import React, { PropTypes } from 'react';
import _ from 'lodash';
import { Editor, Raw } from 'slate';
import PluginDropImages from 'slate-drop-or-paste-images';
import MarkupIt, { SlateUtils } from 'markup-it';
import MediaProxy from '../../../../valueObjects/MediaProxy';
import { emptyParagraphBlock, mediaproxyBlock } from '../constants';
import { DEFAULT_NODE, SCHEMA } from './schema';
import { getNodes, getSyntaxes, getPlugins } from '../../richText';
import StylesMenu from './StylesMenu';
import BlockTypesMenu from './BlockTypesMenu';

/**
 * Slate Render Configuration
 */
export default class VisualEditor extends React.Component {

  static propTypes = {
    onChange: PropTypes.func.isRequired,
    onAddMedia: PropTypes.func.isRequired,
    getMedia: PropTypes.func.isRequired,
    value: PropTypes.string,
  };

  constructor(props) {
    super(props);

    const MarkdownSyntax = getSyntaxes(this.getMedia).markdown;
    this.markdown = new MarkupIt(MarkdownSyntax);

    SCHEMA.nodes = _.merge(SCHEMA.nodes, getNodes());

    this.blockEdit = false;

    let rawJson;
    if (props.value !== undefined) {
      const content = this.markdown.toContent(props.value);
      rawJson = SlateUtils.encode(content, null, ['mediaproxy'].concat(getPlugins().map(plugin => plugin.id)));
    } else {
      rawJson = emptyParagraphBlock;
    }
    this.state = {
      state: Raw.deserialize(rawJson, { terse: true }),
    };

    this.plugins = [
      PluginDropImages({
        applyTransform: (transform, file) => {
          const mediaProxy = new MediaProxy(file.name, file);
          props.onAddMedia(mediaProxy);
          return transform
            .insertBlock(mediaproxyBlock(mediaProxy));
        },
      }),
    ];
  }

  getMedia = (src) => {
    return this.props.getMedia(src);
  };

  /**
   * Slate keeps track of selections, scroll position etc.
   * So, onChange gets dispatched on every interaction (click, arrows, everything...)
   * It also have an onDocumentChange, that get's dispatched only when the actual
   * content changes
   */
  handleChange = (state) => {
    if (this.blockEdit) {
      this.blockEdit = false;
    } else {
      this.setState({ state });
    }
  };

  handleDocumentChange = (document, state) => {
    const rawJson = Raw.serialize(state, { terse: true });
    const content = SlateUtils.decode(rawJson);
    this.props.onChange(this.markdown.toText(content));
  };

  /**
   * Toggle marks / blocks when button is clicked
   */
  handleMarkStyleClick = (type) => {
    let { state } = this.state;

    state = state
      .transform()
      .toggleMark(type)
      .apply();

    this.setState({ state });
  };

  handleBlockStyleClick = (type, isActive, isList) => {
    let { state } = this.state;
    let transform = state.transform();
    const { document } = state;

    // Handle everything but list buttons.
    if (type != 'unordered_list' && type != 'ordered_list') {
      if (isList) {
        transform = transform
          .setBlock(isActive ? DEFAULT_NODE : type)
          .unwrapBlock('unordered_list')
          .unwrapBlock('ordered_list');
      }

      else {
        transform = transform
          .setBlock(isActive ? DEFAULT_NODE : type);
      }
    }

    // Handle the extra wrapping required for list buttons.
    else {
      const isType = state.blocks.some((block) => {
        return !!document.getClosest(block, parent => parent.type == type);
      });

      if (isList && isType) {
        transform = transform
          .setBlock(DEFAULT_NODE)
          .unwrapBlock('unordered_list');
      } else if (isList) {
        transform = transform
          .unwrapBlock(type == 'unordered_list')
          .wrapBlock(type);
      } else {
        transform = transform
          .setBlock('list_item')
          .wrapBlock(type);
      }
    }

    state = transform.apply();
    this.setState({ state });
  };

  /**
   * When clicking a link, if the selection has a link in it, remove the link.
   * Otherwise, add a new link with an href and text.
   *
   * @param {Event} e
   */

  handleInlineClick = (type, isActive) => {
    let { state } = this.state;

    if (type === 'link') {
      if (!state.isExpanded) return;

      if (isActive) {
        state = state
          .transform()
          .unwrapInline('link')
          .apply();
      }

      else {
        const href = window.prompt('Enter the URL of the link:', 'http://www.'); // eslint-disable-line
        state = state
          .transform()
          .wrapInline({
            type: 'link',
            data: { href },
          })
          .collapseToEnd()
          .apply();
      }
    }
    this.setState({ state });
  };

  handleBlockTypeClick = (type) => {
    let { state } = this.state;

    state = state
      .transform()
      .insertBlock({
        type,
        isVoid: true,
      })
      .apply();

    this.setState({ state }, this.focusAndAddParagraph);
  };

  handlePluginClick = (type, data) => {
    let { state } = this.state;

    state = state
      .transform()
      .insertInline({
        type,
        data,
        isVoid: true,
      })
      .collapseToEnd()
      .insertBlock(DEFAULT_NODE)
      .focus()
      .apply();

    this.setState({ state });
  };

  handleImageClick = (mediaProxy) => {
    let { state } = this.state;
    this.props.onAddMedia(mediaProxy);

    state = state
      .transform()
      .insertBlock(mediaproxyBlock(mediaProxy))
      .apply();

    this.setState({ state });
  };

  focusAndAddParagraph = () => {
    const { state } = this.state;
    const blocks = state.document.getBlocks();
    const last = blocks.last();
    const normalized = state
      .transform()
      .focus()
      .collapseToEndOf(last)
      .splitBlock()
      .setBlock(DEFAULT_NODE)
      .apply({
        snapshot: false,
      });
    this.setState({ state: normalized });
  };

  handleKeyDown = (evt) => {
    if (evt.shiftKey && evt.key === 'Enter') {
      this.blockEdit = true;
      let { state } = this.state;
      state = state
        .transform()
        .insertText('\n')
        .apply();

      this.setState({ state });
    }
  };

  renderBlockTypesMenu = () => {
    const currentBlock = this.state.state.blocks.get(0);
    const isOpen = (this.props.value !== undefined && currentBlock.isEmpty && currentBlock.type !== 'horizontal-rule');

    return (
      <BlockTypesMenu
        isOpen={isOpen}
        plugins={getPlugins()}
        onClickBlock={this.handleBlockTypeClick}
        onClickPlugin={this.handlePluginClick}
        onClickImage={this.handleImageClick}
      />
    );
  };

  renderStylesMenu() {
    const { state } = this.state;
    const isOpen = !(state.isBlurred || state.isCollapsed);

    return (
      <StylesMenu
        isOpen={isOpen}
        marks={this.state.state.marks}
        blocks={this.state.state.blocks}
        inlines={this.state.state.inlines}
        onClickMark={this.handleMarkStyleClick}
        onClickInline={this.handleInlineClick}
        onClickBlock={this.handleBlockStyleClick}
      />
    );
  }

  render() {
    return (
      <div>
        {this.renderStylesMenu()}
        {this.renderBlockTypesMenu()}
        <Editor
          placeholder={'Enter some rich text...'}
          state={this.state.state}
          schema={SCHEMA}
          plugins={this.plugins}
          onChange={this.handleChange}
          onKeyDown={this.handleKeyDown}
          onDocumentChange={this.handleDocumentChange}
        />
      </div>
    );
  }
}