// custom-validation.pipe.ts
import { PipeTransform, Injectable, ArgumentMetadata } from '@nestjs/common';
import { CustomException } from './custom.exception';

@Injectable()
export class CustomValidationPipe implements PipeTransform {
  constructor(private readonly schema) {}

  transform(value: any, metadata: ArgumentMetadata) {
    const errors = this.validate(value, this.schema);
    if (errors.length) {
      throw new CustomException(errors);
    }

    return value;
  }

  validate(value: any, schema: any): string[] {
    const errors = [];
    for (const key in schema) {
      if (schema[key].includes('required') && !(key in value)) {
        errors.push(`${key} is required`);
      }
      if (
        schema[key].includes('alpha_only') &&
        typeof value[key] !== 'string'
      ) {
        errors.push(`${key} must be a string`);
      }
      if (
        schema[key].includes('digits_only') &&
        typeof value[key] !== 'number'
      ) {
        errors.push(`${key} must be a number`);
      }
    }

    return errors;
  }
}