from sqlalchemy import create_engine, inspect, text
from sqlalchemy.orm import sessionmaker, DeclarativeBase
from app.config import get_settings

settings = get_settings()

engine = create_engine(
    settings.database_url,
    connect_args={"check_same_thread": False},
)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


class Base(DeclarativeBase):
    pass


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


def init_db():
    """Create all tables."""
    # import models so SQLAlchemy registers them
    from app.models import admin_user, upstream, snapshot, webhook_config, notification_log, custom_page, website, revoked_token  # noqa: F401
    Base.metadata.create_all(bind=engine)
    _migrate_custom_pages()


def _migrate_custom_pages():
    """Apply small SQLite-safe migrations for deployments without Alembic."""
    inspector = inspect(engine)
    if "custom_pages" not in inspector.get_table_names():
        return
    columns = {col["name"] for col in inspector.get_columns("custom_pages")}
    with engine.begin() as conn:
        if "access_mode" not in columns:
            conn.execute(text("ALTER TABLE custom_pages ADD COLUMN access_mode VARCHAR(32) NOT NULL DEFAULT 'direct'"))
            conn.execute(text("UPDATE custom_pages SET access_mode = CASE WHEN use_proxy = 1 THEN 'proxy' ELSE 'direct' END"))
        if "login_username" not in columns:
            conn.execute(text("ALTER TABLE custom_pages ADD COLUMN login_username VARCHAR(255)"))
        if "login_password" not in columns:
            conn.execute(text("ALTER TABLE custom_pages ADD COLUMN login_password TEXT"))
        if "login_username_selector" not in columns:
            conn.execute(text("ALTER TABLE custom_pages ADD COLUMN login_username_selector VARCHAR(512)"))
        if "login_password_selector" not in columns:
            conn.execute(text("ALTER TABLE custom_pages ADD COLUMN login_password_selector VARCHAR(512)"))
        if "login_submit_selector" not in columns:
            conn.execute(text("ALTER TABLE custom_pages ADD COLUMN login_submit_selector VARCHAR(512)"))
        if "login_autofill_enabled" not in columns:
            conn.execute(text("ALTER TABLE custom_pages ADD COLUMN login_autofill_enabled BOOLEAN NOT NULL DEFAULT 0"))
        if "login_autofill_backfilled_at" not in columns:
            conn.execute(text("ALTER TABLE custom_pages ADD COLUMN login_autofill_backfilled_at DATETIME"))
            conn.execute(
                text(
                    "UPDATE custom_pages "
                    "SET login_autofill_enabled = 1, login_autofill_backfilled_at = CURRENT_TIMESTAMP "
                    "WHERE login_autofill_enabled = 0 "
                    "AND NULLIF(TRIM(login_username), '') IS NOT NULL "
                    "AND NULLIF(TRIM(login_password), '') IS NOT NULL"
                )
            )