Enterprise SaaS Platform for ERP Deployment Built from scratch — Powers ERPNext, Odoo, and more

def process_invoice_payment(invoice):
    # Check wallet balance
    wallet = Wallet.query.filter_by(user_id=invoice.user_id).first()
    if float(wallet.balance or 0.0) < float(invoice.amount or 0.0):
        return {"error": "Insufficient wallet balance"}
    
    # Mark invoice paid
    invoice.status = 'paid'
    
    # Activate subscription
    if invoice.subscription:
        subscription.status = 'active'
    
    # Deduct wallet and create transaction
    wallet.balance -= invoice.amount
    transaction = WalletTransaction(...)
    db.session.add(transaction)
    
    db.session.commit()
    return {"success": True}
                                    

def claim_next_operation(status='pending'):
    # Check maintenance status
    if is_maintenance_active():
        logger.info(f"[{WORKER_ID}] Maintenance active, skipping.")
        return None
    
    # Query with row locking for concurrent safety
    candidate = (
        db.session.query(SaaSOperation)
        .filter_by(status=status)
        .order_by(priority_order, SaaSOperation.created_at.asc())
        .with_for_update(skip_locked=True)
        .first()
    )
    
    if candidate:
        # Update operation status
        candidate.status = 'in_progress'
        candidate.started_at = datetime.now(timezone.utc)
        db.session.commit()
        return candidate
    
    return None
                                    

def install_app_by_portal():
    # Validate add‑on and launch eligibility
    addon = AddonApp.query.get_or_404(addon_app_id)
    launch = Launch.query.filter_by(domain_url=launch_domain).first_or_404()
    
    # Business rule checks
    if addon.requires_paid_subscription and not user_package:
        return jsonify({"error": "Paid subscription required"}), 403
    
    # Create installation record
    new_install = UserInstalledAddon(
        user_id=launch.user_id,
        addon_app_id=addon.id,
        launch_id=launch.id,
        install_session_id=secrets.token_hex(8),
        status='inprogress'
    )
    
    # Queue SaaS operation
    new_op = SaaSOperation(
        operation_type='INSTALL_ADDON',
        script_name='install_app_by_portal.sh',
        status='pending'
    )
    
    db.session.add_all([new_install, new_op])
    db.session.commit()
    
    return jsonify({"success": True, "message": "Installation queued"})