// Copyright 2021 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import * as Host from '../../../core/host/host.js';
import {createFakeSetting, describeWithEnvironment} from '../../../testing/EnvironmentHelpers.js';

import * as ThemeSupport from './theme_support.js';

describeWithEnvironment('ThemeSupport', () => {
  let themeSupport: ThemeSupport.ThemeSupport;
  beforeEach(() => {
    const setting = createFakeSetting('theme', 'default');
    themeSupport = ThemeSupport.ThemeSupport.instance({forceNew: true, setting});
  });

  it('calls fetchColors on host ColorThemeChanged', async () => {
    const colorFetchSpy = sinon.spy(themeSupport, 'fetchColorsAndApplyHostTheme');

    Host.InspectorFrontendHost.InspectorFrontendHostInstance.events.dispatchEventToListeners(
        Host.InspectorFrontendHostAPI.Events.ColorThemeChanged);

    assert.isTrue(colorFetchSpy.called);
  });

  describe('fetchColors', () => {
    it('fetchColors updates color node url', () => {
      sinon.stub(Host.InspectorFrontendHost.InspectorFrontendHostInstance, 'isHostedMode').returns(false);
      const originalColorHref = 'devtools://theme/colors.css?sets=ui,chrome';

      const COLORS_CSS_SELECTOR = 'link[href*=\'//theme/colors.css\']';
      const doc = document.implementation.createHTMLDocument();
      const colorsLink = doc.createElement('link');
      colorsLink.href = originalColorHref;
      colorsLink.rel = 'stylesheet';
      doc.head.appendChild(colorsLink);

      themeSupport.addDocumentToTheme(doc);

      const updatedHref = doc.body.querySelector(COLORS_CSS_SELECTOR)!.getAttribute('href');
      assert.notEqual(updatedHref, originalColorHref);
    });
  });

  describe('getComputedValue', () => {
    class StyledComponent extends HTMLElement {
      #shadow = this.attachShadow({mode: 'open'});

      constructor() {
        super();

        this.#shadow.innerHTML = `<style>
          :host {
            --color-primary-old: red;
          }
          </style>`;
      }
    }

    before(() => {
      customElements.define('test-styled-component', StyledComponent);
    });

    afterEach(() => {
      document.body.removeChildren();
    });

    it('obtains computed values correctly (document)', () => {
      assert.isNotEmpty(themeSupport.getComputedValue('--color-primary-old'));
    });

    it('obtains computed values correctly (element)', () => {
      const element = new StyledComponent();
      document.body.appendChild(element);

      const documentValue = themeSupport.getComputedValue('--color-primary-old');
      const elementValue = themeSupport.getComputedValue('--color-primary-old', element);
      assert.isNotEmpty(elementValue);
      assert.notStrictEqual(documentValue, elementValue);
    });

    it('caches computed values (document)', () => {
      const documentValue = themeSupport.getComputedValue('--color-primary-old');

      // Update the styles by adding a new style tag, and confirm that the old
      // value is still returned.
      const newStyle = document.createElement('style');
      newStyle.textContent = ':root { --color-primary-old: green; }';
      document.head.appendChild(newStyle);

      const updatedDocumentValue = themeSupport.getComputedValue('--color-primary-old');
      newStyle.remove();

      assert.strictEqual(documentValue, updatedDocumentValue);
    });

    it('caches computed values (element)', () => {
      const element = new StyledComponent();
      document.body.appendChild(element);

      const elementValue = themeSupport.getComputedValue('--color-primary-old', element);
      assert.isNotEmpty(elementValue);

      // Update the styles by adding a new style tag, and confirm that the old
      // value is still returned.
      const newStyle = document.createElement('style');
      newStyle.textContent = ':root { --color-primary-old: green; }';

      element.shadowRoot!.appendChild(newStyle);
      const updatedElementValue = themeSupport.getComputedValue('--color-primary-old', element);

      assert.strictEqual(elementValue, updatedElementValue);
    });

    it('does not caches empty computed values (element)', () => {
      const documentValue = themeSupport.getComputedValue('--test-value');

      // Update the styles by adding a new style tag, and confirm that the old
      // value is still returned.
      const newStyle = document.createElement('style');
      newStyle.textContent = ':root { --test-value: green; }';
      document.head.appendChild(newStyle);

      const updatedDocumentValue = themeSupport.getComputedValue('--test-value', document.body);
      newStyle.remove();

      assert.isEmpty(documentValue);
      assert.isNotEmpty(updatedDocumentValue);
      assert.notStrictEqual(documentValue, updatedDocumentValue);
    });
  });
});