Strip 5

-- Strip mining turtle program with save-state, vein mining, and inventory management
-- Fixed: robust vein mining (stack-based) and branch resumption

-- CONFIGURATION
local MAIN_LENGTH = 1500
local BRANCH_EVERY = 3
local BRANCH_LENGTH = 5

local ORE_WHITELIST = {
  ["minecraft:coal_ore"] = true,
  ["minecraft:iron_ore"] = true,
  ["minecraft:gold_ore"] = true,
  ["minecraft:redstone_ore"] = true,
  ["minecraft:lapis_ore"] = true,
  ["minecraft:diamond_ore"] = true,
  ["minecraft:emerald_ore"] = true,
}

local DROP_BLACKLIST = {
  ["minecraft:cobblestone"] = true,
  ["minecraft:dirt"] = true,
}

-- STATE
local state = {
  x=0,y=0,z=0,
  facing=0, -- 0=north,1=east,2=south,3=west
  mode="main",
  mainProgress=0,
  branchSide="left",
  branchProgress=0,
  nextBranchAt=BRANCH_EVERY,
  branchMainDir=0,
  -- Branch resumption fields
  branchReturning=false,
  branchBackLeft=0,
  -- Vein mining resumption stack: holds reverse-move directions to backtrack (e.g., "b","l","r","u","d")
  veinStack={},
}

-- HELPERS
local function saveState()
  local f = fs.open("resume.dat","w")
  f.write(textutils.serialize(state))
  f.close()
end

local function loadState()
  if fs.exists("resume.dat") then
    local f = fs.open("resume.dat","r")
    state = textutils.unserialize(f.readAll())
    f.close()
  end
end

local function turnLeft() turtle.turnLeft(); state.facing=(state.facing+3)%4 end
local function turnRight() turtle.turnRight(); state.facing=(state.facing+1)%4 end
local function face(dir)
  while state.facing~=dir do turnRight() end
end
local function forward()
  while not turtle.forward() do turtle.dig(); sleep(0.5) end
  if state.facing==0 then state.z=state.z-1
  elseif state.facing==1 then state.x=state.x+1
  elseif state.facing==2 then state.z=state.z+1
  elseif state.facing==3 then state.x=state.x-1 end
end

-- ORE DETECTION / VEIN MINING (resumable)
local function inspectDir(direction)
  if direction == "forward" then return turtle.inspect()
  elseif direction == "up" then return turtle.inspectUp()
  elseif direction == "down" then return turtle.inspectDown()
  elseif direction == "left" then
    turtle.turnLeft()
    local ok, data = turtle.inspect()
    turtle.turnRight()
    return ok, data
  elseif direction == "right" then
    turtle.turnRight()
    local ok, data = turtle.inspect()
    turtle.turnLeft()
    return ok, data
  elseif direction == "back" then
    turtle.turnLeft(); turtle.turnLeft()
    local ok, data = turtle.inspect()
    turtle.turnRight(); turtle.turnRight()
    return ok, data
  end
end

local function moveDir(dir)
  if dir=="f" then turtle.dig(); forward()
  elseif dir=="b" then turtle.back(); if state.facing==0 then state.z=state.z+1 elseif state.facing==1 then state.x=state.x-1 elseif state.facing==2 then state.z=state.z-1 elseif state.facing==3 then state.x=state.x+1 end
  elseif dir=="l" then turtle.turnLeft(); turtle.dig(); forward(); turtle.turnRight()
  elseif dir=="r" then turtle.turnRight(); turtle.dig(); forward(); turtle.turnLeft()
  elseif dir=="u" then while not turtle.up() do turtle.digUp(); sleep(0.2) end; state.y=state.y+1
  elseif dir=="d" then while not turtle.down() do turtle.digDown(); sleep(0.2) end; state.y=state.y-1 end
end

local function reverseDir(dir)
  if dir=="f" then return "b" elseif dir=="b" then return "f" elseif dir=="l" then return "r" elseif dir=="r" then return "l" elseif dir=="u" then return "d" else return "u" end
end

local function tryFindOreDir()
  -- Prefer lateral/forward first; we intentionally skip checking "back" to avoid thrashing
  for _,probe in ipairs({"forward","left","right","up","down"}) do
    local ok, data = inspectDir(probe)
    if ok and data and ORE_WHITELIST[data.name] then
      if probe=="forward" then return "f"
      elseif probe=="left" then return "l"
      elseif probe=="right" then return "r"
      elseif probe=="up" then return "u"
      elseif probe=="down" then return "d" end
    end
  end
  return nil
end

local function continueVein()
  state.mode="vein"; saveState()
  while true do
    local dir = tryFindOreDir()
    if dir then
      -- Move into the ore block and push the reverse move for backtracking
      moveDir(dir)
      table.insert(state.veinStack, reverseDir(dir))
      saveState()
    else
      -- No adjacent ore; backtrack one step if we have a path
      if #state.veinStack == 0 then
        -- Vein complete
        state.mode = "main"; saveState()
        return
      end
      local back = table.remove(state.veinStack)
      moveDir(back)
      saveState()
    end
  end
end

local function maybeVeinMine()
  if tryFindOreDir() then
    -- Start/resume a vein
    if state.mode ~= "vein" then state.veinStack = {} end
    continueVein()
  end
end
  end
end

-- INVENTORY
local function dropInventory()
  for slot=2,16 do
    turtle.select(slot)
    turtle.dropDown()
  end
  turtle.select(1)
end

local function isInventoryFull()
  for slot=2,16 do
    if turtle.getItemCount(slot)==0 then return false end
  end
  return true
end

-- BRANCHING
local function resumeBranch()
  local branchDir = (state.branchSide=="left") and (state.branchMainDir+3)%4 or (state.branchMainDir+1)%4
  face(branchDir)
  for i=state.branchProgress+1,BRANCH_LENGTH do
    turtle.dig(); forward()
    state.branchProgress=i
    maybeVeinMine()
    saveState()
  end
  -- return to tunnel
  face((branchDir+2)%4)
  for i=1,BRANCH_LENGTH do forward() end
  face(state.branchMainDir)
  state.mode="main"
  saveState()
end

local function doOneBranch(side)
  -- Initialize branch state if starting fresh
  if state.mode ~= "branch" then
    state.mode="branch"
    state.branchSide=side
    state.branchProgress=state.branchProgress or 0
    state.branchMainDir=state.facing
    state.branchReturning=false
    state.branchBackLeft=BRANCH_LENGTH
    saveState()
  end

  local branchDir = (state.branchSide=="left") and (state.branchMainDir+3)%4 or (state.branchMainDir+1)%4

  -- Forward leg
  if not state.branchReturning then
    face(branchDir)
    for i=state.branchProgress+1,BRANCH_LENGTH do
      turtle.dig(); forward()
      state.branchProgress=i
      saveState()
      maybeVeinMine()
    end
    -- Switch to return leg
    state.branchReturning=true
    state.branchBackLeft=BRANCH_LENGTH
    saveState()
  end

  -- Return leg
  face((branchDir+2)%4)
  while state.branchBackLeft>0 do
    forward()
    state.branchBackLeft=state.branchBackLeft-1
    saveState()
  end

  -- Finish: restore facing and clear branch state
  face(state.branchMainDir)
  state.mode="main"
  state.branchProgress=0
  state.branchBackLeft=0
  state.branchReturning=false
  saveState()
end

-- MAIN MINING
local function mineMain()
  state.mode="main"
  while state.mainProgress<MAIN_LENGTH do
    turtle.dig(); forward()
    state.mainProgress=state.mainProgress+1
    saveState()
    maybeVeinMine()
    if state.mainProgress==state.nextBranchAt then
      -- Left branch (resumable)
      if state.mode=="main" then doOneBranch("left") end
      -- Right branch (resumable)
      if state.mode=="main" then doOneBranch("right") end
      state.nextBranchAt=state.nextBranchAt+BRANCH_EVERY
      if isInventoryFull() then
        local stepsBack=state.mainProgress
        face((state.facing+2)%4)
        for i=1,stepsBack do forward() end
        dropInventory()
        -- go forward again to resume
        face((state.facing+2)%4)
        for i=1,stepsBack do forward() end
        face((state.facing+2)%4)
      end
    end
  end
end
        dropInventory()
        face((state.facing+2)%4)
        for i=1,stepsBack do forward() end
        face((state.facing+2)%4)
      end
    end
    saveState()
  end
end

-- MAIN
local function main()
  loadState()
  -- If we crashed mid-vein or mid-branch, resume that first
  if state.mode=="vein" then
    continueVein()
  end
  if state.mode=="branch" then
    doOneBranch(state.branchSide)
  end
  -- Continue main plan
  mineMain()
  print("Mining complete.")
end
  print("Mining complete.")
end

main()