"""Database initialization and seeding functions."""

from app.database import db
from app.models.plan import Plan


def init_database():
    """Initialize database tables and seed with default data."""
    # Create all tables
    db.create_all()

    # Seed plans if they don't exist
    seed_plans()

    # Migrate existing users to have plans
    migrate_users_to_plans()


def seed_plans():
    """Seed the plans table with default plans if empty."""
    # Check if plans already exist
    if Plan.query.count() > 0:
        return

    # Create default plans
    plans_data = [
        {
            "code": "free",
            "name": "Free Plan",
            "description": "Basic features with limited usage",
            "credits": 25,
            "max_credits": 75,
        },
        {
            "code": "premium",
            "name": "Premium Plan",
            "description": "Enhanced features with increased usage limits",
            "credits": 50,
            "max_credits": 150,
        },
        {
            "code": "pro",
            "name": "Pro Plan",
            "description": "Full access with unlimited usage",
            "credits": 100,
            "max_credits": 300,
        },
    ]

    for plan_data in plans_data:
        plan = Plan(**plan_data)
        db.session.add(plan)

    db.session.commit()
    print(f"Seeded {len(plans_data)} plans into database")


def migrate_users_to_plans():
    """Assign plans to existing users who don't have one."""
    from app.models.user import User

    try:
        # Find users without plans
        users_without_plans = User.query.filter(User.plan_id.is_(None)).all()

        # Find users with plans but NULL credits (only if credits column exists)
        # Note: We only migrate users with NULL credits, not 0 credits
        # 0 credits means they spent them, NULL means they never got assigned
        try:
            users_without_credits = User.query.filter(
                User.plan_id.isnot(None), User.credits.is_(None),
            ).all()
        except Exception:
            # Credits column doesn't exist yet, will be handled by create_all
            users_without_credits = []

        if not users_without_plans and not users_without_credits:
            return

        # Get default and pro plans
        default_plan = Plan.get_default_plan()
        pro_plan = Plan.get_pro_plan()

        # Get the first user (admin) from all users ordered by ID
        first_user = User.query.order_by(User.id).first()

        updated_count = 0

        # Assign plans to users without plans
        for user in users_without_plans:
            # First user gets pro plan, others get free plan
            if user.id == first_user.id:
                user.plan_id = pro_plan.id
                # Only set credits if the column exists
                try:
                    user.credits = pro_plan.credits
                except Exception:
                    pass
            else:
                user.plan_id = default_plan.id
                # Only set credits if the column exists
                try:
                    user.credits = default_plan.credits
                except Exception:
                    pass
            updated_count += 1

        # Assign credits to users with plans but no credits
        for user in users_without_credits:
            user.credits = user.plan.credits
            updated_count += 1

        if updated_count > 0:
            db.session.commit()
            print(
                f"Updated {updated_count} existing users with plans and credits",
            )

    except Exception:
        # If there's any error (like missing columns), just skip migration
        # The database will be properly created by create_all()
        pass