"""
Alembic environment configuration for SQLAlchemy with pgvector.
Uses synchronous psycopg2 driver for migrations to avoid pgbouncer issues.
"""
import os
from logging.config import fileConfig

from sqlalchemy import pool, engine_from_config
from sqlalchemy.engine import Connection

from alembic import context
from dotenv import load_dotenv

# Import your models here
from memory.models import Base

# Load environment variables
load_dotenv()

# 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)

# Get database URL from environment
database_url = os.getenv("DATABASE_URL")
if not database_url:
    raise ValueError("DATABASE_URL environment variable is not set")

# For migrations, use psycopg2 (sync driver) to avoid pgbouncer prepared statement issues
# The application uses asyncpg, but migrations work better with psycopg2
if database_url.startswith("postgresql+asyncpg://"):
    database_url = database_url.replace("postgresql+asyncpg://", "postgresql://", 1)
elif database_url.startswith("postgres+asyncpg://"):
    database_url = database_url.replace("postgres+asyncpg://", "postgresql://", 1)

# Override the sqlalchemy.url in alembic.ini
config.set_main_option("sqlalchemy.url", database_url)

# 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 with synchronous engine."""
    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()