specific thumbnail generation view + manual refresh thumbnail generation, progress bar with error handling and thumbnail deletion

viewer/models.py

@@ -7,6 +7,8 @@ from django.db import models
 from django.urls import reverse
 from easy_thumbnails.alias import aliases
 
+from viewer import helpers
+
 if not aliases.get('small'):
     aliases.set('small', {'size': (150, 80), 'crop': True})
 
@@ -34,16 +36,22 @@ class ServedDirectory(models.Model):
         # TODO: Implement separate recursive file matching implementation
         # TODO: Implement RegEx filtering step
         directories = []
-        for file in os.listdir(self.path):
+        files = os.listdir(self.path)
+        for i, file in enumerate(files):
+            print(f'{i} / {len(files)}')
             file_path = os.path.join(self.path, file)
 
             if os.path.isfile(file_path):
                 # Check if the file has been entered before
+                entry: File
                 entry = self.files.filter(filename__exact=file).first()
                 if entry is None:
                     # create the file entry
                     entry = File.create(full_path=file_path, parent=self)
                     entry.save()
+                else:
+                    if entry.thumbnail is None:
+                        entry.generate_thumbnail()
             else:
                 # directory found, remember it
                 directories.append(file_path)
@@ -60,6 +68,7 @@ class File(models.Model):
     filename = models.CharField('Filename', max_length=160)
     mediatype = models.CharField('Mediatype', max_length=30)
     directory = models.ForeignKey(ServedDirectory, on_delete=models.CASCADE, related_name='files')
+    thumbnail = models.CharField('Thumbnail Filename', max_length=160, null=True, default=None)
 
     @classmethod
     def create(cls, full_path: str, parent: ServedDirectory) -> 'File':
@@ -75,6 +84,42 @@ class File(models.Model):
         """Retrieve the direct URL for a given file."""
         return reverse('file', args=(directory.id, self.filename))
 
+    def delete_thumbnail(self) -> None:
+        if self.thumbnail:
+            try:
+                os.remove(os.path.join(self.thumbs_dir, self.thumbnail))
+                self.thumbnail = None
+                self.save()
+            except FileNotFoundError:
+                pass
+
+    @property
+    def thumbnail_url(self):
+        if self.thumbnail:
+            return f'/thumbnails/{self.thumbnail}'
+        return ''
+
+    @property
+    def thumbs_dir(self):
+        return os.path.join(os.path.dirname(os.path.abspath(__file__)), 'static', 'thumbnails')
+
+    def generate_thumbnail(self) -> None:
+        #  TODO: Add django-background-task scheduling
+
+        self.delete_thumbnail()
+
+        thumb_file = f'{uuid.uuid4()}.jpeg'
+        self.thumbnail = thumb_file
+
+        # Generate thumbnail
+        try:
+            helpers.generate_thumbnail(self.path, os.path.join(self.thumbs_dir, self.thumbnail))
+        except Exception:
+            print(f'Could not thumbnail: {self.filename}')
+            self.delete_thumbnail()
+
+        self.save()
+
     @staticmethod
     def get_mediatype(path) -> str:
         """Simple media type categorization based on the given path."""