import React, { Component } from 'react';
import logo from './logo.svg';
import './App.css';

function CategoryFlatList(props) {
  const { error, isLoaded, items } = props.state;
  var content;
  if (error) {
    content = <div>Error: {error.message}</div>
  } else if (!isLoaded) {
    content = <div>Loading</div>
  } else {
    content = (
        <select size="10" defaultValue="" onChange={props.onChange}>
        <option value="">[ANY]</option>
        {items.map(item => (
            <option key={item.item} value={item.item}>{item.item} - {item.count}</option>
        ))}
      </select>
    );
  }
  return (
      <div className="category-list">
      <h2>{props.title}</h2>
      {content}
    </div>
  );
}

function formatDuration(duration) {
  var seconds = duration % 60;
  const minutes = Math.floor(duration / 60);
  if (seconds < 10) {
    seconds = '0' + seconds;
  }
  return minutes + ':' + seconds;
}

function mapAlbums(items) {
  var artists = [], curArtist = {}, curType = {};
  for (const album of items) {
    if (album.artist !== curArtist.name) {
      curArtist = {name: album.artist, types: []}
      curType = {}
      artists.push(curArtist)
    }
    if (album.type !== curType.type) {
      curType = {type: album.type, albums: []}
      curArtist.types.push(curType)
    }
    curType.albums.push(album);
  }
  return artists;
}

function AlbumList(props) {
  const { error, isLoaded, items } = props.state;

  var content;
  if (error) {
    content = <div>Error: {error.message}</div>
  } else if (!isLoaded) {
    content = <div>Loading</div>
  } else {
    const artists = mapAlbums(items);

    content = artists.map(artist => (
      <div key={artist.name}>
        <h3>{artist.name}</h3>
        {artist.types.map(type => (
          <div key={type.type}>
            <h4>{type.type}</h4>
            <table><tbody>
            {type.albums.map(album => (
              <tr key={album.id}>
                <td><img src={album.cover} alt={album.album} /></td>
                <td>{album.year}</td>
                <td>{album.album}</td>
                <td>{album.publisher}</td>
                <td>{album.country}</td>
                <td>{album.genre}</td>
                <td>{album.track_count}</td>
                <td>{formatDuration(album.total_duration)}</td>
              </tr>
            ))}
            </tbody></table>
          </div>
        ))}
      </div>
    ))
  }
  return (
    <div className="AlbumList">
      <h2>{props.title}</h2>
      {content}
    </div>
  );
}

class Player extends Component {
  stateLoading = {
    error: null,
    isLoaded: false,
    items: []
  };
  constructor(props) {
    super(props);
    this.categories = [{type: 'artist', title: 'Artists'},
                       {type: 'year', title: 'Years'},
                       {type: 'genre', title: 'Genres'},
                       {type: 'publisher', title: 'Labels'},
                       {type: 'country', title: 'Countries'},
                       {type: 'type', title: 'Album types'},
                       {type: 'status', title: 'Album statuses'}];
    this.state = {};
    for (var {type} of this.categories) {
      this.state[type] = Object.assign({}, this.stateLoading);
    }
    this.state.album = Object.assign({}, this.stateLoading);
    this.filterTimeout = null;
  }
  fetchCategory(cat) {
    const {restrictions, filter} = this.state;

    function getQueryString(params) {
      var esc = encodeURIComponent;
      return Object.keys(params)
        .map(k => esc(k) + '=' + esc(params[k]))
        .join('&');
    }
    var params = Object.assign({}, restrictions, {offset:0, limit:100});
    if (cat === 'album' && filter) {
      params.filter = filter;
    }
    const qs = getQueryString(params);

    fetch('/cat/' + cat + (qs ? ('?' + qs) : ''))
      .then(res => (res.ok ? res.json() : Promise.reject({message:res.statusText})))
      .then(result => {
        this.setState({[cat]: {
          isLoaded: true,
          items: result
        }});
      })
      .catch(error => {
        this.setState({[cat]: {
          isLoaded: true,
          error: error
        }});
      });
    this.setState({[cat]: Object.assign({}, this.stateLoading)});
  }
  fetchAll() {
    const {restrictions} = this.state;
    console.log(restrictions);
    this.categories.map(({type}) => !restrictions[type] && this.fetchCategory(type))
    this.fetchCategory('album');
  }
  componentDidMount() {
    this.setState({restrictions: {}});
  }
  componentDidUpdate(prevProps, prevState) {
    console.log('stateChange');
    if (this.state.restrictions !== prevState.restrictions) {
      // Reload category filters on restriction changes
      this.fetchAll();
    } else if (this.state.filter !== prevState.filter) {
      this.fetchCategory('album');
    }
  }
  handleCategoryChange(type, value) {
    console.log(type, value);
    var restrictions = Object.assign({}, this.state.restrictions);
    if (value) {
      restrictions[type] = value;
    } else {
      delete restrictions[type];
    }
    this.setState({restrictions: restrictions});
  }
  handleFilterChange = (e) => {
    if (this.filterTimeout) {
      clearInterval(this.filterTimeout);
    }
    const value = e.target.value;
    this.filterTimeout = setTimeout(() => this.setState({filter:value}), 500);
  }
  render() {
    return (
      <div className="Player">
        <div className="PlayerFilters">
        {this.categories.map(({type, title}) => (
          <CategoryFlatList key={type} title={title} state={this.state[type]} onChange={e => this.handleCategoryChange(type, e.target.value)}/>
        ))}
        </div><div style={{clear:'both', paddingBottom:'20px'}}/>
        <input type="text" placeholder="Search albums" onChange={this.handleFilterChange} size={150} />
        <AlbumList title="Albums" state={this.state.album} />
      </div>
    );
  }
}

class App extends Component {
  render() {
    return (
      <div className="App">
        <header className="App-header">
          <img src={logo} className="App-logo" alt="logo" />
          <h1 className="App-title">Chad Music</h1>
        </header>
        <Player />
      </div>
    );
  }
}

export default App;