import os
from logging.config import fileConfig
from sqlalchemy import engine_from_config
from sqlalchemy import pool
from pathlib import Path

from alembic import context

# Import models to ensure they are registered with SQLAlchemy
from app.models.base import Base
# Import Secret model to ensure it's registered
# noqa: F401 is used to tell linters to ignore the unused import
from app.models.secret import Secret  # noqa: F401
from app.core.config import settings

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

# Set the SQLAlchemy URL from the settings
config.set_main_option("sqlalchemy.url", settings.SQLALCHEMY_DATABASE_URL)

# 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)

# add your model's MetaData object here
# for 'autogenerate' support
target_metadata = Base.metadata

# other values from the config, defined by the needs of env.py,
# can be acquired:
# my_important_option = config.get_main_option("my_important_option")
# ... etc.


def run_migrations_offline() -> None:
    """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() -> None:
    """Run migrations in 'online' mode.

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

    """
    # Ensure the DB directory exists
    db_dir = Path(settings.DB_DIR)
    db_dir.mkdir(parents=True, exist_ok=True)
    
    # Ensure directory has write permissions
    try:
        os.chmod(db_dir, 0o777)
    except Exception:
        print(f"Warning: Could not set permissions on {db_dir}")
    
    # Create database file if it doesn't exist and set permissions
    db_file = db_dir / "db.sqlite"
    if not db_file.exists():
        db_file.touch()
        try:
            os.chmod(db_file, 0o666)  # Read-write permissions for everyone
        except Exception:
            print(f"Warning: Could not set permissions on {db_file}")
    
    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
            compare_type=True,
        )

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


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