start working on case_study bulk editiing and add relative dates to the model

atlas/models.py

@@ -840,6 +840,12 @@ class Case(models.Model, AuthorMixin, QuestionMixin):
 
     cimar_uuid = models.CharField(max_length=255, null=True, blank=True)
 
+    study_date = models.DateField(
+        null=True,
+        blank=True,
+        help_text="Optional manually overridden study date for linked case series.",
+    )
+
     def get_ordered_series_details(self):
         cached = getattr(self, "_ordered_series_details_cache", None)
         if cached is not None:
@@ -873,6 +879,41 @@ class Case(models.Model, AuthorMixin, QuestionMixin):
         self._ordered_series_cache = ordered
         return ordered
 
+    @staticmethod
+    def _parse_dicom_date(value):
+        if not value:
+            return None
+        try:
+            return datetime.datetime.strptime(str(value), "%Y%m%d").date()
+        except (TypeError, ValueError):
+            return None
+
+    def get_effective_study_date(self):
+        if self.study_date:
+            return self.study_date
+
+        for series in self.get_ordered_series():
+            image = series.images.filter(removed=False).first()
+            if not image:
+                continue
+            try:
+                ds = image.get_dicom_data()
+            except Exception:
+                ds = None
+            if not ds:
+                continue
+
+            raw_date = (
+                getattr(ds, "StudyDate", None)
+                or getattr(ds, "AcquisitionDate", None)
+                or getattr(ds, "SeriesDate", None)
+            )
+            parsed = self._parse_dicom_date(raw_date)
+            if parsed:
+                return parsed
+
+        return None
+
     def get_app_name(self):
         return "atlas"