musicwebplay/app/main.py

from __future__ import annotations

import json
import mimetypes
import shutil
import threading
import uuid
import base64
import re
import urllib.error
import urllib.parse
import urllib.request
from datetime import datetime, timezone
from pathlib import Path
from typing import Any

from fastapi import FastAPI, File, Form, HTTPException, Request, UploadFile
from fastapi.responses import FileResponse, HTMLResponse, JSONResponse, RedirectResponse, StreamingResponse
from fastapi.staticfiles import StaticFiles
from fastapi.templating import Jinja2Templates
from pydantic import BaseModel

BASE_DIR = Path(__file__).resolve().parent.parent
LOCAL_MUSIC_DIR = BASE_DIR / "mp3file"
CLOUD_MUSIC_DIR = Path("/mnt/baiducloud/百度网盘/mp3file")
CLOUD_WEBDAV_BASE = "http://110.42.102.94:5244/dav"
CLOUD_ALIST_BASE = "http://110.42.102.94:5244"
def _nat_sort_key(name: str) -> tuple:
    """Sort key that treats numeric substrings as integers for natural ordering."""
    parts = re.split(r'(\d+)', name.lower())
    result = []
    for part in parts:
        if part.isdigit():
            result.append((0, int(part), part))
        else:
            result.append((1, 0, part))
    return result


CLOUD_WEBDAV_USER = "sequoia00"
CLOUD_WEBDAV_PASSWORD = "792199bb"
MUSIC_ROOTS: list[tuple[str, Path, str]] = [
    ("", LOCAL_MUSIC_DIR, "本地音乐"),
    ("cloud", CLOUD_MUSIC_DIR, "百度网盘"),
]
PLAYLISTS_FILE = BASE_DIR / "playlists.json"
CACHE_DIR = BASE_DIR / ".cache"
CLOUD_LIBRARY_CACHE_FILE = CACHE_DIR / "cloud_library.json"
CLOUD_COVER_CACHE_DIR = CACHE_DIR / "cloud_covers"
SUPPORTED_EXTENSIONS = {
    ".mp3",
    ".wav",
    ".flac",
    ".m3u",
    ".m3u8",
    ".ogg",
    ".aac",
    ".wma",
    ".opus",
    ".oga",
    ".mp4",
    ".m4a",
    ".webm",
}
IMAGE_EXTENSIONS = {".jpg", ".jpeg", ".png", ".webp", ".gif"}

app = FastAPI(title="MusicWeb", version="1.0.0")
app.mount("/static", StaticFiles(directory=BASE_DIR / "static"), name="static")
templates = Jinja2Templates(directory=str(BASE_DIR / "templates"))
CLOUD_REFRESH_STATE = {"running": False}
CLOUD_REFRESH_LOCK = threading.Lock()
_ALIST_TOKEN_CACHE: dict[str, tuple[str, float]] = {}


class FolderCreateRequest(BaseModel):
    path: str


class MoveRequest(BaseModel):
    source: str
    destination_dir: str


class PlaylistCreateRequest(BaseModel):
    name: str
    tracks: list[str]


class PlaylistUpdateRequest(BaseModel):
    tracks: list[str]


def ensure_storage() -> None:
    LOCAL_MUSIC_DIR.mkdir(parents=True, exist_ok=True)
    CLOUD_MUSIC_DIR.mkdir(parents=True, exist_ok=True)
    CACHE_DIR.mkdir(parents=True, exist_ok=True)
    CLOUD_COVER_CACHE_DIR.mkdir(parents=True, exist_ok=True)
    if not PLAYLISTS_FILE.exists():
        PLAYLISTS_FILE.write_text("[]", encoding="utf-8")


def safe_music_path(relative_path: str) -> Path:
    prefix, _, inner_path = relative_path.partition("/")
    roots = {key: root.resolve() for key, root, _ in MUSIC_ROOTS}
    if prefix in roots:
        candidate = (roots[prefix] / inner_path).resolve()
        if candidate != roots[prefix] and roots[prefix] not in candidate.parents:
            raise HTTPException(status_code=400, detail="Invalid path")
        return candidate

    candidate = (LOCAL_MUSIC_DIR / relative_path).resolve()
    local_root = LOCAL_MUSIC_DIR.resolve()
    if candidate != local_root and local_root not in candidate.parents:
        raise HTTPException(status_code=400, detail="Invalid path")
    return candidate


def load_playlists() -> list[dict[str, Any]]:
    ensure_storage()
    return json.loads(PLAYLISTS_FILE.read_text(encoding="utf-8"))


def save_playlists(playlists: list[dict[str, Any]]) -> None:
    PLAYLISTS_FILE.write_text(
        json.dumps(playlists, ensure_ascii=False, indent=2), encoding="utf-8"
    )


def is_under_root(path: Path, root: Path) -> bool:
    resolved_path = path.resolve()
    resolved_root = root.resolve()
    return resolved_path == resolved_root or resolved_root in resolved_path.parents


def track_path_for(root: Path, path: Path, prefix: str = "") -> str:
    relative = path.relative_to(root).as_posix()
    return f"{prefix}/{relative}" if prefix else relative


def track_path_from_abs(path: Path) -> str:
    if is_under_root(path, LOCAL_MUSIC_DIR):
        return path.relative_to(LOCAL_MUSIC_DIR).as_posix()
    if is_under_root(path, CLOUD_MUSIC_DIR):
        return f"cloud/{path.relative_to(CLOUD_MUSIC_DIR).as_posix()}"
    return path.name


def path_is_under(path: Path, root: Path) -> bool:
    try:
        resolved_path = path.resolve()
        resolved_root = root.resolve()
    except OSError:
        return False
    return resolved_path == resolved_root or resolved_root in resolved_path.parents


def trigger_cloud_cache_refresh_if_needed(*paths: Path) -> None:
    if any(path_is_under(path, CLOUD_MUSIC_DIR) for path in paths):
        start_cloud_library_refresh()


def cloud_cover_cache_path(relative_path: str) -> Path:
    inner_path = relative_path.removeprefix("cloud/").lstrip("/")
    target = (CLOUD_COVER_CACHE_DIR / inner_path).resolve()
    cache_root = CLOUD_COVER_CACHE_DIR.resolve()
    if target != cache_root and cache_root not in target.parents:
        raise HTTPException(status_code=400, detail="Invalid cover path")
    return target


def cloud_webdav_url(relative_path: str) -> str:
    inner_path = relative_path.removeprefix("cloud/").lstrip("/")
    encoded = "/".join(urllib.parse.quote(part) for part in inner_path.split("/") if part)
    base = CLOUD_WEBDAV_BASE.rstrip("/")
    return f"{base}/{encoded}" if encoded else base


def cloud_alist_api_path(relative_path: str) -> str:
    inner_path = relative_path.removeprefix("cloud/").lstrip("/")
    return f"/百度网盘/mp3file/{inner_path}" if inner_path else "/百度网盘/mp3file"


def _alist_list_dir(alist_path: str, token: str) -> list[dict[str, Any]]:
    """List files in an alist directory, handling pagination."""
    items: list[dict[str, Any]] = []
    page = 1
    while True:
        payload = json.dumps({"path": alist_path, "password": "", "page": page, "per_page": 200}).encode("utf-8")
        request = urllib.request.Request(
            f"{CLOUD_ALIST_BASE.rstrip('/')}/api/fs/list",
            data=payload,
            headers={
                "Content-Type": "application/json",
                "Authorization": token,
                "User-Agent": "MusicWebPlayer/1.0",
            },
        )
        try:
            with urllib.request.urlopen(request, timeout=20) as response:
                result = json.loads(response.read().decode("utf-8"))
        except urllib.error.HTTPError:
            break
        except urllib.error.URLError:
            break
        data = result.get("data")
        if not data or not isinstance(data, dict):
            break
        content_list = data.get("content", [])
        if not content_list:
            break
        items.extend(content_list)
        if not data.get("has_more"):
            break
        page += 1
    return items


def _get_alist_token() -> str | None:
    """Get alist login token, cached briefly to avoid repeated logins."""
    now = datetime.now(timezone.utc).timestamp()
    cached = _ALIST_TOKEN_CACHE.get("token")
    if cached and cached[1] > now:
        return cached[0]
    payload = json.dumps(
        {"username": CLOUD_WEBDAV_USER, "password": CLOUD_WEBDAV_PASSWORD}
    ).encode("utf-8")
    request = urllib.request.Request(
        f"{CLOUD_ALIST_BASE.rstrip('/')}/api/auth/login",
        data=payload,
        headers={"Content-Type": "application/json", "User-Agent": "MusicWebPlayer/1.0"},
    )
    try:
        with urllib.request.urlopen(request, timeout=20) as response:
            result = json.loads(response.read().decode("utf-8"))
    except (urllib.error.HTTPError, urllib.error.URLError):
        return None
    token = result.get("data", {}).get("token")
    if token:
        _ALIST_TOKEN_CACHE["token"] = (token, now + 8000)
    return token


def alist_login_token() -> str:
    payload = json.dumps(
        {
            "username": CLOUD_WEBDAV_USER,
            "password": CLOUD_WEBDAV_PASSWORD,
        }
    ).encode("utf-8")
    request = urllib.request.Request(
        f"{CLOUD_ALIST_BASE.rstrip('/')}/api/auth/login",
        data=payload,
        headers={"Content-Type": "application/json", "User-Agent": "MusicWebPlayer/1.0"},
    )
    try:
        with urllib.request.urlopen(request, timeout=20) as response:
            result = json.loads(response.read().decode("utf-8"))
    except urllib.error.HTTPError as error:
        raise HTTPException(status_code=error.code, detail=error.reason)
    except urllib.error.URLError as error:
        raise HTTPException(status_code=502, detail=str(error.reason))

    token = result.get("data", {}).get("token")
    if not token:
        raise HTTPException(status_code=502, detail="AList login failed")
    return token


def cloud_raw_url(relative_path: str) -> str:
    payload = json.dumps({"path": cloud_alist_api_path(relative_path), "password": ""}).encode("utf-8")
    request = urllib.request.Request(
        f"{CLOUD_ALIST_BASE.rstrip('/')}/api/fs/get",
        data=payload,
        headers={
            "Content-Type": "application/json",
            "Authorization": alist_login_token(),
            "User-Agent": "MusicWebPlayer/1.0",
        },
    )
    try:
        with urllib.request.urlopen(request, timeout=20) as response:
            result = json.loads(response.read().decode("utf-8"))
    except urllib.error.HTTPError as error:
        raise HTTPException(status_code=error.code, detail=error.reason)
    except urllib.error.URLError as error:
        raise HTTPException(status_code=502, detail=str(error.reason))

    data = result.get("data", {})
    sign = data.get("sign")
    path = data.get("path")
    if not sign or not path:
        raise HTTPException(status_code=404, detail="Cloud signed url not found")
    encoded_path = "/".join(urllib.parse.quote(part) for part in path.lstrip("/").split("/"))
    quoted_sign = urllib.parse.quote(sign, safe="")
    return f"{CLOUD_ALIST_BASE.rstrip('/')}/d/{urllib.parse.quote('百度网盘')}/{encoded_path}?sign={quoted_sign}"


def is_supported_file(path: Path) -> bool:
    return path.is_file() and path.suffix.lower() in SUPPORTED_EXTENSIONS


def track_url(relative_path: str) -> str:
    return f"/api/stream/{relative_path}"


def build_track(relative_path: str) -> dict[str, str]:
    filename = Path(relative_path).name
    return {
        "id": relative_path,
        "name": filename,
        "path": relative_path,
        "url": track_url(relative_path),
        "folder": str(Path(relative_path).parent).replace(".", "").strip("/"),
    }


def find_cover_for_directory(root: Path, prefix: str = "") -> str | None:
    path = root / "cover.jpg"
    if path.is_file():
        return track_path_for(root, path, prefix)
    return None


def sanitize_cover_value(cover: Any) -> str | None:
    if not isinstance(cover, str) or not cover:
        return None
    parsed = urllib.parse.urlparse(cover)
    path = parsed.path or cover
    return cover if path.lower().endswith("/cover.jpg") else None


def sanitize_library_tree(node: dict[str, Any]) -> dict[str, Any]:
    node["cover"] = sanitize_cover_value(node.get("cover"))
    for child in node.get("folders", []):
        if isinstance(child, dict):
            sanitize_library_tree(child)
    return node


def build_tree(root: Path, prefix: str = "", label: str = "音乐库") -> dict[str, Any]:
    cover_path = find_cover_for_directory(root, prefix)
    node = {
        "name": label,
        "path": prefix,
        "cover": f"/api/cover/{cover_path}" if cover_path else None,
        "folders": [],
        "tracks": [],
    }
    for child in sorted(root.iterdir(), key=lambda item: (item.is_file(), _nat_sort_key(item.name))):
        if child.is_dir():
            child_rel = child.relative_to(root).as_posix()
            child_prefix = f"{prefix}/{child_rel}" if prefix else child_rel
            node["folders"].append(build_tree(child, child_prefix, child.name))
        elif is_supported_file(child):
            node["tracks"].append(build_track(track_path_for(root, child, prefix)))
    return node


def collect_tracks(root: Path, prefix: str = "") -> list[dict[str, str]]:
    tracks: list[dict[str, str]] = []
    for path in sorted(root.rglob("*")):
        if is_supported_file(path):
            tracks.append(build_track(track_path_for(root, path, prefix)))
    return tracks


def _build_cloud_tree_from_alist(alist_path: str, prefix: str, label: str, token: str) -> dict[str, Any]:
    """Build a library tree node by querying the alist API recursively."""
    node = {
        "name": label,
        "path": prefix,
        "cover": None,
        "folders": [],
        "tracks": [],
    }
    try:
        items = _alist_list_dir(alist_path, token)
    except Exception:
        return node
    folders: list[dict[str, Any]] = []
    tracks: list[dict[str, str]] = []
    for item in sorted(items, key=lambda i: (i.get("is_dir", 0), _nat_sort_key(i.get("name", "")))):
        name = item.get("name", "")
        is_dir = bool(item.get("is_dir"))
        if is_dir:
            child_prefix = f"{prefix}/{name}" if prefix else name
            child_path = f"{alist_path.rstrip('/')}/{name}" if alist_path else name
            folders.append(_build_cloud_tree_from_alist(child_path, child_prefix, name, token))
        else:
            track_path = f"{prefix}/{name}" if prefix else name
            tracks.append(build_track(track_path))
    node["folders"] = folders
    node["tracks"] = tracks
    return node


def root_entry(source: str) -> tuple[str, Path, str]:
    for prefix, root, label in MUSIC_ROOTS:
        if prefix == source:
            return prefix, root, label
    raise HTTPException(status_code=404, detail="Library source not found")


def current_timestamp() -> str:
    return datetime.now(timezone.utc).isoformat()


def build_library_payload(source: str | None = None) -> dict[str, Any]:
    ensure_storage()
    entries = MUSIC_ROOTS if source is None else [root_entry(source)]
    tree = {
        "name": "音乐库",
        "path": "",
        "cover": None,
        "folders": [
            build_tree(root, prefix, label)
            for prefix, root, label in entries
            if root.exists()
        ],
        "tracks": [],
    }
    all_tracks: list[dict[str, str]] = []
    for prefix, root, _ in entries:
        if root.exists():
            all_tracks.extend(collect_tracks(root, prefix))
    sanitize_library_tree(tree)
    return {
        "tree": tree,
        "all_tracks": all_tracks,
        "playlists": load_playlists(),
    }


def read_cloud_library_cache() -> dict[str, Any] | None:
    if not CLOUD_LIBRARY_CACHE_FILE.exists():
        return None
    try:
        payload = json.loads(CLOUD_LIBRARY_CACHE_FILE.read_text(encoding="utf-8"))
    except (OSError, json.JSONDecodeError):
        return None
    if not isinstance(payload, dict):
        return None
    tree = payload.get("tree")
    if isinstance(tree, dict):
        sanitize_library_tree(tree)
    return payload


def write_cloud_library_cache(payload: dict[str, Any]) -> dict[str, Any]:
    cached_payload = {
        **payload,
        "cache": {
            "updated_at": current_timestamp(),
            "is_cached": True,
            "refreshing": False,
        },
    }
    CLOUD_LIBRARY_CACHE_FILE.write_text(
        json.dumps(cached_payload, ensure_ascii=False, indent=2),
        encoding="utf-8",
    )
    return cached_payload


def build_cloud_library_payload() -> dict[str, Any]:
    ensure_storage()
    token = _get_alist_token()
    if not token:
        return {
            "tree": {"name": "音乐库", "path": "", "cover": None, "folders": [], "tracks": []},
            "all_tracks": [],
            "playlists": load_playlists(),
        }
    try:
        cloud_tree = _build_cloud_tree_from_alist("/百度网盘/mp3file", "cloud", "百度网盘", token)
    except Exception:
        cloud_tree = {"name": "百度网盘", "path": "cloud", "cover": None, "folders": [], "tracks": []}
    all_tracks: list[dict[str, str]] = []
    def _collect(node: dict[str, Any]) -> None:
        all_tracks.extend(node.get("tracks", []))
        for child in node.get("folders", []):
            _collect(child)
    _collect(cloud_tree)
    sanitize_library_tree(cloud_tree)
    return {
        "tree": {
            "name": "音乐库",
            "path": "",
            "cover": None,
            "folders": [cloud_tree],
            "tracks": [],
        },
        "all_tracks": all_tracks,
        "playlists": load_playlists(),
    }


def cloud_library_payload_from_cache() -> dict[str, Any] | None:
    payload = read_cloud_library_cache()
    if not payload:
        return None
    cache_meta = payload.get("cache") if isinstance(payload.get("cache"), dict) else {}
    payload["cache"] = {
        "updated_at": cache_meta.get("updated_at"),
        "is_cached": True,
        "refreshing": CLOUD_REFRESH_STATE["running"],
    }
    return payload


def refresh_cloud_library_cache_sync() -> dict[str, Any]:
    payload = build_cloud_library_payload()
    return write_cloud_library_cache(payload)


def start_cloud_library_refresh() -> bool:
    with CLOUD_REFRESH_LOCK:
        if CLOUD_REFRESH_STATE["running"]:
            return False
        CLOUD_REFRESH_STATE["running"] = True

    def runner() -> None:
        try:
            refresh_cloud_library_cache_sync()
        finally:
            with CLOUD_REFRESH_LOCK:
                CLOUD_REFRESH_STATE["running"] = False

    threading.Thread(target=runner, daemon=True).start()
    return True


@app.on_event("startup")
def startup_event() -> None:
    ensure_storage()
    if not CLOUD_LIBRARY_CACHE_FILE.exists():
        start_cloud_library_refresh()


@app.get("/", response_class=HTMLResponse)
def index(request: Request) -> HTMLResponse:
    return templates.TemplateResponse("index.html", {"request": request})


@app.get("/api/library")
def library() -> JSONResponse:
    return JSONResponse(build_library_payload())


@app.get("/api/library/{source}")
def library_by_source(source: str) -> JSONResponse:
    normalized = "" if source == "local" else source
    if normalized == "cloud":
        cached = cloud_library_payload_from_cache()
        if cached:
            start_cloud_library_refresh()
            return JSONResponse(cached)

        payload = refresh_cloud_library_cache_sync()
        return JSONResponse(payload)
    return JSONResponse(build_library_payload(normalized))


@app.get("/api/library/{source}/refresh")
def refresh_library_by_source(source: str) -> JSONResponse:
    normalized = "" if source == "local" else source
    if normalized != "cloud":
        return JSONResponse(build_library_payload(normalized))

    started = start_cloud_library_refresh()
    cached = cloud_library_payload_from_cache()
    if cached:
        cached["cache"]["refreshing"] = True
        return JSONResponse({"started": started, "library": cached})

    payload = refresh_cloud_library_cache_sync()
    return JSONResponse({"started": started, "library": payload})


@app.get("/api/stream/{file_path:path}")
def stream_file(request: Request, file_path: str) -> StreamingResponse:
    if file_path.startswith("cloud/"):
        return proxy_cloud_stream(cloud_raw_url(file_path), request.headers.get("range"))

    file = safe_music_path(file_path)
    if not file.exists() or not file.is_file():
        raise HTTPException(status_code=404, detail="File not found")
    media_type = mimetypes.guess_type(file.name)[0] or "application/octet-stream"

    def file_iterator() -> Any:
        with file.open("rb") as handle:
            while chunk := handle.read(1024 * 1024):
                if not chunk:
                    break
                yield chunk

    return StreamingResponse(
        file_iterator(),
        media_type=media_type,
        headers={"Cache-Control": "private, no-cache"},
    )


@app.get("/api/cloud-url/{file_path:path}")
def get_cloud_url(file_path: str) -> JSONResponse:
    if not file_path.startswith("cloud/"):
        raise HTTPException(status_code=400, detail="Not a cloud track")
    return JSONResponse({"url": cloud_raw_url(file_path)})


def proxy_cloud_stream(remote_url: str, range_header: str | None = None) -> StreamingResponse:
    auth = base64.b64encode(f"{CLOUD_WEBDAV_USER}:{CLOUD_WEBDAV_PASSWORD}".encode("utf-8")).decode("ascii")
    headers = {
        "Authorization": f"Basic {auth}",
        "User-Agent": "MusicWebPlayer/1.0",
    }
    if range_header:
        headers["Range"] = range_header
    request = urllib.request.Request(
        remote_url,
        headers=headers,
    )
    try:
        response = urllib.request.urlopen(request, timeout=30)
    except urllib.error.HTTPError as error:
        raise HTTPException(status_code=error.code, detail=error.reason)
    except urllib.error.URLError as error:
        raise HTTPException(status_code=502, detail=str(error.reason))

    media_type = mimetypes.guess_type(urllib.parse.urlparse(remote_url).path)[0] or response.headers.get_content_type() or "audio/mpeg"
    passthrough_headers = {
        "Cache-Control": "private, no-cache",
        "Accept-Ranges": response.headers.get("Accept-Ranges") or "bytes",
        "Content-Type": media_type,
    }
    for key in ("ETag", "Last-Modified", "Content-Range"):
        value = response.headers.get(key)
        if value:
            passthrough_headers[key] = value

    def remote_iterator() -> Any:
        with response:
            while chunk := response.read(1024 * 1024):
                yield chunk

    return StreamingResponse(
        remote_iterator(),
        status_code=getattr(response, "status", 200),
        media_type=media_type,
        headers=passthrough_headers,
    )


def cache_cloud_cover(relative_path: str) -> Path:
    cached_file = cloud_cover_cache_path(relative_path)
    if cached_file.exists() and cached_file.is_file():
        return cached_file

    cached_file.parent.mkdir(parents=True, exist_ok=True)
    remote_url = cloud_raw_url(relative_path)
    request = urllib.request.Request(
        remote_url,
        headers={"User-Agent": "MusicWebPlayer/1.0"},
    )
    try:
        with urllib.request.urlopen(request, timeout=30) as response:
            with cached_file.open("wb") as output:
                shutil.copyfileobj(response, output)
    except urllib.error.HTTPError as error:
        raise HTTPException(status_code=error.code, detail=error.reason)
    except urllib.error.URLError as error:
        raise HTTPException(status_code=502, detail=str(error.reason))
    except OSError as error:
        raise HTTPException(status_code=500, detail=str(error))

    return cached_file


@app.get("/api/cover/{file_path:path}")
def cover_file(request: Request, file_path: str):
    if file_path.startswith("cloud/"):
        if Path(file_path).name.lower() != "cover.jpg":
            raise HTTPException(status_code=404, detail="Cover not found")
        cached_file = cache_cloud_cover(file_path)
        media_type = mimetypes.guess_type(cached_file.name)[0] or "image/jpeg"
        return FileResponse(cached_file, media_type=media_type, filename=cached_file.name)

    file = safe_music_path(file_path)
    if file.name.lower() != "cover.jpg" or not file.exists() or not file.is_file():
        raise HTTPException(status_code=404, detail="Cover not found")
    media_type = mimetypes.guess_type(file.name)[0] or "application/octet-stream"
    return FileResponse(file, media_type=media_type, filename=file.name)


@app.post("/api/upload")
async def upload_files(
    files: list[UploadFile] = File(...),
    target_dir: str = Form(default=""),
) -> JSONResponse:
    destination = safe_music_path(target_dir)
    if not str(destination).startswith(str(LOCAL_MUSIC_DIR.resolve())):
        raise HTTPException(status_code=400, detail="Upload destination must be local music dir")
    destination.mkdir(parents=True, exist_ok=True)
    saved: list[str] = []
    for upload in files:
        suffix = Path(upload.filename or "").suffix.lower()
        if suffix not in SUPPORTED_EXTENSIONS:
            continue
        filename = Path(upload.filename or f"upload-{uuid.uuid4().hex}").name
        file_path = destination / filename
        with file_path.open("wb") as buffer:
            shutil.copyfileobj(upload.file, buffer)
        saved.append(track_path_from_abs(file_path))
    trigger_cloud_cache_refresh_if_needed(destination)
    return JSONResponse({"saved": saved})


@app.post("/api/folder")
def create_folder(payload: FolderCreateRequest) -> JSONResponse:
    folder = safe_music_path(payload.path)
    if not str(folder).startswith(str(LOCAL_MUSIC_DIR.resolve())):
        raise HTTPException(status_code=400, detail="Folder must be created in local music dir")
    folder.mkdir(parents=True, exist_ok=True)
    trigger_cloud_cache_refresh_if_needed(folder)
    return JSONResponse({"created": track_path_from_abs(folder)})


@app.post("/api/move")
def move_file(payload: MoveRequest) -> JSONResponse:
    source = safe_music_path(payload.source)
    destination_dir = safe_music_path(payload.destination_dir)
    if not source.exists():
        raise HTTPException(status_code=404, detail="Source not found")
    if not destination_dir.exists():
        destination_dir.mkdir(parents=True, exist_ok=True)
    destination = destination_dir / source.name
    shutil.move(str(source), str(destination))
    trigger_cloud_cache_refresh_if_needed(source, destination_dir, destination)
    return JSONResponse({"moved": track_path_from_abs(destination)})


@app.post("/api/playlists")
def create_playlist(payload: PlaylistCreateRequest) -> JSONResponse:
    playlists = load_playlists()
    playlist = {
        "id": uuid.uuid4().hex,
        "name": payload.name.strip() or "未命名播放列表",
        "tracks": payload.tracks,
    }
    playlists.append(playlist)
    save_playlists(playlists)
    return JSONResponse(playlist)


@app.put("/api/playlists/{playlist_id}")
def update_playlist(playlist_id: str, payload: PlaylistUpdateRequest) -> JSONResponse:
    playlists = load_playlists()
    for playlist in playlists:
        if playlist["id"] == playlist_id:
            playlist["tracks"] = payload.tracks
            save_playlists(playlists)
            return JSONResponse(playlist)
    raise HTTPException(status_code=404, detail="Playlist not found")


@app.delete("/api/playlists/{playlist_id}")
def delete_playlist(playlist_id: str) -> JSONResponse:
    playlists = load_playlists()
    filtered = [playlist for playlist in playlists if playlist["id"] != playlist_id]
    if len(filtered) == len(playlists):
        raise HTTPException(status_code=404, detail="Playlist not found")
    save_playlists(filtered)
    return JSONResponse({"deleted": playlist_id})