import { Injectable, UnauthorizedException } from '@nestjs/common';
import { PassportStrategy } from '@nestjs/passport';
import { Strategy } from 'passport-local';
import { AuthService } from '../auth.service';
import type { LoginUser } from '../types/auth-user';

@Injectable()
export class LocalStrategy extends PassportStrategy(Strategy) {
  constructor(private authService: AuthService) {
    super({ usernameField: 'username' });
  }

  async validate(username: string, password: string): Promise<LoginUser> {
    const user = await this.authService.validateUser(username, password);
    if (!user) {
      // T-02-01: Generic error message - never reveal whether username or password is wrong
      throw new UnauthorizedException('Invalid credentials');
    }
    return user;
  }
}