import {
  CallHandler,
  ExecutionContext,
  Injectable,
  NestInterceptor,
} from '@nestjs/common';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';
import * as bcrypt from 'bcrypt';

export async function hashPassword(password: string) {
  const salt = await bcrypt.genSalt();
  const passwordHash: string = await bcrypt.hash(password, salt);
  return passwordHash;
}

@Injectable()
export class PasswordToHashInterceptor implements NestInterceptor {
  async hashPasswordInRequest(req) {
    const password = req.body.password;
    if (password) {
      const passwordHash = await hashPassword(password);
      req.body.passwordHash = passwordHash;
    }
  }

  filterPasswordHashFromResponse(data) {
    delete data.passwordHash;
    return data;
  }

  async intercept(
    context: ExecutionContext,
    next: CallHandler,
  ): Promise<Observable<any>> {
    const req = context.switchToHttp().getRequest();
    await this.hashPasswordInRequest(req);
    return next.handle().pipe(map(this.filterPasswordHashFromResponse));
  }
}