using System;

using System.Collections.Generic;

​

​

namespace req4

{

    public class Song:IComparable<Song>

    {

        string _name;

        string _artist;

        string _songType;

        DateTime _dateDownloaded;

        double _rating;

        int _numberOfDownloads;

​

        public Song(string name, string artist, string songType, DateTime dateDownloaded, double rating, int numberOfDownloads)

        {

            _name = name;

            _artist = artist;

            _songType = songType;

            _dateDownloaded = dateDownloaded;

            _rating = rating;

            _numberOfDownloads = numberOfDownloads;

        }

​

        public string Name { get {return _name;} set {_name = value;} }

        public string Artist { get {return _artist;} set { _artist = value;} }

        public string SongType { get{return _songType;} }set { _songType = value;} }

        public DateTime DateDownloaded { get {return _dateDownloaded; }set { _dateDownloaded = value; }}

        public double Rating { get {return _rating;} set { _rating = value;} }

        public int NumberOfDownloads { get {return _numberOfDownloads; } set { _numberOfDownloads = value; }}

​

        public static Song CreateSong(string details)

        {

            string[] input = details.Split(',');

            return new Song(input[0], input[1], input[2], DateTime.ParseExact(input[3], "dd-MM-yyyy", null), double.Parse(input[4]), int.Parse(input[5]));

        }

​

        public override string ToString()

        {

            string rate = string.Format("{0:0.0}", Rating);

​

            return string.Format("{0} {1,15} {2,15} {3,15} {4,15} {5,15}",Name,Artist,SongType,DateDownloaded.ToShortDateString(),rate,NumberOfDownloads);

        }

        public int CompareTo(Song other)

        {   

            return this.Name.CompareTo(other.Name);

        }

        private class RatingComparer : IComparer<Song>

        {

            int IComparer<Song>.Compare(Song x, Song y)

            {

                if (x.Rating > y.Rating)

                    return 1;

​

                if (x.Rating < y.Rating)

                    return -1;

​

                else

                    return 0;

​

            }

        }

​

        private class PopularityComparer : IComparer<Song>

        {

            int IComparer<Song>.Compare(Song x, Song y)

            {

                if (x.NumberOfDownloads > y.NumberOfDownloads)

                    return 1;

​

                if (x.NumberOfDownloads < y.NumberOfDownloads)

                    return -1;

​

                else

                    return 0;

​

            }

        }

​

        public static IComparer<Song> Ratings()

        {

            return (IComparer<Song>) new RatingComparer();

        }

​

        public static IComparer<Song> Popularity()

        {

            return (IComparer<Song>)new PopularityComparer();

        }

​

    }

}