import React from 'react';
import PropTypes from 'prop-types';
import { translate } from 'react-i18next';

import PageRevisionList from './PageHistory/PageRevisionList';

class PageHistory extends React.Component {

  constructor(props) {
    super(props);

    this.state = {
      revisions: [],
      diffOpened: {},
    };

    this.getPreviousRevision = this.getPreviousRevision.bind(this);
    this.onDiffOpenClicked = this.onDiffOpenClicked.bind(this);
  }

  componentDidMount() {
    const pageId = this.props.pageId;

    if (!pageId) {
      return;
    }

    this.props.crowi.apiGet('/revisions.ids', { page_id: pageId })
      .then((res) => {

        const rev = res.revisions;
        const diffOpened = {};
        const lastId = rev.length - 1;
        res.revisions.forEach((revision, i) => {
          const user = this.props.crowi.findUserById(revision.author);
          if (user) {
            rev[i].author = user;
          }

          if (i === 0 || i === lastId) {
            diffOpened[revision._id] = true;
          }
          else {
            diffOpened[revision._id] = false;
          }
        });

        this.setState({
          revisions: rev,
          diffOpened,
        });

        // load 0, and last default
        if (rev[0]) {
          this.fetchPageRevisionBody(rev[0]);
        }
        if (rev[1]) {
          this.fetchPageRevisionBody(rev[1]);
        }
        if (lastId !== 0 && lastId !== 1 && rev[lastId]) {
          this.fetchPageRevisionBody(rev[lastId]);
        }
      })
      .catch((err) => {
      // do nothing
      });
  }

  getPreviousRevision(currentRevision) {
    let cursor = null;
    for (const revision of this.state.revisions) {
      // comparing ObjectId
      // eslint-disable-next-line eqeqeq
      if (cursor && cursor._id == currentRevision._id) {
        cursor = revision;
        break;
      }

      cursor = revision;
    }

    return cursor;
  }

  onDiffOpenClicked(revision) {
    const diffOpened = this.state.diffOpened;
    const revisionId = revision._id;

    diffOpened[revisionId] = !(diffOpened[revisionId]);
    this.setState({
      diffOpened,
    });

    this.fetchPageRevisionBody(revision);
    this.fetchPageRevisionBody(this.getPreviousRevision(revision));
  }

  fetchPageRevisionBody(revision) {
    if (revision.body) {
      return;
    }

    this.props.crowi.apiGet('/revisions.get',
      { page_id: this.props.pageId, revision_id: revision._id })
      .then((res) => {
        if (res.ok) {
          this.setState({
            revisions: this.state.revisions.map((rev) => {
              // comparing ObjectId
              // eslint-disable-next-line eqeqeq
              if (rev._id == res.revision._id) {
                return res.revision;
              }

              return rev;
            }),
          });
        }
      })
      .catch((err) => {

      });
  }

  render() {
    return (
      <div>
        <PageRevisionList
          t={this.props.t}
          revisions={this.state.revisions}
          diffOpened={this.state.diffOpened}
          getPreviousRevision={this.getPreviousRevision}
          onDiffOpenClicked={this.onDiffOpenClicked}
        />
      </div>
    );
  }

}

PageHistory.propTypes = {
  t: PropTypes.func.isRequired, // i18next
  pageId: PropTypes.string,
  crowi: PropTypes.object.isRequired,
};

export default translate()(PageHistory);