stripmine

local dim = { ... }
if #dim ~= 3 then
  print("Usage: stripmine <width> <height> <depth>")
  return
end

width = tonumber(dim[1])
height = tonumber(dim[2])
depth = tonumber(dim[3])

if width < 1 or height < 1 or depth < 1 then
  print("Please ensure all parameters are positive")
  return
end

if height * depth > 750 then
  print("Please select smaller bounds")
  return
end

function moveTo(x, y, z)
  while loc[3] < z do
    if direct ~= 1 then
      redirect(1) end
    if turtle.forward() then
      loc[3] = loc[3] + 1
    else turtle.dig() end
  end
  while loc[3] > z do
    if direct ~= 3 then
      redirect(3) end
    if turtle.forward() then
      loc[3] = loc[3] - 1
    else turtle.dig() end
  end
  while loc[1] < x do
    if direct ~= 2 then
      redirect(2) end
    if turtle.forward() then
      loc[1] = loc[1] + 1
    else turtle.dig() end
  end
  while loc[1] > x do
    if direct ~= 4 then
      redirect(4) end
    if turtle.forward() then
      loc[1] = loc[1] - 1
    else turtle.dig() end
  end
  while loc[2] < y do
    success = turtle.up()
    if success then
      loc[2] = loc[2] + 1
    else turtle.digUp() end
  end
  while loc[2] > y do
    if turtle.down() then
      loc[2] = loc[2] - 1
    else turtle.digDown() end
  end
end

function redirect(newD)
  if newD > 4 then newD = newD - 4 end
  while direct ~= newD do
    if newD - direct == 1 or (direct == 4 and newD == 1) then
      turtle.turnRight()
      direct = direct + 1
    else
      turtle.turnLeft()
      direct = direct - 1
    end
    if direct > 4 then
      direct = direct - 4 end
    if direct == 0 then
      direct = 4 end
  end
end

function isFull()
  for i = 1, 16 do
    if turtle.getItemCount(i) == 0 then
    return false end
  end
  return true
end

function dump()
  local current = {}
  current[1] = loc[1]
  current[2] = loc[2]
  current[3] = loc[3]
  moveTo(1, 1, 1)
  redirect(3)
  foundFuel = false
  for i = 1,16 do
    turtle.select(i)
    if not turtle.refuel(0) then
      turtle.drop()
    else
      if foundFuel then
        turtle.drop()
      else foundFuel = true end
    end
    if i == 16 and isFull() then
      i = 1 end
  end
  moveTo(current[1], current[2], current[3])
end

function digStrip(forward)
  if forward then
    while loc[3] <= depth do
      if loc[3] % 10 == 0 then
      print(string.format("Current depth: %d", loc[3])) end

      moveTo(loc[1], loc[2], loc[3] + 1)
      if isFull() then dump() end
      if loc[2] == 1 then
        moveTo(loc[1], height, loc[3])
      else
        moveTo(loc[1], 1, loc[3])
      end
    end
  else
    while loc[3] > 1 do
      if loc[3] % 10 == 0 then
      print(string.format("Current depth: %d", loc[3])) end

      moveTo(loc[1], loc[2], loc[3] - 1)
      if isFull() then dump() end
      if loc[2] == 1 then
        moveTo(loc[1], height, loc[3])
      else
        moveTo(loc[1], 1, loc[3])
      end
    end
  end
end

--Main:
loc = {}
loc[1] = 1
loc[2] = 1
loc[3] = 1
direct = 1
if width % 3 ~= 1 then
  while width % 3 ~= 1 do
    width = width - 1
  end
  print(string.format("Width truncated to %d", width))
end
forward = true
while true do
  if turtle.getFuelLevel() < 1000 then
    refueled = false
    for i = 1, 16 do
      turtle.select(i)
      if turtle.refuel(16) then
        select(1)
        refueled = true
        break end
    end
    if not refueled then
      moveTo(1, 1, 1)
      redirect(1)
      print("No additional fuel stored")
      print("Opperation cancelled")
      print(string.format("Type \"stripmine %d %d %d\" to resume", width, height, depth))
      return
    end
  else print(string.format("Current fuel: %d", turtle.getFuelLevel()))
  end
  digStrip(forward)
  forward = not forward
  if (loc[1] == width) then
    moveTo(1, 1, 1)
    dump()
    redirect(1)
    return
  end
  for i = 1,3 do
    if loc[2] == 1 then
      moveTo(loc[1] + 1, height, loc[3])
    else
      moveTo(loc[1] + 1, 1, loc[3])
    end
  end
end