Sort gallery media by capture date instead of file name

photologue/management/commands/backfill_capture_dates.py

@@ -0,0 +1,77 @@
+# This file is part of photo21
+# Copyright (C) 2022  Amicale des élèves de l'ENS Paris-Saclay
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from django.core.management.base import BaseCommand
+
+from photologue.models import DATE_FROM_EXIF, DATE_FROM_VIDEO, DATE_MANUAL, Photo, Video
+from photologue.utils import capture_date_from_exif, capture_date_from_video
+
+
+class Command(BaseCommand):
+    help = (
+        "Read the capture date of existing media from their metadata. Media whose "
+        "date was set by hand are never touched. By default only media without a "
+        "date, and media imported before dates were tracked, are read."
+    )
+
+    def add_arguments(self, parser):
+        parser.add_argument(
+            "--force",
+            action="store_true",
+            help="Re-read every media, even those with a known date source.",
+        )
+        parser.add_argument(
+            "--dry-run",
+            action="store_true",
+            help="Report what would change without writing anything.",
+        )
+
+    def handle(self, *args, **options):
+        for model, reader in ((Photo, self.photo_date), (Video, self.video_date)):
+            queryset = model.objects.exclude(date_source=DATE_MANUAL)
+            if not options["force"]:
+                # An empty source means the media predates this field, and its date
+                # may have been stored in the wrong time zone.
+                queryset = queryset.filter(date_taken__isnull=True) | queryset.filter(date_source="")
+            self.process(model, queryset.distinct(), reader, options)
+
+    def process(self, model, queryset, reader, options):
+        name = model._meta.verbose_name_plural
+        found = unchanged = missing = 0
+        for media in queryset.iterator():
+            taken, source = reader(media)
+            if taken is None:
+                missing += 1
+                self.stdout.write(f"  no date in {media.title}")
+                continue
+            if taken == media.date_taken and source == media.date_source:
+                unchanged += 1
+                continue
+            found += 1
+            self.stdout.write(f"  {media.title}: {media.date_taken} -> {taken} ({source})")
+            if not options["dry_run"]:
+                media.set_capture_date(taken, source)
+                media.save(update_fields=["date_taken", "date_source"])
+        done = "would be updated" if options["dry_run"] else "updated"
+        self.stdout.write(
+            self.style.SUCCESS(f"{name}: {found} {done}, {unchanged} already correct, {missing} without metadata")
+        )
+
+    @staticmethod
+    def photo_date(photo):
+        if not photo.image:
+            return None, None
+        try:
+            exif_date = photo.exif(photo.image.file).get("EXIF DateTimeOriginal", None)
+        except Exception:
+            return None, None
+        if exif_date is None:
+            return None, None
+        return capture_date_from_exif(exif_date.values), DATE_FROM_EXIF
+
+    @staticmethod
+    def video_date(video):
+        if not video.file:
+            return None, None
+        return capture_date_from_video(video.file.path), DATE_FROM_VIDEO