var React = require('react')
var { PropTypes } = React
import markdown from '../lib/markdown'
var ReactDOM = require('react-dom')

const electron = require('electron')
const shell = electron.shell

function handleAnchorClick (e) {
  shell.openExternal(e.target.href)
  e.preventDefault()
}

export default class MarkdownPreview extends React.Component {
  componentDidMount () {
    this.addListener()
  }

  componentDidUpdate () {
    this.addListener()
  }

  componentWillUnmount () {
    this.removeListener()
  }

  componentWillUpdate () {
    this.removeListener()
  }

  addListener () {
    var anchors = ReactDOM.findDOMNode(this).querySelectorAll('a')

    for (var i = 0; i < anchors.length; i++) {
      anchors[i].addEventListener('click', handleAnchorClick)
    }
  }

  removeListener () {
    var anchors = ReactDOM.findDOMNode(this).querySelectorAll('a')

    for (var i = 0; i < anchors.length; i++) {
      anchors[i].removeEventListener('click', handleAnchorClick)
    }
  }

  handleClick (e) {
    if (this.props.onClick) {
      this.props.onClick(e)
    }
  }

  handleDoubleClick (e) {
    if (this.props.onDoubleClick) {
      this.props.onDoubleClick(e)
    }
  }

  render () {
    let isEmpty = this.props.content.trim().length === 0
    let content = isEmpty
      ? '(Empty content)'
      : this.props.content
    return (
      <div onDoubleClick={e => this.handleDoubleClick(e)} className={'MarkdownPreview' + (this.props.className != null ? ' ' + this.props.className : '') + (isEmpty ? ' empty' : '')} dangerouslySetInnerHTML={{__html: ' ' + markdown(content)}}/>
    )
  }
}

MarkdownPreview.propTypes = {
  onClick: PropTypes.func,
  onDoubleClick: PropTypes.func,
  className: PropTypes.string,
  content: PropTypes.string
}