import React from "react";
import PropTypes from "prop-types";
import { Motion, spring } from "react-motion";
import { Switch, Route, Link, withRouter } from "react-router-dom";
import WindowSize from "./WindowSize";
import About from "./About";
import Stats from "./Stats";
import Home from "./Home";

class Layout extends React.Component {
  static propTypes = {
    location: PropTypes.object,
    children: PropTypes.node
  };

  state = {
    underlineLeft: 0,
    underlineWidth: 0,
    useSpring: false,
    stats: null
  };

  adjustUnderline = (useSpring = false) => {
    let itemIndex;
    switch (this.props.location.pathname) {
      case "/stats":
        itemIndex = 1;
        break;
      case "/about":
        itemIndex = 2;
        break;
      case "/":
      default:
        itemIndex = 0;
    }

    const itemNodes = this.listNode.querySelectorAll("li");
    const currentNode = itemNodes[itemIndex];

    this.setState({
      underlineLeft: currentNode.offsetLeft,
      underlineWidth: currentNode.offsetWidth,
      useSpring
    });
  };

  componentDidMount() {
    this.adjustUnderline();

    fetch("/_stats?period=last-month")
      .then(res => res.json())
      .then(stats => this.setState({ stats }));

    if (window.localStorage) {
      const savedStats = window.localStorage.savedStats;

      if (savedStats) this.setState({ stats: JSON.parse(savedStats) });

      window.onbeforeunload = () => {
        localStorage.savedStats = JSON.stringify(this.state.stats);
      };
    }
  }

  componentDidUpdate(prevProps) {
    if (prevProps.location.pathname !== this.props.location.pathname)
      this.adjustUnderline(true);
  }

  render() {
    const { underlineLeft, underlineWidth, useSpring } = this.state;

    const style = {
      left: useSpring
        ? spring(underlineLeft, { stiffness: 220 })
        : underlineLeft,
      width: useSpring ? spring(underlineWidth) : underlineWidth
    };

    return (
      <div>
        <WindowSize onChange={this.adjustUnderline} />
        <div className="wrapper">
          <header>
            <h1 className="layout-title">unpkg</h1>
            <nav className="layout-nav">
              <ol
                className="layout-nav-list"
                ref={node => (this.listNode = node)}
              >
                <li>
                  <Link to="/">Home</Link>
                </li>
                <li>
                  <Link to="/stats">Stats</Link>
                </li>
                <li>
                  <Link to="/about">About</Link>
                </li>
              </ol>
              <Motion
                defaultStyle={{ left: underlineLeft, width: underlineWidth }}
                style={style}
                children={style => (
                  <div
                    className="layout-nav-underline"
                    style={{
                      WebkitTransform: `translate3d(${style.left}px,0,0)`,
                      transform: `translate3d(${style.left}px,0,0)`,
                      width: style.width
                    }}
                  />
                )}
              />
            </nav>
          </header>
        </div>

        <Switch>
          <Route
            path="/stats"
            render={() => <Stats data={this.state.stats} />}
          />
          <Route path="/about" component={About} />
          <Route path="/" component={Home} />
        </Switch>
      </div>
    );
  }
}

export default withRouter(Layout);