running = true
distance = 1

local function dropCobblestone()
  dropped = 0
  for i=16,3,-1 do
	turtle.select(i)
    amount = turtle.getItemCount()

	if amount > 0 then
	  data = turtle.getItemDetail()

	  if data.name == "minecraft:cobblestone" then
	    turtle.drop()
		dropped = dropped + amount
	  end
	end

  end

  if dropped > 128 then
    print("Dropped x" .. dropped .. " cobblestone.")
  end

end

local function alternativeFuel()
  print("No main fuel, trying alternative.")

  for i=16,3,-1 do
    turtle.select(i)

    amount = turtle.getItemCount(i)

    if amount > 0 then
  	  data = turtle.getItemDetail(i)
	  if data.name == "minecraft:coal" then
	    turtle.refuel()
	    print("Found coal alternative fuel.")
	  end

    end

  end

  if turtle.getFuelLevel() == 0 then
    print("No alternatives found, quitting.")
    running = false
  end
end

local function depositItems()
  if turtle.getFuelLevel() <= distance then
    turtle.turnLeft()
	turtle.turnLeft()

	for i=turtle.getFuelLevel(),0,-1 do
	  turtle.forward()

	  success, data = turtle.inspect()

	  if success then
	    if data.name == "minecraft:chest" then
		  for o=16,3,-1 do
		    turtle.select(o)
			turtle.drop()
		  end
		else
		  turtle.dig()
		end
	  end

	end
  end
end

local function fuel()
  if turtle.getFuelLevel() == 0 then
    turtle.select(1)
	amount = turtle.getItemCount()

	if amount > 0 then
	  if data.name == "minecraft:bucket" then
	    alternativeFuel()
	  else if data.name == "minecraft:lava_bucket" then
	    turtle.refuel()
	    print("Refuelling.")
	  else
	    alternativeFuel()
	  end
	end
  end

  turtle.select(1)

  end
end

local function checkSide()

  turtle.turnLeft()

  success_left, data_left = turtle.inspect()

  if success_left then
    if data_left.name == "minecraft:gold_ore" then
	  turtle.dig()
	  turtle.select(2)
	  turtle.dig()
	  turtle.select(1)
	end

	if data_left.name == "minecraft:diamond_ore" then
	  turtle.dig()
	  turtle.select(2)
	  turtle.dig()
	  turtle.select(1)
	end
  end

  turtle.turnRight()
  turtle.turnRight()

  success_right, data_right = turtle.inspect()

  if success_right then
    if data_right.name == "minecraft:gold_ore" then
	  turtle.digRight()
	  turtle.select(2)
	  turtle.placeRight()
	  turtle.select(1)
	end

	if data_right.name == "minecraft:diamond_ore" then
	  turtle.digRight()
	  turtle.select(2)
	  turtle.placeRight()
	  turtle.select(1)
	end
  end

  turtle.turnLeft()

end

local function mine()

  fuel()
  -- checkSide()

  turtle.dig()
  turtle.forward()
    distance = distance + 1
  turtle.digUp()

  dropCobblestone()

  success, data = turtle.inspectDown()

  if not success then
  turtle.select(2)
  turtle.placeDown()
  turtle.select(1)
  end

  if success then
    if data.name == "minecraft:flowing_lava" then
	  turtle.select(1)
	  data_item = turtle.getItemDetail(1)

	  if data_item.name == "minecraft:bucket" then
	    turtle.place()
	    data = turtle.getItemDetail()
	    if data.name == "minecraft:lava_bucket" then
	      print("Got more fuel!")
		  if turtle.getFuelLevel() < 10000 then
		    turtle.refuel()
		    print(turtle.getFuelLevel())
		  else
		    print("Turtle is above 10,000 fuel units.")
		  end
	    end
	  else
	    print("Lava found, but bucket is full.")
	  end

	end
  end

end

local function tick()
  depositItems()
  mine()
end

while running do
  tick()

  if not running then
    print("The mining script has terminated.")
  end
end