import React from 'react';
import ReactDOM from 'react-dom';
import { Link } from 'react-router';
import { getTagName, getAttributes, getChildren, isElement } from 'jsonml.js/lib/utils';
import toReactComponent from 'jsonml-to-react-component';
import VideoPlayer from './VideoPlayer';
import ImagePreview from './ImagePreview';

function isHeading(type) {
  return /h[1-6]/i.test(type);
}

export function jsonmlToComponent(pathname, jsonml) {
  return toReactComponent(jsonml, [
    [(node) => React.isValidElement(node), (node, index) => {
      return React.cloneElement(node, { key: index });
    }],
    [(node) => typeof node === 'function', (node, index) => {
      return React.cloneElement(node(React, ReactDOM), { key: index });
    }],
    [(node) => isHeading(getTagName(node)), (node, index) => {
      const children = getChildren(node);
      return React.createElement(getTagName(node), {
        key: index,
        id: children,
        ...getAttributes(node),
      }, [
        <span key="title">{children.map((child) => toReactComponent(child))}</span>,
        <Link to={{ pathname, query: { scrollTo: children } }} className="anchor" key="anchor">#</Link>,
      ]);
    }],
    [(node) => getTagName(node) === 'pre' && getAttributes(node).highlighted, (node, index) => {
      return React.createElement('pre', { key: index, lang: getAttributes(node).lang }, React.createElement(
        'code',
        { dangerouslySetInnerHTML: { __html: getChildren(getChildren(node)[0])[0] } }
      ));
    }],
    [(node) => getTagName(node) === 'video', (node, index) =>
      <VideoPlayer video={getAttributes(node)} key={index} />
    ],
    [(node) => isElement(node) && getTagName(node) === 'a', (node, index) => {
      if (getAttributes(node).class ||
          (getAttributes(node).href && getAttributes(node).href.indexOf('http') === 0)) {
        return toReactComponent(node);
      }
      return <Link to={getAttributes(node).href} key={index}>{toReactComponent(getChildren(node)[0])}</Link>;
    }],
    [(node) => {
      return isElement(node) &&
        getTagName(node) === 'p' &&
        getTagName(getChildren(node)[0]) === 'img' &&
        /preview-img/gi.test(getAttributes(getChildren(node)[0]).class);
    }, (node, index) => {
      const imgs = getChildren(node)
              .filter((img) => isElement(img) && Object.keys(getAttributes(img)).length > 0)
              .map((img) => getAttributes(img));
      return <ImagePreview imgs={imgs} key={index} />;
    }],
  ]);
}

export function setTitle(title) {
  document.title = title;
}