"""Alembic environment — async, schema-isolated to the ClassLens schema.

The DB connection and target schema come from application settings, so the same
migrations run against Supabase (schema=classlens) or local SQLite (schema=None).
Only the ClassLens schema is ever touched — other apps sharing the DB are ignored.
"""

from __future__ import annotations

import asyncio
from logging.config import fileConfig

from alembic import context

from app.db import active_schema, get_engine
from app.models import Base  # noqa: F401  (registers all tables on Base.metadata)

config = context.config
if config.config_file_name:
    fileConfig(config.config_file_name)

target_metadata = Base.metadata
SCHEMA = active_schema()


def _include_object(obj, name, type_, reflected, compare_to):
    """Never let autogenerate manage tables outside our schema."""
    if type_ == "table":
        return getattr(obj, "schema", None) == SCHEMA
    return True


def _configure(connection):
    context.configure(
        connection=connection,
        target_metadata=target_metadata,
        version_table_schema=SCHEMA,
        include_schemas=False,
        include_object=_include_object,
        compare_type=True,
    )


def _run(connection):
    _configure(connection)
    with context.begin_transaction():
        context.run_migrations()


async def run_async():
    engine = get_engine()
    async with engine.connect() as conn:
        await conn.run_sync(_run)
    await engine.dispose()


if context.is_offline_mode():
    context.configure(
        url=str(get_engine().url),
        target_metadata=target_metadata,
        version_table_schema=SCHEMA,
        include_object=_include_object,
        literal_binds=True,
        dialect_opts={"paramstyle": "named"},
    )
    with context.begin_transaction():
        context.run_migrations()
else:
    asyncio.run(run_async())