import { PATH_ALIAS_POLICIES } from "../../infra/path-alias-guards.js";
import type {
  PathSafetyCheck,
  PinnedSandboxDirectoryEntry,
  PinnedSandboxEntry,
} from "./fs-bridge-path-safety.js";
import type { SandboxFsCommandPlan } from "./fs-bridge-shell-command-plans.js";

export const SANDBOX_PINNED_MUTATION_PYTHON_CANDIDATES = [
  "/usr/bin/python3",
  "/usr/local/bin/python3",
  "/opt/homebrew/bin/python3",
  "/bin/python3",
] as const;

export const SANDBOX_PINNED_MUTATION_PYTHON = [
  "import errno",
  "import os",
  "import secrets",
  "import stat",
  "import sys",
  "",
  "operation = sys.argv[1]",
  "",
  "DIR_FLAGS = os.O_RDONLY",
  "if hasattr(os, 'O_DIRECTORY'):",
  "    DIR_FLAGS |= os.O_DIRECTORY",
  "if hasattr(os, 'O_NOFOLLOW'):",
  "    DIR_FLAGS |= os.O_NOFOLLOW",
  "",
  "READ_FLAGS = os.O_RDONLY",
  "if hasattr(os, 'O_NOFOLLOW'):",
  "    READ_FLAGS |= os.O_NOFOLLOW",
  "",
  "WRITE_FLAGS = os.O_WRONLY | os.O_CREAT | os.O_EXCL",
  "if hasattr(os, 'O_NOFOLLOW'):",
  "    WRITE_FLAGS |= os.O_NOFOLLOW",
  "",
  "def split_relative(path_value):",
  "    segments = []",
  "    for segment in path_value.split('/'):",
  "        if not segment or segment == '.':",
  "            continue",
  "        if segment == '..':",
  "            raise OSError(errno.EPERM, 'path traversal is not allowed', segment)",
  "        segments.append(segment)",
  "    return segments",
  "",
  "def open_dir(path_value, dir_fd=None):",
  "    return os.open(path_value, DIR_FLAGS, dir_fd=dir_fd)",
  "",
  "def walk_dir(root_fd, rel_path, mkdir_enabled):",
  "    current_fd = os.dup(root_fd)",
  "    try:",
  "        for segment in split_relative(rel_path):",
  "            try:",
  "                next_fd = open_dir(segment, dir_fd=current_fd)",
  "            except FileNotFoundError:",
  "                if not mkdir_enabled:",
  "                    raise",
  "                os.mkdir(segment, 0o777, dir_fd=current_fd)",
  "                next_fd = open_dir(segment, dir_fd=current_fd)",
  "            os.close(current_fd)",
  "            current_fd = next_fd",
  "        return current_fd",
  "    except Exception:",
  "        os.close(current_fd)",
  "        raise",
  "",
  "def create_temp_file(parent_fd, basename):",
  "    prefix = '.openclaw-write-' + basename + '.'",
  "    for _ in range(128):",
  "        candidate = prefix + secrets.token_hex(6)",
  "        try:",
  "            fd = os.open(candidate, WRITE_FLAGS, 0o600, dir_fd=parent_fd)",
  "            return candidate, fd",
  "        except FileExistsError:",
  "            continue",
  "    raise RuntimeError('failed to allocate sandbox temp file')",
  "",
  "def create_temp_dir(parent_fd, basename, mode):",
  "    prefix = '.openclaw-move-' + basename + '.'",
  "    for _ in range(128):",
  "        candidate = prefix + secrets.token_hex(6)",
  "        try:",
  "            os.mkdir(candidate, mode, dir_fd=parent_fd)",
  "            return candidate",
  "        except FileExistsError:",
  "            continue",
  "    raise RuntimeError('failed to allocate sandbox temp directory')",
  "",
  "def write_atomic(parent_fd, basename, stdin_buffer):",
  "    temp_fd = None",
  "    temp_name = None",
  "    try:",
  "        temp_name, temp_fd = create_temp_file(parent_fd, basename)",
  "        while True:",
  "            chunk = stdin_buffer.read(65536)",
  "            if not chunk:",
  "                break",
  "            os.write(temp_fd, chunk)",
  "        os.fsync(temp_fd)",
  "        os.close(temp_fd)",
  "        temp_fd = None",
  "        os.replace(temp_name, basename, src_dir_fd=parent_fd, dst_dir_fd=parent_fd)",
  "        temp_name = None",
  "        os.fsync(parent_fd)",
  "    finally:",
  "        if temp_fd is not None:",
  "            os.close(temp_fd)",
  "        if temp_name is not None:",
  "            try:",
  "                os.unlink(temp_name, dir_fd=parent_fd)",
  "            except FileNotFoundError:",
  "                pass",
  "",
  "def read_file(parent_fd, basename):",
  "    file_fd = os.open(basename, READ_FLAGS, dir_fd=parent_fd)",
  "    try:",
  "        file_stat = os.fstat(file_fd)",
  "        if not stat.S_ISREG(file_stat.st_mode):",
  "            raise OSError(errno.EPERM, 'only regular files are allowed', basename)",
  "        if file_stat.st_nlink > 1:",
  "            raise OSError(errno.EPERM, 'hardlinked file is not allowed', basename)",
  "        while True:",
  "            chunk = os.read(file_fd, 65536)",
  "            if not chunk:",
  "                break",
  "            os.write(1, chunk)",
  "    finally:",
  "        os.close(file_fd)",
  "",
  "def remove_tree(parent_fd, basename):",
  "    entry_stat = os.lstat(basename, dir_fd=parent_fd)",
  "    if not stat.S_ISDIR(entry_stat.st_mode) or stat.S_ISLNK(entry_stat.st_mode):",
  "        os.unlink(basename, dir_fd=parent_fd)",
  "        return",
  "    dir_fd = open_dir(basename, dir_fd=parent_fd)",
  "    try:",
  "        for child in os.listdir(dir_fd):",
  "            remove_tree(dir_fd, child)",
  "    finally:",
  "        os.close(dir_fd)",
  "    os.rmdir(basename, dir_fd=parent_fd)",
  "",
  "def move_entry(src_parent_fd, src_basename, dst_parent_fd, dst_basename):",
  "    try:",
  "        os.rename(src_basename, dst_basename, src_dir_fd=src_parent_fd, dst_dir_fd=dst_parent_fd)",
  "        os.fsync(dst_parent_fd)",
  "        os.fsync(src_parent_fd)",
  "        return",
  "    except OSError as err:",
  "        if err.errno != errno.EXDEV:",
  "            raise",
  "    src_stat = os.lstat(src_basename, dir_fd=src_parent_fd)",
  "    if stat.S_ISDIR(src_stat.st_mode) and not stat.S_ISLNK(src_stat.st_mode):",
  "        temp_dir_name = create_temp_dir(dst_parent_fd, dst_basename, stat.S_IMODE(src_stat.st_mode) or 0o755)",
  "        temp_dir_fd = open_dir(temp_dir_name, dir_fd=dst_parent_fd)",
  "        src_dir_fd = open_dir(src_basename, dir_fd=src_parent_fd)",
  "        try:",
  "            for child in os.listdir(src_dir_fd):",
  "                move_entry(src_dir_fd, child, temp_dir_fd, child)",
  "        finally:",
  "            os.close(src_dir_fd)",
  "            os.close(temp_dir_fd)",
  "        os.rename(temp_dir_name, dst_basename, src_dir_fd=dst_parent_fd, dst_dir_fd=dst_parent_fd)",
  "        os.rmdir(src_basename, dir_fd=src_parent_fd)",
  "        os.fsync(dst_parent_fd)",
  "        os.fsync(src_parent_fd)",
  "        return",
  "    if stat.S_ISLNK(src_stat.st_mode):",
  "        link_target = os.readlink(src_basename, dir_fd=src_parent_fd)",
  "        try:",
  "            os.unlink(dst_basename, dir_fd=dst_parent_fd)",
  "        except FileNotFoundError:",
  "            pass",
  "        os.symlink(link_target, dst_basename, dir_fd=dst_parent_fd)",
  "        os.unlink(src_basename, dir_fd=src_parent_fd)",
  "        os.fsync(dst_parent_fd)",
  "        os.fsync(src_parent_fd)",
  "        return",
  "    src_fd = os.open(src_basename, READ_FLAGS, dir_fd=src_parent_fd)",
  "    temp_fd = None",
  "    temp_name = None",
  "    try:",
  "        src_file_stat = os.fstat(src_fd)",
  "        if not stat.S_ISREG(src_file_stat.st_mode):",
  "            raise OSError(errno.EPERM, 'only regular files are allowed', src_basename)",
  "        if src_file_stat.st_nlink > 1:",
  "            raise OSError(errno.EPERM, 'hardlinked file is not allowed', src_basename)",
  "        temp_name, temp_fd = create_temp_file(dst_parent_fd, dst_basename)",
  "        while True:",
  "            chunk = os.read(src_fd, 65536)",
  "            if not chunk:",
  "                break",
  "            os.write(temp_fd, chunk)",
  "        try:",
  "            os.fchmod(temp_fd, stat.S_IMODE(src_stat.st_mode))",
  "        except AttributeError:",
  "            pass",
  "        os.fsync(temp_fd)",
  "        os.close(temp_fd)",
  "        temp_fd = None",
  "        os.replace(temp_name, dst_basename, src_dir_fd=dst_parent_fd, dst_dir_fd=dst_parent_fd)",
  "        temp_name = None",
  "        os.unlink(src_basename, dir_fd=src_parent_fd)",
  "        os.fsync(dst_parent_fd)",
  "        os.fsync(src_parent_fd)",
  "    finally:",
  "        if temp_fd is not None:",
  "            os.close(temp_fd)",
  "        if temp_name is not None:",
  "            try:",
  "                os.unlink(temp_name, dir_fd=dst_parent_fd)",
  "            except FileNotFoundError:",
  "                pass",
  "        os.close(src_fd)",
  "",
  "if operation == 'write':",
  "    root_fd = open_dir(sys.argv[2])",
  "    parent_fd = None",
  "    try:",
  "        parent_fd = walk_dir(root_fd, sys.argv[3], sys.argv[5] == '1')",
  "        write_atomic(parent_fd, sys.argv[4], sys.stdin.buffer)",
  "    finally:",
  "        if parent_fd is not None:",
  "            os.close(parent_fd)",
  "        os.close(root_fd)",
  "elif operation == 'read':",
  "    root_fd = open_dir(sys.argv[2])",
  "    parent_fd = None",
  "    try:",
  "        parent_fd = walk_dir(root_fd, sys.argv[3], False)",
  "        read_file(parent_fd, sys.argv[4])",
  "    finally:",
  "        if parent_fd is not None:",
  "            os.close(parent_fd)",
  "        os.close(root_fd)",
  "elif operation == 'mkdirp':",
  "    root_fd = open_dir(sys.argv[2])",
  "    target_fd = None",
  "    try:",
  "        target_fd = walk_dir(root_fd, sys.argv[3], True)",
  "        os.fsync(target_fd)",
  "    finally:",
  "        if target_fd is not None:",
  "            os.close(target_fd)",
  "        os.close(root_fd)",
  "elif operation == 'remove':",
  "    root_fd = open_dir(sys.argv[2])",
  "    parent_fd = None",
  "    try:",
  "        parent_fd = walk_dir(root_fd, sys.argv[3], False)",
  "        try:",
  "            if sys.argv[5] == '1':",
  "                remove_tree(parent_fd, sys.argv[4])",
  "            else:",
  "                entry_stat = os.lstat(sys.argv[4], dir_fd=parent_fd)",
  "                if stat.S_ISDIR(entry_stat.st_mode) and not stat.S_ISLNK(entry_stat.st_mode):",
  "                    os.rmdir(sys.argv[4], dir_fd=parent_fd)",
  "                else:",
  "                    os.unlink(sys.argv[4], dir_fd=parent_fd)",
  "            os.fsync(parent_fd)",
  "        except FileNotFoundError:",
  "            if sys.argv[6] != '1':",
  "                raise",
  "    finally:",
  "        if parent_fd is not None:",
  "            os.close(parent_fd)",
  "        os.close(root_fd)",
  "elif operation == 'rename':",
  "    src_root_fd = open_dir(sys.argv[2])",
  "    dst_root_fd = open_dir(sys.argv[5])",
  "    src_parent_fd = None",
  "    dst_parent_fd = None",
  "    try:",
  "        src_parent_fd = walk_dir(src_root_fd, sys.argv[3], False)",
  "        dst_parent_fd = walk_dir(dst_root_fd, sys.argv[6], sys.argv[8] == '1')",
  "        move_entry(src_parent_fd, sys.argv[4], dst_parent_fd, sys.argv[7])",
  "    finally:",
  "        if src_parent_fd is not None:",
  "            os.close(src_parent_fd)",
  "        if dst_parent_fd is not None:",
  "            os.close(dst_parent_fd)",
  "        os.close(src_root_fd)",
  "        os.close(dst_root_fd)",
  "else:",
  "    raise RuntimeError('unknown sandbox mutation operation: ' + operation)",
].join("\n");

const SANDBOX_PINNED_MUTATION_PYTHON_SHELL_LITERAL = `'${SANDBOX_PINNED_MUTATION_PYTHON.replaceAll("'", `'\\''`)}'`;

function buildPinnedMutationPlan(params: {
  args: string[];
  checks: PathSafetyCheck[];
}): SandboxFsCommandPlan {
  return {
    checks: params.checks,
    recheckBeforeCommand: true,
    // Feed the helper source over fd 3 so stdin stays available for write payload bytes.
    script: [
      "set -eu",
      "python_cmd=''",
      ...SANDBOX_PINNED_MUTATION_PYTHON_CANDIDATES.map(
        (candidate) =>
          `if [ -z "$python_cmd" ] && [ -x '${candidate}' ]; then python_cmd='${candidate}'; fi`,
      ),
      'if [ -z "$python_cmd" ]; then python_cmd=$(command -v python3 2>/dev/null || command -v python 2>/dev/null || true); fi',
      'if [ -z "$python_cmd" ]; then',
      "  echo >&2 'sandbox pinned mutation helper requires python3 or python'",
      "  exit 127",
      "fi",
      `python_script=${SANDBOX_PINNED_MUTATION_PYTHON_SHELL_LITERAL}`,
      'exec "$python_cmd" -c "$python_script" "$@"',
    ].join("\n"),
    args: params.args,
  };
}

export function buildPinnedWritePlan(params: {
  check: PathSafetyCheck;
  pinned: PinnedSandboxEntry;
  mkdir: boolean;
}): SandboxFsCommandPlan {
  return buildPinnedMutationPlan({
    checks: [params.check],
    args: [
      "write",
      params.pinned.mountRootPath,
      params.pinned.relativeParentPath,
      params.pinned.basename,
      params.mkdir ? "1" : "0",
    ],
  });
}

export function buildPinnedMkdirpPlan(params: {
  check: PathSafetyCheck;
  pinned: PinnedSandboxDirectoryEntry;
}): SandboxFsCommandPlan {
  return buildPinnedMutationPlan({
    checks: [params.check],
    args: ["mkdirp", params.pinned.mountRootPath, params.pinned.relativePath],
  });
}

export function buildPinnedRemovePlan(params: {
  check: PathSafetyCheck;
  pinned: PinnedSandboxEntry;
  recursive?: boolean;
  force?: boolean;
}): SandboxFsCommandPlan {
  return buildPinnedMutationPlan({
    checks: [
      {
        target: params.check.target,
        options: {
          ...params.check.options,
          aliasPolicy: PATH_ALIAS_POLICIES.unlinkTarget,
        },
      },
    ],
    args: [
      "remove",
      params.pinned.mountRootPath,
      params.pinned.relativeParentPath,
      params.pinned.basename,
      params.recursive ? "1" : "0",
      params.force === false ? "0" : "1",
    ],
  });
}

export function buildPinnedRenamePlan(params: {
  fromCheck: PathSafetyCheck;
  toCheck: PathSafetyCheck;
  from: PinnedSandboxEntry;
  to: PinnedSandboxEntry;
}): SandboxFsCommandPlan {
  return buildPinnedMutationPlan({
    checks: [
      {
        target: params.fromCheck.target,
        options: {
          ...params.fromCheck.options,
          aliasPolicy: PATH_ALIAS_POLICIES.unlinkTarget,
        },
      },
      params.toCheck,
    ],
    args: [
      "rename",
      params.from.mountRootPath,
      params.from.relativeParentPath,
      params.from.basename,
      params.to.mountRootPath,
      params.to.relativeParentPath,
      params.to.basename,
      "1",
    ],
  });
}