import { Injectable, UnauthorizedException } from '@nestjs/common';
import { JwtService } from '@nestjs/jwt';
import { Repository } from 'typeorm';
import { InjectRepository } from '@nestjs/typeorm';
import * as bcrypt from 'bcrypt';
import { User } from 'src/modules/users/entities/user.entity';

@Injectable()
export class AuthService {
  constructor(
    @InjectRepository(User) private readonly userRepository: Repository<User>,
    private readonly jwtService: JwtService,
  ) {}

  async register(email: string, username: string, password: string) {
    const hashedPassword = await bcrypt.hash(password, 10);
    const user = this.userRepository.create({ email, username, password: hashedPassword });
    await this.userRepository.save(user);
    const token = this.generateToken(user.id, user.email, user.role);
    return { user, token };
  }

  async login(email: string, password: string) {
    const user = await this.userRepository.findOne({ where: { email } });
    if (!user) throw new UnauthorizedException('Invalid credentials');

    const valid = await bcrypt.compare(password, user.password);
    if (!valid) throw new UnauthorizedException('Invalid credentials');

    const token = this.generateToken(user.id, user.email, user.role);
    return { user, token };
  }
  
  private generateToken(userId: number, email: string, role: string) {
    return this.jwtService.sign({ sub: userId, email, role });
  }
}