import { valueConverter } from 'aurelia-binding';
import { inject } from 'aurelia-dependency-injection';
import { HTMLSanitizer } from './html-sanitizer';

/**
 * Simple html sanitization converter to preserve whitelisted elements and attributes on a bound property containing html.
 */
@valueConverter('sanitizeHTML')
@inject(HTMLSanitizer)
export class SanitizeHTMLValueConverter {
  /**@internal */
  sanitizer: HTMLSanitizer;
  /**
   * Creates an instanse of the value converter.
   * @param sanitizer The html sanitizer.
   */
  constructor(sanitizer: HTMLSanitizer) {
    this.sanitizer = sanitizer;
  }

  /**
   * Process the provided markup that flows to the view.
   * @param untrustedMarkup The untrusted markup to be sanitized.
   */
  toView(untrustedMarkup) {
    if (untrustedMarkup === null || untrustedMarkup === undefined) {
      return null;
    }

    return this.sanitizer.sanitize(untrustedMarkup);
  }
}