feat:Initial commit

StoreService/Services/OrderService.cs

@@ -0,0 +1,172 @@
+using Microsoft.EntityFrameworkCore;
+using StoreService.Database.Entities;
+using StoreService.Models;
+using StoreService.Repositories;
+
+namespace StoreService.Services;
+
+/// <summary>
+/// Implements order creation, payment, redemption and price calculation logic.
+/// </summary>
+public class OrderService : IOrderService
+{
+    #region Fields
+    private readonly IUnitOfWork _uow;
+    private readonly ILogger<OrderService> _logger;
+    #endregion
+
+    #region Ctor
+    public OrderService(IUnitOfWork uow, ILogger<OrderService> logger)
+    {
+        _uow = uow;
+        _logger = logger;
+    }
+    #endregion
+
+    #region Public Methods
+    /// <inheritdoc/>
+    public async Task<OrderDto> CreateOrderAsync(CreateOrderRequest request, CancellationToken ct = default)
+    {
+        if (request.StoreItemIds.Count == 0)
+            throw new ArgumentException("No store items specified", nameof(request.StoreItemIds));
+
+        // Ensure uniqueness
+        var uniqueIds = request.StoreItemIds.Distinct().ToList();
+
+        // Load items with potential discount items and discounts for calculation.
+        var items = await _uow.StoreItems
+            .Get(i => uniqueIds.Contains(i.Id), includes: i => i.DiscountItems)
+            .Include(i => i.DiscountItems) // ensure collection loaded
+            .ToListAsync(ct);
+
+        if (items.Count != uniqueIds.Count)
+        {
+            var missing = uniqueIds.Except(items.Select(i => i.Id)).ToArray();
+            throw new KeyNotFoundException($"Store items not found: {string.Join(", ", missing)}");
+        }
+
+        // Preload discounts referenced by items for efficient calculation.
+        var discountIds = items.SelectMany(i => i.DiscountItems.Select(di => di.StoreDiscountId)).Distinct().ToList();
+        var discounts = await _uow.StoreDiscounts
+            .Get(d => discountIds.Contains(d.Id))
+            .ToListAsync(ct);
+
+        var now = DateTime.UtcNow;
+
+        var order = new StoreOrder
+        {
+            UserId = request.UserId,
+            CostUpdateDate = now,
+            OrderItems = new List<StoreOrderItem>()
+        };
+
+        foreach (var item in items)
+        {
+            var applicableDiscounts = discounts
+                .Where(d => item.DiscountItems.Any(di => di.StoreDiscountId == d.Id) && d.IsActive(now))
+                .ToList();
+
+            var calculatedPrice = CalculatePrice(item.ManaBuyPrice, applicableDiscounts);
+
+            var orderItem = new StoreOrderItem
+            {
+                StoreItemId = item.Id,
+                CalculatedPrice = calculatedPrice,
+                AppliedDiscounts = applicableDiscounts.Select(d => new StoreOrderItemDiscount
+                {
+                    StoreDiscountId = d.Id
+                }).ToList()
+            };
+
+            order.OrderItems.Add(orderItem);
+        }
+
+        await _uow.StoreOrders.AddAsync(order);
+        await _uow.SaveChangesAsync(ct);
+
+        _logger.LogInformation("Created order {OrderId} for user {UserId}", order.Id, order.UserId);
+
+        return MapOrder(order);
+    }
+
+    /// <inheritdoc/>
+    public async Task<OrderDto?> GetOrderAsync(long id, CancellationToken ct = default)
+    {
+        var order = await _uow.StoreOrders
+            .Get(o => o.Id == id, includes: o => o.OrderItems)
+            .Include(o => o.OrderItems)
+            .ThenInclude(oi => oi.AppliedDiscounts)
+            .FirstOrDefaultAsync(ct);
+        return order == null ? null : MapOrder(order);
+    }
+
+    /// <inheritdoc/>
+    public async Task<OrderDto> PayOrderAsync(long id, CancellationToken ct = default)
+    {
+        var order = await _uow.StoreOrders
+            .Get(o => o.Id == id, includes: o => o.OrderItems)
+            .FirstOrDefaultAsync(ct) ?? throw new KeyNotFoundException($"Order {id} not found");
+
+        if (order.PaidDate != null)
+            throw new InvalidOperationException("Order already paid");
+
+        order.PaidDate = DateTime.UtcNow;
+        await _uow.SaveChangesAsync(ct);
+        _logger.Information("Order {OrderId} paid", id);
+        return await GetOrderRequiredAsync(id, ct);
+    }
+
+    /// <inheritdoc/>
+    public async Task<OrderDto> RedeemOrderItemsAsync(long id, CancellationToken ct = default)
+    {
+        var order = await _uow.StoreOrders.Get(o => o.Id == id).FirstOrDefaultAsync(ct) ??
+                    throw new KeyNotFoundException($"Order {id} not found");
+
+        if (order.PaidDate == null)
+            throw new InvalidOperationException("Order not paid yet");
+        if (order.ItemsRedeemed)
+            throw new InvalidOperationException("Order items already redeemed");
+
+        // TODO: integrate with external inventory service. For now we just toggle flag.
+        order.ItemsRedeemed = true;
+        await _uow.SaveChangesAsync(ct);
+        _logger.Information("Order {OrderId} items redeemed", id);
+        return await GetOrderRequiredAsync(id, ct);
+    }
+    #endregion
+
+    #region Helpers
+    private int CalculatePrice(int basePrice, IEnumerable<StoreDiscount> discounts)
+    {
+        // Assumption: sum discount percentages, cap at 90% to avoid free unless explicitly 100%. Documented decision.
+        var totalPercent = discounts.Sum(d => d.Percentage);
+        if (totalPercent > 100m) totalPercent = 100m; // absolute cap
+        var discounted = basePrice - (int)Math.Floor(basePrice * (decimal)totalPercent / 100m);
+        return Math.Max(0, discounted);
+    }
+
+    private async Task<OrderDto> GetOrderRequiredAsync(long id, CancellationToken ct)
+    {
+        var dto = await GetOrderAsync(id, ct);
+        if (dto == null) throw new KeyNotFoundException($"Order {id} not found after update");
+        return dto;
+    }
+
+    private static OrderDto MapOrder(StoreOrder order) => new()
+    {
+        Id = order.Id,
+        UserId = order.UserId,
+        CostUpdateDate = order.CostUpdateDate,
+        PaidDate = order.PaidDate,
+        ItemsRedeemed = order.ItemsRedeemed,
+        Items = order.OrderItems.Select(oi => new OrderItemDto
+        {
+            Id = oi.Id,
+            StoreItemId = oi.StoreItemId,
+            CalculatedPrice = oi.CalculatedPrice,
+            AppliedDiscountIds = oi.AppliedDiscounts.Select(ad => ad.StoreDiscountId ?? 0).ToList()
+        }).ToList()
+    };
+    #endregion
+}
+