import { Injectable, UnauthorizedException } from '@nestjs/common';
import { JwtService } from '@nestjs/jwt';
import { UsersService } from '../users/users.service';
import * as bcrypt from 'bcryptjs';

@Injectable()
export class AuthService {
  constructor(
    private readonly usersService: UsersService,
    private readonly jwtService: JwtService,
  ) {}

  async register(username: string, password: string, name: string, email: string, roleId: string) {
    // 检查用户名是否已存在
    const existingUser = await this.usersService.findByUsername(username);
    if (existingUser) {
      throw new Error('Username already exists');
    }

    // 检查邮箱是否已存在
    const existingEmail = await this.usersService.findByEmail(email);
    if (existingEmail) {
      throw new Error('Email already exists');
    }

    // 哈希密码
    const hashedPassword = await bcrypt.hash(password, 10);

    // 创建用户
    const user = await this.usersService.create({
      username,
      password: hashedPassword,
      name,
      email,
      roleId,
    });

    return user;
  }

  async login(username: string, password: string) {
    // 查找用户
    console.log('Login attempt for user:', username);
    const user = await this.usersService.findByUsername(username);
    console.log('Found user:', user);
    if (!user) {
      throw new UnauthorizedException('Invalid credentials');
    }

    // 验证密码
    const isPasswordValid = await bcrypt.compare(password, user.password);
    console.log('Password valid:', isPasswordValid);
    if (!isPasswordValid) {
      throw new UnauthorizedException('Invalid credentials');
    }

    // 生成JWT token
    const payload = { sub: user.id, username: user.username, role: user.role.name };
    const token = this.jwtService.sign(payload);

    const response = {
      access_token: token,
      user: {
        id: user.id,
        username: user.username,
        name: user.name,
        email: user.email,
        role: user.role.name,
      },
    };
    console.log('Login response:', response);
    return response;
  }
}