'use strict'

/*
A Library has a name and a creator (both strings)
These are the only things required in order to create a music library
A Library has many playlists (starts as an empty array)
Playlist objects can be added to an instance of a library
Each Playlist has a name which is required upon creation
A Playlist also has many tracks
A Track has a title, a rating (an integer from 1 to 5) and a length (integer in seconds) all of which are required when creating a new track
Each Playlist also has an overallRating function which will calculate the rating by averaging the rating of its tracks
Each Playlist also has a totalDuration function which will sum the duration of all of its tracks
*/

//A Library has a name and a creator (both strings)
class Library {
  constructor(name, creator) {
    this.name = name;
    this.creator = creator;
    //A Library has many playlists (starts as an empty array)
    this.playlists = [];
  }

  //Playlist objects can be added to an instance of a library
  addPlaylist(playlist) {
    if (playlist instanceof Playlist) {
      this.playlists.push(playlist)
    }
  }
}

//Each Playlist has a name which is required upon creation
class Playlist {
  constructor (name) {
    this.name = name;
    //A Playlist also has many tracks
    this.tracks = [];
  }

  addTrack(track) {
    if (track instanceof Track) {
      this.tracks.push(track);
    }
  }

  //Each Playlist also has an overallRating function which will calculate the rating by averaging the rating of its tracks
  overallRating() {
    let sum = 0;
    this.tracks.forEach((element) => {
      sum += element.rating;
    })
    return sum / this.tracks.length
  }

  //Each Playlist also has a totalDuration function which will sum the duration of all of its tracks
  totalDuration() {
    let total = 0;
    this.tracks.forEach((element) => {
      total += element.length;
    })
    return total;
  }
}

//A Track has a title, a rating (an integer from 1 to 5)
//and a length (integer in seconds) all of which are required
//when creating a new track
class Track {
  constructor(title, rating, length){
    this.title = title;
    this.rating = rating;
    this.length = length;
  }
}

const library1 = new Library("My Classical Music", "Matt");
const playlist1 = new Playlist("The Best of Liszt");
const track1 = new Track("Liebestraum", 4, 350);

library1.addPlaylist(playlist1);
playlist1.addTrack(track1);

console.log("library1:", library1);
//console.log("playlist1:", playlist1);
//console.log("track1:", track1);
console.log("playlist1.overallRating():", playlist1.overallRating());
console.log("playlist1.totalDuration():", playlist1.totalDuration());