Jul 30 - Allow customer to flag follow-up a inspection

migrations/versions/phase46_followup_requested_by.py

@@ -0,0 +1,74 @@
+"""phase46 — follow-up request attribution (customer-raised follow-ups)
+
+Adds to `inspections`:
+
+    follow_up_requested_by  INT NULL  FK → users(id) ON DELETE SET NULL
+    follow_up_requested_at  DATETIME NULL
+
+Customers can now request a follow-up re-inspection of a completed inspection at
+their own facilities (previously admin/director only), so `follow_up_required`
+alone is no longer enough — staff need to see WHO is waiting on the
+re-inspection, and a client request must be visibly distinct from an internal
+one. `flag_followup()` sets both columns; `clear_followup()` nulls them.
+
+No backfill: legacy rows keep NULL, which the UI renders as an unattributed
+follow-up exactly as it did before. FK is SET NULL so deleting a user never
+deletes inspection history.
+
+Uses INFORMATION_SCHEMA checks — safe to re-run.
+"""
+
+revision      = 'phase46_followup_req_by'
+down_revision = 'phase45_sched_parent_insp'
+branch_labels = None
+depends_on    = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+_FK_NAME = 'fk_inspections_follow_up_requested_by'
+
+
+def _column_exists(conn, table, column):
+    return conn.execute(sa.text(
+        "SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS "
+        "WHERE TABLE_SCHEMA = DATABASE() "
+        "AND TABLE_NAME = :t AND COLUMN_NAME = :c"
+    ), {"t": table, "c": column}).scalar() > 0
+
+
+def _fk_exists(conn, table, name):
+    return conn.execute(sa.text(
+        "SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS "
+        "WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = :t "
+        "AND CONSTRAINT_NAME = :n AND CONSTRAINT_TYPE = 'FOREIGN KEY'"
+    ), {"t": table, "n": name}).scalar() > 0
+
+
+def upgrade():
+    bind = op.get_bind()
+
+    if not _column_exists(bind, 'inspections', 'follow_up_requested_by'):
+        op.execute(sa.text(
+            "ALTER TABLE inspections ADD COLUMN follow_up_requested_by INT NULL"
+        ))
+    if not _column_exists(bind, 'inspections', 'follow_up_requested_at'):
+        op.execute(sa.text(
+            "ALTER TABLE inspections ADD COLUMN follow_up_requested_at DATETIME NULL"
+        ))
+    if not _fk_exists(bind, 'inspections', _FK_NAME):
+        op.execute(sa.text(
+            f"ALTER TABLE inspections ADD CONSTRAINT {_FK_NAME} "
+            "FOREIGN KEY (follow_up_requested_by) REFERENCES users(id) "
+            "ON DELETE SET NULL"
+        ))
+
+
+def downgrade():
+    bind = op.get_bind()
+    if _fk_exists(bind, 'inspections', _FK_NAME):
+        op.execute(sa.text(f"ALTER TABLE inspections DROP FOREIGN KEY {_FK_NAME}"))
+    for col in ('follow_up_requested_at', 'follow_up_requested_by'):
+        if _column_exists(bind, 'inspections', col):
+            op.execute(sa.text(f"ALTER TABLE inspections DROP COLUMN {col}"))