# -*- coding: utf-8 -*-
"""播客单集下载 worker 的行为契约测试（沙箱，不触碰生产 data/）。

为什么：``services/podcast.py::_podcast_download_worker`` 是播客单集下载的**唯一**
后台执行路径（解析 → 音质降级直链 → 流式下载 → 可选 ZIP → /download/result 交付），
此前**零直接测试覆盖**（test_podcast_stream.py 只覆盖到流式下载这一层）。它有三条
except 分支各写一遍「结算 + 删任务目录」，正文里散着三处取消检查——改坏任意一处
都不会有测试报警。

按惯例：**先在未改动的原始实现上跑绿**，这批测试因此忠实编码了旧行为，重构时本身
即等价性验证器。断言只依赖「调用 worker 后世界里发生了什么」（任务终态、磁盘上的
文件、ZIP 内容、账本行、余额），不引用 worker 内部函数名。

替身边界（与真实契约一一对应）：
- ``podcast.get_program_detail`` / ``podcast.resolve_episode_url``：可编程节目信息与直链；
- ``_podcast_stream_download``：契约是「成功写 target 并返回字节数；取消抛
  DownloadCanceled；失败抛 DownloadException」，替身照此实现，不模拟字节流；
- ``fetch_cover_bytes``：失败返回 None（真实契约内部吞异常），不抛。

账本口径：一律用 ``reserve_and_open`` 真预扣（与 test_single_worker.py 同理由）。
"""
import asyncio
import threading
import time
import zipfile
from pathlib import Path
from typing import Any

import pytest

import auth_system as auth
import core.db as core_db
from core.state import DOWNLOAD_TASKS, DOWNLOAD_TASKS_LOCK
from music_downloader import DownloadCanceled, DownloadException
from services import podcast as podcast_svc
from services.api_service import api_service

PW = 'Passw0rd12'
CREDITS = 50


# ============ 测试替身 ============

class _NullLogger:
    """吞掉 api_service.logger 输出，避免测试往项目根 music_api.log 追加。"""

    def debug(self, *a: Any, **k: Any) -> None: ...
    def info(self, *a: Any, **k: Any) -> None: ...
    def warning(self, *a: Any, **k: Any) -> None: ...
    def error(self, *a: Any, **k: Any) -> None: ...


def _program(**over: Any) -> dict[str, Any]:
    """标准节目详情替身（字段与 music_api.podcast.get_program_detail 对齐）。"""
    d: dict[str, Any] = {
        'main_song_id': 999,
        'name': '第一集 测试',
        'serial_num': 3,
        'cover_url': 'https://cover.example/x.jpg',
        'radio_name': '测试电台',
        'dj_name': '主播甲',
        'duration_text': '10:00',
    }
    d.update(over)
    return d


def _url_info(**over: Any) -> dict[str, Any]:
    d: dict[str, Any] = {'url': 'https://cdn.example/a.mp3', 'type': 'mp3',
                         'size': 11, 'level': 'standard'}
    d.update(over)
    return d


class _FakeStream:
    """``_podcast_stream_download`` 替身。

    ``on_call`` 在写入 target 之前被调用（注入取消置位 / 外部终态 / 抛错）；
    ``fail`` 模拟流式下载失败（如完整性不达标）。
    """

    def __init__(self, *, fail: Exception | None = None, on_call: Any = None):
        self.fail = fail
        self.on_call = on_call
        self.calls: list[dict[str, Any]] = []

    async def __call__(self, url: str, target: Path, total_size: int,
                       cancel_ev: threading.Event, task_id: str = '',
                       progress_label: str = '') -> int:
        self.calls.append({'url': url, 'target': Path(target),
                           'total_size': total_size})
        if self.on_call is not None:
            self.on_call()
        if cancel_ev.is_set():
            raise DownloadCanceled('任务已取消')
        if self.fail is not None:
            raise self.fail
        Path(target).write_bytes(b'audio-bytes')
        return 11


# ============ 沙箱 ============

@pytest.fixture()
def sandbox(tmp_path, monkeypatch):
    """临时站点库 + 临时下载目录 + 空任务表 + 播客上游替身。"""
    db_path = tmp_path / 'site.db'
    monkeypatch.setattr(auth.db, 'DATA_DIR', tmp_path)
    monkeypatch.setattr(auth.db, 'DB_PATH', db_path)
    monkeypatch.setattr(auth.db, 'BACKUP_DIR', tmp_path / 'backups')
    monkeypatch.setattr(auth.db, 'SECRET_KEY_PATH', tmp_path / 'secret.key')
    monkeypatch.setattr(core_db, 'DATA_DIR', tmp_path)
    monkeypatch.setattr(core_db, 'DB_PATH', db_path)
    asyncio.run(auth.init_db())
    asyncio.run(auth.create_user('payer', PW, email='p@example.com', credits=CREDITS))

    downloads = tmp_path / 'downloads'
    downloads.mkdir()
    monkeypatch.setattr(api_service, 'downloads_path', downloads)
    monkeypatch.setattr(api_service, 'logger', _NullLogger())
    # 操作记录写进程内共享列表——隔离掉，断言改由个例捕获
    monkeypatch.setattr(podcast_svc, '_record_log', lambda *a: None)

    with DOWNLOAD_TASKS_LOCK:
        DOWNLOAD_TASKS.clear()
    yield {'root': tmp_path, 'downloads': downloads}
    with DOWNLOAD_TASKS_LOCK:
        DOWNLOAD_TASKS.clear()


# ============ 工具 ============

def _uid(username: str = 'payer') -> int:
    u = asyncio.run(auth.get_user_by_name(username))
    assert u is not None
    return int(u['id'])


def _balance(username: str = 'payer') -> int:
    u = asyncio.run(auth.get_user_by_name(username))
    assert u is not None
    return int(u['duration_seconds'] or 0)


def _status(task_id: str) -> str:
    with DOWNLOAD_TASKS_LOCK:
        return str(DOWNLOAD_TASKS.get(task_id, {}).get('status') or '')


def _register_podcast(sandbox, *, program_id: int = 777, user_id: int,
                      reserved: int = 1, **params: Any) -> tuple[str, dict[str, Any]]:
    tid = 'p' + str(int(time.time() * 1000000) % 10 ** 10)
    left = asyncio.run(auth.reserve_and_open(user_id, reserved, tid))
    assert left is not None, '预扣失败（余额不足，检查 fixture 的 credits）'
    task: dict[str, Any] = {
        'type': 'single', 'task_id': tid,
        'user_id': user_id, 'billing_user_id': user_id, 'billing_reserved': reserved,
        'total': 1, 'done': 0, 'failed': 0,
        'status': 'queued', 'start': time.time(), 'msg': '排队中...',
        'cancel': threading.Event(), 'pause': threading.Event(),
        'device_id': 'dev-test', 'result': None,
        'params': {
            'program_id': program_id, 'quality': 'standard',
            'need_zip': False, 'cookies': {}, 'remote_ip': '1.2.3.4',
            **params,
        },
    }
    with DOWNLOAD_TASKS_LOCK:
        DOWNLOAD_TASKS[tid] = task
    return tid, task


def _install_upstream(monkeypatch, *, program: dict[str, Any] | None = None,
                      url_info: dict[str, Any] | None = None,
                      stream: Any = None,
                      cover: Any = None) -> None:
    """装上播客上游替身（节目详情 / 直链 / 流式下载 / 封面）。"""
    async def _detail(pid: Any, cookies: Any) -> dict[str, Any]:
        return program if program is not None else _program()

    async def _resolve(sid: Any, cookies: Any, quality: str) -> dict[str, Any]:
        return url_info if url_info is not None else _url_info()

    monkeypatch.setattr(podcast_svc.podcast, 'get_program_detail', _detail)
    monkeypatch.setattr(podcast_svc.podcast, 'resolve_episode_url', _resolve)
    if cover is None:
        async def _default_cover(_url: str) -> bytes:
            return b'\xff\xd8\xff cover'
        cover = _default_cover
    if stream is None:
        stream = _FakeStream()
    monkeypatch.setattr(podcast_svc, '_podcast_stream_download', stream)
    monkeypatch.setattr(podcast_svc, 'fetch_cover_bytes', cover)


def _run(task_id: str) -> threading.Thread:
    """把 worker 协程跑在独立线程的私有事件循环里（等价于生产的任务循环）。"""
    def _target() -> None:
        asyncio.run(podcast_svc._podcast_download_worker(task_id))

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


def _zip_names(path: str) -> list[str]:
    with zipfile.ZipFile(path) as zf:
        return zf.namelist()


# ============ 正常路径 ============

def test_podcast_download_completes(sandbox, monkeypatch):
    """常规单集（不打包）：终态 done、音频落在任务目录、账本按交付结算、余额 -1。"""
    uid = _uid()
    before = _balance()
    _install_upstream(monkeypatch)
    tid, task = _register_podcast(sandbox, program_id=777, user_id=uid)

    th = _run(tid)
    th.join(timeout=30)
    assert not th.is_alive(), 'worker 未在 30s 内结束'

    assert _status(tid) == 'done', f"终态={_status(tid)} msg={task.get('msg')}"
    assert task['msg'] == '下载完成'
    assert task['done'] == 1 and task['completed_at'] > 0
    res = task['result']
    assert res is not None
    # 交付名干净（不带节目 ID），磁盘名带 [节目ID]
    assert res['filename'] == '003 - 第一集 测试.mp3'
    assert res['mimetype'] == 'audio/mp3'
    assert res['audio_files'] == [res['file_path']]
    assert 'zip_path' not in res

    delivered = Path(res['file_path'])
    assert delivered.exists()
    assert delivered.name == '003 - 第一集 测试 [777].mp3'
    assert delivered.parent == sandbox['downloads'] / 'tasks' / tid
    assert delivered.read_bytes() == b'audio-bytes'

    row = asyncio.run(auth.ledger_get(tid))
    assert row is not None and row['status'] != 'open'
    assert row['delivered'] == 1
    assert _balance() == before - 1, '交付成功：只扣预扣的 1 次，无退款'


def test_no_serial_prefix_when_serial_zero(sandbox, monkeypatch):
    """serial_num 缺失/为 0：文件名不带序号前缀，直接用单集名。"""
    uid = _uid()
    _install_upstream(monkeypatch, program=_program(serial_num=0))
    tid, task = _register_podcast(sandbox, user_id=uid)
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'done'
    assert task['result']['filename'] == '第一集 测试.mp3'


def test_ext_follows_url_info_type(sandbox, monkeypatch):
    """直链 type=m4a：交付名/磁盘名扩展名随之变化。"""
    uid = _uid()
    _install_upstream(monkeypatch, url_info=_url_info(type='m4a'))
    tid, task = _register_podcast(sandbox, user_id=uid)
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'done'
    res = task['result']
    assert res['filename'] == '003 - 第一集 测试.m4a'
    assert res['mimetype'] == 'audio/m4a'


def test_record_log_gets_episode_name(sandbox, monkeypatch):
    """成功交付后按单集名记一条操作记录（IP 取 params.remote_ip）。"""
    uid = _uid()
    logs: list[tuple] = []
    _install_upstream(monkeypatch)
    monkeypatch.setattr(podcast_svc, '_record_log', lambda *a: logs.append(a))
    tid, _ = _register_podcast(sandbox, user_id=uid)
    th = _run(tid)
    th.join(timeout=30)

    assert logs == [('下载', '1.2.3.4', '[播客] 第一集 测试')], logs


def test_remote_ip_defaults_when_missing(sandbox, monkeypatch):
    """params 无 remote_ip：按 '-' 记录，不因缺字段报错。"""
    uid = _uid()
    logs: list[tuple] = []
    _install_upstream(monkeypatch)
    monkeypatch.setattr(podcast_svc, '_record_log', lambda *a: logs.append(a))
    tid, task = _register_podcast(sandbox, user_id=uid)
    del task['params']['remote_ip']
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'done'
    assert logs == [('下载', '-', '[播客] 第一集 测试')], logs


def test_zip_contains_audio_cover_and_info(sandbox, monkeypatch):
    """need_zip=true：包内含音频 + 封面 + info.txt，result 走 zip 交付形状。"""
    uid = _uid()
    _install_upstream(monkeypatch)
    tid, task = _register_podcast(sandbox, user_id=uid, need_zip=True)
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'done', f"终态={_status(tid)} msg={task.get('msg')}"
    res = task['result']
    assert res is not None
    assert res['filename'] == '003 - 第一集 测试.zip'
    assert res['mimetype'] == 'application/zip'
    assert sorted(_zip_names(res['zip_path'])) == [
        '003 - 第一集 测试.jpg', '003 - 第一集 测试.mp3', 'info.txt']

    with zipfile.ZipFile(res['zip_path']) as zf:
        info = zf.read('info.txt').decode('utf-8')
    assert '单集: 第一集 测试' in info
    assert '播客: 测试电台' in info
    assert '主播: 主播甲' in info
    assert '时长: 10:00' in info
    assert '音质: ' in info
    # 音频正文同时留在任务目录（result.file_path 指向它）
    assert Path(res['file_path']).exists()


def test_zip_without_cover_when_cover_url_empty(sandbox, monkeypatch):
    """节目无 cover_url：ZIP 不含封面条目，其余照常（封面非交付必要条件）。"""
    uid = _uid()
    _install_upstream(monkeypatch, program=_program(cover_url=''))
    tid, task = _register_podcast(sandbox, user_id=uid, need_zip=True)
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'done'
    names = _zip_names(task['result']['zip_path'])
    assert not [n for n in names if n.endswith('.jpg')], names
    assert [n for n in names if n.endswith('.mp3')], names


def test_cover_fetch_failure_still_delivers_zip(sandbox, monkeypatch):
    """取封面抛异常：被吞掉，ZIP 照常交付（历史行为：封面失败不炸任务）。"""
    uid = _uid()

    async def _boom(url: str) -> bytes:
        raise RuntimeError('cover cdn down')

    _install_upstream(monkeypatch, cover=_boom)
    tid, task = _register_podcast(sandbox, user_id=uid, need_zip=True)
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'done', f"终态={_status(tid)} msg={task.get('msg')}"
    names = _zip_names(task['result']['zip_path'])
    assert not [n for n in names if n.endswith('.jpg')], names


# ============ 解析失败 ============

def test_missing_song_id_marks_error_and_refunds(sandbox, monkeypatch):
    """单集缺 main_song_id：转 error（文案透出）、退费、任务目录清理。"""
    uid = _uid()
    before = _balance()
    _install_upstream(monkeypatch, program=_program(main_song_id=None))
    tid, task = _register_podcast(sandbox, user_id=uid)

    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'error', f"终态={_status(tid)} msg={task.get('msg')}"
    assert task['msg'] == '该单集缺少音频信息（mainSong）'
    assert task['result'] is None
    assert _balance() == before, '失败应全额退回预扣'
    row = asyncio.run(auth.ledger_get(tid))
    assert row is not None and row['delivered'] == 0 and row['status'] != 'open'
    assert not (sandbox['downloads'] / 'tasks' / tid).exists(), '失败应清掉任务目录'


def test_no_url_marks_error_and_refunds(sandbox, monkeypatch):
    """直链解析为空（下架/版权）：转 error、退费、目录清理。"""
    uid = _uid()
    before = _balance()
    _install_upstream(monkeypatch, url_info=_url_info(url=''))
    tid, task = _register_podcast(sandbox, user_id=uid)
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'error'
    assert task['msg'] == '未获取到音频直链（单集可能已下架或受版权限制）'
    assert _balance() == before
    assert not (sandbox['downloads'] / 'tasks' / tid).exists()


def test_stream_failure_marks_error_and_refunds(sandbox, monkeypatch):
    """流式下载失败（如完整性不达标）：转 error、退费、目录清理。"""
    uid = _uid()
    before = _balance()
    _install_upstream(monkeypatch,
                      stream=_FakeStream(fail=DownloadException('下载不完整（5/11 字节）')))
    tid, task = _register_podcast(sandbox, user_id=uid)
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'error'
    assert task['msg'] == '下载不完整（5/11 字节）'
    assert _balance() == before
    assert not (sandbox['downloads'] / 'tasks' / tid).exists()


def test_unexpected_exception_uses_generic_message(sandbox, monkeypatch):
    """非预期异常：用户可见文案泛化（不泄上游细节），原文进日志、余额退回。"""
    uid = _uid()
    before = _balance()

    async def _boom(pid: Any, cookies: Any) -> dict[str, Any]:
        raise RuntimeError('upstream host=10.0.0.9 refused')

    _install_upstream(monkeypatch)
    monkeypatch.setattr(podcast_svc.podcast, 'get_program_detail', _boom)
    tid, task = _register_podcast(sandbox, user_id=uid)
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'error', f"终态={_status(tid)}"
    assert task['msg'] == '下载失败，请稍后重试'
    assert '10.0.0.9' not in task['msg'], '上游细节不得出现在用户可见文案里'
    assert _balance() == before
    assert not (sandbox['downloads'] / 'tasks' / tid).exists()


# ============ 取消 ============

def test_cancel_before_stream_start(sandbox, monkeypatch):
    """流式下载启动前取消已置位：canceled、退费、目录清理。"""
    uid = _uid()
    before = _balance()
    holder: dict[str, Any] = {}

    def _cancel_first():
        holder['task']['cancel'].set()

    _install_upstream(monkeypatch, stream=_FakeStream(on_call=_cancel_first))
    tid, task = _register_podcast(sandbox, user_id=uid)
    holder['task'] = task
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'canceled', f"终态={_status(tid)} msg={task.get('msg')}"
    assert task['result'] is None
    assert _balance() == before, '取消应全额退回预扣'
    assert not (sandbox['downloads'] / 'tasks' / tid).exists()


def test_cancel_after_download_before_publish(sandbox, monkeypatch):
    """下载已落盘但取消随即置位：不发布交付，转 canceled 并退费。"""
    uid = _uid()
    before = _balance()
    holder: dict[str, Any] = {}

    def _cancel_after():
        threading.Timer(0.0, lambda: holder['task']['cancel'].set()).start()

    _install_upstream(monkeypatch, stream=_FakeStream(on_call=_cancel_after))
    tid, task = _register_podcast(sandbox, user_id=uid)
    holder['task'] = task
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'canceled', f"终态={_status(tid)} msg={task.get('msg')}"
    assert task['result'] is None, '取消后不得发布交付'
    assert _balance() == before
    assert not (sandbox['downloads'] / 'tasks' / tid).exists()


def test_cancel_during_zip_stage(sandbox, monkeypatch):
    """打包阶段取消置位（封面回调里触发）：ZIP 不发布、canceled、退费。"""
    uid = _uid()
    before = _balance()
    holder: dict[str, Any] = {}

    async def _cancel_in_cover(url: str) -> bytes:
        holder['task']['cancel'].set()
        return b'\xff\xd8\xff cover'

    _install_upstream(monkeypatch, cover=_cancel_in_cover)
    tid, task = _register_podcast(sandbox, user_id=uid, need_zip=True)
    holder['task'] = task
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'canceled', f"终态={_status(tid)} msg={task.get('msg')}"
    assert task['result'] is None
    assert _balance() == before
    assert not (sandbox['downloads'] / 'tasks' / tid).exists()


def test_terminal_state_not_overwritten_by_late_success(sandbox, monkeypatch):
    """任务已被外部置终态（canceled）时，worker 的成功路径不得覆盖为 done。"""
    uid = _uid()
    before = _balance()
    holder: dict[str, Any] = {}

    def _mark_canceled():
        with DOWNLOAD_TASKS_LOCK:
            holder['task']['status'] = 'canceled'
            holder['task']['completed_at'] = time.time()

    _install_upstream(monkeypatch, stream=_FakeStream(on_call=_mark_canceled))
    tid, task = _register_podcast(sandbox, user_id=uid)
    holder['task'] = task
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'canceled', f"终态={_status(tid)}"
    assert task['result'] is None, '已终态不得被覆盖为 done'
    assert _balance() == before


# ============ 结算兜底 ============

def test_settle_failure_does_not_flip_done_to_error(sandbox, monkeypatch):
    """交付已落定后结算抛错：任务仍为 done（钱由重启对账兜底，不坑已付费用户）。"""
    uid = _uid()

    def _boom(*a: Any, **k: Any) -> None:
        raise RuntimeError('库锁超时')

    _install_upstream(monkeypatch)
    monkeypatch.setattr(podcast_svc.auth_system, 'ledger_settle', _boom)
    tid, task = _register_podcast(sandbox, user_id=uid)
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'done', f"终态={_status(tid)} msg={task.get('msg')}"
    assert task['result'] is not None


def test_ledger_open_when_worker_crashes_before_settle(sandbox, monkeypatch):
    """worker 在结算前崩掉：账本行仍为 open（留给重启对账兜底，不是静默丢失）。

    注意：光让 ledger_settle 抛错不够——成功路径对结算失败有 try/except 吞掉
    （上一条测试验证的行为）。必须让下载本身先抛非预期异常走进通用 except，
    连「退款结算」也没走成，账本才停留在 open。
    """
    uid = _uid()

    def _boom(*a: Any, **k: Any) -> None:
        raise RuntimeError('db busy')

    _install_upstream(monkeypatch,
                      stream=_FakeStream(fail=RuntimeError('boom')))
    monkeypatch.setattr(podcast_svc.auth_system, 'ledger_settle', _boom)
    tid, _task = _register_podcast(sandbox, user_id=uid)
    th = _run(tid)
    th.join(timeout=30)

    assert _status(tid) == 'error'
    row = asyncio.run(auth.ledger_get(tid))
    assert row is not None
    assert row['status'] == 'open', f"应留给对账兜底，实际 status={row['status']}"