Reworked "find" to allow for more sophisticated searches.

The usage of the "find" command is as follows:
	find SEARCH
where SEARCH is either a simple string to search for, or key:value pairs
with the following keys:
	artist
	album
	title

1 files changed, 64 insertions, 6 deletions

diff --git a/music.cpp b/music.cpp
index eb16226..7356274 100644
--- a/music.cpp
+++ b/music.cpp
@@ -24,7 +24,7 @@ void music::init(std::string root) {
 	root_directory = root;
 }
 
-/** Fetches a MusicListing object from the given path.
+/** Fetches a MusicListing object from the given \p path.
  *  Prefixes the given path with the music root directory.
  *  This can be either a track (file) or a directory.
  */
@@ -52,7 +52,7 @@ MusicListing::p music::get(const HTTP::Connection::PathList& path) {
 	return MusicListing::p();
 }
 
-/** Fetches a MusicListing object from the given path.
+/** Fetches a MusicListing object from the given \p path.
  *  Splits the given string and calls the above function.
  */
 MusicListing::p music::get(const std::string& path) {
@@ -74,21 +74,76 @@ MusicDirectory::p music::get_directory(const std::string& path) {
 	return dir;
 }
 
-std::vector<MusicListing::p> music::find_artist(const std::string artist) {
+/** Find tracks in the database.
+ *  Does a search on specific fields given by \p search.
+ */
+std::vector<MusicListing::p> music::find(std::map<std::string, std::string> search) {
+	soci::session sql(config::vm["audist.database"].as<std::string>());
+	soci::statement st(sql);
+	std::string filename, artist, album, title;
+	st.exchange(soci::into(filename));
+	std::string query = "SELECT file_name FROM tracks WHERE ";
+	std::vector<std::string> where_conditions;
+
+	if(search.find("artist") != search.end()) {
+		where_conditions.push_back("artist_id IN (SELECT id FROM artists WHERE name LIKE :artist)");
+		artist = "%"+search["artist"]+"%";
+		st.exchange(soci::use(artist, "artist"));
+	}
+
+	if(search.find("album") != search.end()) {
+		where_conditions.push_back("album_id IN (SELECT id FROM albums WHERE name LIKE :album)");
+		album = "%"+search["album"]+"%";
+		st.exchange(soci::use(album, "album"));
+	}
+
+	if(search.find("title") != search.end()) {
+		where_conditions.push_back("name LIKE :title");
+		artist = "%"+search["title"]+"%";
+		st.exchange(soci::use(title, "title"));
+	}
+
+	query += boost::algorithm::join(where_conditions, " AND ");
+	st.alloc();
+	st.prepare(query);
+	st.define_and_bind();
+	std::cout << "query: " << query << std::endl;
+	std::cout << "st.execute: " << st.execute(true) << std::endl;
+	std::cout << "st.got_data: " << st.got_data() << std::endl;
+
+	std::vector<MusicListing::p> results;
+	while(st.fetch()) {
+		MusicListing::p ml(new MusicTrack(filename));
+		results.push_back(ml);
+	}
+	sql.close();
+
+	return results;
+}
+
+/** Find tracks in the database.
+ *  Returns tracks where title, artist, album or filename matches \p search.
+ */
+std::vector<MusicListing::p> music::find(std::string search) {
 	soci::session sql(config::vm["audist.database"].as<std::string>());
 
-	soci::rowset<std::string> rs = (sql.prepare << "SELECT file_name FROM tracks WHERE artist_id IN (SELECT id FROM artists WHERE name LIKE :name)",
-		soci::use("%"+artist+"%"));
+	search = "%"+search+"%";
+	soci::rowset<std::string> rs = (sql.prepare << "SELECT DISTINCT file_name FROM tracks WHERE name LIKE :search OR file_name LIKE :search OR "
+		"artist_id IN (SELECT id FROM artists WHERE name LIKE :search) OR album_id IN (SELECT id FROM albums WHERE name LIKE :search)",
+		soci::use(search, "search"));
 
 	std::vector<MusicListing::p> results;
 	for(soci::rowset<std::string>::const_iterator it = rs.begin(); it != rs.end(); it++) {
-		boost::shared_ptr<MusicListing> ml(new MusicTrack(*it));
+		MusicListing::p ml(new MusicTrack(*it));
 		results.push_back(ml);
 	}
 
 	return results;
 }
 
+/** Initiate an update on \p path and its subdirs.
+ *  music::update does the actual work.
+ */
 void music::begin_update(const std::string path) {
 	MusicDirectory::p dir = get_directory(path);
 	std::cout << boost::format("updater(%s) called") % path << std::endl;
@@ -97,7 +152,10 @@ void music::begin_update(const std::string path) {
 	}
 }
 
+/** Recursively update \p dir and its subdirectories.
+ */
 void music::update(const MusicDirectory& dir) {
+	// TODO: Fix engine-specific SQL syntax inside this function.
 	soci::session sql(config::vm["audist.database"].as<std::string>());
 
 	BOOST_FOREACH(fs::path t, dir.tracks) {