from sqlmodel import SQLModel, Session, create_engine
from sqlalchemy import inspect, text
from sqlalchemy.pool import StaticPool
from .config import get_settings

settings = get_settings()
if settings.meta_bridge_database_url == "sqlite://":
    engine = create_engine(settings.meta_bridge_database_url, echo=False, connect_args={"check_same_thread": False}, poolclass=StaticPool)
else:
    connect_args = {"check_same_thread": False} if settings.meta_bridge_database_url.startswith("sqlite") else {}
    engine = create_engine(settings.meta_bridge_database_url, echo=False, connect_args=connect_args)

def init_db() -> None:
    SQLModel.metadata.create_all(engine)
    _ensure_draft_media_columns()

def _ensure_draft_media_columns() -> None:
    inspector = inspect(engine)
    if "draft" not in inspector.get_table_names():
        return
    existing = {column["name"] for column in inspector.get_columns("draft")}
    statements = []
    if "media_attachments" not in existing:
        statements.append("ALTER TABLE draft ADD COLUMN media_attachments JSON DEFAULT '[]'")
    if "media_required" not in existing:
        statements.append("ALTER TABLE draft ADD COLUMN media_required BOOLEAN DEFAULT 0")
    if "publish_mode" not in existing:
        statements.append("ALTER TABLE draft ADD COLUMN publish_mode VARCHAR DEFAULT 'now'")
    if "scheduled_publish_time" not in existing:
        statements.append("ALTER TABLE draft ADD COLUMN scheduled_publish_time DATETIME")
    if not statements:
        return
    with engine.begin() as conn:
        for statement in statements:
            conn.execute(text(statement))

def get_session():
    with Session(engine) as session:
        yield session