import java.io.*;
import java.net.*;
import java.nio.*;
import java.nio.channels.*;
import java.nio.file.*;
import java.util.*;

import org.json.simple.JSONArray;
import org.json.simple.JSONObject;

class MusicRecord {
    private String track_url_;
    private String title_;
    private String artist_;
    private String year_;
    private String audio_url_;
    
    public MusicRecord(String track_url,String title, String artist, String year, String audio_url) {
	track_url_ = track_url;
	title_  = title;
	artist_ = artist;
	year_   = (year.matches("^\\s*$")) ? null : year;
	audio_url_  = audio_url;
    }

    public String getAudioURL() {
	return audio_url_;
    }
    
    public String toString()
    {
	
	return String.format("[title=%s, artist=%s, year=%s; track_url=%s, audio_url=%s]",
			     title_,artist_,year_, track_url_, audio_url_);
    }

    public JSONObject toJSON() 
    {
	JSONObject obj = new JSONObject();

	boolean object_is_all_null = true;

	if (title_ != null) {
	    obj.put("title",title_);
	    object_is_all_null = false;
	}

	if (artist_ != null) {
	    obj.put("artist",artist_);
	    object_is_all_null = false;
	}

	if (year_ != null) {
	    obj.put("year",year_);
	    object_is_all_null = false;
	}

	if (track_url_ != null) {
	    obj.put("track_url",track_url_);
	    object_is_all_null = false;
	}

	if (audio_url_ != null) {
	    obj.put("audio_url",audio_url_);
	    object_is_all_null = false;
	}

	if (object_is_all_null) {
	    System.err.println("Warning: MusicRecord '" + this + "' only has null values in it");
	}

	return obj;
    }

    public String toJSONString() 
    {
	String jsonText = null;
	JSONObject obj = toJSON();

	try {
	    StringWriter out = new StringWriter();
	    obj.writeJSONString(out);
      
	    jsonText = out.toString();
	}
	catch (IOException ioe) {
	    ioe.printStackTrace();
	}

	return jsonText;
    }


}