import React from 'react';
import PropTypes from 'prop-types';

import SplitButton from 'react-bootstrap/es/SplitButton';
import MenuItem from 'react-bootstrap/es/MenuItem';

import * as toastr from 'toastr';

import HackmdEditor from './PageEditorByHackmd/HackmdEditor';

export default class PageEditorByHackmd extends React.PureComponent {

  constructor(props) {
    super(props);

    this.state = {
      markdown: this.props.markdown,
      isInitialized: false,
      isInitializing: false,
      initialRevisionId: this.props.revisionId,
      revisionId: this.props.revisionId,
      revisionIdHackmdSynced: this.props.revisionIdHackmdSynced,
      pageIdOnHackmd: this.props.pageIdOnHackmd,
      hasDraftOnHackmd: this.props.hasDraftOnHackmd,
    };

    this.getHackmdUri = this.getHackmdUri.bind(this);
    this.startToEdit = this.startToEdit.bind(this);
    this.resumeToEdit = this.resumeToEdit.bind(this);
    this.hackmdEditorChangeHandler = this.hackmdEditorChangeHandler.bind(this);

    this.apiErrorHandler = this.apiErrorHandler.bind(this);
  }

  componentWillMount() {
  }

  /**
   * return markdown document of HackMD
   * @return {Promise<string>}
   */
  getMarkdown() {
    if (!this.state.isInitialized) {
      return Promise.reject(new Error('HackmdEditor component has not initialized'));
    }

    return this.refs.hackmdEditor.getValue()
      .then(document => {
        this.setState({ markdown: document });
        return document;
      });
  }

  setMarkdown(markdown, updateEditorValue = true) {
    this.setState({ markdown });
    if (this.state.isInitialized && updateEditorValue) {
      this.refs.hackmdEditor.setValue(markdown);
    }
  }

  /**
   * reset initialized status
   */
  reset() {
    this.setState({ isInitialized: false });
  }

  /**
   * clear revision status (invoked when page is updated by myself)
   */
  clearRevisionStatus(updatedRevisionId, updatedRevisionIdHackmdSynced) {
    this.setState({
      initialRevisionId: updatedRevisionId,
      revisionId: updatedRevisionId,
      revisionIdHackmdSynced: updatedRevisionIdHackmdSynced,
      isDraftUpdatingInRealtime: false,
    });
  }

  /**
   * update revisionId of state
   * @param {string} revisionId
   * @param {string} revisionIdHackmdSynced
   */
  setRevisionId(revisionId, revisionIdHackmdSynced) {
    this.setState({ revisionId, revisionIdHackmdSynced });
  }

  getRevisionIdHackmdSynced() {
    return this.state.revisionIdHackmdSynced;
  }

  /**
   * update hasDraftOnHackmd of state
   * @param {bool} hasDraftOnHackmd
   */
  setHasDraftOnHackmd(hasDraftOnHackmd) {
    this.setState({ hasDraftOnHackmd });
  }

  getHackmdUri() {
    const envVars = this.props.crowi.config.env;
    return envVars.HACKMD_URI;
  }

  /**
   * Start integration with HackMD
   */
  startToEdit() {
    const hackmdUri = this.getHackmdUri();

    if (hackmdUri == null) {
      // do nothing
      return;
    }

    this.setState({
      isInitialized: false,
      isInitializing: true,
    });

    const params = {
      pageId: this.props.pageId,
    };
    this.props.crowi.apiPost('/hackmd.integrate', params)
      .then(res => {
        if (!res.ok) {
          throw new Error(res.error);
        }

        this.setState({
          isInitialized: true,
          pageIdOnHackmd: res.pageIdOnHackmd,
          revisionIdHackmdSynced: res.revisionIdHackmdSynced,
        });
      })
      .catch(this.apiErrorHandler)
      .then(() => {
        this.setState({isInitializing: false});
      });
  }

  /**
   * Start to edit w/o any api request
   */
  resumeToEdit() {
    this.setState({isInitialized: true});
  }

  /**
   * Reset draft
   */
  discardChanges() {
    this.setState({hasDraftOnHackmd: false});
  }

  /**
   * onChange event of HackmdEditor handler
   */
  hackmdEditorChangeHandler(body) {
    const hackmdUri = this.getHackmdUri();

    if (hackmdUri == null) {
      // do nothing
      return;
    }

    // do nothing if contents are same
    if (this.props.markdown === body) {
      return;
    }

    const params = {
      pageId: this.props.pageId,
    };
    this.props.crowi.apiPost('/hackmd.saveOnHackmd', params)
      .then(res => {
        // do nothing
      })
      .catch(err => {
        // do nothing
      });
  }

  apiErrorHandler(error) {
    toastr.error(error.message, 'Error occured', {
      closeButton: true,
      progressBar: true,
      newestOnTop: false,
      showDuration: '100',
      hideDuration: '100',
      timeOut: '3000',
    });
  }

  render() {
    const hackmdUri = this.getHackmdUri();

    const isPageExistsOnHackmd = (this.state.pageIdOnHackmd != null);
    const isResume = isPageExistsOnHackmd && this.state.hasDraftOnHackmd;

    if (this.state.isInitialized) {
      return (
        <HackmdEditor
          ref='hackmdEditor'
          hackmdUri={hackmdUri}
          pageIdOnHackmd={this.state.pageIdOnHackmd}
          initializationMarkdown={isResume ? null : this.state.markdown}
          onChange={this.hackmdEditorChangeHandler}
          onSaveWithShortcut={(document) => {
            this.props.onSaveWithShortcut(document);
          }}
        >
        </HackmdEditor>
      );
    }

    const isRevisionOutdated = this.state.initialRevisionId !== this.state.revisionId;
    const isHackmdDocumentOutdated = this.state.revisionId !== this.state.revisionIdHackmdSynced;

    let content = undefined;
    /*
     * HackMD is not setup
     */
    if (hackmdUri == null) {
      content = (
        <div>
          <p className="text-center hackmd-status-label"><i className="fa fa-file-text"></i> HackMD is not set up.</p>
        </div>
      );
    }
    /*
     * Resume to edit or discard changes
     */
    else if (isResume) {
      const revisionIdHackmdSynced = this.state.revisionIdHackmdSynced;
      const title = (
        <React.Fragment>
          <span className="btn-label"><i className="icon-control-end"></i></span>
          Resume to edit with HackMD
        </React.Fragment>);
      content = (
        <div>
          <p className="text-center hackmd-status-label"><i className="fa fa-file-text"></i> HackMD is READY!</p>
          <div className="text-center hackmd-resume-button-container mb-3">
            <SplitButton id='split-button-resume-hackmd' title={title} bsStyle="success" bsSize="large"
                className="btn-resume waves-effect waves-light" onClick={() => this.resumeToEdit()}>
              <MenuItem className="text-center" onClick={() => this.discardChanges()}>
                <i className="icon-control-rewind"></i> Discard changes
              </MenuItem>
            </SplitButton>
          </div>
          <p className="text-center">
            Click to edit from the previous continuation<br />
            or <button className="btn btn-link text-danger p-0 hackmd-discard-button" onClick={() => this.discardChanges()}>Discard changes</button>.
          </p>
          { isHackmdDocumentOutdated &&
            <div className="panel panel-warning mt-5">
              <div className="panel-heading"><i className="icon-fw icon-info"></i> DRAFT MAY BE OUTDATED</div>
              <div className="panel-body text-center">
                The current draft on HackMD is based on&nbsp;
                <a href={`?revision=${revisionIdHackmdSynced}`}><span className="label label-default">{revisionIdHackmdSynced.substr(-8)}</span></a>.<br />
                <button className="btn btn-link text-danger p-0 hackmd-discard-button" onClick={() => this.discardChanges()}>Discard it</button> to start to edit with current revision.
              </div>
            </div>
          }
        </div>
      );
    }
    /*
     * Start to edit
     */
    else {
      content = (
        <div>
          <p className="text-center hackmd-status-label"><i className="fa fa-file-text"></i> HackMD is READY!</p>
          <div className="text-center hackmd-start-button-container mb-3">
            <button className="btn btn-info btn-lg waves-effect waves-light" type="button" disabled={isRevisionOutdated || this.state.isInitializing}
                onClick={() => this.startToEdit()}>
              <span className="btn-label"><i className="icon-paper-plane"></i></span>
              Start to edit with HackMD
            </button>
          </div>
          <p className="text-center">Click to clone page content and start to edit.</p>
        </div>
      );
    }

    return (
      <div className="hackmd-preinit d-flex justify-content-center align-items-center">
        {content}
      </div>
    );
  }
}

PageEditorByHackmd.propTypes = {
  crowi: PropTypes.object.isRequired,
  markdown: PropTypes.string.isRequired,
  onSaveWithShortcut: PropTypes.func.isRequired,
  pageId: PropTypes.string,
  revisionId: PropTypes.string,
  pageIdOnHackmd: PropTypes.string,
  revisionIdHackmdSynced: PropTypes.string,
  hasDraftOnHackmd: PropTypes.bool,
};
