"""Add chat_file table

Revision ID: c440947495f3
Revises: 81cc2ce44d79
Create Date: 2025-12-21 20:27:41.694897

"""

from typing import Sequence, Union

from alembic import op
import sqlalchemy as sa

# revision identifiers, used by Alembic.
revision: str = 'c440947495f3'
down_revision: Union[str, None] = '81cc2ce44d79'
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    op.create_table(
        'chat_file',
        sa.Column('id', sa.Text(), primary_key=True),
        sa.Column('user_id', sa.Text(), nullable=False),
        sa.Column(
            'chat_id',
            sa.Text(),
            sa.ForeignKey('chat.id', ondelete='CASCADE'),
            nullable=False,
        ),
        sa.Column(
            'file_id',
            sa.Text(),
            sa.ForeignKey('file.id', ondelete='CASCADE'),
            nullable=False,
        ),
        sa.Column('message_id', sa.Text(), nullable=True),
        sa.Column('created_at', sa.BigInteger(), nullable=False),
        sa.Column('updated_at', sa.BigInteger(), nullable=False),
        # indexes
        sa.Index('ix_chat_file_chat_id', 'chat_id'),
        sa.Index('ix_chat_file_file_id', 'file_id'),
        sa.Index('ix_chat_file_message_id', 'message_id'),
        sa.Index('ix_chat_file_user_id', 'user_id'),
        # unique constraints
        sa.UniqueConstraint('chat_id', 'file_id', name='uq_chat_file_chat_file'),  # prevent duplicate entries
    )
    pass


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