import React, {Component} from 'react';
import ReactDOM from 'react-dom';
import PropTypes from 'prop-types';

export class HashRouter extends Component {
  constructor(props) {
    super(props);
    this.checkHash = this.checkHash.bind(this);
    this.selectRoute = this.selectRoute.bind(this);
    window.onhashchange = this.checkHash.bind(this);

    this.state = {
      currentComponent : null,
      currentProps : {}
    };
  }

  parseUrl(url) {
    var parts = url.split("#");
    return parts[1] || "";
  }

  selectRoute(route) {
    var currentConfig;

    if (route === "") {
      route = "empty";
    }

    var checkRoute = typeof this.props.config[route];

    if (checkRoute === 'undefined' && route === 'notfound') {
      // prevent resursive endless loop
      console.warn(`HashRouter: undefined 'notfound' route. define a notfound route in your config to handle unknown routes`);
      return;
    }

    if (checkRoute === 'undefined') {
      currentConfig = this.selectRoute('notfound')
    } else if (checkRoute === 'string') {
      currentConfig = this.props.config[this.props.config[route]];
    } else if (checkRoute === 'object') {
      currentConfig = this.props.config[route];
    }
    return currentConfig
  }

  checkHash(h) {
    var oldRoute, route;
    if (h) {
      oldRoute = this.parseUrl(h.oldURL);
      route = this.parseUrl(h.newURL);
    } else {
      oldRoute = "";
      route = document.location.hash.substring(1);
    }

    document.body.id = route || "home";
    var routeInfo = this.selectRoute(route);

    var newProps = Object.assign({}, routeInfo.props || {}, {
      prevRoute: oldRoute,
      route : route
    });

    this.setState({
      currentComponent : routeInfo.component,
      currentProps : newProps
    });
  }

  componentWillMount() {
    this.checkHash();
  }

  render() {
    let ThisComp = <div />;
    if (this.state.currentComponent) {
      ThisComp = this.state.currentComponent;
    }

    console.log(<ThisComp {...this.state.currentProps} />);
    return (
      <ThisComp {...this.state.currentProps} />
    )
  }
}

HashRouter.propTypes = {
  config: PropTypes.object.isRequired
};