"""asyncpg connection pool for Spore Commons."""

import asyncpg
import logging
from pathlib import Path

log = logging.getLogger(__name__)

_pool: asyncpg.Pool | None = None


async def init_pool(database_url: str) -> asyncpg.Pool:
    """Initialize the connection pool and run migrations."""
    global _pool
    _pool = await asyncpg.create_pool(
        database_url,
        min_size=2,
        max_size=10,
        command_timeout=30,
    )
    await _run_migrations(_pool)
    log.info("Database pool initialized")
    return _pool


async def _run_migrations(pool: asyncpg.Pool) -> None:
    """Run SQL migration files in order."""
    migrations_dir = Path(__file__).parent / "migrations"
    if not migrations_dir.exists():
        return

    async with pool.acquire() as conn:
        # Create migrations tracking table
        await conn.execute("""
            CREATE TABLE IF NOT EXISTS _migrations (
                filename TEXT PRIMARY KEY,
                applied_at TIMESTAMPTZ DEFAULT now()
            )
        """)

        applied = {
            row["filename"]
            for row in await conn.fetch("SELECT filename FROM _migrations")
        }

        sql_files = sorted(migrations_dir.glob("*.sql"))
        for sql_file in sql_files:
            if sql_file.name in applied:
                continue
            log.info(f"Applying migration: {sql_file.name}")
            sql = sql_file.read_text()
            async with conn.transaction():
                await conn.execute(sql)
                await conn.execute(
                    "INSERT INTO _migrations (filename) VALUES ($1)",
                    sql_file.name,
                )


def get_pool() -> asyncpg.Pool:
    """Get the current connection pool."""
    if _pool is None:
        raise RuntimeError("Database pool not initialized")
    return _pool


async def close_pool() -> None:
    """Close the connection pool."""
    global _pool
    if _pool:
        await _pool.close()
        _pool = None