/// Widget/单元测试共用替身（P3 计划 Task 3）。
///
/// 与 test/core/api_client_test.dart 中的手写打桩同款：FakeAdapter 为
/// dio HttpClientAdapter，按路由分发预设响应并记录全部请求；未引入
/// http_mock_adapter（零额外 dev 依赖，打桩面完全可控）。
library;

import 'dart:async';
import 'dart:convert';

import 'package:dio/dio.dart';
import 'package:photo_live/core/session_store.dart';

/// 内存会话存储（测试替身）。
class FakeSessionStore implements SessionStore {
  Session? session;

  @override
  Future<Session?> read() async => session;

  @override
  Future<void> save(Session value) async => session = value;

  @override
  Future<void> clear() async => session = null;
}

/// 记录到适配器的请求快照。
class RecordedRequest {
  const RecordedRequest({
    required this.method,
    required this.path,
    required this.headers,
    required this.body,
  });

  final String method;
  final String path;
  final Map<String, dynamic> headers;
  final Object? body;
}

/// 手写 dio 打桩适配器：按路由分发预设响应并记录全部请求。
///
/// [router] 返回 `(status, body)`（可为 async 以模拟慢响应/加载态）；
/// body 为 null 表示无响应体（204）。
class FakeAdapter implements HttpClientAdapter {
  FakeAdapter(this.router);

  final FutureOr<(int, Object?)> Function(RequestOptions options) router;

  final List<RecordedRequest> requests = <RecordedRequest>[];

  @override
  Future<ResponseBody> fetch(
    RequestOptions options,
    Stream? requestStream,
    Future? cancelFuture,
  ) async {
    requests.add(
      RecordedRequest(
        method: options.method,
        path: options.path,
        headers: Map<String, dynamic>.from(options.headers),
        body: options.data,
      ),
    );
    final (status, body) = await router(options);
    if (body == null) {
      // 204 等：空体且不带 JSON content-type（transformer 不解码）。
      return ResponseBody.fromString('', status);
    }
    return ResponseBody.fromString(
      jsonEncode(body),
      status,
      headers: {
        Headers.contentTypeHeader: [Headers.jsonContentType],
      },
    );
  }

  @override
  void close({bool force = false}) {}
}

/// 常用响应体：登录成功（openapi LoginResponse 形状）。
Map<String, dynamic> loginOkBody({
  String token = 'tok-new',
  String expiresAt = '2026-09-20T12:00:00Z',
}) => <String, dynamic>{
        'sessionToken': token,
        'expiresAt': expiresAt,
      };

/// 常用响应体：契约 Error 形状。
Map<String, dynamic> errorBody(String code) => <String, dynamic>{
        'code': code,
        'message': 'stub message',
        'requestId': 'req-stub',
      };