CDDB/GraceNote Lookup in C#

This weekend I spent some time trying to find a web service that would lookup album information. To my frustration I was unable to find anything useful. Yahoo has a web service, but the information it provides is limited. The Musicbrainz code is a bunch of crazy C that I just don't want to deal with. Therefore I whipped together some code to query CDDB and parse the results. It doesn't support the full range of options that I can imagine so I might add those in the future. If you grab this code and make additions, send it back to me and I'll post the updated code. Here's the source:


using System;
using System.IO;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Text.RegularExpressions;
namespace CDLookup
{
public class AlbumReference
{
private String m_strName;
private String m_strUrl;
internal AlbumReference(String name, String url)
{
this.m_strName = name;
this.m_strUrl = url;
}
public String Name
{
get
{
return this.m_strName;
}
}
public AlbumInfo GetInfo()
{
return CDDBLookup.GetAlbumInfo(this.m_strUrl);
}
}
public class AlbumInfo
{
private String m_strArtist;
private String m_strAlbum;
private String m_strLabel;
private String m_strYear;
private List m_strTracks;
internal AlbumInfo(String artist, String album, String label, String year, List tracks)
{
this.m_strArtist = artist;
this.m_strAlbum = album;
this.m_strLabel = label;
this.m_strYear = year;
this.m_strTracks = tracks;
}
public String Artist
{
get
{
return this.m_strArtist;
}
}
public String Album
{
get
{
return this.m_strAlbum;
}
}
public String Label
{
get
{
return this.m_strLabel;
}
}
public String Year
{
get
{
return this.m_strYear;
}
}
public List Tracks
{
get
{
return this.m_strTracks;
}
}
}
public static class CDDBLookup
{
private static String s_baseInfoUrl =
"http://www.gracenote.com/music/album.html/";
private static String s_baseQueryUrl =
"http://www.gracenote.com/music/search-adv.html?q=&qartist={ARTIST}&qdisc={ALBUM}&qtrack=&n=10&x=39&y=6";
private static String s_queryRegex =
".*)\".*>(?.*)";
private static String s_infoRegex =
"(?.*)
Label:(?.*)
Year:(?.*)
";
private static String s_altInfoRegex =
"(?.*)
";
private static String s_trackRegex =
".*(?.*)";
private static String s_notFoundRegex =
"Your search could not be completed";
public static List Lookup(String artist, String album)
{
String strUrl = s_baseQueryUrl.Replace("{ARTIST}", artist).Replace("{ALBUM}", album);
WebRequest request = WebRequest.Create(strUrl);
WebResponse response = request.GetResponse();
String strResponse = new StreamReader(response.GetResponseStream()).ReadToEnd();
List references = new List();
Regex regexNotFound = new Regex(s_notFoundRegex);
if (regexNotFound.Match(strResponse).Success)
return references;
Regex regexBase = new Regex(s_queryRegex);
MatchCollection matches = regexBase.Matches(strResponse);
if (matches.Count != 0)
{
foreach (Match match in matches)
{
String url = match.Groups["Url"].Value;
String name = match.Groups["Name"].Value;
references.Add(new AlbumReference(name, url));
}
}
else
{
Regex regexInfo = new Regex(s_infoRegex);
Match match = regexInfo.Match(strResponse);
if (!match.Success)
{
Regex regexAltInfo = new Regex(s_altInfoRegex, RegexOptions.Multiline);
match = regexAltInfo.Match(strResponse);
if (!match.Success)
throw new ArgumentException("Unable to parse response.");
}
references.Add(new AlbumReference(
match.Groups["Name"].Value,
response.ResponseUri.AbsoluteUri.Substring(s_baseInfoUrl.Length)));
}
return references;
}
internal static AlbumInfo GetAlbumInfo(String subUrl)
{
String strUrl = s_baseInfoUrl + subUrl;
WebRequest request = WebRequest.Create(strUrl);
WebResponse response = request.GetResponse();
String strResponse = new StreamReader(response.GetResponseStream()).ReadToEnd();
Regex regexInfo = new Regex(s_infoRegex);
Match match = regexInfo.Match(strResponse);
if (!match.Success)
{
Regex regexAltInfo = new Regex(s_altInfoRegex, RegexOptions.Multiline);
match = regexAltInfo.Match(strResponse);
if (!match.Success)
throw new ArgumentException("Unable to parse response.");
}
Regex regexTracks = new Regex(s_trackRegex);
List tracks = new List();
foreach (Match matchTrack in regexTracks.Matches(strResponse))
{
tracks.Add(matchTrack.Groups["Track"].Value);
}
int iSlash = match.Groups["Name"].Value.IndexOf('/');
return new AlbumInfo(
match.Groups["Name"].Value.Substring(0, iSlash).Trim(),
match.Groups["Name"].Value.Substring(iSlash+1).Trim(),
GetGroupValue(match, "Label"),
GetGroupValue(match, "Year"),
tracks);
}
private static String GetGroupValue(Match match, String groupName)
{
Group group = match.Groups[groupName];
if (group == null)
return "";
return group.Value;
}
}
}