Quarry

--Computercraft quarry script
--(c) jeremiah Lowe 2018
width = 3  --The width of the hole
height = 3 --The height of the hole
depth = 5  --The depth of the hole
--The inventory slot for the fuel
fuelSlot = 1
--The minimum allowed free slots
allowedFreeSlots = 4

print("Initializing SmartTurtle")
if not os.loadAPI("sturtle") then
  print("Failed to load SmartTurtle API")
end
sturtle.setFuelSlot(fuelSlot)
sturtle.setFuelBufferSize(width * height)
sturtle.enableAutoRefuel()
sturtle.createHome("original")
print("Done")
print("Mining an area of " .. width .. ", " .. height .. ", " .. depth)
function emptyInventory()
  sturtle.createHome("back")
  sturtle.home("original")
  side = 4
  for i=0,3 do
    sturtle.turnRight()
    e, b = turtle.inspect()
    if e and b.name ~= nil then
      if string.match(string.lower(b.name), "chest") then
        side = sturtle.getDirection()
        break
      end
    end
  end
  if side == 4 then
    error("No chest beside turtle at home position")
  end
  sturtle.pointTo(side)
  for i=1,16 do
    if i ~= fuelSlot then
      turtle.select(i)
      turtle.drop()
    end
  end
  sturtle.home("back")
end
function digTurn(left)
  turn = sturtle.turnRight
  if left then turn = sturtle.turnLeft end
  if not turn() then return false end
  if not sturtle.digForward(1) then return false end
  if not turn() then return false end
  return true
end
function mineLayer()
  for i=1,height do
    if not sturtle.digForward(width-1) then return false end
    if sturtle.getFreeSlots() < allowedFreeSlots then
      emptyInventory()
    end
    if i ~= height then
      if not digTurn(i % 2 == 0) then return false end
    end
  end
  return true
end
sturtle.digForward()
for i=1,depth do
  sturtle.createHome("layer")
  while not mineLayer() do
    sturtle.home("layer")
  end
  if i ~= depth then --No need here, were done!
    sturtle.home("layer")
    sturtle.digDown()
  end
end
sturtle.home("original")
emptyInventory()