Aug 5 - Update code to follow up ST - MT14b

migrations/versions/phase50_sched_acknowledged.py

@@ -0,0 +1,83 @@
+"""phase50 — inspection schedule receipt acknowledgement
+
+Ports single-tenant phase47 onto MT's `inspection_schedules` table. Adds:
+
+    acknowledged_at DATETIME NULL
+
+Stamped when the assigned inspector confirms they have received/seen a scheduled
+inspection request. NULL = awaiting confirmation.
+
+Scope of the acknowledgement
+----------------------------
+It is per ASSIGNMENT, not per occurrence. `fulfill()` and `advance_due_date()`
+deliberately leave this column alone as the schedule rolls forward — an
+inspector who confirmed "yes, this weekly restroom round is mine" should not be
+asked again every week. The edit route resets it to NULL when the schedule is
+reassigned to a DIFFERENT inspector, because the new assignee has confirmed
+nothing.
+
+The acknowledger is always the assigned inspector — the only person the routes
+permit to confirm — so no separate `acknowledged_by` column is stored.
+
+Only meaningful for `plan` mode: an `auto` schedule materialises its inspection
+without anyone starting it, so there is no request to receive. The UI shows the
+control for plan-mode rows only.
+
+No backfill: legacy rows keep NULL and render as "awaiting confirmation", which
+is the correct initial state for an assignment nobody has confirmed yet.
+
+Revision id note
+----------------
+`alembic_version.version_num` is VARCHAR(32); the id below is 24 characters.
+The filename stays descriptive — Alembic keys on the `revision` string.
+
+Uses an INFORMATION_SCHEMA check — safe to re-run on every tenant DB. Additive
+only: nothing is renamed, retyped or dropped.
+"""
+
+revision      = 'phase50_sched_acknowledged'
+down_revision = 'phase49_followup_req_by'
+branch_labels = None
+depends_on    = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+_TABLE  = 'inspection_schedules'
+_COLUMN = 'acknowledged_at'
+
+
+def _table_exists(conn, table):
+    return conn.execute(sa.text(
+        "SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES "
+        "WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = :t"
+    ), {"t": table}).scalar() > 0
+
+
+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 upgrade():
+    bind = op.get_bind()
+    if not _table_exists(bind, _TABLE):
+        return
+    if not _column_exists(bind, _TABLE, _COLUMN):
+        op.execute(sa.text(
+            f"ALTER TABLE {_TABLE} ADD COLUMN {_COLUMN} DATETIME NULL"
+        ))
+
+
+def downgrade():
+    bind = op.get_bind()
+    if not _table_exists(bind, _TABLE):
+        return
+    if _column_exists(bind, _TABLE, _COLUMN):
+        op.execute(sa.text(
+            f"ALTER TABLE {_TABLE} DROP COLUMN {_COLUMN}"
+        ))