import { Inject, Optional, Pipe, PipeTransform } from '@angular/core';
import { DEPLOY_URL } from './token';

/**
 * Normalizes the given url based on the `DEPLOY_URL` injection token.
 *
 * Usage Notes
 *
 * ```html
 * <img [src]="myUrl | talyNormalizeUrl" data-testid="image2" />
 * ```
 *
 * If `DEPLOY_URL` token is not provided, then the given value is returned as it is.
 * If `DEPLOY_URL` token is provided, then the url is intelligently prefixed with the given
 *  `DEPLOY_URL` dependent on the input.
 *
 * | DEPLOY_URL                       |Input                                |Output                                            |
 * |----------------------------------|-------------------------------------|--------------------------------------------------|
 * |`null`                            |`'assets/image1.png'`                |`'assets/image1.png'`                             |
 * |`'http://my-domain.com/my-prj'`   |`'assets/image1.png'`                |`'http://my-domain.com/my-prj/assets/image1.png'` |
 * |`'http://my-domain.com/my-prj'`   |`'./assets/image1.png'`              |`'http://my-domain.com/my-prj/assets/image1.png'` |
 * |`'http://my-domain.com/my-prj'`   |`'/assets/image1.png'`               |`'http://my-domain.com/assets/image1.png'`        |
 * |`'http://my-domain.com/my-prj'`   |`'http://cdn.com/assets/image1.png'` |`'http://cdn.com/assets/image1.png'`              |
 *
 */

@Pipe({
  name: 'talyNormalizeUrl'
})
export class NormalizeUrlPipe implements PipeTransform {
  constructor(@Optional() @Inject(DEPLOY_URL) private deployUrl: string | null) {}

  transform(value: string): string {
    if (!value) return value;

    return this.deployUrl ? new URL(value, this.deployUrl).toString() : value;
  }
}