import { Editor, Plain } from 'slate'
import React from 'react'

/**
 * Define the default node type.
 */

const DEFAULT_NODE = 'paragraph'

/**
 * Define a schema.
 *
 * @type {Object}
 */

const schema = {
  nodes: {
    'block-quote': props => <blockquote {...props.attributes}>{props.children}</blockquote>,
    'bulleted-list': props => <ul {...props.attributes}>{props.children}</ul>,
    'heading-one': props => <h1 {...props.attributes}>{props.children}</h1>,
    'heading-two': props => <h2 {...props.attributes}>{props.children}</h2>,
    'list-item': props => <li {...props.attributes}>{props.children}</li>,
    'numbered-list': props => <ol {...props.attributes}>{props.children}</ol>,
  },
  marks: {
    bold: {
      fontWeight: 'bold'
    },
    code: {
      fontFamily: 'monospace',
      backgroundColor: '#eee',
      padding: '3px',
      borderRadius: '4px'
    },
    italic: {
      fontStyle: 'italic'
    },
    underlined: {
      textDecoration: 'underline'
    }
  }
}

/**
 * The rich text example.
 *
 * @type {Component}
 */

class SlateEditor extends React.Component {

  /**
   * Deserialize the initial editor state.
   *
   * @type {Object}
   */
  constructor(props) {
    super(props);
    this.state = {
      state: Plain.deserialize('')
    };
  }

  componentDidMount() {
    this.focus();
  }

  /**
   * Check if the current selection has a mark with `type` in it.
   *
   * @param {String} type
   * @return {Boolean}
   */

  hasMark = (type) => {
    const { state } = this.state
    return state.marks.some(mark => mark.type === type)
  }

  /**
   * Check if the any of the currently selected blocks are of `type`.
   *
   * @param {String} type
   * @return {Boolean}
   */

  hasBlock = (type) => {
    const { state } = this.state
    return state.blocks.some(node => node.type === type)
  }

  /**
   * On change, save the new state.
   *
   * @param {State} state
   */

  onChange = (state) => {
    this.setState({ state })
    if (typeof this.props.onChange === 'function') {
      this.props.onChange(state);
    }
  }

  asPlain = () => {
    return Plain.serialize(this.state.state);
  }

  clear = () => {
    const state = Plain.deserialize('');
    this.onChange(state);
  }

  focus = () => {
    this.refs.editor.focus();
  }

  /**
   * On key down, if it's a formatting command toggle a mark.
   *
   * @param {Event} e
   * @param {Object} data
   * @param {State} state
   * @return {State}
   */

  onKeyDown = (e, data, state) => {
    if (!data.isMod) return
    let mark

    switch (data.key) {
      case 'b':
        mark = 'bold'
        break
      case 'i':
        mark = 'italic'
        break
      case 'u':
        mark = 'underlined'
        break
      case '`':
        mark = 'code'
        break
      default:
        return
    }

    state = state
      .transform()
      .toggleMark(mark)
      .apply()

    e.preventDefault()
    return state
  }

  /**
   * When a mark button is clicked, toggle the current mark.
   *
   * @param {Event} e
   * @param {String} type
   */

  onClickMark = (e, type) => {
    e.preventDefault()
    let { state } = this.state

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

    this.setState({ state })
  }

  /**
   * When a block button is clicked, toggle the block type.
   *
   * @param {Event} e
   * @param {String} type
   */

  onClickBlock = (e, type) => {
    e.preventDefault()
    let { state } = this.state
    const transform = state.transform()
    const { document } = state

    // Handle everything but list buttons.
    if (type !== 'bulleted-list' && type !== 'numbered-list') {
      const isActive = this.hasBlock(type)
      const isList = this.hasBlock('list-item')

      if (isList) {
        transform
          .setBlock(isActive ? DEFAULT_NODE : type)
          .unwrapBlock('bulleted-list')
          .unwrapBlock('numbered-list')
      }

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

    // Handle the extra wrapping required for list buttons.
    else {
      const isList = this.hasBlock('list-item')
      const isType = state.blocks.some((block) => {
        return !!document.getClosest(block.key, parent => parent.type === type)
      })

      if (isList && isType) {
        transform
          .setBlock(DEFAULT_NODE)
          .unwrapBlock('bulleted-list')
          .unwrapBlock('numbered-list')
      } else if (isList) {
        transform
          .unwrapBlock(type === 'bulleted-list' ? 'numbered-list' : 'bulleted-list')
          .wrapBlock(type)
      } else {
        transform
          .setBlock('list-item')
          .wrapBlock(type)
      }
    }

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

  // /**
  //  *
  //  * @param {*Cosntructor} props
  //  */
  // componentWillMount() {
  //   const initialValue = Raw.deserialize(initialState, { terse: true });
  //   this.state = { state: initialValue};
  //   this.onChange(initialValue);
  // }

  /**
   * Render.
   *
   * @return {Element}
   */

  render = () => {
    return (
      <div>
        {this.renderToolbar()}
        {this.renderEditor()}
      </div>
    )
  }

  /**
   * Render the toolbar.
   *
   * @return {Element}
   */

  renderToolbar = () => {
    return (
      <div className="menu toolbar-menu">
        {this.renderMarkButton('bold', 'format_bold')}
        {this.renderMarkButton('italic', 'format_italic')}
        {this.renderMarkButton('underlined', 'format_underlined')}
        {this.renderMarkButton('code', 'code')}
        {this.renderBlockButton('heading-one', 'looks_one')}
        {this.renderBlockButton('heading-two', 'looks_two')}
        {this.renderBlockButton('block-quote', 'format_quote')}
        {this.renderBlockButton('numbered-list', 'format_list_numbered')}
        {this.renderBlockButton('bulleted-list', 'format_list_bulleted')}
      </div>
    )
  }

  /**
   * Render a mark-toggling toolbar button.
   *
   * @param {String} type
   * @param {String} icon
   * @return {Element}
   */

  renderMarkButton = (type, icon) => {
    const isActive = this.hasMark(type)
    const onMouseDown = e => this.onClickMark(e, type)

    return (
      <span className="button" onMouseDown={onMouseDown} data-active={isActive}>
        <span className="material-icons">{icon}</span>
      </span>
    )
  }

  /**
   * Render a block-toggling toolbar button.
   *
   * @param {String} type
   * @param {String} icon
   * @return {Element}
   */

  renderBlockButton = (type, icon) => {
    const isActive = this.hasBlock(type)
    const onMouseDown = e => this.onClickBlock(e, type)

    return (
      <span className="button" onMouseDown={onMouseDown} data-active={isActive}>
        <span className="material-icons">{icon}</span>
      </span>
    )
  }

  /**
   * Render the Slate editor.
   *
   * @return {Element}
   */

  renderEditor = () => {
    return (
      <div className="editor">
        <Editor
          ref="editor"
          spellCheck
          placeholder={'Enter some rich text...'}
          schema={schema}
          state={this.state.state}
          onChange={this.onChange}
          onKeyDown={this.onKeyDown}
        />
      </div>
    )
  }

}

/**
 * Export.
 */

export default SlateEditor