# -*- coding: utf-8 -*-
"""下载/计费端点沙箱测试（不触碰生产 data/site.db）。

重点验证账本守恒：
- 未登录 401
- 无效歌曲 ID：400 且**预扣已退**（账本不留 open 行、余额不变）
- 次数不足：401/expired 且不建任务
- 批量超 500：400 且退款
- 参数校验失败各分支均按「只退 open 行」退费
"""
import pytest
from fastapi.testclient import TestClient

import auth_system as auth
import core.db as db

SECRET = 'download-test-secret'
PW = 'Passw0rd12'


@pytest.fixture()
def env(tmp_path, monkeypatch):
    db_path = tmp_path / 'site.db'
    monkeypatch.setattr(auth, 'DATA_DIR', tmp_path)
    monkeypatch.setattr(auth, 'DB_PATH', db_path)
    monkeypatch.setattr(auth, 'BACKUP_DIR', tmp_path / 'backups')
    monkeypatch.setattr(auth, 'SECRET_KEY_PATH', tmp_path / 'secret.key')
    monkeypatch.setattr(db, 'DATA_DIR', tmp_path)
    monkeypatch.setattr(db, 'DB_PATH', db_path)
    auth.init_db()
    # 单一密钥源：web 层统一经 web.deps.secret_key 取密钥（调用期解析），
    # patch 它即让登录签发与依赖校验同源
    monkeypatch.setattr('web.deps.secret_key', lambda: SECRET)

    # 造 3 次余额用户 + 0 次余额用户
    auth.create_user('payer', PW, email='p@example.com', credits=3)
    auth.create_user('broke', PW, email='b@example.com', credits=0)
    auth.create_user('rich', PW, email='r@example.com', credits=600)

    from web.app import create_app
    return TestClient(create_app())


def _login(env, username):
    """登录并返回 (cookie_value, body)。

    直接取 Set-Cookie 原始值并用 Cookie 头携带——httpx 的 cookie jar 会对含
    base64 padding('=') 的值加双引号，导致服务端签名解析失败（真实浏览器不会），
    故测试避开 jar。
    """
    r = env.post('/auth/login', json={'username': username, 'password': PW})
    assert r.status_code == 200, r.text
    raw = r.headers.get('set-cookie', '')
    cookie = ''
    for part in raw.split(';'):
        if part.strip().startswith('session='):
            cookie = part.strip()[len('session='):]
            break
    assert cookie, f'no session cookie in: {raw!r}'
    return cookie, r.json()


def _balance(username):
    u = auth.get_user_by_name(username)
    assert u is not None, f'用户 {username} 不存在，余额无从校验'
    return int(u['duration_seconds'] or 0)


def _open_ledger_rows():
    conn = auth.get_conn()
    rows = conn.execute("SELECT task_id, reserved, status FROM billing_ledger WHERE status='open'").fetchall()
    conn.close()
    return [dict(r) for r in rows]


def test_download_requires_login(env):
    r = env.post('/download', json={'id': '347230'})
    assert r.status_code == 401


def test_download_bad_id_refunds(env):
    ck, _ = _login(env, 'payer')
    H = {'Cookie': f'session={ck}'}
    before = _balance('payer')
    r = env.post('/download', json={'id': 'not-a-number'}, headers=H)
    assert r.status_code == 400
    assert '无效' in r.json()['message']
    # 预扣已退回，且无 open 账本行残留
    assert _balance('payer') == before
    assert _open_ledger_rows() == []


def test_download_bad_quality_refunds(env):
    ck, _ = _login(env, 'payer')
    H = {'Cookie': f'session={ck}'}
    before = _balance('payer')
    r = env.post('/download', json={'id': '347230', 'quality': 'nope'}, headers=H)
    assert r.status_code == 400
    assert _balance('payer') == before
    assert _open_ledger_rows() == []


def test_download_bad_format_refunds(env):
    ck, _ = _login(env, 'payer')
    H = {'Cookie': f'session={ck}'}
    before = _balance('payer')
    r = env.post('/download', json={'id': '347230', 'format': 'xml'}, headers=H)
    assert r.status_code == 400
    assert _balance('payer') == before


def test_download_insufficient_credits(env):
    ck, _ = _login(env, 'broke')
    H = {'Cookie': f'session={ck}'}
    r = env.post('/download', json={'id': '347230'}, headers=H)
    assert r.status_code == 401
    assert r.json().get('error_code') == 'expired'
    # 未开账
    assert _open_ledger_rows() == []


def test_batch_zip_too_many_refunds(env):
    # 需足够余额才能为「封顶 500」预扣成功，再验证 400 时把 500 全额退回
    ck, _ = _login(env, 'rich')
    H = {'Cookie': f'session={ck}'}
    before = _balance('rich')
    ids = ','.join(str(1000 + i) for i in range(501))
    r = env.post('/download/batch_zip', json={'ids': ids}, headers=H)
    assert r.status_code == 400
    assert '500' in r.json()['message']
    # 预扣（封顶 500）已全额退回，余额回到 600
    assert _balance('rich') == before
    assert _open_ledger_rows() == []


def test_batch_zip_missing_ids_refunds(env):
    ck, _ = _login(env, 'payer')
    H = {'Cookie': f'session={ck}'}
    before = _balance('payer')
    r = env.post('/download/batch_zip', json={}, headers=H)
    assert r.status_code == 400
    assert _balance('payer') == before