homework/src/app/services/user.service.ts

// services/user.service.ts
import { Injectable } from '@angular/core';

@Injectable({
  providedIn: 'root'
})
export class UserService {
  private readonly STORAGE_KEY = 'registered_users';
   private readonly PROFILE_KEY = 'user_profiles';

  constructor() {}

  // 注册新用户
  async register(username: string, password: string): Promise<boolean> {
    const users = await this.getUsers();
    
    // 检查用户名是否已存在
    if (users.some(u => u.username === username)) {
      return false;
    }
    
    users.push({ username, password });
    localStorage.setItem(this.STORAGE_KEY, JSON.stringify(users));
    return true;
  }

  // 用户登录
  async login(username: string, password: string): Promise<boolean> {
  const users = await this.getUsers();
  const isLoggedIn = users.some(u => u.username === username && u.password === password);
  
  if (isLoggedIn) {
    localStorage.setItem('isLoggedIn', 'true');
    localStorage.setItem('currentUser', username); // 保存当前用户名
  }
  return isLoggedIn;
}

  // 获取所有用户
  private async getUsers(): Promise<any[]> {
    const usersStr = localStorage.getItem(this.STORAGE_KEY);
    return usersStr ? JSON.parse(usersStr) : [];
  }
    // 保存当前用户
  setCurrentUser(username: string): void {
    localStorage.setItem('currentUser', username);
    localStorage.setItem('isLoggedIn', 'true');
  }

  // 获取当前用户
  getCurrentUser(): string | null {
    return localStorage.getItem('currentUser');
  }

  // 清除当前用户
  clearCurrentUser(): void {
    localStorage.removeItem('currentUser');
    localStorage.removeItem('isLoggedIn');
  }

   // 保存用户资料
  async saveProfile(username: string, profileData: any): Promise<boolean> {
    const profiles = await this.getProfiles();
    const existingIndex = profiles.findIndex(p => p.username === username);
    
    if (existingIndex >= 0) {
      profiles[existingIndex] = { username, ...profileData };
    } else {
      profiles.push({ username, ...profileData });
    }
    
    localStorage.setItem(this.PROFILE_KEY, JSON.stringify(profiles));
    return true;
  }

  // 获取用户资料
  async getProfile(username: string): Promise<any> {
    const profiles = await this.getProfiles();
    return profiles.find(p => p.username === username) || {};
  }

  // 获取所有用户资料
  private async getProfiles(): Promise<any[]> {
    const profilesStr = localStorage.getItem(this.PROFILE_KEY);
    return profilesStr ? JSON.parse(profilesStr) : [];
  }
}