last.fm for album art

Whenever a new song is loaded, we check the cache for album art.  If we
don't have art yet, then we place a request to the last.fm to find an
image.

libsaria/__init__.py

@@ -23,6 +23,7 @@ cache = Cache()
 
 plugin = None
 music  = None
+lastfm = None
 
 
 # Initialize helpful variables
@@ -30,10 +31,12 @@ def init():
 	global vars
 	global prefs
 	global music
+	global lastfm
 
 	vars = Map()
 	prefs = Map("preferences")
 	import music
+	import lastfm
 
 	event.start("POSTINIT")
 

libsaria/lastfm.py

@@ -0,0 +1,68 @@
+# Bryan Schumaker (10/24/2010)
+
+import libsaria
+import web
+import xm
+
+cache     = libsaria.cache
+pref_attr = xm.find_preferred_attribute
+
+pref_sizes = ["extralarge", "large", "medium", "small"]
+
+APIROOT = "http://ws.audioscrobbler.com/2.0/"
+APIKEY = "2c76f85a6704efd74b5a358821284ef9"
+SECRET = "3a6012bfb627b60a884cf33fc044885c"
+
+
+class LastFmRequest(dict):
+	def __init__(self, method):
+		self.method = method
+
+	def print_file(self, file):
+		for line in file:
+			print line.strip()
+		file.seek(0)
+
+	def place(self, printfile=False):
+		url = web.Url(APIROOT + "?method=" + self.method)
+		url["api_key"] = APIKEY
+		for param in self:
+			url[param] = self[param]
+		file = url.open()
+		if printfile==True:
+			self.print_file(file)
+		doc = xm.parse( file )
+		lfm = xm.child(doc)
+		if xm.attributes(lfm)["status"] == "ok":
+			return xm.child(lfm)
+		else:
+			return None
+
+def lfm_cache_album(file, artist, album):
+	req = LastFmRequest("album.getInfo")
+	req["album"]  = album
+	req["artist"] = artist
+	doc = req.place()
+	node = pref_attr(doc, "image", "size", pref_sizes)
+	node = xm.child(node)
+	if node == None:
+		return
+	try:
+		url = web.Url(node.data)
+		for line in url.open():
+			file.write(line)
+		return True
+	except:
+		pass
+	return False
+
+def get_artwork(filepath):
+	id = libsaria.collection.lib_find_id(filepath)
+	if id == None:
+		return
+	artist = libsaria.collection.lib_get_attr(id, "artist")
+	album  = libsaria.collection.lib_get_attr(id, "album")
+	cached = cache[artist]
+	file = cached.get("%s.jpg" % album, lfm_cache_album, artist, album)
+	libsaria.event.start("POSTGETART", file)
+libsaria.event.invite("POSTLOAD", get_artwork, True)