor-distance)*6 + 1
	if (turtle.getFuelLevel() < fuelNeeded)
		print("Need more fuel")
		return
	end
end

local function full()
	for n=2, 16 do
		if nCount == 0 then
			return false
		end
	end
	return true
end

local function dumpItems()
        for n=2,16 do
                turtle.select(n)
                turtle.drop()
        end
        turtle.select(1)
end

local function returnCargo()
	if direction = 1 then
		turtle.turnLeft()
	elseif direction = 2 then
		turtle.turnRight()
	else
		turtle.turnLeft()
		turtle.turnLeft()
	end

	for h=0, height do
		turtle.down()
	end

	for n=0, distance do
		turtle.forward()
	end

	dumpItems()


	turtle.turnLeft()
	turtle.turnLeft()

	checkFuel()

	for n=0, distance do
		turtle.forward()
	end
	for h=0, height do
		turtle.up()
	end

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


local function digRow()
	while turtle.detect() then
		if turtle.dig() then
			if full() then
				returnCargo()
			end
		end
	end

	turtle.turnLeft()
	direction = 1

	while turtle.detect() then
		if turtle.dig() then
			if full() then
				returnCargo()
			end
		end
	end

	turtle.turnRight()
	turtle.turnRight()
	direction = 2

	while turtle.detect() then
		if turtle.dig() then
			if full() then
				returnCargo()
			end
		end
	end

	turtle.turnLeft()
	direction = 0
end

local function tryUp()

end

local function tryForward()
	while not turtle.forward() do -- if we can't more forward
		if turtle.detect() then -- check if something there
			if turtle.dig() then -- attempt to dig
				if full() then
					returnCargo()
				end
			else
				return false
			end
		elseif turtle.attack() then
			if full() then
				returnCargo()
			end
		else
			sleep( 1 )
		end
	end

	distance = distance + 1
	return true
end

local function tryUp()
	while not turtle.up() do -- if we can't more forward
		if turtle.detect() then -- check if something there
			if turtle.digUp() then -- attempt to dig
				if full() then
					returnCargo()
				end
			else
				return false
			end
		elseif turtle.attack() then
			if full() then
				returnCargo()
			end
		else
			sleep( 1 )
		end
	end

	height = height + 1
	return true
end


checkFuel() -- make sure we have fuel

local done = false
while not done do
	for n=1, digFor do
		if not tryForward() then
			done = true
			break
		end

		digRow()

		if not tryUp() then
			done = true
			break
		end

		digRow()


		if not tryUp() then
			done = true
			break
		end

		digRow()

		turtle.down()
		turtle.down()
		height = 0
end

print( "Done Digging" )

turtle.turnLeft()
turtle.turnLeft()
for n=0, distance do
	turtle.forward()
end

dumpItems()