package com.github.hakko.musiccabinet.parser.lastfm;
import static com.github.hakko.musiccabinet.parser.lastfm.ArtistTopTracksHandler.State.ARTIST;
import static com.github.hakko.musiccabinet.parser.lastfm.ArtistTopTracksHandler.State.NAME;
import static com.github.hakko.musiccabinet.parser.lastfm.ArtistTopTracksHandler.State.TRACK;
import java.util.ArrayList;
import java.util.List;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import com.github.hakko.musiccabinet.domain.model.music.Artist;
import com.github.hakko.musiccabinet.domain.model.music.Track;
public class ArtistTopTracksHandler extends DefaultHandler {
private String artistName; // artist name this similarity is based on
private Artist sourceArtist; // artist based on artist name
private List<Track> topTracks = new ArrayList<>();
private Track currentTrack; // used internally while parsing
private State scope; // stores if we're currently reading a track or an artist
private State state; // stores state based on latest encountered start tag
private StringBuilder characterData; // used to assemble xml text passed by parser
private static final String TAG_TOP_TRACKS = "toptracks";
private static final String TAG_ARTIST = "artist";
private static final String TAG_TRACK = "track";
private static final String TAG_NAME = "name";
enum State {
TRACK, ARTIST, NAME;
}
@Override
public void startElement(String uri, String localName, String qName, Attributes attributes)
throws SAXException {
if (TAG_TOP_TRACKS.equals(qName)) {
artistName = attributes.getValue(TAG_ARTIST);
sourceArtist = new Artist(artistName);
} else if (TAG_TRACK.equals(qName)) {
scope = TRACK;
currentTrack = new Track();
currentTrack.setArtist(sourceArtist);
} else if (TAG_ARTIST.equals(qName)) {
scope = ARTIST;
} else if (TAG_NAME.equals(qName)) {
state = NAME;
characterData = new StringBuilder();
} else {
state = null;
}
}
@Override
public void endElement(String uri, String localName, String qName)
throws SAXException {
if (state == NAME && scope == TRACK) {
String chars = characterData.toString();
currentTrack.setName(chars);
}
if (TAG_TRACK.equals(qName)) {
topTracks.add(currentTrack);
}
}
@Override
public void characters(char[] ch, int start, int length) throws SAXException {
if (state == NAME && scope == TRACK) {
characterData.append(ch, start, length);
}
}
/* Variables to be exposured after parsing */
public Artist getArtist() {
return sourceArtist;
}
public List<Track> getTopTracks() {
return topTracks;
}
}