running = true
distance = 1

local function dropCobblestone()
  lastItem = turtle.getItemCount(16)

  if lastItem > 0 then
    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

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.getItemCount(16) > 0 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
          turtle.turnLeft()
          turtle.turnLeft()
        else
          turtle.dig()
        end
      end

    end
  end

  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
          turtle.turnLeft()
          turtle.turnLeft()
        else
          turtle.dig()
        end
      end

    end
  end
end

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

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

      if data.name == "minecraft:bucket" then
        alternativeFuel()
      end

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

    end

  end

  turtle.select(1)

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()

  turtle.select(1)
  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()
  if distance > 1 then
    depositItems()
  end
  mine()
end

while running do
  tick()

  if not running then
    turtle.select(1)
    print("The mining script has terminated.")
  end
end