// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import {LitElement, html, css} from 'lit-element';
import {ifDefined} from 'lit-html/directives/if-defined';
import {autolink} from 'autolink.js';
import {connectStore} from 'reducers/base.js';
import * as issueV0 from 'reducers/issueV0.js';
import * as projectV0 from 'reducers/projectV0.js';
import * as userV0 from 'reducers/userV0.js';
import {SHARED_STYLES, MD_STYLES} from 'shared/shared-styles.js';
import {shouldRenderMarkdown, renderMarkdown} from 'shared/md-helper.js';
import {unsafeHTML} from 'lit-html/directives/unsafe-html.js';

/**
 * `<mr-comment-content>`
 *
 * Displays text for a comment.
 *
 */
export class MrCommentContent extends connectStore(LitElement) {
  /** @override */
  constructor() {
    super();

    this.content = '';
    this.commentReferences = new Map();
    this.isDeleted = false;
    this.projectName = '';
    this.author = '';
    this.prefs = {};
  }

  /** @override */
  static get properties() {
    return {
      content: {type: String},
      commentReferences: {type: Object},
      revisionUrlFormat: {type: String},
      isDeleted: {
        type: Boolean,
        reflect: true,
      },
      projectName: {type: String},
      author: {type: String},
      prefs: {type: Object},
    };
  }

  /** @override */
  static get styles() {
    return [
      SHARED_STYLES,
      MD_STYLES,
      css`
        :host {
          word-break: break-word;
          font-size: var(--chops-main-font-size);
          line-height: 130%;
          font-family: var(--mr-toggled-font-family);
        }
        :host([isDeleted]) {
          color: #888;
          font-style: italic;
        }
        .line {
          white-space: pre-wrap;
        }
        .strike-through {
          text-decoration: line-through;
        }
      `,
    ];
  }

  /** @override */
  render() {
    if (shouldRenderMarkdown({project: this.projectName, author: this.author,
          enabled: this._renderMarkdown})) {
      return html`
        <link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet">
        <div class="markdown">
          ${unsafeHTML(renderMarkdown(this.content))}
        </div>
        `;
    }
    const runs = autolink.markupAutolinks(
        this.content, this.commentReferences, this.projectName,
        this.revisionUrlFormat);
    const templates = runs.map((run) => {
      switch (run.tag) {
        case 'b':
          return html`<b class="line">${run.content}</b>`;
        case 'br':
          return html`<br>`;
        case 'a':
          return html`<a
            class="line"
            target="_blank"
            href=${run.href}
            class=${run.css}
            title=${ifDefined(run.title)}
          >${run.content}</a>`;
        default:
          return html`<span class="line">${run.content}</span>`;
      }
    });
    return html`${templates}`;
  }

  /**
   * Helper to get state of Markdown rendering.
   * @return {boolean} Whether to render Markdown.
   */
  get _renderMarkdown() {
    const {prefs} = this;
    if (!prefs) return true;
    return prefs.get('render_markdown');
  }

  /** @override */
  stateChanged(state) {
    this.commentReferences = issueV0.commentReferences(state);
    this.projectName = issueV0.viewedIssueRef(state).projectName;
    this.revisionUrlFormat =
      projectV0.viewedPresentationConfig(state).revisionUrlFormat;
    this.prefs = userV0.prefs(state);
  }
}
customElements.define('mr-comment-content', MrCommentContent);