using System;

using System.Collections.Generic;

using Microsoft.Extensions.DependencyInjection;

using System.Linq;

​

namespace ECommerceMicroservices

{

    // Represents a product in the e-commerce system

    public class Product

    {

        public string Name { get; set; }

        public decimal Price { get; set; }

​

        // Override ToString method for easy product representation

        public override string ToString()

        {

            return $"Name: {Name}, Price: {Price}";

        }

    }

​

    // Represents a customer in the e-commerce system

    public class Customer

    {

        public string Name { get; set; }

        public string Email { get; set; }

​

        // Override ToString method for easy customer representation

        public override string ToString()

        {

            return $"Name: {Name}, Email: {Email}";

        }

    }

​

    // Interface for product service

    public interface IProductService

    {

        // Adds a new product to the inventory

        void AddProduct(Product product);

​

        // Retrieves all products from the inventory

        IEnumerable<Product> GetAllProducts();

    }

​

    // Interface for order service

    public interface IOrderService

    {

        // Places a new order for a customer

        void PlaceOrder(Customer customer, Product product);

​

        // Retrieves the details of a specific order

        void GetOrderDetails(int orderId);

    }

​

    // Interface for customer service

    public interface ICustomerService

    {

        // Adds a new customer to the system

        void AddCustomer(Customer customer);

​

        // Retrieves a customer by their email

        Customer GetCustomer(string email);

    }

​

    // Implementation of the product service

    public class ProductService : IProductService

    {

        // In-memory product inventory (replace with a database in a real application)

        private readonly List<Product> _products = new List<Product>();

​

        // Adds a new product to the inventory

        public void AddProduct(Product product)

        {

            _products.Add(product);

            Console.WriteLine($"Product added: {product}");

        }

​

        // Retrieves all products from the inventory

        public IEnumerable<Product> GetAllProducts()

        {

            return _products;

        }

    }

​

    // Implementation of the order service

    public class OrderService : IOrderService

    {

        // Product service instance (injected through constructor)

        private readonly IProductService _productService;

​

        // Customer service instance (injected through constructor)

        private readonly ICustomerService _customerService;

​

        // In-memory order storage (replace with a database in a real application)

        private readonly Dictionary<int, string> _orders = new Dictionary<int, string>();

​

        // Order ID counter

        private int _orderIdCounter = 1;

​

        // Constructor with dependency injection

        public OrderService(IProductService productService, ICustomerService customerService)

        {

            _productService = productService;

            _customerService = customerService;

        }

​

        // Places a new order for a customer

        public void PlaceOrder(Customer customer, Product product)

        {

            // Check if the product is available in the inventory

            if (_productService.GetAllProducts().Any(p => p.Name == product.Name && p.Price == product.Price))

            {

                // Create order details string

                var orderDetails = $"Order ID: {_orderIdCounter}, Customer: {customer.Name}, Product: {product.Name}, Price: {product.Price}";

​

                // Add order to storage

                _orders.Add(_orderIdCounter++, orderDetails);

​

                Console.WriteLine($"Order placed: {orderDetails}");

            }

            else

            {

                Console.WriteLine("Product not available in inventory.");

            }

        }

​

        // Retrieves the details of a specific order

        public void GetOrderDetails(int orderId)

        {

            // Check if the order exists

            if (_orders.ContainsKey(orderId))

            {

                Console.WriteLine($"Order Details: {_orders[orderId]}");

            }

            else

            {

                Console.WriteLine("Order not found.");

            }

        }

    }

​

    // Implementation of the customer service

    public class CustomerService : ICustomerService

    {

        // In-memory customer storage (replace with a database in a real application)

        private readonly List<Customer> _customers = new List<Customer>();

​

        // Adds a new customer to the system

        public void AddCustomer(Customer customer)

        {

            _customers.Add(customer);

            Console.WriteLine($"Customer added: {customer}");

        }

​

        // Retrieves a customer by their email

        public Customer GetCustomer(string email)

        {

            // Find customer by email

            var customer = _customers.Find(c => c.Email == email);

​

            // Return customer if found, otherwise return null

            return customer ?? null;

        }

    }

​

    // E-commerce microservice class

    public class ECommerceMicroservice

    {

        // Product service instance (injected through constructor)

        private readonly IProductService _productService;

​

        // Order service instance (injected through constructor)

        private readonly IOrderService _orderService;

​

        // Customer service instance (injected through constructor)

        private readonly ICustomerService _customerService;

​

        // Constructor with dependency injection

        public ECommerceMicroservice(IProductService productService, IOrderService orderService, ICustomerService customerService)

        {

            _productService = productService;

            _orderService = orderService;

            _customerService = customerService;

        }

​

        // Run method to demonstrate microservice functionality

        public void Run()

        {

            // Add products to inventory

            _productService.AddProduct(new Product { Name = "Laptop", Price = 1000 });

            _productService.AddProduct(new Product { Name = "Smartphone", Price = 600 });

            _productService.AddProduct(new Product { Name = "Headphones", Price = 150 });

​

            // Create a new customer

            var customer = new Customer { Name = "John Doe", Email = "john.doe@example.com" };

​

            // Add customer to system

            _customerService.AddCustomer(customer);

​

            // Place an order for the customer

            var product = new Product { Name = "Laptop", Price = 1000 };

            _orderService.PlaceOrder(customer, product);

​

            // Retrieve order details

            _orderService.GetOrderDetails(1); // Changed to 1, since we only placed one order

        }

    }

​

    class Program

    {

        static void Main(string[] args)

        {

            // Create a new service collection

            var serviceCollection = new ServiceCollection();

​

            // Register services with their implementations

            serviceCollection.AddScoped<IProductService, ProductService>();

            serviceCollection.AddScoped<IOrderService, OrderService>();

            serviceCollection.AddScoped<ICustomerService, CustomerService>();

            serviceCollection.AddScoped<ECommerceMicroservice>();

​

            // Build the service provider

            var serviceProvider = serviceCollection.BuildServiceProvider();

​

            // Get an instance of the e-commerce microservice

            var ecommerceMicroservice = serviceProvider.GetRequiredService<ECommerceMicroservice>();

​

            // Run the microservice

            ecommerceMicroservice.Run();

        }

    }

}