"""Alembic environment configuration.

T11: Setup Alembic and initial schema migration
"""
import os
import sys
from logging.config import fileConfig

from sqlalchemy import engine_from_config, pool

from alembic import context

# Add src to path to import models
sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'src'))

# Import models to register them with Base
from openrouter_monitor.database import Base
from openrouter_monitor.models import User, ApiKey, UsageStats, ApiToken

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

# Override sqlalchemy.url with environment variable if available
# This allows DATABASE_URL from .env to be used
database_url = os.getenv('DATABASE_URL')
if database_url:
    config.set_main_option('sqlalchemy.url', 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)

# Set target_metadata to the Base.metadata from our models
# This is required for 'autogenerate' support
target_metadata = Base.metadata


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.

    """
    # For SQLite, we need to handle check_same_thread=False
    db_url = config.get_main_option("sqlalchemy.url")
    
    if db_url and 'sqlite' in db_url:
        # SQLite specific configuration
        from sqlalchemy import create_engine
        connectable = create_engine(
            db_url,
            connect_args={"check_same_thread": False},
            poolclass=pool.NullPool,
        )
    else:
        connectable = engine_from_config(
            config.get_section(config.config_ini_section, {}),
            prefix="sqlalchemy.",
            poolclass=pool.NullPool,
        )

    with connectable.connect() as connection:
        context.configure(
            connection=connection, target_metadata=target_metadata
        )

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


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