import { Injectable } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import { PassportStrategy } from '@nestjs/passport';
import { Strategy } from 'passport-github2';
import { AuthService } from '../services/auth.service';

@Injectable()
export class GithubStrategy extends PassportStrategy(Strategy, 'github') {
  constructor(
    private readonly configService: ConfigService,
    private readonly authService: AuthService,
  ) {
    const clientID = configService.get<string>('GITHUB_CLIENT_ID') || 'dummy-client-id';
    const clientSecret = configService.get<string>('GITHUB_CLIENT_SECRET') || 'dummy-client-secret';
    const callbackURL = configService.get<string>('GITHUB_CALLBACK_URL') || 'http://localhost:3001/api/auth/github/callback';

    super({
      clientID,
      clientSecret,
      callbackURL,
      scope: ['user:email'],
    });
  }

  /**
   * Validate the GitHub profile and return the user
   */
  async validate(accessToken: string, refreshToken: string, profile: any) {
    // Extract user information from GitHub profile
    const { id, displayName, emails, photos } = profile;

    // Get primary email or first email
    const email = emails && emails.length > 0 
      ? (emails.find(e => e.primary)?.value || emails[0].value)
      : null;

    // Get avatar URL
    const avatarUrl = photos && photos.length > 0 ? photos[0].value : null;

    // Validate or create user
    const user = await this.authService.validateGithubUser(
      id,
      email,
      displayName || 'GitHub User',
      avatarUrl,
    );

    return user;
  }
}