Truncate time from discharge_date (#1734)

* Truncate time from `discharge_date`

* Exclude weird records

* correct output_field

care/facility/migrations/0397_truncate_discharge_time.py

@@ -0,0 +1,59 @@
+# Generated by Django 4.2.5 on 2023-11-30 11:58
+
+import datetime
+
+from django.db import migrations
+from django.db.models import DateTimeField, ExpressionWrapper, F
+from django.db.models.functions import TruncDay
+from django.utils import timezone
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("facility", "0396_merge_20231122_0240"),
+    ]
+
+    def clean_discharge_date(apps, schema_editor):
+        """
+        Clean discharge_date field to be 00:00:00 IST
+
+        For example:
+
+        `2023-10-06 06:00:00 +05:30 IST` (`2023-10-06 00:30:00 +00:00 UTC`) would be updated to
+        `2023-10-06 00:00:00 +05:30 IST` (`2023-10-05 18:30:00 +00:00 UTC`)
+
+        Equivalent to the following SQL:
+
+        ```sql
+        UPDATE facility_patientconsultation
+        SET discharge_date =
+            timezone('IST', discharge_date) AT TIME ZONE 'UTC' +
+            (date_trunc('day', timezone('IST', discharge_date)) - timezone('IST', discharge_date)) +
+            (interval '-5 hours -30 minutes')
+        WHERE discharge_date IS NOT NULL;
+        ```
+        """
+
+        current_timezone = timezone.get_current_timezone()
+        tz_offset = timezone.timedelta(
+            minutes=current_timezone.utcoffset(datetime.datetime.utcnow()).seconds / 60
+        )
+
+        PatientConsultation = apps.get_model("facility", "PatientConsultation")
+        PatientConsultation.objects.filter(discharge_date__isnull=False).exclude(
+            admission_date__isnull=False, discharge_date__lt=F("admission_date")
+        ).update(
+            discharge_date=ExpressionWrapper(
+                # Convert the discharge_date to UTC by subtracting the current offset
+                F("discharge_date") - tz_offset +
+                # Get the day part of the discharge_date and subtract the actual discharge_date from it
+                (TruncDay(F("discharge_date")) - F("discharge_date")),
+                output_field=DateTimeField(),
+            )
+        )
+
+    operations = [
+        migrations.RunPython(
+            clean_discharge_date, reverse_code=migrations.RunPython.noop
+        ),
+    ]