from __future__ import annotations

from sqlalchemy import text
from sqlalchemy.ext.asyncio import AsyncSession


async def _ensure_table_id_sequence(db: AsyncSession, *, table_name: str) -> None:
    bind = db.get_bind()
    dialect_name = str(getattr(getattr(bind, "dialect", None), "name", "")).lower()
    if dialect_name != "postgresql":
        return

    await db.execute(
        text(
            f"""
            SELECT setval(
                pg_get_serial_sequence('{table_name}', 'id'),
                GREATEST(
                    COALESCE((SELECT MAX(id) FROM {table_name}), 0),
                    COALESCE((SELECT last_value FROM {table_name}_id_seq), 0),
                    1
                ),
                true
            )
            """
        )
    )


async def ensure_project_id_sequence(db: AsyncSession) -> None:
    """Keep the PostgreSQL `projects.id` sequence ahead of existing rows."""
    await _ensure_table_id_sequence(db, table_name="projects")


async def ensure_signal_id_sequence(db: AsyncSession) -> None:
    """Keep the PostgreSQL `signals.id` sequence ahead of existing rows."""
    await _ensure_table_id_sequence(db, table_name="signals")