# -*- coding: utf-8 -*-
"""黄金契约回归：FastAPI 严格复现 Flask 时代的响应。

tests/golden/responses.json 是**删除 Flask 之前**从 Flask 应用捕获的快照
（状态码 + 响应体）。本测试让 FastAPI（根路径模式）跑同一批请求，
逐字段断言一致——这样删除 Flask 巨石后，行为回归仍有硬证据。

说明：
- 会话 Cookie 在运行时用当前库的 login_seq 动态构造（快照不存 Cookie）。
- 请求为只读/确定性调用，不含实时上游数据（那些由 parity/单测覆盖）。
"""
import hashlib
import json
import sqlite3
import time
from pathlib import Path

import pytest
from fastapi.testclient import TestClient

import auth_system
from core import session as cs

_GOLDEN = Path(__file__).parent / 'golden' / 'responses.json'
SECRET = 'golden-secret'


def _load_cases():
    return json.loads(_GOLDEN.read_text(encoding='utf-8'))


def _session_for(role):
    """按当前库中该角色用户的 login_seq 造一份合法会话 Cookie。"""
    conn = sqlite3.connect('data/site.db')
    conn.row_factory = sqlite3.Row
    try:
        where = "role = 'admin'" if role == 'admin' else "role != 'admin' AND status = 1"
        row = conn.execute(
            f'SELECT id, login_seq FROM users WHERE {where} AND login_seq IS NOT NULL LIMIT 1'
        ).fetchone()
    finally:
        conn.close()
    if row is None:
        return None
    return cs.dumps(SECRET, {
        'site_uid': int(row['id']), 'site_uid_seq': int(row['login_seq']),
        'site_uid_ts': int(time.time()),
    })


@pytest.fixture()
def client(tmp_path, monkeypatch):
    # 站点库仍用生产 data/site.db（只读），密钥 patch 成固定值以便造 Cookie
    monkeypatch.setattr('web.deps.secret_key', lambda: SECRET)
    monkeypatch.setattr(auth_system, 'get_secret_key', lambda: SECRET)
    from web.app import create_app
    return TestClient(create_app(api_prefix=''))


# 响应对比前剔除的易变字段（时钟）
_VOLATILE = {'timestamp'}


def _strip(obj):
    if isinstance(obj, dict):
        return {k: _strip(v) for k, v in obj.items() if k not in _VOLATILE}
    if isinstance(obj, list):
        return [_strip(v) for v in obj]
    return obj


def _request(client, method, path, payload, cookie):
    headers = {'Cookie': f'session={cookie}'} if cookie else {}
    if method == 'GET':
        return client.get(path, headers=headers)
    return client.post(path, json=payload or {}, headers=headers)


def test_golden_contract(client):
    """逐例复现 Flask 快照。"""
    cases = _load_cases()
    failures = []
    for c in cases:
        if c.get('html_len'):
            r = client.get(c['path'])
            if r.status_code != c['status'] or len(r.content) != c['html_len']:
                failures.append(f"{c['name']}: html {r.status_code}/{len(r.content)} "
                                f"!= {c['status']}/{c['html_len']}")
            continue
        cookie = None
        if c['auth'] == 'admin':
            cookie = _session_for('admin')
        elif c['auth'] == 'user':
            cookie = _session_for('user')
        r = _request(client, c['method'], c['path'], c['payload'], cookie)
        body = r.json() if r.headers.get('content-type', '').startswith('application/json') else None
        if r.status_code != c['status']:
            failures.append(f"{c['name']}: status {r.status_code} != {c['status']}")
        elif _strip(body) != _strip(c['body']):
            failures.append(f"{c['name']}: body\n  fastapi={body}\n  golden ={c['body']}")
    assert not failures, '黄金契约回归失败:\n' + '\n'.join(failures)


def test_index_html_stable(client):
    """首页渲染逐字节稳定（模板未改时）。"""
    cases = {c['name']: c for c in _load_cases()}
    c = cases['index']
    r = client.get('/')
    assert hashlib.sha256(r.content).hexdigest() == c['html_sha256']