import { h, cloneElement, Component } from 'preact';

/**
 *  <Views view="home">
 *    <Home name="home" />
 *    <Other name="other" />
 *  </Views>
 */
class Views extends Component {
  state = {
    view: this.props.view,   // can pass default view in as a prop
    params: {}
  };

  // route to a given view
  route = (view, params) => {
    params = params || {};
    this.setState({ view, params });
  };

  componentWillReceiveProps({ view }) {
    if (view!==this.props.view) this.route(view);
  }

  // child components can call:  this.context.route('some-view');
  getChildContext() {
    return { route: this.route };
  }

  render({ children }, { view, params }) {
    // just render the child whose `name` prop matches the current view:
    let child = children.filter( child => child.attributes.name===view )[0];
    return child ? cloneElement(child, params) : null;
  }
}



/**
 *  <Link to="home">Home</Link>
 *  <Link to="foo" params={{ foo:'bar' }} />
 */
const Link = ({ to, params, ...props }, context) => (
  <a onClick={ () => context.route(to, params) } {...props} />
);