"""Database connection pool and helpers (psycopg v3)."""

from __future__ import annotations

import json
from typing import Any

import psycopg
from psycopg.rows import dict_row
from psycopg_pool import ConnectionPool

from app.config import DATABASE_URL

_pool: ConnectionPool | None = None


def get_pool() -> ConnectionPool:
    global _pool
    if _pool is None:
        _pool = ConnectionPool(
            conninfo=DATABASE_URL,
            kwargs={"row_factory": dict_row},
            min_size=1,
            max_size=8,
            open=True,
        )
    return _pool


def close_pool() -> None:
    global _pool
    if _pool is not None:
        _pool.close()
        _pool = None


def get_conn() -> psycopg.Connection:
    """Get a raw connection (for use as context manager)."""
    return psycopg.connect(DATABASE_URL, row_factory=dict_row)


# --- repository helpers ---


def fetch_one(sql: str, params: tuple[Any, ...] = ()) -> dict[str, Any] | None:
    pool = get_pool()
    with pool.connection() as conn:
        with conn.cursor() as cur:
            cur.execute(sql, params)
            return cur.fetchone()


def fetch_all(sql: str, params: tuple[Any, ...] = ()) -> list[dict[str, Any]]:
    pool = get_pool()
    with pool.connection() as conn:
        with conn.cursor() as cur:
            cur.execute(sql, params)
            return cur.fetchall()


def execute(sql: str, params: tuple[Any, ...] = ()) -> dict[str, Any] | None:
    pool = get_pool()
    with pool.connection() as conn:
        with conn.cursor() as cur:
            cur.execute(sql, params)
            conn.commit()
            if cur.description:
                return cur.fetchone()
            return None


# JSON adaptation for psycopg v3
def adapt_jsonb(value: Any) -> str:
    return json.dumps(value)


def convert_uuid(value: Any) -> str | None:
    if value is None:
        return None
    return str(value)