Aug 17 - Update customer roles management

migrations/versions/phase51_user_notification_matrix.py

@@ -0,0 +1,63 @@
+"""phase51 — per-account notification overrides
+
+Creates `user_notification_matrix`, the per-account layer over the global
+NotificationMatrix. One row = one account's explicit answer for one event
+(enabled True/False); NO row means "inherit the global column".
+
+See app/models/user_notification_matrix.py for the semantics.
+
+**No backfill, deliberately.** An empty table means every account inherits,
+which is exactly today's behaviour — so this migration cannot change who gets
+notified. Overrides are created only when an admin sets one on the account's
+page in Customer Management. Backfilling from the current global matrix would
+freeze every account at today's routing and quietly break future changes to the
+global columns.
+
+The rest of phase51 (Customer Director / Customer Inspector) is a LABEL-only
+rename over the existing 'customer' and 'external_inspector' ENUM values, so
+there is no ENUM change and no user row is touched here.
+
+Table-existence check — safe to re-run.
+"""
+
+revision      = 'phase51_user_notif_matrix'
+down_revision = 'phase50_default_modern'
+branch_labels = None
+depends_on    = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def _has_table(conn, name):
+    return conn.execute(sa.text(
+        "SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES "
+        "WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = :t"
+    ), {'t': name}).scalar() > 0
+
+
+def upgrade():
+    conn = op.get_bind()
+    if _has_table(conn, 'user_notification_matrix'):
+        return
+
+    op.create_table(
+        'user_notification_matrix',
+        sa.Column('id', sa.Integer, primary_key=True),
+        sa.Column('user_id', sa.Integer,
+                  sa.ForeignKey('users.id', ondelete='CASCADE'),
+                  nullable=False, index=True),
+        sa.Column('event_type', sa.String(50), nullable=False),
+        sa.Column('enabled', sa.Boolean, nullable=False,
+                  server_default=sa.text('1')),
+        sa.UniqueConstraint('user_id', 'event_type',
+                            name='uq_user_notif_matrix_user_event'),
+    )
+
+
+def downgrade():
+    conn = op.get_bind()
+    if _has_table(conn, 'user_notification_matrix'):
+        # Every row here is an explicit admin decision; dropping the table
+        # discards them and returns all accounts to global-matrix routing.
+        op.drop_table('user_notification_matrix')