"""Small, dependency-free schema migrations for the deployed SQLite database."""
from sqlalchemy import inspect, text

from .extensions import db


def upgrade_schema() -> None:
    """Create new tables and add authentication columns without losing existing data."""
    db.create_all()
    inspector = inspect(db.engine)
    columns = {item["name"] for item in inspector.get_columns("users")}
    additions = {
        "email": "VARCHAR(254)",
        "email_verified_at": "DATETIME",
        "is_active_account": "BOOLEAN NOT NULL DEFAULT 0",
        "auth_version": "INTEGER NOT NULL DEFAULT 1",
    }
    for name, sql_type in additions.items():
        if name not in columns:
            db.session.execute(text(f"ALTER TABLE users ADD COLUMN {name} {sql_type}"))
    db.session.execute(text("CREATE UNIQUE INDEX IF NOT EXISTS ix_users_email_unique ON users (email) WHERE email IS NOT NULL"))
    db.session.commit()