"""
Alembic environment script for database migrations
"""
import sys
from logging.config import fileConfig
from pathlib import Path

from alembic import context

# Custom module to help with finding modules in containerized environments
from alembic.find_modules import setup_python_path
from sqlalchemy import engine_from_config, pool

# Setup Python path to find app modules in various environments
setup_python_path()

# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config

# Interpret the config file for Python logging.
# This line sets up loggers basically.
if config.config_file_name is not None:
    fileConfig(config.config_file_name)

# Try different import strategies to handle various deployment environments
try:
    # Standard import approach
    from app.models import Todo  # noqa
    from app.core.database import Base  # noqa
except ImportError:
    try:
        # Path-based import for some container setups
        import importlib.util
        import sys

        # Try to find the module file
        for base_path in sys.path:
            model_path = Path(base_path) / "app" / "models" / "todo.py"
            db_path = Path(base_path) / "app" / "core" / "database.py"

            if model_path.exists() and db_path.exists():
                # Load the todo module
                spec = importlib.util.spec_from_file_location("todo", model_path)
                todo_module = importlib.util.module_from_spec(spec)
                spec.loader.exec_module(todo_module)

                # Load the database module
                spec = importlib.util.spec_from_file_location("database", db_path)
                db_module = importlib.util.module_from_spec(spec)
                spec.loader.exec_module(db_module)

                # Get the required objects
                Todo = getattr(todo_module, "Todo")
                Base = getattr(db_module, "Base")
                break
        else:
            raise ImportError("Could not find app modules in any path")
    except Exception as e:
        print(f"Error importing models: {e}")
        print(f"Current sys.path: {sys.path}")
        raise

target_metadata = Base.metadata


def run_migrations_offline():
    """Run migrations in 'offline' mode.

    This configures the context with just a URL
    and not an Engine, though an Engine is acceptable
    here as well.  By skipping the Engine creation
    we don't even need a DBAPI to be available.

    Calls to context.execute() here emit the given string to the
    script output.

    """
    url = config.get_main_option("sqlalchemy.url")
    context.configure(
        url=url,
        target_metadata=target_metadata,
        literal_binds=True,
        dialect_opts={"paramstyle": "named"},
    )

    with context.begin_transaction():
        context.run_migrations()


def run_migrations_online():
    """Run migrations in 'online' mode.

    In this scenario we need to create an Engine
    and associate a connection with the context.

    """
    connectable = engine_from_config(
        config.get_section(config.config_ini_section),
        prefix="sqlalchemy.",
        poolclass=pool.NullPool,
    )

    with connectable.connect() as connection:
        is_sqlite = connection.dialect.name == 'sqlite'
        context.configure(
            connection=connection,
            target_metadata=target_metadata,
            render_as_batch=is_sqlite,  # Key configuration for SQLite
        )

        with context.begin_transaction():
            context.run_migrations()


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