Jul 26 - Update scheduled inspection settings (weekly/monthly)

migrations/versions/phase43_scheduled_recurrence.py

@@ -0,0 +1,66 @@
+"""phase43 — scheduled inspection day-of-week / day-of-month recurrence
+
+Adds the recurrence-detail columns to `scheduled_inspections` so a weekly
+schedule can name the weekdays it runs on (Mon/Wed/Fri) and a monthly schedule
+can name either a day of the month ("the 15th") or an nth weekday ("the 2nd
+Tuesday"):
+
+    weekdays     VARCHAR(20)  -- CSV of Python weekday ints, Mon=0, e.g. '0,2,4'
+    month_mode   VARCHAR(20)  -- 'day_of_month' | 'nth_weekday'
+    day_of_month SMALLINT     -- 1–31, clamped to the month's last day
+    nth_week     SMALLINT     -- 1–5, or -1 for "last"
+    nth_weekday  SMALLINT     -- 0–6, Mon=0
+
+All nullable with no backfill: existing phase36 rows keep NULLs and fall back to
+the legacy "+7 days" / "same day next month" behaviour in
+ScheduledInspection._add_interval(), so no schedule changes cadence on deploy.
+
+`month_mode` is VARCHAR rather than ENUM so adding a recurrence style later
+needs no 3-step MySQL ENUM migration (CLAUDE.md rule 3).
+
+Uses INFORMATION_SCHEMA column-existence checks — safe to re-run.
+"""
+
+revision      = 'phase43_sched_recurrence'
+down_revision = 'phase42_internal_contact'
+branch_labels = None
+depends_on    = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+_COLUMNS = (
+    ('weekdays',     'VARCHAR(20) NULL'),
+    ('month_mode',   'VARCHAR(20) NULL'),
+    ('day_of_month', 'SMALLINT NULL'),
+    ('nth_week',     'SMALLINT NULL'),
+    ('nth_weekday',  'SMALLINT NULL'),
+)
+
+
+def _column_exists(conn, table, column):
+    result = 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})
+    return result.scalar() > 0
+
+
+def upgrade():
+    bind = op.get_bind()
+    for name, ddl in _COLUMNS:
+        if not _column_exists(bind, 'scheduled_inspections', name):
+            op.execute(sa.text(
+                f"ALTER TABLE scheduled_inspections ADD COLUMN {name} {ddl}"
+            ))
+
+
+def downgrade():
+    bind = op.get_bind()
+    for name, _ in reversed(_COLUMNS):
+        if _column_exists(bind, 'scheduled_inspections', name):
+            op.execute(sa.text(
+                f"ALTER TABLE scheduled_inspections DROP COLUMN {name}"
+            ))