"""Convert notification title/body from text to jsonb (i18n dict).

title and body become jsonb objects keyed by locale code:
  {"zh": "欢迎来到觅爻", "zh_Hant": "...", "en": "..."}

Existing data is wrapped under the "zh" key (simplified Chinese default).

Revision ID: 20260428_0001
"""

from alembic import op
import sqlalchemy as sa

revision = "20260428_0001"
down_revision = "20260427_0002"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.execute(
        """
        ALTER TABLE notifications
            ALTER COLUMN title TYPE jsonb USING jsonb_build_object('zh', title),
            ALTER COLUMN body  TYPE jsonb USING jsonb_build_object('zh', body);
        """
    )

    op.execute(
        """
        ALTER TABLE notifications DROP CONSTRAINT IF EXISTS ck_notifications_payload_object;
        """
    )

    op.execute(
        """
        ALTER TABLE notifications
            ADD CONSTRAINT ck_notifications_payload_object
            CHECK (jsonb_typeof(payload) = 'object');
        """
    )


def downgrade() -> None:
    op.execute(
        """
        ALTER TABLE notifications
            ALTER COLUMN title TYPE text USING COALESCE(title ->> 'zh', ''),
            ALTER COLUMN body  TYPE text USING COALESCE(body  ->> 'zh', '');
        """
    )