import React, { Children, cloneElement } from 'react';
import PropTypes from 'prop-types';
import { FormattedMessage } from 'react-intl';
import DocumentTitle from 'react-document-title';
import { getChildren } from 'jsonml.js/lib/utils';
import { Timeline, Alert, Affix } from 'antd';
import EditButton from './EditButton';

export default class Article extends React.Component {
  static contextTypes = {
    intl: PropTypes.object.isRequired,
  };

  shouldComponentUpdate(nextProps) {
    const { location } = this.props;
    const { location: nextLocation } = nextProps;

    if (nextLocation.pathname === location.pathname) {
      return false;
    }
    return true;
  }

  onResourceClick = e => {
    if (!window.gtag) {
      return;
    }
    const cardNode = e.target.closest('.resource-card');
    if (cardNode) {
      window.gtag('event', 'resource', {
        event_category: 'Download',
        event_label: cardNode.href,
      });
    }
    if (
      window.location.href.indexOf('docs/react/recommendation') > 0 &&
      e.target.matches('.markdown > table td > a[href]')
    ) {
      window.gtag('event', 'recommendation', {
        event_category: 'Click',
        event_label: e.target.href,
      });
    }
  };

  getArticle(article) {
    const { content } = this.props;
    const { meta } = content;
    if (!meta.timeline) {
      return article;
    }
    const timelineItems = [];
    let temp = [];
    let i = 1;
    Children.forEach(article.props.children, child => {
      if (child.type === 'h2' && temp.length > 0) {
        timelineItems.push(<Timeline.Item key={i}>{temp}</Timeline.Item>);
        temp = [];
        i += 1;
      }
      temp.push(child);
    });
    if (temp.length > 0) {
      timelineItems.push(<Timeline.Item key={i}>{temp}</Timeline.Item>);
    }
    return cloneElement(article, {
      children: <Timeline>{timelineItems}</Timeline>,
    });
  }

  render() {
    const { props } = this;
    const { content } = props;
    const { meta, description } = content;
    const { title, subtitle, filename } = meta;
    const {
      intl: { locale },
    } = this.context;
    const isNotTranslated = locale === 'en-US' && typeof title === 'object';
    return (
      <DocumentTitle title={`${title[locale] || title} - Ant Design`}>
        {/* eslint-disable-next-line */}
        <article className="markdown" onClick={this.onResourceClick}>
          {isNotTranslated && (
            <Alert
              type="warning"
              message={
                <span>
                  This article has not been translated yet. Wanna help us out?&nbsp;
                  <a href="https://github.com/ant-design/ant-design/issues/1471">
                    See this issue on GitHub.
                  </a>
                </span>
              }
            />
          )}
          <h1>
            {title[locale] || title}
            {!subtitle || locale === 'en-US' ? null : <span className="subtitle">{subtitle}</span>}
            <EditButton
              title={<FormattedMessage id="app.content.edit-page" />}
              filename={filename}
            />
          </h1>
          {!description
            ? null
            : props.utils.toReactComponent(
                ['section', { className: 'markdown' }].concat(getChildren(description)),
              )}
          {!content.toc || content.toc.length <= 1 || meta.toc === false ? null : (
            <Affix className="toc-affix" offsetTop={16}>
              {props.utils.toReactComponent(
                ['ul', { className: 'toc' }].concat(getChildren(content.toc)),
              )}
            </Affix>
          )}
          {this.getArticle(
            props.utils.toReactComponent(
              ['section', { className: 'markdown' }].concat(getChildren(content.content)),
            ),
          )}
          {props.utils.toReactComponent(
            [
              'section',
              {
                className: 'markdown api-container',
              },
            ].concat(getChildren(content.api || ['placeholder'])),
          )}
        </article>
      </DocumentTitle>
    );
  }
}