terom@27: import datetime
terom@41: import hashlib
terom@80: import logging
terom@41: import os.path
terom@27: 
terom@41: import django.core.files.storage
terom@4: import django.utils.http
terom@4: from django.contrib.sites.models import get_current_site
terom@82: from django.core.cache import cache
terom@82: from django.core.urlresolvers import reverse
terom@82: from django.db import models
terom@6: from django.utils import timezone
terom@4: 
terom@80: log = logging.getLogger('qrurls.models')
terom@80: 
terom@18: QRCODE_API = 'https://chart.googleapis.com/chart?cht=qr&chs={width}x{height}&chl={url}&chld=H'
terom@41: IMAGES_MEDIA = 'qrurls-images'
terom@41: 
terom@41: class SecretFileSystemStorage (django.core.files.storage.FileSystemStorage) :
terom@41:     """
terom@41:         Store files named by a sha1 hash of their contents.
terom@41:     """
terom@41: 
terom@41:     HASH = hashlib.sha1
terom@41:     
terom@41:     def _hash (self, content) :
terom@41:         """Compute hash for given UploadedFile (as a hex string)."""
terom@41:         hash = self.HASH()
terom@41: 
terom@41:         for chunk in content.chunks() :
terom@41:             hash.update(chunk)
terom@41: 
terom@41:         return hash.hexdigest()
terom@41:     
terom@41:     def save (self, name, content) :
terom@66:         """Convert uploaded filename to a hash of the contents for storage."""
terom@41:         if name is None:
terom@41:             name = content.name
terom@41:         
terom@41:         dirname, filename = os.path.split(name)
terom@41:         basename, fileext = os.path.splitext(filename)
terom@41:         
terom@41:         # hash
terom@41:         name = "%s/%s%s" % (dirname, self._hash(content), fileext)
terom@41: 
terom@41:         return super(SecretFileSystemStorage, self).save(name, content)
terom@0: 
terom@2: class URL(models.Model):
terom@48:     shorturl = models.SlugField(unique=True,
terom@48:             help_text="Changing this will break existing QR-codes!")
terom@47:     publishing_time = models.TimeField(default=datetime.time(),
terom@47:             help_text="Default time to publish new URLItems (in timezone)")
terom@63:     publishing_days = models.IntegerField(default=1,
terom@63:             help_text="Default interval for publishing new URLItems")
terom@51:     title = models.CharField(max_length=1024, blank=True, null=True,
terom@51:             help_text="Text to display together with images.")
terom@2: 
terom@3:     class Meta:
terom@12:         verbose_name = u"URL Feed"
terom@12:         verbose_name_plural = u"URL Feeds"
terom@3: 
terom@4:     def qrcode_img (self, size=512) :
terom@4:         return QRCODE_API.format(
terom@4:                 width=size, height=size,
terom@4:                 url=django.utils.http.urlquote(self.qrcode_url()),
terom@4:         )
terom@4: 
terom@4:     def qrcode_url (self) :
terom@22:         return 'HTTP://{domain}{url}'.format(
terom@22:                 domain = get_current_site(None).domain.upper(),
terom@23:                 url = self.get_absolute_url(),
terom@22:         )
terom@4: 
terom@2:     def get_absolute_url (self) :
terom@2:         return reverse('shorturl', args=[self.shorturl])
terom@2: 
terom@47:     def now (self, now=None) :
terom@47:         """
terom@47:             Return database-compatible concept of "now".
terom@47: 
terom@47:             All datetimes are strictly stored and compared as UTC. Any
terom@47:             timezone-aware logic should happen in the admin.
terom@47:         """
terom@47:         if now :
terom@47:             return now
terom@47:         else :
terom@47:             return timezone.now()
terom@47:     
terom@47:     def active_item (self, now=None) :
terom@7:         """Currently published URLItem."""
terom@47:         now = self.now(now)
terom@6: 
terom@16:         try :
terom@69:             return self.urlitem_set.filter(published__lt=now).order_by('-published')[0]
terom@16:         except IndexError :
terom@16:             return None
terom@6: 
terom@27:     def upcoming_item (self, now=None) :
terom@47:         """Next-up to-be-published URLItem."""
terom@47:         now = self.now(now)
terom@7: 
terom@16:         try :
terom@69:             return self.urlitem_set.filter(published__gt=now).order_by('published')[0]
terom@16:         except IndexError :
terom@16:             return None
terom@7: 
terom@27:     def last_item (self) :
terom@27:         """The last URLItem available."""
terom@27: 
terom@27:         try :
terom@69:             return self.urlitem_set.order_by('-published')[0]
terom@27:         except IndexError :
terom@27:             return None
terom@27: 
terom@56:     @property
terom@56:     def publishing_timetz (self) :
terom@56:         """publishing_time, with tzinfo on the correct timezone."""
terom@56:         return self.publishing_time.replace(tzinfo=timezone.get_current_timezone())
terom@56:     
terom@63:     @property
terom@63:     def publishing_offset (self) :
terom@63:         return datetime.timedelta(days=self.publishing_days)
terom@56: 
terom@56:     def publishing_schedule (self) :
terom@56:         """Calculate initial URLItem.published values for feed."""
terom@56: 
terom@56:         # following the last item in the queue
terom@56:         item = self.last_item()
terom@56: 
terom@56:         if item and item.published > self.now():
terom@56:             # starting from the following day
terom@56:             date = item.published.date() + self.publishing_offset
terom@56:         else :
terom@56:             # defaults to today
terom@56:             date = self.now().date()
terom@56:         
terom@56:         return date, self.publishing_timetz, self.publishing_offset
terom@56:     
terom@56:     @classmethod
terom@56:     def apply_publishing_schedule (self, date, time, offset, count) :
terom@56:         """Yield publishing times off given date/time to offset * count."""
terom@56:         for index in xrange(0, count) :
terom@56:             yield datetime.datetime.combine(date + offset * index, time)
terom@56: 
terom@2:     def __unicode__ (self) :
terom@2:         return self.shorturl
terom@2: 
terom@28: class URLImage(models.Model):
terom@41:     image = models.ImageField(upload_to=IMAGES_MEDIA, storage=SecretFileSystemStorage())
terom@66:     name = models.CharField(max_length=512, blank=False)
terom@51:     title = models.CharField(max_length=1024, blank=True)
terom@30:     uploaded = models.DateTimeField(auto_now_add=True)
terom@30: 
terom@30:     class Meta:
terom@30:         verbose_name = u"URL Image"
terom@30:         verbose_name_plural = u"URL Images"
terom@30:         ordering = ['uploaded']
terom@30: 
terom@66:     def save (self) :
terom@66:         # keep real filename before saving with hash
terom@77:         # but not when updating!
terom@77:         if not self.name:
terom@77:             self.name = self.image.name
terom@66: 
terom@66:         super(URLImage, self).save()
terom@66: 
terom@32:     def get_absolute_url (self) :
terom@32:         return self.image.url
terom@32: 
terom@30:     def __unicode__ (self) :
terom@66:         return "[%s] %s" % (self.uploaded.strftime("%Y-%m-%d"), self.name)
terom@28: 
terom@2: class URLItem(models.Model):
terom@2:     shorturl = models.ForeignKey(URL)
terom@68:     published = models.DateTimeField(db_index=True) # UTC
terom@32: 
terom@32:     # either-or
terom@32:     url = models.URLField(blank=True) # populated from image
terom@32:     image = models.ForeignKey(URLImage, null=True, blank=True)
terom@2:     
terom@3:     class Meta:
terom@3:         verbose_name = u"URL Item"
terom@3:         verbose_name_plural = u"URL Items"
terom@3:         ordering = ['published']
terom@3: 
terom@80:     @classmethod
terom@82:     def get_item (cls, shorturl, item_id=None, related=()) :
terom@80:         """
terom@80:             Return the URLItem for a given shorturl, either the given specific one,
terom@80:             or the latest, from the database.
terom@80: 
terom@80:             Raises URLItem.NotFound
terom@80:         """
terom@80:         # JOIN against shorturl, urlimage
terom@80:         url_item = cls.objects.select_related(*related)
terom@80: 
terom@81:         if not shorturl:
terom@81:             raise cls.DoesNotExist()
terom@81:         elif shorturl.isdigit():
terom@81:             shorturl_id = int(shorturl)
terom@80:             url_item = url_item.filter(shorturl__id=shorturl_id)
terom@80:         else:
terom@81:             url_item = url_item.filter(shorturl__shorturl=shorturl)
terom@80:         
terom@80:         # match for published items
terom@80:         now = timezone.now()
terom@80:         url_item = url_item.filter(published__lt=now).order_by('-published')
terom@80:        
terom@80:         if item_id :
terom@80:             # specific, but still the published on
terom@82:             item_id = int(item_id)
terom@82:             log.debug("search @ %d", item_id)
terom@82: 
terom@82:             return url_item.get(id=item_id) # raises DoesNotExist
terom@80:         else :
terom@80:             # most recent
terom@82:             log.debug("search @ %s", now)
terom@80:             try:
terom@80:                 return url_item[0]
terom@80:             except IndexError:
terom@80:                 raise DoesNotExist()
terom@80: 
terom@82:     @classmethod
terom@82:     def get_url (cls, shorturl) :
terom@82:         """
terom@82:             Return the current URL for a given shorturl, from cache or DB.
terom@82:             
terom@82:             Returns url:str, modified:datetime
terom@82:             Raises URLItem.NotFound
terom@82:         """
terom@82: 
terom@82:         key = 'qrurls/url/{shorturl}'.format(shorturl=shorturl)
terom@82:         get = cache.get(key)
terom@82:         
terom@82:         if get :
terom@82:             url, modified = get
terom@82:             log.debug("get cache: %s: %s", key, url)
terom@82:         else:
terom@82:             # from db
terom@82:             url_item = cls.get_item(shorturl=shorturl)
terom@82: 
terom@82:             url = url_item.get_absolute_url()
terom@82:             modified = url_item.last_modified()
terom@82:             
terom@82:             log.debug("set cache: %s: %s", key, url)
terom@82:             cache.set(key, (url, modified)) # XXX: expiry
terom@82:         
terom@82:         return url, modified
terom@82: 
terom@2:     def get_absolute_url (self) :
terom@43:         if self.url :
terom@43:             return self.url
terom@44:         elif self.shorturl and self.id :
terom@44:             return reverse('shorturl_item', kwargs=dict(shorturl=self.shorturl, item_id=self.id))
terom@35:         else :
terom@44:             return None
terom@47:    
terom@7:     def published_age (self) :
terom@47:         now = self.shorturl.now() # UTC
terom@6: 
terom@6:         if now > self.published:
terom@6:             td = now - self.published
terom@6:         else :
terom@6:             td = self.published - now
terom@6: 
terom@6:         days, seconds = td.days, td.seconds
terom@6:         m, s = divmod(seconds, 60)
terom@6:         h, m = divmod(m, 60)
terom@7: 
terom@9:         return (self.published < now), days, "{h}h {m}m {s}s".format(h=h, m=m, s=s)
terom@7: 
terom@7:     def published_state (self) :
terom@9:         date = self.published.strftime("%Y-%m-%d")
terom@9:         published, days, age = self.published_age()
terom@6: 
terom@9:         if published and days :
terom@9:             return "[{date}]".format(date=date)
terom@9:         elif published :
terom@9:             return "[{age}]".format(age=age)
terom@6:         elif days :
terom@9:             return "({when})".format(when=date)
terom@6:         else :
terom@9:             return "({age})".format(age=age)
terom@6: 
terom@72:     def last_modified (self) :
terom@72:         # XXX: this asumes that URLImage is never changed after publishing..
terom@72:         return self.published
terom@72: 
terom@78:     def title (self) :
terom@78:         if self.image and self.image.title.strip() :
terom@78:             return self.image.title
terom@78:         else :
terom@78:             return self.shorturl.title
terom@78:     
terom@2:     def __unicode__ (self) :
terom@9:         return u"{published_state} {url}".format(
terom@9:                 published_state=self.published_state(),
terom@7:                 url=self.get_absolute_url(),
terom@7:         )
terom@32: