From 33fa80ade43e0ee8f94c69ca2484488020afea4c Mon Sep 17 00:00:00 2001
From: Nikolai Kristiansen <nikolaik@gmail.com>
Date: Mon, 30 May 2011 00:01:20 +0200
Subject: [PATCH] Probably fixed false negative when polling in the middle of
 switching tracks.

---
 oliver_screen/tracks/models.py | 11 ++++++--
 oliver_screen/tracks/views.py  | 51 ++++++++++++++++++++++++++++++++--
 2 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/oliver_screen/tracks/models.py b/oliver_screen/tracks/models.py
index def9fa4..c604248 100644
--- a/oliver_screen/tracks/models.py
+++ b/oliver_screen/tracks/models.py
@@ -1,7 +1,14 @@
 from django.db import models
 
-# Create your models here.
-#
+class CurrentTrack(models.Model):
+    title = models.CharField(max_length=200)
+    artist = models.CharField(max_length=200)
+    image = models.CharField(max_length=200)
+    retries = models.IntegerField()
+
+    def __unicode__(self):
+        return self.title + " - " + self.artist
+
 class LastFMUser(models.Model):
     name = models.CharField(max_length=200)
     active = models.BooleanField()
diff --git a/oliver_screen/tracks/views.py b/oliver_screen/tracks/views.py
index 8b1bc17..9c4ec2a 100644
--- a/oliver_screen/tracks/views.py
+++ b/oliver_screen/tracks/views.py
@@ -2,7 +2,7 @@ from django.http import HttpResponse
 from django.shortcuts import render_to_response, get_object_or_404
 from django.template import RequestContext
 
-from oliver_screen.tracks.models import LastFMUser, YouTubeVideo
+from oliver_screen.tracks.models import LastFMUser, YouTubeVideo, CurrentTrack
 
 import pylast
 from datetime import datetime
@@ -44,7 +44,6 @@ def get_now_playing(request):
     user = get_lastfmuser()
     track = user.get_now_playing()
     now_playing = []
-    video = ""
     if not track is None:
         artist = track.get_artist()
         video = get_youtubevideo(artist.get_name(), track.get_title())
@@ -58,8 +57,56 @@ def get_now_playing(request):
             'image': image,
             'video': video
         }
+        cache_current(now_playing)
+    else:
+        # No response from LastFM db?
+        now_playing = get_current_from_cache()
+        
     return render_to_response("public/now_playing.html", {'now_playing':now_playing}, context_instance=RequestContext(request));
 
+def cache_current(now_playing):
+    # Fetch the one CurrentTrack entry in the db and update it with the current track.
+    current = CurrentTrack.objects.get(pk=1)
+    if not current is None:
+        #update
+        current.artist = now_playing['artist']
+        current.title = now_playing['title']
+        current.image = now_playing['image']
+        current.retries = 0
+        current.save()
+    else:
+        # First time running? Then creat it.
+        current = CurrentTrack(artist=now_playing.artist, title=now_playing.title, image=now_playing.image, retries=0)
+        current.save()
+
+def get_current_from_cache():
+    current = []
+    try:
+        current = CurrentTrack.objects.get(pk=1)
+    except:
+        current = CurrentTrack(artist="", title="", image="", retries=0)
+        current.save()
+
+    now_playing = {}
+
+    # try 3 times before clearing the cache
+    if current.artist != "" and current.retries < 3:
+        now_playing = {
+                'artist': current.artist,
+                'title': current.title,
+                'image': current.image
+                }
+
+        current.retries = current.retries + 1
+        current.save()
+    else:
+        current.artist = ""
+        current.title = ""
+        current.image = ""
+        current.save()
+
+    return now_playing
+
 # Mock views
 def dummy_get_last_track(request):
     played = {'artist': 'The Album Leaf', 'title': 'Another Day (Revised)'}