tunnel

local tArgs = { ... }
if #tArgs ~= 2 then
	print( "Usage: t <length> <place torches y/n>" )

	return
end

-- Mine 3x1 tunnel until we hit end
local size = tonumber( tArgs[1] )
if size < 1 then
	print( "Excavate diameter must be positive" )
	return
end

local placeTorches = false
local slotStart = 1

if string.lower(tArgs[2]) == 'y' then
	placeTorches = true
	slotStart = 2
end

local depth = 0
local unloaded = 0
local collected = 0

local xPos,zPos = 0,0
local xDir,zDir = 0,1

local goTo -- Filled in further down
local refuel -- Filled in further down


local function unload()
	print( "Unloading items..." )
	for n=slotStart,16 do
		unloaded = unloaded + turtle.getItemCount(n)
		turtle.select(n)
		turtle.drop()
	end
	collected = 0
	turtle.select(1)
end

local function returnSupplies()
	local x,y,z,xd,zd = xPos,depth,zPos,xDir,zDir
	print( "Returning to surface..." )
	goTo( 0,0,0,0,-1 )

	local fuelNeeded = x+y+z + x+y+z + 1
	if not refuel( fuelNeeded ) then
		unload()
		print( "Waiting for fuel" )
		while not refuel( fuelNeeded ) do
			sleep(1)
		end
	else
		unload()
	end


	while not torchCheck() do
		print( "Waiting for torches" )
		while not torchCheck() do
			sleep(1)
		end
	end

	print( "Resuming mining..." )
	goTo( x,y,z,xd,zd )
end

local function collect()
	local bFull = true
	local nTotalItems = 0
	for n=1,16 do
		local nCount = turtle.getItemCount(n)
		if nCount == 0 then
			bFull = false
		end
		nTotalItems = nTotalItems + nCount
	end

	if nTotalItems > collected then
		collected = nTotalItems
		if math.fmod(collected + unloaded, 50) == 0 then
			print( "Mined "..(collected + unloaded).." items." )
		end
	end

	if bFull then
		print( "No empty slots left." )
		return false
	end
	return true
end

function torchCheck()
	if placeTorches  then
		if turtle.getItemCount(1) > 0 then
			return true
		else
			return false
		end
	else
		return true
	end

end

function refuel( ammount )
	local fuelLevel = turtle.getFuelLevel()
	if fuelLevel == "unlimited" then
		return true
	end

	local needed = ammount or (xPos + zPos + depth + 1)
	if turtle.getFuelLevel() < needed then
		local fueled = false
		for n=1,16 do
			if turtle.getItemCount(n) > 0 then
				turtle.select(n)
				if turtle.refuel(1) then
					while turtle.getItemCount(n) > 0 and turtle.getFuelLevel() < needed do
						turtle.refuel(1)
					end
					if turtle.getFuelLevel() >= needed then
						turtle.select(1)
						return true
					end
				end
			end
		end
		turtle.select(1)
		return false
	end

	return true
end

local function tryDigUp()
	--Dig Up
	while turtle.detectUp() do
		if turtle.detectUp() then
			if turtle.digUp() then
				if not collect() then
					returnSupplies()
				end
			else
				return false
			end
		elseif turtle.attackUp() then
			if not collect() then
				returnSupplies()
			end
		else
			sleep( 0.1 )
		end
	end
	return true
end

local function tryDigUp()
	--Dig Up
	while turtle.detectUp() do
		if turtle.detectUp() then
			if turtle.digUp() then
				if not collect() then
					returnSupplies()
				end
			else
				return false
			end
		elseif turtle.attackUp() then
			if not collect() then
				returnSupplies()
			end
		else
			sleep( 0.1 )
		end
	end
	return true
end

local function tryDigDown()
	--Dig Down
	while turtle.detectDown() do
		if turtle.detectDown() then
			if turtle.digDown() then
				if not collect() then
					returnSupplies()
				end
			else
				return false
			end
		elseif turtle.attackDown() then
			if not collect() then
				returnSupplies()
			end
		else
			sleep( 0.1 )
		end
	end
	return true
end

local function tryDigForward()
	while turtle.detect() do
		if turtle.detect() then
			if turtle.dig() then
				if not collect() then
					returnSupplies()
				end

			else
				return false
			end
		elseif turtle.attack() then
			if not collect() then
				returnSupplies()
			end
		else
			sleep( 0.1 )
		end
	end
	return true
end


local function tryForwards()
	if not refuel() then
		print( "Not enough Fuel" )
		returnSupplies()
	end

	tryDigForward()

	while not turtle.forward() do
		if not tryDigForward() then
			return false
		end
	end

	xPos = xPos + xDir
	zPos = zPos + zDir
	return true
end

local function tryUp()
	if not refuel() then
		print( "Not enough Fuel" )
		returnSupplies()
	end

	tryDigUp()

	while not turtle.up() do
		if not tryDigUp() then
			return false
		end
	end

	depth = depth - 1
	if math.fmod( depth, 10 ) == 0 then
		print( "Descended "..depth.." metres." )
	end
	return true
end

local function tryDown()
	if not refuel() then
		print( "Not enough Fuel" )
		returnSupplies()
	end

	tryDigDown()
	while not turtle.down() do
		if not tryDigDown() then
			return false
		end
	end

	--print("Moved down one");

	depth = depth + 1
	if math.fmod( depth, 10 ) == 0 then
		print( "Descended "..depth.." metres." )
	end
	return true
end

local function turnLeft()
	turtle.turnLeft()
	xDir, zDir = -zDir, xDir
end

local function turnRight()
	turtle.turnRight()
	xDir, zDir = zDir, -xDir
end

local function placeTorch()
	turtle.select(1)
	turtle.placeDown()
end

function goTo( x, y, z, xd, zd )
	while depth > y do
		if turtle.up() then
			depth = depth - 1
		elseif turtle.digUp() or turtle.attackUp() then
			collect()
		else
			sleep( 0.5 )
		end
	end

	if xPos > x then
		while xDir ~= -1 do
			turnLeft()
		end
		while xPos > x do
			if turtle.forward() then
				xPos = xPos - 1
			elseif turtle.dig() or turtle.attack() then
				collect()
			else
				sleep( 0.5 )
			end
		end
	elseif xPos < x then
		while xDir ~= 1 do
			turnLeft()
		end
		while xPos < x do
			if turtle.forward() then
				xPos = xPos + 1
			elseif turtle.dig() or turtle.attack() then
				collect()
			else
				sleep( 0.5 )
			end
		end
	end

	if zPos > z then
		while zDir ~= -1 do
			turnLeft()
		end
		while zPos > z do
			if turtle.forward() then
				zPos = zPos - 1
			elseif turtle.dig() or turtle.attack() then
				collect()
			else
				sleep( 0.5 )
			end
		end
	elseif zPos < z then
		while zDir ~= 1 do
			turnLeft()
		end
		while zPos < z do
			if turtle.forward() then
				zPos = zPos + 1
			elseif turtle.dig() or turtle.attack() then
				collect()
			else
				sleep( 0.5 )
			end
		end
	end

	while depth < y do
		if turtle.down() then
			depth = depth + 1
		elseif turtle.digDown() or turtle.attackDown() then
			collect()
		else
			sleep( 0.5 )
		end
	end

	while zDir ~= zd or xDir ~= xd do
		turnLeft()
	end
end

if not refuel() then
	print( "Out of Fuel" )
	return
end

print( "Tunneling..." )

turtle.select(1)

local alternate = 0

if placeTorches then
	while not torchCheck() do
		print( "Waiting for torches" )
		while not torchCheck() do
			sleep(1)
		end
	end
end

tryUp()
tryDigUp()

for n=1,size do
	if n<size then
		tryForwards()
		tryDigUp()
		tryDigDown()
		if placeTorches then
			if math.fmod(n+4,5) == 0 then
				placeTorch()
			end
		end
	else
		print( "Tunnel complete." )
	end

end

if placeTorches then
	placeTorch()
end



print( "Returning to start..." )

-- Return to where we started
goTo( 0,0,0,0,-1 )
unload()
goTo( 0,0,0,0,1 )



print( "Mined "..(collected + unloaded).." items total." )