function clearInv()
  for i=1,16 do
   turtle.select(i)
   turtle.drop()
  end
  turtle.select(1)
end

function getItem(itemName, itemSpotNumber)
  clearInv()
  isCoal = false
  coalSlot = 0
  i = 1
  while not isCoal do
    turtle.select(i)
    turtle.suck()
    data = turtle.getItemDetail()
    if data.name == itemName then
      isCoal = true
    end
    i = i+1
  end
  coalSlot = i
  for i=i-2, 1, -1 do
    turtle.select(i)
    turtle.drop()
  end
  turtle.select(coalSlot-1)
  turtle.transferTo(itemSpotNumber)
  turtle.select(1)
end

function gatherDiamond()
  for i = 1, 4 do
    turtle.turnLeft()
    result, data = turtle.inspect()
    if result and data.name == "minecraft:diamond_ore" then
      while turtle.dig() do
        print("Digging!")
      end
      turtle.suck()
      turtle.forward()
      gatherDiamond()
      turtle.back()
    end
  end
  result, data = turtle.inspectUp()
  if result and data.name == "minecraft:diamond_ore" then
    while turtle.digUp() do
      print("digging up!")
    end
    turtle.up()
    gatherDiamond()
    turtle.down()
  end
  result1, data1 = turtle.inspectDown()
  if result1 and data1.name == "minecraft:diamond_ore" then
    while turtle.digDown() do
      print("digging down!")
    end
    turtle.down()
    gatherDiamond()
    turtle.up()
  end
end

function placeTorch()
  turtle.select(2)
  turtle.turnLeft()
  turtle.placeUp()
  turtle.turnRight()
end

function digMultipleTimes(times)
  for i = 1, times do
    gatherDiamond()

    while not turtle.up() do
        turtle.digUp()
    end
    gatherDiamond()
    while true do
      if not turtle.dig() then
        break
      end
    end
    turtle.down()
    if i % 5 == 0 then
      placeTorch()
    end
    while not turtle.forward() do
      turtle.dig()
    end
  end
end


function digTunnel()
    digMultipleTimes(100)
    turtle.turnRight()
    digMultipleTimes(4)
    turtle.turnRight()
    digMultipleTimes(100)
end

function go(i)
  for j = 1, i do
    while true do
      if not turtle.dig() then
        break
      end
    end
    turtle.up()
    while not turtle.forward() do
      turtle.dig()
    end
    turtle.down()
  end
end

function mine()
  while true do
    i = 0
    while turtle.getFuelLevel() < 1000 do
      getItem("minecraft:coal", 1)
      turtle.refuel()
    end
    turtle.select(2)
    while turtle.getItemCount() < 50 do
      getItem("minecraft:torch", 2)
    end
    turtle.turnRight()
    turtle.turnRight()
    turtle.forward()
    i = i + 1
    turtle.turnLeft()
    result, data = turtle.inspect()
    while not result do
      turtle.turnRight()
      go(8)
      i = i + 8
      turtle.turnLeft()
      result, data = turtle.inspect()
    end
    digTunnel()
    turtle.turnRight()
    go(4)
    for j = 1, i do
      turtle.forward()
    end
  end
end

mine()