Chunk Eater

-- === CONFIG ===
local CHUNK_SIZE = 16
local LAYER_HEIGHT = 3
local FUEL_BUFFER = 100
local SAVE_FILE = "resume.dat"

-- Whitelist mode: only keep these blocks
local WHITELISTED_BLOCKS = {
  ["minecraft:coal_ore"] = true,
  ["minecraft:iron_ore"] = true,
  ["minecraft:copper_ore"] = true,
  ["minecraft:gold_ore"] = true,
  ["minecraft:redstone_ore"] = true,
  ["minecraft:lapis_ore"] = true,
  ["minecraft:diamond_ore"] = true,
  ["minecraft:emerald_ore"] = true,
  ["minecraft:deepslate_coal_ore"] = true,
  ["minecraft:deepslate_iron_ore"] = true,
  ["minecraft:deepslate_copper_ore"] = true,
  ["minecraft:deepslate_gold_ore"] = true,
  ["minecraft:deepslate_redstone_ore"] = true,
  ["minecraft:deepslate_lapis_ore"] = true,
  ["minecraft:deepslate_diamond_ore"] = true,
  ["minecraft:deepslate_emerald_ore"] = true
}

-- === STATE ===
local x, y, z = 0, 0, 0
local dir = 1
local layer = 1
local startX, startY, startZ, startDir = x, y, z, dir

-- === SAVE / LOAD ===
local function saveState()
  local f = fs.open(SAVE_FILE, "w")
  f.write(textutils.serialize({x=x, y=y, z=z, dir=dir, layer=layer}))
  f.close()
end

local function loadState()
  if not fs.exists(SAVE_FILE) then return false end
  local f = fs.open(SAVE_FILE, "r")
  local data = textutils.unserialize(f.readAll())
  f.close()
  x, y, z = data.x, data.y, data.z
  dir = data.dir
  layer = data.layer
  startX, startY, startZ, startDir = 0, 0, 0, 1
  return true
end

local function clearState()
  if fs.exists(SAVE_FILE) then fs.delete(SAVE_FILE) end
end

-- === DIRECTION HELPERS ===
local function turnRight() turtle.turnRight(); dir = (dir + 1) % 4 end
local function turnLeft() turtle.turnLeft(); dir = (dir - 1) % 4 end
local function face(target) while dir ~= target do turnRight() end end
local function faceExact(targetDir) while dir ~= targetDir do turnRight() end end
local function updatePosition(dx, dy, dz) x, y, z = x + dx, y + dy, z + dz; saveState() end

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

local function dropUnlistedBlocks()
  for i = 1, 16 do
    turtle.select(i)
    local item = turtle.getItemDetail()
    if item and not WHITELISTED_BLOCKS[item.name] then
      turtle.drop()
    end
  end
end

-- === POSITIONING ===
local function goTo(xT, yT, zT)
  while y < yT do turtle.down(); updatePosition(0, 1, 0) end
  while y > yT do turtle.up(); updatePosition(0, -1, 0) end
  face(1) while x < xT do turtle.forward(); updatePosition(1, 0, 0) end
  face(3) while x > xT do turtle.forward(); updatePosition(-1, 0, 0) end
  face(2) while z < zT do turtle.forward(); updatePosition(0, 0, 1) end
  face(0) while z > zT do turtle.forward(); updatePosition(0, 0, -1) end
end

-- === UNLOAD AT ORIGIN ===
local function returnToStartAndUnload()
  goTo(startX, startY, startZ)
  faceExact(startDir)
  turnLeft(); turnLeft()
  for i = 1, 16 do
    turtle.select(i)
    turtle.drop()
  end
  turnLeft(); turnLeft()
end

-- === FUEL ===
local function refuelFromInventory()
  for i = 1, 16 do
    turtle.select(i)
    if turtle.refuel(0) then
      turtle.refuel()
      return true
    end
  end
  return false
end

local function refuelFromLeftChest()
  turnLeft()
  for i = 1, 16 do
    turtle.select(i)
    if turtle.getFuelLevel() < turtle.getFuelLimit() then
      turtle.suck()
      if turtle.refuel(0) then
        turtle.refuel()
      else
        turtle.drop()
      end
    end
  end
  turnRight()
end

local function checkFuel()
  local dist = math.abs(x - startX) + math.abs(y - startY) + math.abs(z - startZ)
  if turtle.getFuelLevel() < dist + FUEL_BUFFER then
    local sx, sy, sz, sd = x, y, z, dir
    returnToStartAndUnload()
    if not refuelFromInventory() then refuelFromLeftChest() end
    goTo(sx, sy, sz)
    faceExact(sd)
  end
end

-- === BEDROCK CHECK ===
local function reachedBedrock()
  local success, data = turtle.inspectDown()
  return success and data.name == "minecraft:bedrock"
end

-- === MOVEMENT ===
local function tryForward()
  if isFull() then
    local sx, sy, sz, sd = x, y, z, dir
    returnToStartAndUnload()
    checkFuel()
    goTo(sx, sy, sz)
    faceExact(sd)
  end
  checkFuel()
  while not turtle.forward() do
    turtle.dig()
    sleep(0.3)
  end
  turtle.digUp()
  turtle.digDown()
  dropUnlistedBlocks()
  if dir == 0 then updatePosition(0, 0, -1)
  elseif dir == 1 then updatePosition(1, 0, 0)
  elseif dir == 2 then updatePosition(0, 0, 1)
  elseif dir == 3 then updatePosition(-1, 0, 0) end
end

local function tryDown()
  checkFuel()
  while not turtle.down() do
    turtle.digDown()
    sleep(0.3)
  end
  updatePosition(0, 1, 0)
end

-- === DIG LAYER ===
local function digLayer()
  print("⛏ Digging layer " .. layer .. " at y=" .. y)
  for row = 1, CHUNK_SIZE do
    for col = 1, CHUNK_SIZE - 1 do
      tryForward()
    end
    if row < CHUNK_SIZE then
      if row % 2 == 1 then turnRight(); tryForward(); turnRight()
      else turnLeft(); tryForward(); turnLeft() end
    end
  end
  -- Return to origin column
  if x > 0 then face(3) while x > 0 do turtle.forward(); updatePosition(-1, 0, 0) end end
  if x < 0 then face(1) while x < 0 do turtle.forward(); updatePosition(1, 0, 0) end end
  if z > 0 then face(0) while z > 0 do turtle.forward(); updatePosition(0, 0, -1) end end
  if z < 0 then face(2) while z < 0 do turtle.forward(); updatePosition(0, 0, 1) end end
  face(1)
end

-- === MAIN ===
if fs.exists(SAVE_FILE) then
  print("Resume previous run? (y/n)")
  local input = read()
  if input:lower() == "y" then
    loadState()
    print("📍 Resumed at: x="..x.." y="..y.." z="..z.." dir="..dir.." layer="..layer)
  else
    clearState()
    x, y, z = 0, 0, 0
    dir = 1
    layer = 1
  end
end

print("📦 Starting Chunk Eater. Will stop at bedrock.")

while true do
  digLayer()
  layer = layer + LAYER_HEIGHT
  saveState()
  if reachedBedrock() then
    print("🛑 Bedrock detected. Stopping dig.")
    break
  end
  print("⬇️ Descending to next layer...")
  for i = 1, LAYER_HEIGHT do
    if not reachedBedrock() then
      tryDown()
    else
      print("🛑 Bedrock reached during descent.")
      break
    end
  end
end

returnToStartAndUnload()
clearState()
print("✅ Chunk excavation complete.")