"""Add channel file table

Revision ID: 6283dc0e4d8d
Revises: 3e0e00844bb0
Create Date: 2025-12-10 15:11:39.424601

"""

from typing import Sequence, Union

import open_webui.internal.db
import sqlalchemy as sa
from alembic import op

# revision identifiers, used by Alembic.
revision: str = '6283dc0e4d8d'
down_revision: Union[str, None] = '3e0e00844bb0'
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    conn = op.get_bind()
    inspector = sa.inspect(conn)
    existing_tables = set(inspector.get_table_names())

    if 'channel_file' not in existing_tables:
        op.create_table(
            'channel_file',
            sa.Column('id', sa.Text(), primary_key=True),
            sa.Column('user_id', sa.Text(), nullable=False),
            sa.Column(
                'channel_id',
                sa.Text(),
                sa.ForeignKey('channel.id', ondelete='CASCADE'),
                nullable=False,
            ),
            sa.Column(
                'file_id',
                sa.Text(),
                sa.ForeignKey('file.id', ondelete='CASCADE'),
                nullable=False,
            ),
            sa.Column('created_at', sa.BigInteger(), nullable=False),
            sa.Column('updated_at', sa.BigInteger(), nullable=False),
            # indexes
            sa.Index('ix_channel_file_channel_id', 'channel_id'),
            sa.Index('ix_channel_file_file_id', 'file_id'),
            sa.Index('ix_channel_file_user_id', 'user_id'),
            # unique constraints
            sa.UniqueConstraint(
                'channel_id', 'file_id', name='uq_channel_file_channel_file'
            ),  # prevent duplicate entries
        )


def downgrade() -> None:
    op.drop_table('channel_file')
