]> kaliko git repositories - mpd-sima.git/blobdiff - sima/lib/simafm.py
Add toptrack method for Last.fm webservice
[mpd-sima.git] / sima / lib / simafm.py
index 18625a6761bbc80c4aee7e060e90918193d0696a..8d82d52ccc90798b4a933d53a7f3737fc4945423 100644 (file)
 #
 
 """
-Consume EchoNest web service
+Consume Last.fm web service
 """
 
-__version__ = '0.5.0'
+__version__ = '0.5.1'
 __author__ = 'Jack Kaliko'
 
 
-from datetime import datetime, timedelta
 
-from requests import get, Request, Timeout, ConnectionError
+from requests import Session, Request, Timeout, ConnectionError
 
-from sima import LFM
+from sima import LFM, SOCKET_TIMEOUT, WAIT_BETWEEN_REQUESTS
 from sima.lib.meta import Artist
+from sima.lib.track import Track
+
+from sima.lib.http import CacheController
 from sima.utils.utils import WSError, WSNotFound, WSTimeout, WSHTTPError
-from sima.utils.utils import getws, Throttle, Cache, purge_cache
+from sima.utils.utils import getws, Throttle
 if len(LFM.get('apikey')) == 43:  # simple hack allowing imp.reload
     getws(LFM)
 
-# Some definitions
-WAIT_BETWEEN_REQUESTS = timedelta(0, 1)
-SOCKET_TIMEOUT = 6
-
 
-class SimaFM():
-    """
+class SimaFM:
+    """Last.fm http client
     """
     root_url = 'http://{host}/{version}/'.format(**LFM)
-    cache = {}
-    timestamp = datetime.utcnow()
-    name = 'Last.fm'
     ratelimit = None
+    name = 'Last.fm'
+    cache = False
+    stats = {'etag':0,
+            'ccontrol':0,
+            'total':0}
 
-    def __init__(self, cache=True):
+    def __init__(self):
+        self.controller = CacheController(self.cache)
         self.artist = None
-        self._url = self.__class__.root_url
-        self.current_element = None
-        self.caching = cache
-        purge_cache(self.__class__)
 
     def _fetch(self, payload):
-        """Use cached elements or proceed http request"""
-        url = Request('GET', self._url, params=payload,).prepare().url
-        if url in SimaFM.cache:
-            self.current_element = SimaFM.cache.get(url).elem
-            return
+        """
+        Prepare http request
+        Use cached elements or proceed http request
+        """
+        req = Request('GET', SimaFM.root_url, params=payload,
+                      ).prepare()
+        SimaFM.stats.update(total=SimaFM.stats.get('total')+1)
+        if self.cache:
+            cached_response = self.controller.cached_request(req.url, req.headers)
+            if cached_response:
+                SimaFM.stats.update(ccontrol=SimaFM.stats.get('ccontrol')+1)
+                return cached_response.json()
         try:
-            self._fetch_ech(payload)
+            return self._fetch_ws(req)
         except Timeout:
             raise WSTimeout('Failed to reach server within {0}s'.format(
                                SOCKET_TIMEOUT))
@@ -72,32 +76,34 @@ class SimaFM():
             raise WSError(err)
 
     @Throttle(WAIT_BETWEEN_REQUESTS)
-    def _fetch_ech(self, payload):
+    def _fetch_ws(self, prepreq):
         """fetch from web service"""
-        req = get(self._url, params=payload,
-                            timeout=SOCKET_TIMEOUT)
-        #self.__class__.ratelimit = req.headers.get('x-ratelimit-remaining', None)
-        if req.status_code is not 200:
-            raise WSHTTPError(req.status_code)
-        self.current_element = req.json()
-        self._controls_answer()
-        if self.caching:
-            SimaFM.cache.update({req.url:
-                                 Cache(self.current_element)})
-
-    def _controls_answer(self):
+        sess = Session()
+        resp = sess.send(prepreq, timeout=SOCKET_TIMEOUT)
+        if resp.status_code == 304:
+            SimaFM.stats.update(etag=SimaFM.stats.get('etag')+1)
+            resp = self.controller.update_cached_response(prepreq, resp)
+        elif resp.status_code != 200:
+            raise WSHTTPError('{0.status_code}: {0.reason}'.format(resp))
+        ans = resp.json()
+        self._controls_answer(ans)
+        if self.cache:
+            self.controller.cache_response(resp.request, resp)
+        return ans
+
+    def _controls_answer(self, ans):
         """Controls answer.
         """
-        if 'error' in self.current_element:
-            code = self.current_element.get('error')
-            mess = self.current_element.get('message')
+        if 'error' in ans:
+            code = ans.get('error')
+            mess = ans.get('message')
             if code == 6:
                 raise WSNotFound('{0}: "{1}"'.format(mess, self.artist))
             raise WSError(mess)
         return True
 
     def _forge_payload(self, artist, method='similar', track=None):
-        """
+        """Build payload
         """
         payloads = dict({'similar': {'method':'artist.getsimilar',},
                         'top': {'method':'artist.gettoptracks',},
@@ -112,21 +118,53 @@ class SimaFM():
         if artist.mbid:
             payload.update(mbid='{0}'.format(artist.mbid))
         else:
-           payload.update(artist=artist.name)
+            payload.update(artist=artist.name,
+                           autocorrect=1)
         payload.update(results=100)
         if method == 'track':
             payload.update(track=track)
-        return payload
+        # > hashing the URL into a cache key
+        # return a sorted list of 2-tuple to have consistent cache
+        return sorted(payload.items(), key=lambda param: param[0])
 
     def get_similar(self, artist=None):
-        """
+        """Fetch similar artists
         """
         payload = self._forge_payload(artist)
         # Construct URL
-        self._fetch(payload)
-        for art in self.current_element.get('similarartists').get('artist'):
+        ans = self._fetch(payload)
+        # Artist might be found be return no 'artist' list…
+        # cf. "Mulatu Astatqe" vs. "Mulatu Astatqé" with autocorrect=0
+        # json format is broken IMHO, xml is more consistent IIRC
+        # Here what we got:
+        # >>> {"similarartists":{"#text":"\n","artist":"Mulatu Astatqe"}}
+        # autocorrect=1 should fix it, checking anyway.
+        simarts = ans.get('similarartists').get('artist')
+        if not isinstance(simarts, list):
+            raise WSError('Artist found but no similarities returned')
+        for art in ans.get('similarartists').get('artist'):
             yield Artist(name=art.get('name'), mbid=art.get('mbid', None))
 
+    def get_toptrack(self, artist=None):
+        """Fetch artist top tracks
+        """
+        payload = self._forge_payload(artist, method='top')
+        ans = self._fetch(payload)
+        tops = ans.get('toptracks').get('track')
+        art = {
+                'artist': artist.name,
+                'musicbrainz_artistid': artist.mbid,
+                }
+        for song in tops:
+            for key in ['artist', 'streamable', 'listeners',
+                        'url', 'image', '@attr']:
+                if key in song:
+                    song.pop(key)
+            song.update(art)
+            song.update(title=song.pop('name'))
+            song.update(time=song.pop('duration'))
+            yield Track(**song)
+        #return tops
 
 # VIM MODLINE
 # vim: ai ts=4 sw=4 sts=4 expandtab