Improved, simplified and optimized the document signature verification model and manager

apps/document_signatures/models.py

@@ -6,6 +6,7 @@ from django.utils.translation import ugettext_lazy as _
 
 from documents.models import DocumentVersion, get_filename_from_uuid
 from documents.conf.settings import STORAGE_BACKEND
+from django_gpg.runtime import gpg
 
 from .managers import DocumentVersionSignatureManager
 
@@ -17,11 +18,19 @@ class DocumentVersionSignature(models.Model):
     Model that describes a document version signature properties
     '''
     document_version = models.ForeignKey(DocumentVersion, verbose_name=_(u'document version'), editable=False)
-    signature_state = models.CharField(blank=True, null=True, max_length=16, verbose_name=_(u'signature state'), editable=False)
     signature_file = models.FileField(blank=True, null=True, upload_to=get_filename_from_uuid, storage=STORAGE_BACKEND(), verbose_name=_(u'signature file'), editable=False)
+    has_embedded_signature = models.BooleanField(default=False, verbose_name=_(u'has embedded signature'), editable=False)
 
     objects = DocumentVersionSignatureManager()
 
+    def delete_detached_signature(self):
+        self.signature_file.storage.delete(self.signature_file.path)
+
+    def save(self, *args, **kwargs):
+        if not self.pk:
+            self.has_embedded_signature = gpg.has_embedded_signature(self.document_version.open(raw=True))            
+        super(DocumentVersionSignature, self).save(*args, **kwargs)
+
     class Meta:
         verbose_name = _(u'document version signature')
         verbose_name_plural = _(u'document version signatures')