import { Injectable, Logger } from '@nestjs/common';
import { HttpService } from '@nestjs/axios';
import { ConfigService } from '@nestjs/config';
import { firstValueFrom } from 'rxjs';
import { IIdentityServiceClient } from '../../domain/services/leaderboard-calculation.service';

/**
 * Identity Service 客户端实现
 *
 * 从身份服务获取用户信息
 */
@Injectable()
export class IdentityServiceClient implements IIdentityServiceClient {
  private readonly logger = new Logger(IdentityServiceClient.name);
  private readonly baseUrl: string;

  constructor(
    private readonly httpService: HttpService,
    private readonly configService: ConfigService,
  ) {
    this.baseUrl = this.configService.get<string>('IDENTITY_SERVICE_URL', 'http://localhost:3001');
  }

  async getUserSnapshots(userIds: bigint[]): Promise<Map<string, {
    userId: bigint;
    nickname: string;
    avatar: string | null;
    accountNo: string | null;
  }>> {
    const result = new Map<string, {
      userId: bigint;
      nickname: string;
      avatar: string | null;
      accountNo: string | null;
    }>();

    if (userIds.length === 0) {
      return result;
    }

    try {
      const response = await firstValueFrom(
        this.httpService.post(`${this.baseUrl}/api/users/batch`, {
          userIds: userIds.map(id => id.toString()),
        }),
      );

      const users = response.data.data || [];
      for (const user of users) {
        result.set(user.userId.toString(), {
          userId: BigInt(user.userId),
          nickname: user.nickname || user.username || '用户' + user.userId.slice(-4),
          avatar: user.avatar || null,
          accountNo: user.accountNo || null,
        });
      }
    } catch (error) {
      this.logger.error('获取用户信息失败', error);
      // 为找不到的用户创建默认快照
      for (const userId of userIds) {
        if (!result.has(userId.toString())) {
          result.set(userId.toString(), {
            userId,
            nickname: '用户' + userId.toString().slice(-4),
            avatar: null,
            accountNo: null,
          });
        }
      }
    }

    return result;
  }
}