NeteaseUrl/services/downloads.py

# -*- coding: utf-8 -*-
"""单曲下载、账号探测与任务交付。
"""

import os
import shutil
import time
import traceback
import zipfile
from pathlib import Path

import auth_system
from core.config import (
    USER_COOKIE_FILE,
)
from core.state import (
    DOWNLOAD_TASKS,
    DOWNLOAD_TASKS_LOCK,
)
from core.state import GLOBAL_MUSIC_U_CACHE as _GLOBAL_MUSIC_U_CACHE
from core.state import VIP_PROBE_LOCK as _VIP_PROBE_LOCK
from core.utils import format_lyric as _format_lyric
from music_api import (
    account_info,
    detect_vip_by_probe,
)
from music_api.qr_client import QRLoginClient
from music_downloader import (
    DownloadCanceled,
    DownloadException,
    fetch_cover_bytes,
)

from ._shared import (
    _build_download_base,
    _record_log,
)
from ._taskcore import (
    _mark_task_terminal,
)
from .api_service import (
    api_service,
)


def _parse_cookie_str(raw) -> dict[str, str]:
    """将 'k=v;k2=v2' 格式的 Cookie 字符串解析为字典"""
    cookies: dict[str, str] = {}
    if not raw:
        return cookies
    for part in str(raw).split(';'):
        if '=' in part:
            k, v = part.strip().split('=', 1)
            if k:
                cookies[k] = v
    return cookies


# _GLOBAL_MUSIC_U_CACHE 已迁出至 core.state（此处 import 同名共享）


def _global_music_u() -> str:
    """全局账号 MUSIC_U（5 分钟缓存；后台重新扫码后自动跟随新值）"""
    now = time.time()
    if _GLOBAL_MUSIC_U_CACHE['v'] is None or now - _GLOBAL_MUSIC_U_CACHE['ts'] > 300:
        try:
            ck = api_service._get_cookies()
            _GLOBAL_MUSIC_U_CACHE['v'] = (ck.get('MUSIC_U') or '').strip()
        except Exception:
            _GLOBAL_MUSIC_U_CACHE['v'] = ''
        _GLOBAL_MUSIC_U_CACHE['ts'] = now
    # 契约返回 str：缓存未命中且读取失败时 v 会是 None，统一收敛为空串
    return _GLOBAL_MUSIC_U_CACHE['v'] or ''


def _vip_name(vip_type: int) -> str:
    """根据 vipType 返回会员类型名称（兼容新旧取值）"""
    return {
        0: '普通用户',
        1: '音乐包',
        11: '黑胶VIP',
        100: '黑胶VIP',
        10: '黑胶SVIP',
        110: '黑胶SVIP'
    }.get(vip_type, '普通用户')


def _detect_vip(cookies: dict[str, str]) -> tuple[int, str, list[str]]:
    """检测账号会员类型与可解析音质：
    优先账号接口（vipType 精确），并始终用音质探测接口实测可解析列表。
    探测单飞锁（有界等待 0.5s）——上游黑洞时并发请求不再各自串行
    8 级探测（最坏 16 分钟线程滞留），等锁超时者直接用账号接口给降级结果"""
    if not _VIP_PROBE_LOCK.acquire(timeout=0.5):
        info = account_info(cookies)
        if info:
            return info.get('vipType', 0), 'account', []
        return 0, 'probe', []
    try:
        probe = detect_vip_by_probe(cookies)
        levels_ok = probe.get('levels_ok', [])
        info = account_info(cookies)
        if info:
            return info.get('vipType', 0), 'account', levels_ok
        return probe.get('vip_type', 0), 'probe', levels_ok
    finally:
        _VIP_PROBE_LOCK.release()


# ============ 管理员设置（二维码登录 / Cookie 管理） ============

def _admin_client() -> QRLoginClient:
    """创建二维码登录客户端（基于 cookie.txt）"""
    return QRLoginClient()


# ============ 个人歌单（游客扫码登录自己的账号） ============

def _user_client() -> QRLoginClient:
    """创建个人用户二维码登录客户端（后不再落盘 user_cookie.txt，
    USER_COOKIE_FILE 仅作 QRLoginClient 构造参数遗留）"""
    return QRLoginClient(USER_COOKIE_FILE)


def _task_delivery_copy(task_id: str, src: Path, filename: str) -> str:
    """把共享缓存文件复制/硬链接为任务专属交付文件（任务成果与共享缓存分离，
    任何任务的清理都不会再删掉别的任务的成果）"""
    task_dir = api_service.downloads_path / 'tasks' / task_id
    task_dir.mkdir(parents=True, exist_ok=True)
    dst = task_dir / filename
    if dst.exists():
        return str(dst)
    try:
        os.link(str(src), str(dst))   # 同卷硬链接：零拷贝
    except OSError:
        shutil.copy2(str(src), str(dst))
    return str(dst)


# _cleanup_task_dir 死代码删除——worker 直接 rmtree、监控线程直接
# rmtree，本函数全文件零调用（审计确认）。


def _single_download_worker(task_id: str) -> None:
    """后台单曲下载：下载音频（可选 ZIP 打包），支持取消；完成后由 /download/result 交付，35 分钟保留期清理"""
    import tempfile as _tempfile

    file_path_str: str | None = None
    zip_tmp_path: str | None = None
    task_dir_path: str | None = None
    try:
        with DOWNLOAD_TASKS_LOCK:
            task = DOWNLOAD_TASKS[task_id]
            task['status'] = 'running'
            task['msg'] = '下载中...'
        params = task['params']
        cancel_ev = task['cancel']
        music_id = params['music_id']
        quality = params['quality']
        filename_format = params['filename_format']
        write_meta = params['write_meta']
        meta_fields = params['meta_fields']
        lyric_format = params['lyric_format']
        need_zip = params['need_zip']
        cookies = params['cookies']
        remote_ip = params.get('remote_ip') or '-'

        # 一次预取歌曲完整信息（URL/详情/歌词三接口并行），
        # 替代原先 name_v1 + url_v1 + 下载器内部 get_music_info 的重复串行调用
        mi = api_service.downloader.get_music_info(music_id, quality, cookies)
        music_info = {
            'id': music_id,
            'name': mi.name,
            'artist_string': mi.artists,
            'album': mi.album,
            'pic_url': mi.pic_url,
            'file_type': mi.file_type,
            'file_size': mi.file_size,
            'duration': mi.duration * 1000,
            'download_url': mi.download_url,
        }
        base = _build_download_base(filename_format, music_info)
        filename = f"{base}.{music_info['file_type']}"

        # 字节级进度回调（限频 0.4s）：写进任务 live_percent，/api/batch_progress
        # 对运行中的单曲任务优先返回它——原实现 done 按首计数，单曲进度条全程 0%
        _cb_ts = {'t': 0.0}

        def _progress_cb(written, total_bytes):
            try:
                now = time.time()
                if now - _cb_ts['t'] < 0.4 and written < (total_bytes or 0):
                    return
                _cb_ts['t'] = now
                with DOWNLOAD_TASKS_LOCK:
                    t = DOWNLOAD_TASKS.get(task_id)
                    if not t or t.get('status') != 'running':
                        return
                    if total_bytes:
                        pct = min(99.0, written / total_bytes * 100)
                        t['live_percent'] = pct
                        t['msg'] = (f"下载中 {int(pct)}% · "
                                    f"{api_service._format_file_size(written)}/{api_service._format_file_size(total_bytes)}")
                    else:
                        t['msg'] = f"下载中 · 已接收 {api_service._format_file_size(written)}"
            except Exception:
                pass   # 进度上报故障绝不影响下载

        download_result = api_service.downloader.download_music_file(
            music_id, quality,
            write_meta=write_meta,
            meta_fields=meta_fields,
            cookies=cookies,
            cancel_event=cancel_ev,
            music_info=mi,
            progress_cb=_progress_cb,
        )
        if not download_result.success:
            raise DownloadException(download_result.error_message or "下载失败")
        # 下载完成后的每一阶段都可能已被取消，发布前统一校验
        if cancel_ev.is_set():
            raise DownloadCanceled("任务已取消")
        assert download_result.file_path is not None
        cache_path = Path(download_result.file_path)
        # 交付文件用任务专属副本，共享缓存不进清理清单
        file_path_str = _task_delivery_copy(task_id, cache_path, filename)
        task_dir_path = str(Path(file_path_str).parent)

        if need_zip:
            fd, zip_tmp_path = _tempfile.mkstemp(prefix='single_zip_', suffix='.zip',
                                                 dir=str(Path(file_path_str).parent))
            os.close(fd)
            with zipfile.ZipFile(zip_tmp_path, 'w', zipfile.ZIP_DEFLATED) as zf:
                zf.write(file_path_str, arcname=filename)
                # 歌词已在预取时一并拿到，无需再请求一次
                if mi.lyric:
                    try:
                        zf.writestr(f"{base}.{lyric_format}", _format_lyric(mi.lyric, lyric_format))
                    except Exception:
                        pass
                # 封面走共享缓存（与元数据写入共用同一次网络请求）
                cover = fetch_cover_bytes(mi.pic_url)
                if cover:
                    zf.writestr(f"{base}.jpg", cover)
                info_txt = (
                    f"歌曲: {music_info['name']}\n"
                    f"歌手: {music_info['artist_string']}\n"
                    f"专辑: {music_info['album']}\n"
                    f"音质: {api_service._get_quality_display_name(quality)}\n"
                )
                zf.writestr("info.txt", info_txt)
            # 打包阶段同样以取消检查收口
            if cancel_ev.is_set():
                raise DownloadCanceled("任务已取消")
            result = {
                'file_path': file_path_str,
                'zip_path': zip_tmp_path,
                'filename': f"{base}.zip",
                'mimetype': 'application/zip',
                'audio_files': [file_path_str],
            }
        else:
            result = {
                'file_path': file_path_str,
                'filename': filename,
                'mimetype': f"audio/{music_info['file_type']}",
                'audio_files': [file_path_str],
            }

        # 最终发布前的取消检查（末段取消不得覆盖为 done）
        if cancel_ev.is_set():
            raise DownloadCanceled("任务已取消")
        with DOWNLOAD_TASKS_LOCK:
            t = DOWNLOAD_TASKS.get(task_id)
            if t is None or t.get('status') in ('canceled', 'error'):
                raise DownloadCanceled("任务已取消")
            t['status'] = 'done'
            t['completed_at'] = time.time()
            t['done'] = 1
            t['msg'] = '下载完成'
            t['result'] = result
        # 交付已落定；结算失败不再把任务改标 error（钱由重启对账兜底，宁可商家小损不坑用户）
        try:
            auth_system.ledger_settle(task_id, 1, 'delivered')
        except Exception as _e:
            api_service.logger.error(f"单曲交付结算失败（重启对账兜底）: {task_id} {_e}")
        try:
            _record_log('下载', remote_ip, music_info['name'])
        except Exception:
            pass
        api_service.logger.info(f"单曲下载完成: {filename} ({task_id})")
    except DownloadCanceled:
        _mark_task_terminal(task_id, 'canceled', '任务已取消')
        try:
            auth_system.ledger_settle(task_id, 0, 'canceled')
        except Exception:
            pass
        if task_dir_path:
            shutil.rmtree(task_dir_path, ignore_errors=True)
        api_service.logger.info(f"单曲下载已取消: {task_id}")
    except DownloadException as e:
        _mark_task_terminal(task_id, 'error', str(e))
        try:
            auth_system.ledger_settle(task_id, 0, 'error')
        except Exception:
            pass
        if task_dir_path:
            shutil.rmtree(task_dir_path, ignore_errors=True)
        api_service.logger.error(f"单曲下载失败: {task_id} {e}")
    except Exception as e:
        # 非预期异常的 repr 可能含上游主机/连接细节——用户可见文案
        # 泛化为固定文案，原文 logger 先行留档（教训：先记录再泛化）
        api_service.logger.error(f"单曲下载异常: {task_id} {e}\n{traceback.format_exc()}")
        _mark_task_terminal(task_id, 'error', '下载失败，请稍后重试')
        try:
            auth_system.ledger_settle(task_id, 0, 'error')
        except Exception:
            pass
        if task_dir_path:
            shutil.rmtree(task_dir_path, ignore_errors=True)