# QC Élection Forecast — Plateforme de prévision électorale du Québec 2026
# Auteur : Simon-Pierre Boucher
# Contact : contact@spboucher.ai
# https://www.qc-election.com
from __future__ import annotations

from sqlalchemy import create_engine
from sqlalchemy.orm import DeclarativeBase, Session, sessionmaker

from .config import settings


class Base(DeclarativeBase):
    pass


engine = create_engine(
    settings.database_url,
    connect_args={"check_same_thread": False} if settings.database_url.startswith("sqlite") else {},
)
SessionLocal = sessionmaker(bind=engine, autoflush=False, expire_on_commit=False)


def get_db():
    db: Session = SessionLocal()
    try:
        yield db
    finally:
        db.close()


def init_db() -> None:
    from . import models  # noqa: F401
    Base.metadata.create_all(engine)
    _migrate()


def _migrate() -> None:
    """Micro-migrations SQLite : create_all n'ALTÈRE pas les tables existantes —
    on ajoute ici les colonnes manquantes (idempotent, additif seulement)."""
    from sqlalchemy import inspect, text
    added = {
        "social_posts": [("content_class", "VARCHAR(20) DEFAULT 'public_discussion'")],
    }
    insp = inspect(engine)
    with engine.begin() as conn:
        for table, cols in added.items():
            if table not in insp.get_table_names():
                continue
            existing = {c["name"] for c in insp.get_columns(table)}
            for name, ddl in cols:
                if name not in existing:
                    conn.execute(text(
                        f"ALTER TABLE {table} ADD COLUMN {name} {ddl}"))