/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

import { Rule, SchematicsException, Tree } from '@angular-devkit/schematics';
import {
  appendHtmlElementToHead,
  getProjectFromWorkspace,
  getProjectIndexFiles,
} from '@angular/cdk/schematics';
import { getWorkspace } from '@schematics/angular/utility/workspace';
import { Schema } from './schema';

/** Adds the Material Design fonts to the index HTML file. */
export function addFontsToIndex(options: Schema): Rule {
  return async (host: Tree) => {
    const workspace = await getWorkspace(host);
    const project = getProjectFromWorkspace(workspace, options.project);
    const projectIndexFiles = getProjectIndexFiles(project);
    if (!projectIndexFiles.length) {
      throw new SchematicsException('No project index HTML file could be found.');
    }

    const preconnect = `<link rel="preconnect" href="https://fonts.gstatic.com">`;
    const fonts = [
      'fonts/Material_Icons.css',
      'https://fonts.googleapis.com/icon?family=Material+Icons',
    ];

    projectIndexFiles.forEach(indexFilePath => {
      appendHtmlElementToHead(host, indexFilePath, preconnect);

      fonts.forEach(font => {
        appendHtmlElementToHead(host, indexFilePath, `<link href="${font}" rel="stylesheet">`);
      });
    });
  };
}