"""Add message_history_json column to conversation.

Revision ID: 0020_add_message_history_json
Revises: 0019_cascade_message_fk_and_language_column
Create Date: 2026-03-11
"""

from collections.abc import Sequence

import sqlalchemy as sa

from alembic import op

revision: str = "0020_add_message_history_json"
down_revision: str | None = "0019_cascade_message_fk_and_language_column"
branch_labels: str | Sequence[str] | None = None
depends_on: str | Sequence[str] | None = None


def upgrade() -> None:
    op.add_column(
        "conversation",
        sa.Column("message_history_json", sa.Text(), nullable=True),
    )


def downgrade() -> None:
    op.drop_column("conversation", "message_history_json")