import { CanActivate, ExecutionContext, Injectable, UnauthorizedException } from '@nestjs/common';
import admin from './firebase-admin';

@Injectable()
export class AuthGuard implements CanActivate {
  async canActivate(context: ExecutionContext): Promise<boolean> {
    const request = context.switchToHttp().getRequest<Request>();
    const token = this.extractTokenFromHeader(request);

    if (!token) {
      throw new UnauthorizedException('No token provided');
    }

    try {
      const decodedToken = await admin.auth().verifyIdToken(token);
      request['user'] = decodedToken; // Fügen Sie die Benutzerdaten dem Request-Objekt hinzu
      return true;
    } catch (error) {
      throw new UnauthorizedException('Invalid token');
    }
  }

  private extractTokenFromHeader(request: Request): string | undefined {
    const [type, token] = request.headers['authorization']?.split(' ') ?? [];
    return type === 'Bearer' ? token : undefined;
  }
}