Multi-Tenant Electronics POS & Shop Management System

A multi-tenant Point of Sale (POS) and inventory management web application built with C# ASP.NET Core MVC and Entity Framework Core, featuring a Google Gemini API integration for automated customer support and ClosedXML for disaster recovery backups.

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Key Features

• Multi-Tenant Architecture: Built-in ShopId isolation across all entities, allowing multiple shops to operate independently with distinct inventories, users, and customer databases.
• Role-Based Access Control (RBAC): Tiered cookie authentication (Owner, Manager, Staff) restricting sensitive settings, user registration, and financial dashboards.
• Point of Sale (POS) & Receipt Snapshots: Fast checkout engine supporting barcode/IMEI tracking, dynamic pricing, cash/credit billing, and snapshot receipts that preserve historical shop details.
• Qist / Installment Engine: Multi-month installment plan management that automatically recalculates pending amounts, generates payment schedules, and adjusts product inventory upon plan creation.
• Repair & Service Tracking: Device servicing pipeline tracking lifecycle statuses (Received, In Progress, Ready, Collected) alongside technician notes and estimated costs.
• AI Help Desk (Google Gemini API): Integrated conversational AI module using per-tenant Gemini API keys to handle automated customer inquiries and product troubleshooting.
• Disaster Recovery (ClosedXML): Full bidirectional Excel data export and import engine for offline backups, customer data restoration, and stock synchronization.

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Tech Stack

• Backend / Framework: C# (.NET 8 / ASP.NET Core MVC), Entity Framework Core
• Database: Relational Database (SQL Server / MySQL compatible via DbContext)
• Frontend: Razor Views (CSHTML), Bootstrap 5, JavaScript, HTML5/CSS3
• Libraries & APIs: Google Gemini API, ClosedXML (Excel Automation)
• Authentication: ASP.NET Core Cookie Authentication with Claims

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Database Schema Overview

• Core & Auth: Users, Shops
• Inventory & Orders: Products, Categories, Suppliers, PurchaseOrders
• Sales & Billing: Sales, SaleItems, Customers, Expenses
• Services & Credit: Repairs, InstallmentPlans, InstallmentMonths