First commit

migrations/versions/phase22_comment_visibility.py

@@ -0,0 +1,41 @@
+"""phase22 — add is_customer_visible to issue_comments
+
+Staff comments default to hidden from customers (is_customer_visible=FALSE).
+Staff can tick a checkbox to share a comment with the customer.
+Customer comments are always visible (is_customer_visible=TRUE, set at write time).
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+revision      = 'phase22_comment_visibility'
+down_revision = 'phase21_performance_indexes'
+branch_labels = None
+depends_on    = None
+
+
+def _column_exists(bind, table: str, column: str) -> bool:
+    result = bind.execute(sa.text(
+        "SELECT COUNT(*) FROM information_schema.columns "
+        "WHERE table_schema = DATABASE() "
+        "  AND table_name   = :table "
+        "  AND column_name  = :column"
+    ), {'table': table, 'column': column})
+    return result.scalar() > 0
+
+
+def upgrade():
+    bind = op.get_bind()
+    if not _column_exists(bind, 'issue_comments', 'is_customer_visible'):
+        op.execute(sa.text(
+            'ALTER TABLE issue_comments '
+            'ADD COLUMN is_customer_visible BOOLEAN NOT NULL DEFAULT FALSE'
+        ))
+
+
+def downgrade():
+    bind = op.get_bind()
+    if _column_exists(bind, 'issue_comments', 'is_customer_visible'):
+        op.execute(sa.text(
+            'ALTER TABLE issue_comments DROP COLUMN is_customer_visible'
+        ))