CC: Tweaked Quarry

-- Description: Quarries a 16 x 16 area, and returns to a drop off inventory directly above it's starting location.

-- Usage info:
  -- 1: type in pastebin get <code at end of url> <desired program name>
  -- 2: Place mining turtle in bottom right corner of chunk you want to quarry, put it with in the quarry boundaries.
  -- 3: Place chest or other drop off inventory above the turtle.
  -- 4: Place fuel in slot one of turtle.
  -- 5: Run program, and come back to see the hole later.

-- Variable declaration zone
local level = 0 -- Level turtle just completed
local currentLevel = 0 -- Level turtle is currently on
local layer = 0 -- Layers dug
local direction = "right" -- Direction turtle must turn in next
local x = 1 -- x location
local z = 1 -- z location
local noBedrock = true
local slot = 1
local goHome = 0
-- End variable declaration zone

-- Function delaration zone
-- Refuel script
function refuel()
  print("Checking fuel...")
  if turtle.getFuelLevel() < 500 then
    print("Refueling. Only ", turtle.getFuelLevel(), " left.")
    turtle.select(1)
    turtle.refuel(15)
    print("Fuel inceased to: ", turtle.getFuelLevel())
  end
end
-- Digs a layer
function digLayer()
  print("Preparing to dig...")
  for x = 1,16 do
    -- Digs a 16 block long line
    for z = 1,15 do
      turtle.dig()
      while turtle.attack() do
        sleep(1)
      end
      turtle.forward()
    end
    -- Determines if it needs to turn left or right to dig the next row
    if direction == "left" and x ~= 16 then
      turtle.turnLeft()
      turtle.dig()
      while turtle.attack() do
        sleep(1)
      end
      turtle.forward()
      turtle.turnLeft()
      direction = "right"
    elseif direction == "right" and x ~= 16 then
      turtle.turnRight()
      turtle.dig()
      while turtle.attack() do
        sleep(1)
      end
      turtle.forward()
      turtle.turnRight()
      direction = "left"
    end
  end
  print("Layer complete.")
end
-- Checks for bedrock
function checkBedrock()
  print("Checking for bedrock...")
  if turtle.digDown() == true then
    turtle.select(2)
    turtle.placeDown()
    print("Not yet at bedrock.")
  elseif turtle.down() == true then
    turtle.up()
    print("Not yet at bedrock.")
  else
    noBedrock = false
    print("At bedrock.")
  end
end
-- Returns to home location to drop off resources
function dropOff()
  print("Preparing dropoff sequence...")
  -- Return home location
  print("Returning home...")
  turtle.turnRight()
  for goHome = 1,15 do
    while turtle.attack() do
      sleep(1)
    end
    turtle.forward()
  end
  -- Rises to the surface to drop items off
  level = 0
  while turtle.attackUp() do
    sleep(1)
  end
  while turtle.up() do
    level = level + 1
    while turtle.attackUp() do
      sleep(1)
    end
  end
  -- Empties inventory into drop off
  print("Preparing to empty inventory...")
  for slot = 2,16 do
    turtle.select(slot)
    turtle.dropUp()
  end
  print("Inventory cleared. All items dropped off.")
  -- Goes back down to desired layer
  retriveFuel()
  print("Returning to correct floor...")
  currentLevel = 0
  while turtle.attackDown() do
    sleep(1)
  end
  while level ~= currentLevel do
    turtle.down()
    while turtle.attackDown() do
      sleep(1)
    end
    currentLevel = currentLevel + 1
  end
  print("Back at correct floor.")
end
-- Ending sequence
function endSequence()
  print("Starting end sequence...")
  while turtle.attackUp() do
    sleep(1)
  end
  while turtle.up() do
    while turtle.attackUp() do
      sleep(1)
    end
  end
  print("Total number of layers dug: ", layer)
  print("Mission complete. Master shall not punish me.")
end
-- Layer preparation
function layerPrep()
  print("Preforming next layer preparation...")
  turtle.turnRight()
  direction = "right"
  turtle.digDown()
  turtle.down()
  print("Next layer prepared")
end

function retriveFuel()
  turtle.turnLeft()
  turtle.select(1)
  local fuelCount = turtle.getItemCount(1)
  local toRefuel = 64 - fuelCount
  print("Retrieving fuel... ", toRefuel, " needed.")
  turtle.suck(toRefuel)
  turtle.turnRight()
end

-- End function declaration zone

-- Main running sequence
while noBedrock do
  refuel()
  checkBedrock()
  if noBedrock == true then
    digLayer()
    dropOff()
    layerPrep()
  end
  layer = layer + 1
end
endSequence()
-- End main running sequence