"""drop source_dialect/target_dialect from terminology_dictionaries

Revision ID: f1a2b3c4d5e6
Revises: dabc97097e0e
Create Date: 2026-06-02 12:00:00.000000

"""
from collections.abc import Sequence

from alembic import op
from sqlalchemy import inspect


# revision identifiers, used by Alembic.
revision: str = 'f1a2b3c4d5e6'
down_revision: str | Sequence[str] | None = 'dabc97097e0e'
branch_labels: str | Sequence[str] | None = None
depends_on: str | Sequence[str] | None = None


def _column_exists(table_name: str, column_name: str) -> bool:
    conn = op.get_bind()
    inspector = inspect(conn)
    columns = [c["name"] for c in inspector.get_columns(table_name)]
    return column_name in columns


def upgrade() -> None:
    """Drop source_dialect and target_dialect from terminology_dictionaries."""
    if not _column_exists("terminology_dictionaries", "source_dialect"):
        return
    op.drop_column("terminology_dictionaries", "source_dialect")
    op.drop_column("terminology_dictionaries", "target_dialect")


def downgrade() -> None:
    """Re-add source_dialect and target_dialect to terminology_dictionaries."""
    import sqlalchemy as sa
    op.add_column("terminology_dictionaries", sa.Column(
        "source_dialect", sa.String(), nullable=False, server_default="",
    ))
    op.add_column("terminology_dictionaries", sa.Column(
        "target_dialect", sa.String(), nullable=False, server_default="",
    ))