import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'airQualityIndex',
})
/**
 * Convert air quality index into readable data
 */
export class AirQualityIndexPipe implements PipeTransform {
  private airQualityCode = ['Good', 'Fair', 'Moderate', 'Poor', 'Very poor'];

  /**
   * Convert air quality index into readable data
   *
   * @param value of air quality index
   * @returns human readable air quality
   */
  transform(value: string | number | undefined): string {
    if (value === undefined || value === null) {
      return '';
    }

    return this.airQualityCode[+value];
  }
}