Merge pull request #1567 from bcgov/fix/alex-transfer-count-1518

Fix: Transfer Counts - 1518

backend/lcfs/db/migrations/versions/2024-12-30-13-54_9329e38396e1.py

@@ -0,0 +1,84 @@
+"""add update_count_transfers_in_progress db function and update existing counts
+
+Revision ID: 9329e38396e1
+Revises: d9cdd9fca0ce
+Create Date: 2024-12-30 13:54:09.361644
+
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "9329e38396e1"
+down_revision = "d9cdd9fca0ce"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # Create or replace the trigger function without considering Draft transfers
+    op.execute(
+        """
+        CREATE OR REPLACE FUNCTION update_count_transfers_in_progress()
+        RETURNS TRIGGER AS $$
+        BEGIN
+            -- Update count_transfers_in_progress for from_organization_id and to_organization_id
+            UPDATE organization o
+            SET count_transfers_in_progress = (
+                SELECT COUNT(DISTINCT t.transfer_id)
+                FROM transfer t
+                WHERE 
+                    t.current_status_id IN (3, 4)
+                    AND (t.from_organization_id = o.organization_id OR t.to_organization_id = o.organization_id)
+            )
+            WHERE o.organization_id = COALESCE(NEW.from_organization_id, OLD.from_organization_id)
+               OR o.organization_id = COALESCE(NEW.to_organization_id, OLD.to_organization_id);
+
+            RETURN NEW;
+        END;
+        $$ LANGUAGE plpgsql;
+        """
+    )
+
+    # Create the trigger
+    op.execute(
+        """
+        CREATE TRIGGER update_count_transfers_in_progress_trigger
+        AFTER INSERT OR UPDATE OR DELETE ON transfer
+        FOR EACH ROW
+        EXECUTE FUNCTION update_count_transfers_in_progress();
+        """
+    )
+
+    # Update existing counts for all organizations by aggregating both sent and received transfers without double-counting
+    op.execute(
+        """
+        UPDATE organization o
+        SET count_transfers_in_progress = COALESCE(sub.total_transfer_count, 0)
+        FROM (
+            SELECT
+                org.organization_id,
+                COUNT(DISTINCT t.transfer_id) AS total_transfer_count
+            FROM
+                organization org
+                LEFT JOIN transfer t ON org.organization_id = t.from_organization_id
+                                      OR org.organization_id = t.to_organization_id
+            WHERE
+                t.current_status_id IN (3, 4)
+            GROUP BY
+                org.organization_id
+        ) sub
+        WHERE
+            o.organization_id = sub.organization_id;
+        """
+    )
+
+
+def downgrade() -> None:
+    # Drop the trigger
+    op.execute(
+        "DROP TRIGGER IF EXISTS update_count_transfers_in_progress_trigger ON transfer;"
+    )
+    # Drop the trigger function
+    op.execute("DROP FUNCTION IF EXISTS update_count_transfers_in_progress();")