"""Alembic: синхронный движок SQLAlchemy + psycopg3 (отдельно от asyncpg в рантайме)."""

from __future__ import annotations

import os
from logging.config import fileConfig
from pathlib import Path

from alembic import context
from dotenv import load_dotenv
from sqlalchemy import create_engine, pool

ROOT = Path(__file__).resolve().parent.parent
load_dotenv(ROOT / ".env")

config = context.config
if config.config_file_name is not None:
    fileConfig(config.config_file_name)

target_metadata = None


def _ensure_psycopg_client_encoding(url: str) -> str:
    """Иначе psycopg3 при SQL_ASCII на сервере отдаёт version() как bytes → падает SQLAlchemy re.match."""
    if "+psycopg" not in url or "client_encoding=" in url:
        return url
    join = "&" if "?" in url else "?"
    return f"{url}{join}client_encoding=utf8"


def get_sync_url() -> str:
    url = os.environ.get("DATABASE_URL", "").strip()
    if not url:
        raise RuntimeError("Задай DATABASE_URL для alembic upgrade")
    if url.startswith("postgres://"):
        url = url.replace("postgres://", "postgresql://", 1)
    if url.startswith("postgresql://") and "+psycopg" not in url and "+asyncpg" not in url:
        url = url.replace("postgresql://", "postgresql+psycopg://", 1)
    if "+asyncpg" in url:
        url = url.replace("+asyncpg", "+psycopg")
    return _ensure_psycopg_client_encoding(url)


def run_migrations_offline() -> None:
    context.configure(
        url=get_sync_url(),
        literal_binds=True,
        dialect_opts={"paramstyle": "named"},
    )
    with context.begin_transaction():
        context.run_migrations()


def run_migrations_online() -> None:
    connectable = create_engine(get_sync_url(), poolclass=pool.NullPool)
    with connectable.connect() as connection:
        context.configure(connection=connection)
        with context.begin_transaction():
            context.run_migrations()


if context.is_offline_mode():
    run_migrations_offline()
else:
    run_migrations_online()