Merge pull request 'Refactored shasher payfast confirmation response handling' (#55) from payments into master

Reviewed-on: #55

LiteCharms.Features.MidrandBooks.Seed/CategorySeederService.cs

@@ -3,7 +3,7 @@ using LiteCharms.Features.MidrandBooks.Products;
 
 namespace LiteCharms.Features.MidrandBooks.Seed;
 
-public class CategorySeederService(CategoryService categoryService, ProductService productService, IFeatureManager features,
+public sealed class CategorySeederService(CategoryService categoryService, ProductService productService, IFeatureManager features,
     ILogger<CategorySeederService> logger) : BackgroundService
 {
     protected override async Task ExecuteAsync(CancellationToken stoppingToken)

LiteCharms.Features.MidrandBooks.Seed/Configuration/CdnSettings.cs

@@ -1,6 +1,6 @@
 namespace LiteCharms.Features.MidrandBooks.Seed.Configuration;
 
-public class CdnSettings
+public sealed class CdnSettings
 {
     public string? BaseCdn { get; set; }
 

LiteCharms.Features.MidrandBooks.Seed/CustomerSeederService.cs

@@ -5,7 +5,7 @@ using LiteCharms.Features.MidrandBooks.Orders.Models;
 
 namespace LiteCharms.Features.MidrandBooks.Seed;
 
-public class CustomerSeederService(CustomerService customerService, OrderService orderService, IFeatureManager features,
+public sealed class CustomerSeederService(CustomerService customerService, OrderService orderService, IFeatureManager features,
     ILogger<CustomerSeederService> logger) : BackgroundService
 {
     protected override async Task ExecuteAsync(CancellationToken stoppingToken)

LiteCharms.Features.MidrandBooks.Seed/ProductsSeederService.cs

@@ -5,7 +5,7 @@ using LiteCharms.Features.MidrandBooks.Seed.Configuration;
 
 namespace LiteCharms.Features.MidrandBooks.Seed;
 
-public class ProductsSeederService(ProductService productService, AuthorService authorService, BooksService booksService,
+public sealed class ProductsSeederService(ProductService productService, AuthorService authorService, BooksService booksService,
     IFeatureManager features, IOptions<CdnSettings> options, ILogger<ProductsSeederService> logger) : BackgroundService
 {
     private readonly CdnSettings cdnSettings = options.Value;

LiteCharms.Features.MidrandBooks.Tests/AuthorServiceFeatureTests.cs

@@ -5,7 +5,7 @@ using LiteCharms.Features.Models;
 
 namespace LiteCharms.Features.MidrandBooks.Tests;
 
-public class AuthorServiceFeatureTests(Fixture fixture, ITestOutputHelper output) : IClassFixture<Fixture>
+public class AuthorServiceFeatureTests(Fixture fixture) : IClassFixture<Fixture>
 {
     private readonly AuthorService authorService = fixture.Services.GetRequiredService<AuthorService>();
 

LiteCharms.Features.MidrandBooks.Tests/Common/Fixture.cs

@@ -1,5 +1,4 @@
 using LiteCharms.Features.Extensions;
-using LiteCharms.Features.MidrandBooks.Abstractions;
 using LiteCharms.Features.MidrandBooks.Extensions;
 
 namespace LiteCharms.Features.MidrandBooks.Tests.Common;

LiteCharms.Features.MidrandBooks.Tests/PaymentServiceFeatureTests.cs

@@ -0,0 +1,98 @@
+using LiteCharms.Features.MidrandBooks.Payments;
+using LiteCharms.Features.MidrandBooks.Payments.Models;
+using LiteCharms.Features.MidrandBooks.Tests.Common;
+
+namespace LiteCharms.Features.MidrandBooks.Tests;
+
+public sealed class PaymentServiceFeatureTests(Fixture fixture) : IClassFixture<Fixture>
+{
+    private readonly PaymentService paymentService = fixture.Services.GetRequiredService<PaymentService>();
+
+    [IntegrationFact]
+    public async Task CreateRefundAsync_ShouldReturn_ResultWithRefundId()
+    {
+        var request = new CreateRefund
+        {
+            Amount = 50,
+            OrderId = 2,
+            Type = RefundTypes.Partial,
+            Reason = "Returned damaged book",
+            Status = RefundStatus.Completed,            
+        };
+
+        var result = await paymentService.CreateRefundAsync(request, fixture.CancellationToken);
+
+        Assert.True(result.IsSuccess);
+        Assert.True(result.Value > 0);
+    }
+
+    [IntegrationFact]
+    public async Task WriteLedgerEntryAsync_ShouldReturn_ResultWithSuccess()
+    {
+        var request = new CreateLedgerEntry
+        {
+            CustomerId = 1,
+            OrderId = 1,
+            PaymentGatewayId = 1,
+            PaymentGatewayReference = "TEST REFERENCE",
+            PaymentId = 1,
+            Status = LedgerStatuses.Received,
+        };
+
+        var result = await paymentService.WriteLedgerEntryAsync(request, fixture.CancellationToken);
+
+        Assert.True(result.IsSuccess);
+    }
+
+    [IntegrationFact]
+    public async Task GetPaymentGatewayAsync_ShouldReturn_ResultWithPaymentGateway()
+    {
+        var result = await paymentService.GetPaymentGatewayAsync(1, fixture.CancellationToken);
+
+        Assert.True(result.IsSuccess);
+        Assert.NotNull(result.Value);
+    }
+
+    [IntegrationFact]
+    public async Task CreatePaymentGatewayAsync_ShouldReturn_ResultWithGatewayId()
+    {
+        var request = new CreatePaymentGateway
+        {
+            IsSandbox = true,
+            MerchantId = "10049307",
+            MerchantKey = "ju6navn0jcbf0",
+            Name = "Payfast",
+            Website = "https://sandbox.payfast.co.za/eng/process",
+        };
+
+        var result = await paymentService.CreatePaymentGatewayAsync(request, fixture.CancellationToken);
+
+        Assert.True(result.IsSuccess);
+        Assert.True(result.Value > 0);
+    }
+
+    [IntegrationFact]
+    public async Task CompletePaymentAsync_ShouldReturn_ResultWithSuccess()
+    {
+        var result = await paymentService.CompletePaymentAsync(1, PaymentStatuses.Paid, fixture.CancellationToken);
+
+        Assert.True(result.IsSuccess);
+    }
+
+    [IntegrationFact]
+    public async Task UpdatePaymentAsync_ShouldReturn_ResultWithSuccess()
+    {
+        var result = await paymentService.UpdatePaymentAsync(1, 200, fixture.CancellationToken);
+
+        Assert.True(result.IsSuccess);
+    }
+
+    [IntegrationFact]
+    public async Task CreatePaymentAsync_ShouldReturn_ResultWithPaymentId()
+    {
+        var result = await paymentService.CreatePaymentAsync(100, 1, "HASHEDID", fixture.CancellationToken);
+
+        Assert.True(result.IsSuccess);
+        Assert.True(result.Value > 0);
+    }
+}

LiteCharms.Features.MidrandBooks.Tests/ProductServiceFeatureTests.cs

@@ -9,6 +9,47 @@ public class ProductServiceFeatureTests(Fixture fixture, ITestOutputHelper outpu
 {
     private readonly ProductService productService = fixture.Services.GetRequiredService<ProductService>();
 
+    [IntegrationFact]
+    public async Task CheckProductStockAvailabilityAsync_ShouldReturn_ResultWithProductInventory()
+    {
+        var result = await productService.CheckProductStockAvailabilityAsync(1, 1, fixture.CancellationToken);
+
+        Assert.True(result.IsSuccess);
+        Assert.NotNull(result.Value);
+    }
+
+    [IntegrationFact]
+    public async Task ReserveProductInventoryAsync_ShouldReturn_ResultWithSuccess()
+    {
+        var request = new ReserveStock
+        {
+            ProductId = 1,
+            ProductPriceId = 1,
+            Reservation = 100,            
+        };
+
+        var result = await productService.ReserveProductInventoryAsync(request, fixture.CancellationToken);
+
+        Assert.True(result.IsSuccess);
+        Assert.True(result.Value > 0);
+    }
+
+    [IntegrationFact]
+    public async Task AllocateProductInventoryAsync_ShouldReturn_ResultWithSuccess()
+    {
+        var request = new AllocateStock
+        {
+            ProductId = 1, 
+            ProductPriceId = 1,
+            Allocation = 500,
+        };
+
+        var result = await productService.AllocateProductInventoryAsync(request, fixture.CancellationToken);
+
+        Assert.True(result.IsSuccess);
+        Assert.True(result.Value > 0);
+    }
+
     [IntegrationFact]
     public async Task AddProductCategoryAsync_ShouldReturn_ResultWithId()
     {

LiteCharms.Features.MidrandBooks/Abstractions/IService.cs

@@ -1,3 +0,0 @@
-namespace LiteCharms.Features.MidrandBooks.Abstractions;
-
-public interface IService;

LiteCharms.Features.MidrandBooks/AuthorBooks/BooksService.cs

@@ -1,4 +1,4 @@
-using LiteCharms.Features.MidrandBooks.Abstractions;
+using LiteCharms.Features.Abstractions;
 using LiteCharms.Features.MidrandBooks.AuthorBooks.Models;
 using LiteCharms.Features.MidrandBooks.Extensions;
 using LiteCharms.Features.MidrandBooks.Postgres;

LiteCharms.Features.MidrandBooks/Authors/AuthorService.cs

@@ -1,4 +1,4 @@
-using LiteCharms.Features.MidrandBooks.Abstractions;
+using LiteCharms.Features.Abstractions;
 using LiteCharms.Features.MidrandBooks.Authors.Models;
 using LiteCharms.Features.MidrandBooks.Extensions;
 using LiteCharms.Features.MidrandBooks.Postgres;
@@ -8,6 +8,29 @@ namespace LiteCharms.Features.MidrandBooks.Authors;
 
 public sealed class AuthorService(IDbContextFactory<MidrandBooksDbContext> contextFactory) : IService
 {
+    public async ValueTask<Result<Author>> GetAuthorByProductIdAsync(long productId, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            var author = await context.Books
+                .AsNoTracking()
+                .Include(i => i.Author)
+                .Where(b => b.ProductId == productId)                
+                .FirstOrDefaultAsync(cancellationToken);
+
+            if (author is null)
+                return Result.Fail<Author>(new Error($"No author association discovered for Product ID {productId}"));
+
+            return Result.Ok(author.Author!.ToModel());
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail<Author>(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
     public async ValueTask<Result> UpdateAuthorStatusAsync(long authorId, bool isEnabled, CancellationToken cancellationToken = default)
     {
         try

LiteCharms.Features.MidrandBooks/Categories/CategoryService.cs

@@ -1,4 +1,4 @@
-using LiteCharms.Features.MidrandBooks.Abstractions;
+using LiteCharms.Features.Abstractions;
 using LiteCharms.Features.MidrandBooks.Categories.Models;
 using LiteCharms.Features.MidrandBooks.Extensions;
 using LiteCharms.Features.MidrandBooks.Postgres;

LiteCharms.Features.MidrandBooks/Customers/CustomerService.cs

@@ -1,4 +1,4 @@
-using LiteCharms.Features.MidrandBooks.Abstractions;
+using LiteCharms.Features.Abstractions;
 using LiteCharms.Features.MidrandBooks.Customers.Models;
 using LiteCharms.Features.MidrandBooks.Extensions;
 using LiteCharms.Features.MidrandBooks.Postgres;

LiteCharms.Features.MidrandBooks/Enums.cs

@@ -1,62 +0,0 @@
-namespace LiteCharms.Features.MidrandBooks;
-
-public enum PublisherTypes : int
-{
-    Individual = 0,
-    Company = 1,
-    Organization = 2,
-    SelfPublished = 3,
-    UniversityPress = 4,
-    GovernmentAgency = 5,
-    NonProfit = 6,
-    Independent = 7
-}
-
-public enum BookTypes : int
-{
-    Fiction = 0,
-    NonFiction = 1,
-    Academic = 2,
-    SelfHelp = 3,
-    Biography = 4,
-    Poetry = 5,
-    Children = 6,
-    YoungAdult = 7,
-    ScienceFiction = 8,
-    Fantasy = 9
-}
-
-public enum BookContentTypes : int
-{
-    Text = 0,
-    Image = 1,
-    Video = 2,
-    Audio = 3,
-    Interactive = 4,
-    Markdown = 5,
-    Html = 6,
-    Json = 7,
-    Yaml = 8
-}
-
-public enum BookPageTypes : int
-{
-    Cover = 0,
-    Preface = 1,
-    Introduction = 2,
-    Content = 3,
-    Closing = 4,
-    Referencer = 5,
-    Credits = 6,
-    BackCover = 7
-}
-
-public enum ProductTypes : int
-{
-    Book = 1,
-    Journal = 2,
-    Magazine = 3,
-    EBook = 4,
-    Audiobook = 5,
-    Accessory = 6
-}

LiteCharms.Features.MidrandBooks/Extensions/Mappers.cs

@@ -4,12 +4,73 @@ using LiteCharms.Features.MidrandBooks.Categories.Models;
 using LiteCharms.Features.MidrandBooks.Customers.Models;
 using LiteCharms.Features.MidrandBooks.Orders.Models;
 using LiteCharms.Features.MidrandBooks.Pages.Models;
+using LiteCharms.Features.MidrandBooks.Payments.Models;
 using LiteCharms.Features.MidrandBooks.Products.Models;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
 
 namespace LiteCharms.Features.MidrandBooks.Extensions;
 
 public static class Mappers
 {
+    public static Refund ToModel(this Payments.Entities.Refund entity) => new()
+    {
+        CreatedAt = entity.CreatedAt,
+        Amount = entity.Amount,
+        Id = entity.Id,
+        OrderId = entity.OrderId,
+        Reason = entity.Reason,
+        Status = entity.Status,
+        Type = entity.Type,
+        UpdatedAt = entity.UpdatedAt,        
+    };
+
+    public static PaymentLedger ToModel(this Payments.Entities.PaymentLedger entity) => new()
+    {
+        Id = entity.Id,
+        CreatedAt = entity.CreatedAt,
+        CustomerId = entity.CustomerId,
+        OrderId = entity.OrderId,
+        PaymentGatewayId = entity.PaymentGatewayId,
+        PaymentGatewayReference = entity.PaymentGatewayReference,
+        PaymentId = entity.PaymentId,
+        Status = entity.Status,        
+    };
+
+    public static PaymentGateway ToModel(this Payments.Entities.PaymentGateway entity) => new()
+    {
+        Id = entity.Id,
+        CreatedAt = entity.CreatedAt,
+        UpdatedAt = entity.UpdatedAt,
+        Enabled = entity.Enabled,
+        IsSandbox = entity.IsSandbox,
+        MerchantId = entity.MerchantId,
+        MerchantKey = entity.MerchantKey,
+        Name = entity.Name,
+        Website = entity.Website,
+    };
+
+    public static Payment ToModel(this Payments.Entities.Payment entity) => new()
+    {
+        Id = entity.Id,
+        Amount = entity.Amount,
+        CreatedAt = entity.CreatedAt,
+        OrderId = entity.OrderId,
+        Reference = entity.Reference,
+        Status = entity.Status,
+        UpdatedAt = entity.UpdatedAt,        
+    };
+
+    public static ProductInventory ToModel(this Products.Entities.ProductInventory entity) => new()
+    {
+        Id = entity.Id,
+        CreatedAt = entity.CreatedAt,
+        ProductId = entity.ProductId,
+        ProductPriceId = entity.ProductPriceId,
+        Status = entity.Status,
+        TotalAllocated = entity.TotalAllocated,
+        TotalReserved = entity.TotalReserved,
+    };
+
     public static Category ToModel(this Categories.Entities.Category entity) => new()
     {
         Id = entity.Id,

LiteCharms.Features.MidrandBooks/Extensions/Shop.cs

@@ -1,4 +1,4 @@
-using LiteCharms.Features.MidrandBooks.Abstractions;
+using LiteCharms.Features.Abstractions;
 
 namespace LiteCharms.Features.MidrandBooks.Extensions;
 

LiteCharms.Features.MidrandBooks/Orders/OrderService.cs

@@ -1,4 +1,4 @@
-using LiteCharms.Features.MidrandBooks.Abstractions;
+using LiteCharms.Features.Abstractions;
 using LiteCharms.Features.MidrandBooks.Extensions;
 using LiteCharms.Features.MidrandBooks.Orders.Models;
 using LiteCharms.Features.MidrandBooks.Postgres;

LiteCharms.Features.MidrandBooks/Pages/PageService.cs

@@ -1,4 +1,4 @@
-using LiteCharms.Features.MidrandBooks.Abstractions;
+using LiteCharms.Features.Abstractions;
 using LiteCharms.Features.MidrandBooks.Extensions;
 using LiteCharms.Features.MidrandBooks.Pages.Models;
 using LiteCharms.Features.MidrandBooks.Postgres;

LiteCharms.Features.MidrandBooks/Payments/Entities/Payment.cs

@@ -0,0 +1,9 @@
+using LiteCharms.Features.MidrandBooks.Orders.Entities;
+
+namespace LiteCharms.Features.MidrandBooks.Payments.Entities;
+
+[EntityTypeConfiguration<PaymentConfiguration, Payment>]
+public class Payment : Models.Payment
+{
+    public virtual Order? Order { get; set; }
+}

LiteCharms.Features.MidrandBooks/Payments/Entities/PaymentConfiguration.cs

@@ -0,0 +1,22 @@
+namespace LiteCharms.Features.MidrandBooks.Payments.Entities;
+
+public sealed class PaymentConfiguration : IEntityTypeConfiguration<Payment>
+{
+    public void Configure(EntityTypeBuilder<Payment> builder)
+    {
+        builder.ToTable("Payments");
+
+        builder.HasKey(f => f.Id);
+        builder.Property(f => f.CreatedAt).IsRequired().ValueGeneratedOnAdd().HasDefaultValueSql("now()");
+        builder.Property(f => f.UpdatedAt);
+        builder.Property(f => f.Status).IsRequired();
+        builder.Property(f => f.Reference).IsRequired();
+        builder.Property(f => f.OrderId).IsRequired();
+        builder.Property(f => f.Amount).IsRequired().HasPrecision(18, 2);
+
+        builder.HasOne(f => f.Order)
+            .WithMany()
+            .HasForeignKey(f => f.OrderId)
+            .OnDelete(DeleteBehavior.Restrict);
+    }
+}

LiteCharms.Features.MidrandBooks/Payments/Entities/PaymentGateway.cs

@@ -0,0 +1,4 @@
+namespace LiteCharms.Features.MidrandBooks.Payments.Entities;
+
+[EntityTypeConfiguration<PaymentGatewayConfiguration, PaymentGateway>]
+public class PaymentGateway : Models.PaymentGateway;

LiteCharms.Features.MidrandBooks/Payments/Entities/PaymentGatewayConfiguration.cs

@@ -0,0 +1,19 @@
+namespace LiteCharms.Features.MidrandBooks.Payments.Entities;
+
+public sealed class PaymentGatewayConfiguration : IEntityTypeConfiguration<PaymentGateway>
+{
+    public void Configure(EntityTypeBuilder<PaymentGateway> builder)
+    {
+        builder.ToTable("Gateways");
+
+        builder.HasKey(f => f.Id);
+        builder.Property(f => f.CreatedAt).IsRequired().ValueGeneratedOnAdd().HasDefaultValueSql("now()");
+        builder.Property(f => f.UpdatedAt);
+        builder.Property(f => f.Website).IsRequired(false);
+        builder.Property(f => f.IsSandbox);
+        builder.Property(f => f.MerchantKey).IsRequired();
+        builder.Property(f => f.MerchantId).IsRequired();
+        builder.Property(f => f.Enabled);
+        builder.Property(f => f.Name).IsRequired();
+    }
+}

LiteCharms.Features.MidrandBooks/Payments/Entities/PaymentLedger.cs

@@ -0,0 +1,16 @@
+using LiteCharms.Features.MidrandBooks.Customers.Entities;
+using LiteCharms.Features.MidrandBooks.Orders.Entities;
+
+namespace LiteCharms.Features.MidrandBooks.Payments.Entities;
+
+[EntityTypeConfiguration<PaymentLedgerConfiguration, PaymentLedger>]
+public class PaymentLedger : Models.PaymentLedger
+{
+    public virtual Payment? Payment { get; set; }
+
+    public virtual Order? Order { get; set; }
+
+    public virtual Customer? Customer { get; set; }
+
+    public virtual PaymentGateway? Gateway { get; set; }
+}

LiteCharms.Features.MidrandBooks/Payments/Entities/PaymentLedgerConfiguration.cs

@@ -0,0 +1,41 @@
+namespace LiteCharms.Features.MidrandBooks.Payments.Entities;
+
+public sealed class PaymentLedgerConfiguration : IEntityTypeConfiguration<PaymentLedger>
+{
+    public void Configure(EntityTypeBuilder<PaymentLedger> builder)
+    {
+        builder.ToTable("Ledger");
+
+        builder.HasKey(f => f.Id);
+        builder.Property(f => f.CreatedAt).IsRequired().ValueGeneratedOnAdd().HasDefaultValueSql("now()");
+        builder.Property(f => f.Status).IsRequired();
+        builder.Property(f => f.PaymentGatewayReference).IsRequired(false);
+        builder.Property(f => f.PaymentGatewayId).IsRequired(false);
+        builder.Property(f => f.OrderId).IsRequired();
+        builder.Property(f => f.CustomerId).IsRequired();
+        builder.Property(f => f.PaymentId).IsRequired();
+
+        builder.HasOne(f => f.Payment)
+            .WithMany()
+            .IsRequired()
+            .HasForeignKey(f => f.PaymentId)
+            .OnDelete(DeleteBehavior.Cascade);
+
+        builder.HasOne(f => f.Order)
+            .WithMany()
+            .IsRequired()
+            .HasForeignKey(f => f.OrderId)
+            .OnDelete(DeleteBehavior.Cascade);
+
+        builder.HasOne(f => f.Customer)
+            .WithMany()
+            .IsRequired()
+            .HasForeignKey(f => f.CustomerId);
+
+        builder.HasOne(f => f.Gateway)
+            .WithMany()
+            .IsRequired(false)
+            .HasForeignKey(f => f.PaymentGatewayId)
+            .OnDelete(DeleteBehavior.Cascade);
+    }
+}

LiteCharms.Features.MidrandBooks/Payments/Models/Payment.cs

@@ -0,0 +1,18 @@
+namespace LiteCharms.Features.MidrandBooks.Payments.Models;
+
+public class Payment
+{
+    public long Id { get; set; }
+
+    public DateTime CreatedAt { get; set; }
+
+    public DateTime? UpdatedAt { get; set; }
+
+    public decimal Amount { get; set; }
+
+    public long OrderId { get; set; }
+
+    public string? Reference { get; set; }
+
+    public PaymentStatuses Status { get; set; }
+}

LiteCharms.Features.MidrandBooks/Payments/Models/PaymentGateway.cs

@@ -0,0 +1,22 @@
+namespace LiteCharms.Features.MidrandBooks.Payments.Models;
+
+public class PaymentGateway
+{
+    public long Id { get; set; }
+
+    public DateTime CreatedAt { get; set; }
+
+    public DateTime? UpdatedAt { get; set; }
+
+    public string? Name { get; set; }
+
+    public string? Website { get; set; }
+
+    public string? MerchantId { get; set; }
+
+    public string? MerchantKey { get; set; }
+
+    public bool IsSandbox { get; set; }
+
+    public bool Enabled { get; set; }
+}

LiteCharms.Features.MidrandBooks/Payments/Models/PaymentLedger.cs

@@ -0,0 +1,20 @@
+namespace LiteCharms.Features.MidrandBooks.Payments.Models;
+
+public class PaymentLedger
+{
+    public long Id { get; set; }
+
+    public DateTime CreatedAt { get; set; }
+
+    public LedgerStatuses Status { get; set; }
+
+    public long OrderId { get; set; }
+
+    public long PaymentId { get; set; }
+
+    public long CustomerId { get; set; }
+
+    public string? PaymentGatewayReference { get; set; }
+
+    public long? PaymentGatewayId { get; set; }
+}

LiteCharms.Features.MidrandBooks/Payments/Models/Records.cs

@@ -0,0 +1,53 @@
+namespace LiteCharms.Features.MidrandBooks.Payments.Models;
+
+public sealed record UpdateRefund
+{
+    public long OrderId { get; set; }
+
+    public RefundStatus Status { get; set; }
+
+    public string? Reason { get; set; }
+
+    public decimal Amount { get; set; }
+};
+
+public sealed record CreateRefund
+{
+    public long OrderId { get; set; }
+
+    public RefundTypes Type { get; set; }
+
+    public RefundStatus Status { get; set; }
+
+    public string? Reason { get; set; }
+
+    public decimal Amount { get; set; }
+}
+
+public sealed record CreateLedgerEntry
+{
+    public required LedgerStatuses Status { get; set; }
+
+    public required long OrderId { get; set; }
+
+    public required long PaymentId { get; set; }
+
+    public required long CustomerId { get; set; }
+
+    public string? PaymentGatewayReference { get; set; }
+
+    public long? PaymentGatewayId { get; set; }
+}
+
+public sealed record CreatePaymentGateway
+{
+    public required string? Name { get; set; }
+
+    public string? Website { get; set; }
+
+    public required string? MerchantId { get; set; }
+
+    public required string? MerchantKey { get; set; }
+
+    public bool IsSandbox { get; set; }
+}

LiteCharms.Features.MidrandBooks/Payments/PaymentService.cs

@@ -1,7 +1,264 @@
-using LiteCharms.Features.MidrandBooks.Abstractions;
+using LiteCharms.Features.Abstractions;
+using LiteCharms.Features.MidrandBooks.Extensions;
+using LiteCharms.Features.MidrandBooks.Payments.Models;
+using LiteCharms.Features.MidrandBooks.Postgres;
 
 namespace LiteCharms.Features.MidrandBooks.Payments;
 
-public sealed class PaymentService : IService
+public sealed class PaymentService(IDbContextFactory<MidrandBooksDbContext> contextFactory) : IService
 {
+    public async ValueTask<Result<Refund>> GetRefundAsync(long refundId, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            var refund = await context.Refunds.AsNoTracking()
+                .FirstOrDefaultAsync(r => r.Id == refundId, cancellationToken);
+
+            return refund is not null
+                ? Result.Ok(refund.ToModel())
+                : Result.Fail<Refund>("Could not find refund");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail<Refund>(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
+    public async ValueTask<Result> UpdateRefundAsync(long refundId, UpdateRefund request, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            if (!await context.Orders.AnyAsync(o => o.Id == request.OrderId, cancellationToken))
+                return Result.Fail("Order not found");
+
+            var updatedRows = await context.Refunds
+                .Where(r => r.Id == refundId && r.OrderId == request.OrderId)
+                .ExecuteUpdateAsync(setters => setters
+                    .SetProperty(r => r.Status, request.Status)
+                    .SetProperty(r => r.Reason, request.Reason)
+                    .SetProperty(r => r.UpdatedAt, DateTime.UtcNow)
+                    .SetProperty(r => r.Amount, request.Amount), cancellationToken);
+
+            return updatedRows > 0
+                ? Result.Ok()
+                : Result.Fail("Failed to update refund");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
+    public async ValueTask<Result<long>> CreateRefundAsync(CreateRefund request, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            var order = await context.Orders.AsNoTracking()
+                .FirstOrDefaultAsync(o => o.Id == request.OrderId
+                    && o.Status == OrderStatus.Completed, cancellationToken);
+
+            if (order is null) return Result.Fail("Order not found");
+
+            if (request.Amount > order.Total)
+                return Result.Fail<long>("Refund amount cannot be greater than order total");
+
+            var totalRefundsPaid = await context.Refunds
+                .Where(r => r.OrderId == request.OrderId)
+                .SumAsync(r => r.Amount, cancellationToken);
+
+            if (request.Amount > (order.Total - totalRefundsPaid))
+                return Result.Fail<long>("Refund amount exceeds amount available for refund");
+
+            var refund = context.Refunds.Add(new Entities.Refund
+            {
+                Amount = request.Amount,
+                CreatedAt = DateTime.UtcNow,
+                OrderId = request.OrderId,
+                Reason = request.Reason,
+                Status = request.Status,
+                Type = request.Type,
+            });
+
+            return await context.SaveChangesAsync(cancellationToken) > 0
+                ? Result.Ok(refund.Entity.Id)
+                : Result.Fail<long>("Failed to create refund");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
+    public async ValueTask<Result> WriteLedgerEntryAsync(CreateLedgerEntry request, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            if (!await context.Orders.AnyAsync(o => o.Id == request.OrderId, cancellationToken))
+                return Result.Fail("Order not found");
+
+            if (!await context.Customers.AnyAsync(o => o.Id == request.CustomerId, cancellationToken))
+                return Result.Fail("Customer not found");
+
+            if (!await context.Orders.AnyAsync(oc => oc.Id == request.OrderId && oc.CustomerId == request.CustomerId, cancellationToken))
+                return Result.Fail("Customer does not match the order");
+
+            if (!await context.Payments.AnyAsync(o => o.Id == request.PaymentId && o.OrderId == request.OrderId, cancellationToken))
+                return Result.Fail("Payment not found");
+
+            if (request.PaymentGatewayId is not null)
+                if (!await context.Gateways.AnyAsync(o => o.Id == request.PaymentGatewayId, cancellationToken))
+                    return Result.Fail("Gateway not found");
+
+            context.Ledger.Add(new Entities.PaymentLedger
+            {
+                CreatedAt = DateTime.UtcNow,
+                CustomerId = request.CustomerId,
+                OrderId = request.OrderId,
+                PaymentGatewayId = request.PaymentGatewayId,
+                PaymentGatewayReference = request.PaymentGatewayReference,
+                PaymentId = request.PaymentId,
+                Status = request.Status,
+            });
+
+            return await context.SaveChangesAsync(cancellationToken) > 0
+                ? Result.Ok()
+                : Result.Fail("Failed to create ledger entry");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
+    public async ValueTask<Result<PaymentGateway>> GetPaymentGatewayAsync(long paymentGatewayId, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            var gateway = await context.Gateways.AsNoTracking().FirstOrDefaultAsync(g => g.Id == paymentGatewayId, cancellationToken);
+
+            return gateway is not null
+                ? Result.Ok(gateway.ToModel())
+                : Result.Fail<PaymentGateway>("Could not find gateway");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail<PaymentGateway>(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
+    public async ValueTask<Result<long>> CreatePaymentGatewayAsync(CreatePaymentGateway request, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            if (await context.Gateways.AnyAsync(g => g.MerchantId == request.MerchantId && g.MerchantKey == request.MerchantKey, cancellationToken))
+                return Result.Fail<long>("A gateway with the same credentials already exists");
+
+            var gateway = context.Gateways.Add(new Entities.PaymentGateway
+            {
+                CreatedAt = DateTime.UtcNow,
+                Enabled = true,
+                IsSandbox = request.IsSandbox,
+                MerchantId = request.MerchantId,
+                MerchantKey = request.MerchantKey,
+                Name = request.Name,
+                Website = request.Website,
+            });
+
+            return await context.SaveChangesAsync(cancellationToken) > 0
+                ? Result.Ok(gateway.Entity.Id)
+                : Result.Fail<long>("Failed to create payment gateway");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail<long>(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
+    public async ValueTask<Result> CompletePaymentAsync(long paymentId, PaymentStatuses status, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            if (status == PaymentStatuses.NotPaid)
+                return Result.Fail("Cannot finalise a payment using NotPaid status");
+
+            var updatedRecords = await context.Payments
+                .Where(p => p.Id == paymentId && p.Status != PaymentStatuses.Paid && p.Status != status)
+                .ExecuteUpdateAsync(setters => setters
+                    .SetProperty(u => u.Status, status)
+                    .SetProperty(u => u.UpdatedAt, DateTime.UtcNow), cancellationToken);
+
+            return updatedRecords > 0
+                ? Result.Ok()
+                : Result.Fail("Failed to update payment");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
+    public async ValueTask<Result> UpdatePaymentAsync(long paymentId, decimal amount, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            var updatedRecords = await context.Payments
+                .Where(p => p.Id == paymentId && p.Status == PaymentStatuses.NotPaid)
+                .ExecuteUpdateAsync(setters => setters
+                    .SetProperty(u => u.Amount, amount)
+                    .SetProperty(u => u.Status, PaymentStatuses.NotPaid)
+                    .SetProperty(u => u.UpdatedAt, DateTime.UtcNow), cancellationToken);
+
+            return updatedRecords > 0
+                ? Result.Ok()
+                : Result.Fail("Failed to update payment");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
+    public async ValueTask<Result<long>> CreatePaymentAsync(decimal amount, long orderId, string reference, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            if (await context.Payments.AnyAsync(p => p.OrderId == orderId && p.Amount == amount && p.Status != PaymentStatuses.Paid, cancellationToken))
+                return Result.Fail<long>("An order with the same amount already exists in the system");
+
+            var payment = context.Payments.Add(new Entities.Payment
+            {
+                CreatedAt = DateTime.UtcNow,
+                Amount = amount,
+                OrderId = orderId,
+                Reference = reference,
+                Status = PaymentStatuses.NotPaid,
+            });
+
+            return await context.SaveChangesAsync(cancellationToken) > 0
+                ? Result.Ok(payment.Entity.Id)
+                : Result.Fail<long>("Failed to make payment");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail<long>(new Error(ex.Message).CausedBy(ex));
+        }
+    }
 }

LiteCharms.Features.MidrandBooks/Postgres/MidrandBooksDbContext.cs

@@ -40,4 +40,12 @@ public sealed class MidrandBooksDbContext(DbContextOptions<MidrandBooksDbContext
     public DbSet<Category> Categories => Set<Category>();
 
     public DbSet<ProductCategory> ProductCategories => Set<ProductCategory>();
+
+    public DbSet<ProductInventory> Inventories => Set<ProductInventory>();
+
+    public DbSet<Payment> Payments => Set<Payment>();
+
+    public DbSet<PaymentGateway> Gateways => Set<PaymentGateway>();
+
+    public DbSet<PaymentLedger> Ledger => Set<PaymentLedger>();
 }

LiteCharms.Features.MidrandBooks/Postgres/Migrations/20260531094401_AddedPaymentObjects.cs

@@ -0,0 +1,185 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace LiteCharms.Features.MidrandBooks.Postgres.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddedPaymentObjects : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "Gateways",
+                columns: table => new
+                {
+                    Id = table.Column<long>(type: "bigint", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    CreatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()"),
+                    UpdatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: true),
+                    Name = table.Column<string>(type: "text", nullable: false),
+                    Website = table.Column<string>(type: "text", nullable: true),
+                    MerchantId = table.Column<string>(type: "text", nullable: false),
+                    MerchantKey = table.Column<string>(type: "text", nullable: false),
+                    Passphrase = table.Column<string>(type: "text", nullable: false),
+                    IsSandbox = table.Column<bool>(type: "boolean", nullable: false),
+                    Enabled = table.Column<bool>(type: "boolean", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Gateways", x => x.Id);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "Inventories",
+                columns: table => new
+                {
+                    Id = table.Column<long>(type: "bigint", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    CreatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()"),
+                    Status = table.Column<int>(type: "integer", nullable: false),
+                    ProductId = table.Column<long>(type: "bigint", nullable: false),
+                    ProductPriceId = table.Column<long>(type: "bigint", nullable: false),
+                    TotalAllocated = table.Column<int>(type: "integer", nullable: false),
+                    TotalReserved = table.Column<int>(type: "integer", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Inventories", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_Inventories_Prices_ProductPriceId",
+                        column: x => x.ProductPriceId,
+                        principalTable: "Prices",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "FK_Inventories_Products_ProductId",
+                        column: x => x.ProductId,
+                        principalTable: "Products",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "Payments",
+                columns: table => new
+                {
+                    Id = table.Column<long>(type: "bigint", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    CreatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()"),
+                    UpdatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: true),
+                    Amount = table.Column<decimal>(type: "numeric(18,2)", precision: 18, scale: 2, nullable: false),
+                    OrderId = table.Column<long>(type: "bigint", nullable: false),
+                    Reference = table.Column<string>(type: "text", nullable: false),
+                    Status = table.Column<int>(type: "integer", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Payments", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_Payments_Orders_OrderId",
+                        column: x => x.OrderId,
+                        principalTable: "Orders",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Restrict);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "Ledger",
+                columns: table => new
+                {
+                    Id = table.Column<long>(type: "bigint", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    CreatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()"),
+                    Status = table.Column<int>(type: "integer", nullable: false),
+                    OrderId = table.Column<long>(type: "bigint", nullable: false),
+                    PaymentId = table.Column<long>(type: "bigint", nullable: false),
+                    CustomerId = table.Column<long>(type: "bigint", nullable: false),
+                    PaymentGatewayReference = table.Column<string>(type: "text", nullable: true),
+                    PaymentGatewayId = table.Column<long>(type: "bigint", nullable: true)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Ledger", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_Ledger_Customers_CustomerId",
+                        column: x => x.CustomerId,
+                        principalTable: "Customers",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "FK_Ledger_Gateways_PaymentGatewayId",
+                        column: x => x.PaymentGatewayId,
+                        principalTable: "Gateways",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "FK_Ledger_Orders_OrderId",
+                        column: x => x.OrderId,
+                        principalTable: "Orders",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "FK_Ledger_Payments_PaymentId",
+                        column: x => x.PaymentId,
+                        principalTable: "Payments",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Inventories_ProductId",
+                table: "Inventories",
+                column: "ProductId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Inventories_ProductPriceId",
+                table: "Inventories",
+                column: "ProductPriceId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Ledger_CustomerId",
+                table: "Ledger",
+                column: "CustomerId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Ledger_OrderId",
+                table: "Ledger",
+                column: "OrderId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Ledger_PaymentGatewayId",
+                table: "Ledger",
+                column: "PaymentGatewayId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Ledger_PaymentId",
+                table: "Ledger",
+                column: "PaymentId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Payments_OrderId",
+                table: "Payments",
+                column: "OrderId");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "Inventories");
+
+            migrationBuilder.DropTable(
+                name: "Ledger");
+
+            migrationBuilder.DropTable(
+                name: "Gateways");
+
+            migrationBuilder.DropTable(
+                name: "Payments");
+        }
+    }
+}

LiteCharms.Features.MidrandBooks/Postgres/Migrations/20260601071804_RemovedPassphraseFromPaymentGateway.cs

@@ -0,0 +1,29 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace LiteCharms.Features.MidrandBooks.Postgres.Migrations
+{
+    /// <inheritdoc />
+    public partial class RemovedPassphraseFromPaymentGateway : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "Passphrase",
+                table: "Gateways");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "Passphrase",
+                table: "Gateways",
+                type: "text",
+                nullable: false,
+                defaultValue: "");
+        }
+    }
+}

LiteCharms.Features.MidrandBooks/Postgres/Migrations/MidrandBooksDbContextModelSnapshot.cs

@@ -536,6 +536,129 @@ namespace LiteCharms.Features.MidrandBooks.Postgres.Migrations
                     b.ToTable("BookPages", (string)null);
                 });
 
+            modelBuilder.Entity("LiteCharms.Features.MidrandBooks.Payments.Entities.Payment", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<decimal>("Amount")
+                        .HasPrecision(18, 2)
+                        .HasColumnType("numeric(18,2)");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("timestamp with time zone")
+                        .HasDefaultValueSql("now()");
+
+                    b.Property<long>("OrderId")
+                        .HasColumnType("bigint");
+
+                    b.Property<string>("Reference")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("integer");
+
+                    b.Property<DateTime?>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("OrderId");
+
+                    b.ToTable("Payments", (string)null);
+                });
+
+            modelBuilder.Entity("LiteCharms.Features.MidrandBooks.Payments.Entities.PaymentGateway", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<DateTime>("CreatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("timestamp with time zone")
+                        .HasDefaultValueSql("now()");
+
+                    b.Property<bool>("Enabled")
+                        .HasColumnType("boolean");
+
+                    b.Property<bool>("IsSandbox")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("MerchantId")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("MerchantKey")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<DateTime?>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("Website")
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Gateways", (string)null);
+                });
+
+            modelBuilder.Entity("LiteCharms.Features.MidrandBooks.Payments.Entities.PaymentLedger", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<DateTime>("CreatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("timestamp with time zone")
+                        .HasDefaultValueSql("now()");
+
+                    b.Property<long>("CustomerId")
+                        .HasColumnType("bigint");
+
+                    b.Property<long>("OrderId")
+                        .HasColumnType("bigint");
+
+                    b.Property<long?>("PaymentGatewayId")
+                        .HasColumnType("bigint");
+
+                    b.Property<string>("PaymentGatewayReference")
+                        .HasColumnType("text");
+
+                    b.Property<long>("PaymentId")
+                        .HasColumnType("bigint");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("integer");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("CustomerId");
+
+                    b.HasIndex("OrderId");
+
+                    b.HasIndex("PaymentGatewayId");
+
+                    b.HasIndex("PaymentId");
+
+                    b.ToTable("Ledger", (string)null);
+                });
+
             modelBuilder.Entity("LiteCharms.Features.MidrandBooks.Payments.Entities.Refund", b =>
                 {
                     b.Property<long>("Id")
@@ -653,6 +776,43 @@ namespace LiteCharms.Features.MidrandBooks.Postgres.Migrations
                     b.ToTable("ProductCategories", (string)null);
                 });
 
+            modelBuilder.Entity("LiteCharms.Features.MidrandBooks.Products.Entities.ProductInventory", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<DateTime>("CreatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("timestamp with time zone")
+                        .HasDefaultValueSql("now()");
+
+                    b.Property<long>("ProductId")
+                        .HasColumnType("bigint");
+
+                    b.Property<long>("ProductPriceId")
+                        .HasColumnType("bigint");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("TotalAllocated")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("TotalReserved")
+                        .HasColumnType("integer");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("ProductId");
+
+                    b.HasIndex("ProductPriceId");
+
+                    b.ToTable("Inventories", (string)null);
+                });
+
             modelBuilder.Entity("LiteCharms.Features.MidrandBooks.Products.Entities.ProductPrice", b =>
                 {
                     b.Property<long>("Id")
@@ -891,6 +1051,51 @@ namespace LiteCharms.Features.MidrandBooks.Postgres.Migrations
                     b.Navigation("References");
                 });
 
+            modelBuilder.Entity("LiteCharms.Features.MidrandBooks.Payments.Entities.Payment", b =>
+                {
+                    b.HasOne("LiteCharms.Features.MidrandBooks.Orders.Entities.Order", "Order")
+                        .WithMany()
+                        .HasForeignKey("OrderId")
+                        .OnDelete(DeleteBehavior.Restrict)
+                        .IsRequired();
+
+                    b.Navigation("Order");
+                });
+
+            modelBuilder.Entity("LiteCharms.Features.MidrandBooks.Payments.Entities.PaymentLedger", b =>
+                {
+                    b.HasOne("LiteCharms.Features.MidrandBooks.Customers.Entities.Customer", "Customer")
+                        .WithMany()
+                        .HasForeignKey("CustomerId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("LiteCharms.Features.MidrandBooks.Orders.Entities.Order", "Order")
+                        .WithMany()
+                        .HasForeignKey("OrderId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("LiteCharms.Features.MidrandBooks.Payments.Entities.PaymentGateway", "Gateway")
+                        .WithMany()
+                        .HasForeignKey("PaymentGatewayId")
+                        .OnDelete(DeleteBehavior.Cascade);
+
+                    b.HasOne("LiteCharms.Features.MidrandBooks.Payments.Entities.Payment", "Payment")
+                        .WithMany()
+                        .HasForeignKey("PaymentId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Customer");
+
+                    b.Navigation("Gateway");
+
+                    b.Navigation("Order");
+
+                    b.Navigation("Payment");
+                });
+
             modelBuilder.Entity("LiteCharms.Features.MidrandBooks.Payments.Entities.Refund", b =>
                 {
                     b.HasOne("LiteCharms.Features.MidrandBooks.Orders.Entities.Order", "Order")
@@ -950,6 +1155,25 @@ namespace LiteCharms.Features.MidrandBooks.Postgres.Migrations
                     b.Navigation("Product");
                 });
 
+            modelBuilder.Entity("LiteCharms.Features.MidrandBooks.Products.Entities.ProductInventory", b =>
+                {
+                    b.HasOne("LiteCharms.Features.MidrandBooks.Products.Entities.Product", "Product")
+                        .WithMany()
+                        .HasForeignKey("ProductId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("LiteCharms.Features.MidrandBooks.Products.Entities.ProductPrice", "Price")
+                        .WithMany()
+                        .HasForeignKey("ProductPriceId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Price");
+
+                    b.Navigation("Product");
+                });
+
             modelBuilder.Entity("LiteCharms.Features.MidrandBooks.Products.Entities.ProductPrice", b =>
                 {
                     b.HasOne("LiteCharms.Features.MidrandBooks.Products.Entities.Product", "Product")

LiteCharms.Features.MidrandBooks/Products/Entities/ProductInventory.cs

@@ -0,0 +1,9 @@
+namespace LiteCharms.Features.MidrandBooks.Products.Entities;
+
+[EntityTypeConfiguration<ProductInventoryConfiguration, ProductInventory>]
+public class ProductInventory : Models.ProductInventory
+{
+    public virtual Product? Product { get; set; }
+
+    public virtual ProductPrice? Price { get; set; }
+}

LiteCharms.Features.MidrandBooks/Products/Entities/ProductInventoryConfiguration.cs

@@ -0,0 +1,27 @@
+namespace LiteCharms.Features.MidrandBooks.Products.Entities;
+
+public sealed class ProductInventoryConfiguration : IEntityTypeConfiguration<ProductInventory>
+{
+    public void Configure(EntityTypeBuilder<ProductInventory> builder)
+    {
+        builder.ToTable("Inventories");
+
+        builder.HasKey(f => f.Id);
+        builder.Property(f => f.CreatedAt).IsRequired().ValueGeneratedOnAdd().HasDefaultValueSql("now()");
+        builder.Property(f => f.Status).IsRequired();        
+        builder.Property(f => f.TotalAllocated).IsRequired();        
+        builder.Property(f => f.TotalReserved).IsRequired();        
+        builder.Property(f => f.ProductId).IsRequired();
+        builder.Property(f => f.ProductPriceId).IsRequired();
+
+        builder.HasOne(f => f.Product)
+            .WithMany()
+            .HasForeignKey(f => f.ProductId)
+            .OnDelete(DeleteBehavior.Cascade);
+
+        builder.HasOne(f => f.Price)
+            .WithMany()
+            .HasForeignKey(f => f.ProductPriceId)
+            .OnDelete(DeleteBehavior.Cascade);
+    }
+}

LiteCharms.Features.MidrandBooks/Products/Models/ProductInventory.cs

@@ -0,0 +1,18 @@
+namespace LiteCharms.Features.MidrandBooks.Products.Models;
+
+public class ProductInventory
+{
+    public long Id { get; set; }
+
+    public DateTime CreatedAt { get; set; }
+
+    public InventoryStatuses Status { get; set; }
+
+    public long ProductId { get; set; }
+
+    public long ProductPriceId { get; set; }
+
+    public int TotalAllocated { get; set; }
+
+    public int TotalReserved { get; set; }
+}

LiteCharms.Features.MidrandBooks/Products/Models/Records.cs

@@ -2,6 +2,24 @@
 
 namespace LiteCharms.Features.MidrandBooks.Products.Models;
 
+public sealed record ReserveStock
+{
+    public required long ProductId { get; set; }
+
+    public required long ProductPriceId { get; set; }
+
+    public int Reservation { get; set; }
+}
+
+public sealed record AllocateStock
+{
+    public required long ProductId { get; set; }
+
+    public required long ProductPriceId { get; set; }
+
+    public int Allocation { get; set; }
+}
+
 public sealed record CreateProduct
 {
     public required ProductTypes Type { get; set; }

LiteCharms.Features.MidrandBooks/Products/ProductService.cs

@@ -1,14 +1,132 @@
-using LiteCharms.Features.MidrandBooks.Abstractions;
+using LiteCharms.Features.Abstractions;
 using LiteCharms.Features.MidrandBooks.Categories.Models;
 using LiteCharms.Features.MidrandBooks.Extensions;
 using LiteCharms.Features.MidrandBooks.Postgres;
 using LiteCharms.Features.MidrandBooks.Products.Models;
 using LiteCharms.Features.Models;
+using Org.BouncyCastle.Asn1.Ocsp;
 
 namespace LiteCharms.Features.MidrandBooks.Products;
 
 public sealed class ProductService(IDbContextFactory<MidrandBooksDbContext> contextFactory) : IService
 {
+    public async ValueTask<Result<ProductInventory>> CheckProductStockAvailabilityAsync(long productId, long productPriceId, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            var inventory = await context.Inventories
+                .AsNoTracking()
+                .Where(i => i.ProductPriceId == productPriceId && i.ProductId == productId)
+                .OrderByDescending(o => o.Id)
+                .FirstOrDefaultAsync(cancellationToken);
+
+            return inventory is not null
+                ? Result.Ok(inventory.ToModel())
+                : Result.Fail<ProductInventory>("Product sold out");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail<ProductInventory>(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
+    public async ValueTask<Result<long>> ReserveProductInventoryAsync(ReserveStock request, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            var oldInventory = await context.Inventories
+                .AsNoTracking()
+                .Where(i => i.ProductPriceId == request.ProductPriceId && i.ProductId == request.ProductId)
+                .OrderByDescending(o => o.Id)
+                .FirstOrDefaultAsync(cancellationToken);
+
+            var newAllocation = 0;
+            var newReservation = 0;
+
+            if (oldInventory is not null)
+            {
+                newAllocation = oldInventory.TotalAllocated;
+                newReservation = oldInventory.TotalReserved + request.Reservation;
+            }
+            else
+            {
+                newAllocation = 0;
+                newReservation = request.Reservation;
+            }
+
+            if (newAllocation - newReservation < 0)
+                return Result.Fail<long>("Allocation failure: The requested book quantity exceeds current physical inventory availability.");
+
+            var inventory = context.Inventories.Add(new Entities.ProductInventory
+            {
+                CreatedAt = DateTime.UtcNow,
+                ProductId = request.ProductId,
+                ProductPriceId = request.ProductPriceId,
+                Status = InventoryStatuses.Reserved,
+                TotalAllocated = newAllocation,
+                TotalReserved = newReservation,
+            });
+
+            return await context.SaveChangesAsync(cancellationToken) > 0
+                ? Result.Ok(inventory.Entity.Id)
+                : Result.Fail<long>("Failed to create inventory entry");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail<long>(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
+    public async ValueTask<Result<long>> AllocateProductInventoryAsync(AllocateStock request, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            var oldInventory = await context.Inventories
+                .AsNoTracking()
+                .Where(i => i.ProductPriceId == request.ProductPriceId && i.ProductId == request.ProductId)
+                .OrderByDescending(o => o.Id)
+                .FirstOrDefaultAsync(cancellationToken);
+
+            var newAllocation = 0;
+            var newReservation = 0;
+
+            if (oldInventory is not null)
+            {
+                newAllocation = oldInventory.TotalAllocated + request.Allocation;
+                newReservation = oldInventory.TotalReserved;
+            }
+            else
+            {
+                newAllocation = request.Allocation;
+                newReservation = 0;
+            }
+
+            var inventory = context.Inventories.Add(new Entities.ProductInventory
+            {
+                CreatedAt = DateTime.UtcNow,
+                ProductId = request.ProductId,
+                ProductPriceId = request.ProductPriceId,
+                Status = InventoryStatuses.Adjustment,
+                TotalAllocated = newAllocation,
+                TotalReserved = newReservation,
+            });
+
+            return await context.SaveChangesAsync(cancellationToken) > 0
+                ? Result.Ok(inventory.Entity.Id)
+                : Result.Fail<long>("Failed to create inventory entry");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail<long>(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
     public async ValueTask<Result> AddProductCategoryAsync(long productId, long categoryId, CancellationToken cancellationToken = default)
     {
         try
@@ -304,7 +422,8 @@ public sealed class ProductService(IDbContextFactory<MidrandBooksDbContext> cont
         {
             await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
 
-            var product = await context.Products.AsNoTracking().FirstOrDefaultAsync(p => p.Id == productId, cancellationToken);
+            var product = await context.Products                
+                .AsNoTracking().FirstOrDefaultAsync(p => p.Id == productId, cancellationToken);
 
             return product is null
                 ? Result.Fail<Product>(new Error($"Product with ID {productId} not found."))

LiteCharms.Features.TechShop/Leads/LeadService.cs

@@ -1,9 +1,8 @@
-using LiteCharms.Features.Extensions;
+using LiteCharms.Features.Hasher;
 using LiteCharms.Features.Models;
 using LiteCharms.Features.TechShop.Extensions;
 using LiteCharms.Features.TechShop.Leads.Models;
 using LiteCharms.Features.TechShop.Postgres;
-using static LiteCharms.Features.Extensions.Hash;
 
 namespace LiteCharms.Features.TechShop.Leads;
 
@@ -29,7 +28,7 @@ public class LeadService(IDbContextFactory<ShopDbContext> contextFactory)
                 FeedItemId = request.FeedItemId,
                 Status = LeadStatus.New,
                 TargetId = request.TargetId,
-                AttributionHash = StringToSha256Hash.Invoke($"{request.ClickId}{request.AppClickId}{request.WebClickId}")
+                AttributionHash = HashService.StringToSha256Hash($"{request.ClickId}{request.AppClickId}{request.WebClickId}")
             });
 
             return await context.SaveChangesAsync(cancellationToken) > 0

LiteCharms.Features.Tests/Fixture.cs

@@ -26,6 +26,7 @@ public class Fixture : IDisposable
             .AddGarageS3(Configuration)
             .AddEmailServices(Configuration)
             .AddSingleton(Configuration)
+            .AddHashServices(Configuration)
             .BuildServiceProvider();
 
         Mediator = Services.GetRequiredService<IMediator>();

LiteCharms.Features.Tests/HashServiceFeatureTests.cs

@@ -0,0 +1,155 @@
+using LiteCharms.Features.Hasher;
+using LiteCharms.Features.Models;
+using static LiteCharms.Features.Extensions.Hash;
+
+namespace LiteCharms.Features.Tests;
+
+public class HashServiceFeatureTests(Fixture fixture) : IClassFixture<Fixture>
+{
+    private readonly HashService hashService = fixture.Services.GetRequiredService<HashService>();
+    private readonly string payfastPassphrase = fixture.Configuration.GetSection("HasherSettings:PayfastPassphrase").Value!;
+
+    [Fact]
+    public void StringToSha256Hash_Should_GenerateHash()
+    {
+        var input = "We are the best";
+        var expectedHash = "96E17275B53F6BEB7A0D1C4F789F226D3C71CBE398585F25B3028F2B432E78AB";
+
+        var result = HashService.StringToSha256Hash(input);
+
+        Assert.NotNull(result);
+        Assert.True(HashService.IsSha256Hash(result));
+        Assert.Equal(expectedHash, result);
+    }
+
+    [Fact]
+    public void StreamToSha256Hash_Should_GenerateHash()
+    {
+        var input = "We are successful";
+        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(input));
+        var expectedHash = "C27872EE494B09D72203C98FC858268F3CD3492D62AA7B766A873520C2C73AFB";
+
+        var result = HashService.StreamToSha256Hash(stream);
+
+        Assert.NotNull(result);
+        Assert.True(HashService.IsSha256Hash(result));
+        Assert.Equal(expectedHash, result);
+    }
+
+    [Fact]
+    public void BytesToSha256Hash_Should_GenerateHash()
+    {
+        var inputBytes = Encoding.UTF8.GetBytes("We are wealthy");
+        var expectedHash = "3876BF98F6E4A8E42B22C40415687D6FF13F0E887F3F508B71852298FC665737";
+
+        var result = HashService.BytesToSha256Hash(inputBytes);
+
+        Assert.NotNull(result);
+        Assert.True(HashService.IsSha256Hash(result));
+        Assert.Equal(expectedHash, result);
+    }
+
+    [Fact]
+    public void ToMd5Hash_Should_GenerateHash()
+    {
+        var input = "We manifest our desired destiny";
+        var expectedMd5Lowercase = "6c7816869bcebe4634f7afe9c66dfa08";
+
+        var result = HashService.ToMd5Hash(input);
+
+        Assert.True(result.IsSuccess);
+        Assert.True(HashService.IsMd5Hash(result.Value));
+        Assert.Equal(expectedMd5Lowercase, result.Value);
+    }
+
+    [Fact]
+    public void VerifyPayfastWebhookSignature_Should_GenerateHash()
+    {
+        var paymentId = hashService.HashEncodeLongId(1001).Value;
+
+        var payload = new PayfastWebhookPayload
+        {
+            Amount = "350.00",
+            ItemName = "System Architecture Book",
+            MPaymentId = paymentId,            
+        };
+
+        var rawPayload = payload.ToRawPayfastPayload(payfastPassphrase);
+
+        var generatedSignature = HashService.ToMd5Hash(rawPayload).Value;
+
+        var result = hashService.VerifyPayfastWebhookSignature(payload, generatedSignature);
+
+        Assert.True(result.IsSuccess);
+        Assert.True(result.Value);
+    }
+
+    [Fact]
+    public void HashEncodeHex_Should_GenerateHash()
+    {
+        var validHexInput = "DEADBEEF42";
+
+        var result = hashService.HashEncodeHex(validHexInput);
+
+        Assert.True(result.IsSuccess);
+        Assert.False(string.IsNullOrWhiteSpace(result.Value));
+    }
+
+    [Fact]
+    public void HashEncodeIntId_Should_GenerateHash()
+    {
+        int targetId = 42;
+
+        var result = hashService.HashEncodeIntId(targetId);
+
+        Assert.True(result.IsSuccess);
+        Assert.True(result.Value.Length >= 10);
+    }
+
+    [Fact]
+    public void HashEncodeLongId_Should_GenerateHash()
+    {
+        long targetId = 9904185012L;
+
+        var result = hashService.HashEncodeLongId(targetId);
+
+        Assert.True(result.IsSuccess);
+        Assert.True(result.Value.Length >= 10);
+    }
+
+    [Fact]
+    public void DecodeIntIdHash_Should_GenerateHash()
+    {
+        int originalId = 88041;
+        var hashedString = hashService.HashEncodeIntId(originalId).Value;
+
+        var result = hashService.DecodeIntIdHash(hashedString);
+
+        Assert.True(result.IsSuccess);
+        Assert.Equal(originalId, result.Value);
+    }
+
+    [Fact]
+    public void DecodeLongIdHash_Should_GenerateHash()
+    {
+        long originalId = 9081230491823L;
+        var hashedString = hashService.HashEncodeLongId(originalId).Value;
+
+        var result = hashService.DecodeLongIdHash(hashedString);
+
+        Assert.True(result.IsSuccess);
+        Assert.Equal(originalId, result.Value);
+    }
+
+    [Fact]
+    public void DecodeHexHash_Should_GenerateHash()
+    {
+        var originalHex = "ABCDEF12345";
+        var hashedString = hashService.HashEncodeHex(originalHex).Value;
+
+        var result = hashService.DecodeHexHash(hashedString);
+
+        Assert.True(result.IsSuccess);
+        Assert.Equal(originalHex, result.Value);
+    }
+}

LiteCharms.Features.Tests/LiteCharms.Features.Tests.csproj

@@ -27,6 +27,8 @@
 
   <!-- Global Usings -->
   <ItemGroup>
+    <Using Include="System.Net" />
+    <Using Include="System.Text" />
     <Using Include="Mediator" />
     <Using Include="Xunit.Abstractions" />
     <Using Include="Microsoft.Extensions.DependencyInjection" />

LiteCharms.Features/Abstractions/IService.cs

@@ -0,0 +1,3 @@
+namespace LiteCharms.Features.Abstractions;
+
+public interface IService;

LiteCharms.Features/Enums.cs

@@ -1,5 +1,35 @@
 namespace LiteCharms.Features;
 
+public enum InventoryStatuses : int
+{
+    Adjustment = 0,
+    Reserved = 1,
+    Released = 2,
+    Sold = 3,
+    Replenished = 4,
+    Correction = 5,
+}
+
+public enum LedgerStatuses : int
+{
+    Changed = 0,
+    Sent = 1,
+    Received = 2,
+    Refunded = 3,
+    Cancelled = 4,
+    Failed = 5,
+    Partial = 6,
+}
+
+public enum PaymentStatuses : int
+{
+    NotPaid = 0,
+    Paid = 1,
+    Cancelled = 2,
+    Requested = 3,
+    Failed = 4,
+}
+
 public enum ShippingProviderTypes : int
 {
     Dsv = 0,
@@ -114,4 +144,65 @@ public enum Priorities : int
     Low = 0,
     Medium = 1,
     High = 2,
+}
+
+public enum PublisherTypes : int
+{
+    Individual = 0,
+    Company = 1,
+    Organization = 2,
+    SelfPublished = 3,
+    UniversityPress = 4,
+    GovernmentAgency = 5,
+    NonProfit = 6,
+    Independent = 7
+}
+
+public enum BookTypes : int
+{
+    Fiction = 0,
+    NonFiction = 1,
+    Academic = 2,
+    SelfHelp = 3,
+    Biography = 4,
+    Poetry = 5,
+    Children = 6,
+    YoungAdult = 7,
+    ScienceFiction = 8,
+    Fantasy = 9
+}
+
+public enum BookContentTypes : int
+{
+    Text = 0,
+    Image = 1,
+    Video = 2,
+    Audio = 3,
+    Interactive = 4,
+    Markdown = 5,
+    Html = 6,
+    Json = 7,
+    Yaml = 8
+}
+
+public enum BookPageTypes : int
+{
+    Cover = 0,
+    Preface = 1,
+    Introduction = 2,
+    Content = 3,
+    Closing = 4,
+    Referencer = 5,
+    Credits = 6,
+    BackCover = 7
+}
+
+public enum ProductTypes : int
+{
+    Book = 1,
+    Journal = 2,
+    Magazine = 3,
+    EBook = 4,
+    Audiobook = 5,
+    Accessory = 6
 }

LiteCharms.Features/Extensions/Hash.cs

@@ -1,13 +1,85 @@
-namespace LiteCharms.Features.Extensions;
+using LiteCharms.Features.Hasher;
+using LiteCharms.Features.Hasher.Configuration;
+using LiteCharms.Features.Models;
+
+namespace LiteCharms.Features.Extensions;
 
 public static class Hash
 {
-    public static readonly Func<string?, string?> StringToSha256Hash = (input) => 
+    public const string HasherConfigSectionName = "HasherSettings";
-        Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(input!)));
 
-    public static readonly Func<Stream, string?> StreamToSha256Hash = (stream) =>
+    public static IServiceCollection AddHashServices(this IServiceCollection services, IConfiguration configuration)
-        Convert.ToHexString(SHA256.HashData(stream));
+    {
+        services.Configure<HasherSettings>(configuration.GetSection(HasherConfigSectionName));
 
-    public static readonly Func<byte[], string?> BytesToSha256Hash = (bytes) =>
+        var settings = configuration.GetSection(HasherConfigSectionName).Get<HasherSettings>();
-        Convert.ToHexString(SHA256.HashData(bytes));
+
-}
+        services.AddSingleton<IHashids>(_ =>
+            new Hashids(settings!.Salt, minHashLength: settings.MinHashLength));
+
+        services.AddSingleton<HashService>();
+
+        return services;
+    }
+
+    public static string ToRawPayfastPayload(this PayfastWebhookPayload input, string passphrase)
+    {
+        var parameters = new List<string>();
+
+        if (!string.IsNullOrWhiteSpace(input.Amount))
+            parameters.Add($"amount={WebUtility.UrlEncode(input.Amount)}");
+
+        if (!string.IsNullOrWhiteSpace(input.ItemName))
+            parameters.Add($"item_name={WebUtility.UrlEncode(input.ItemName)}");
+
+        if (!string.IsNullOrWhiteSpace(input.MPaymentId))
+            parameters.Add($"m_payment_id={WebUtility.UrlEncode(input.MPaymentId)}");
+
+        string payload = string.Join("&", parameters);
+
+        if (!string.IsNullOrWhiteSpace(passphrase))
+            payload += $"&passphrase={WebUtility.UrlEncode(passphrase)}";
+
+        return payload;
+    }
+
+    public static (PayfastWebhookPayload Payload, string Passphrase) FromRawPayfastPayload(this string rawPayload)
+    {
+        string passphrase = string.Empty;
+        var payload = new PayfastWebhookPayload();
+
+        if (string.IsNullOrWhiteSpace(rawPayload)) return (payload, passphrase);
+
+        var segments = rawPayload.Split('&', StringSplitOptions.RemoveEmptyEntries);
+
+        foreach (var segment in segments)
+        {
+            int delimiterIndex = segment.IndexOf('=');
+            if (delimiterIndex == -1)
+                continue;
+
+            string key = segment[..delimiterIndex].Trim();
+            string rawValue = segment[(delimiterIndex + 1)..];
+
+            string decodedValue = WebUtility.UrlDecode(rawValue);
+
+            switch (key.ToLowerInvariant())
+            {
+                case "amount":
+                    payload.Amount = decodedValue;
+                    break;
+                case "item_name":
+                    payload.ItemName = decodedValue;
+                    break;
+                case "m_payment_id":
+                    payload.MPaymentId = decodedValue;
+                    break;
+                case "passphrase":
+                    passphrase = decodedValue;
+                    break;
+            }
+        }
+
+        return (payload, passphrase);
+    }
+}

LiteCharms.Features/Hasher/Configuration/HasherSettings.cs

@@ -0,0 +1,10 @@
+namespace LiteCharms.Features.Hasher.Configuration;
+
+public sealed class HasherSettings
+{
+    public string? Salt { get; set; }
+
+    public int MinHashLength { get; set; }
+
+    public string? PayfastPassphrase { get; set; }
+}

LiteCharms.Features/Hasher/HashService.cs

@@ -0,0 +1,131 @@
+using LiteCharms.Features.Abstractions;
+using LiteCharms.Features.Hasher.Configuration;
+using LiteCharms.Features.Models;
+
+namespace LiteCharms.Features.Hasher;
+
+public sealed partial class HashService(IHashids hasher, IOptions<HasherSettings> options) : IService
+{
+    private readonly HasherSettings settings = options.Value;
+
+    [GeneratedRegex(@"\A\b[0-9a-fA-F]+\b\Z")]
+    private static partial Regex HexHashRegex { get; }
+
+    [GeneratedRegex(@"\A[0-9a-fA-F]{32}\Z", RegexOptions.None, matchTimeoutMilliseconds: 100)]
+    private static partial Regex Md5Regex { get; }
+
+    [GeneratedRegex(@"\A[0-9a-fA-F]{64}\Z", RegexOptions.None, matchTimeoutMilliseconds: 100)]
+    private static partial Regex Sha256Regex { get; }
+
+    public static bool IsMd5Hash(string? value) =>
+        !string.IsNullOrWhiteSpace(value) && Md5Regex.IsMatch(value);
+
+    public static bool IsSha256Hash(string? value) =>
+        !string.IsNullOrWhiteSpace(value) && Sha256Regex.IsMatch(value);
+
+    public static string? StringToSha256Hash(string? input) =>
+        string.IsNullOrEmpty(input) ? null : Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(input)));
+
+    public static string? StreamToSha256Hash(Stream stream) =>
+        stream is null ? null : Convert.ToHexString(SHA256.HashData(stream));
+
+    public static string? BytesToSha256Hash(byte[] bytes) =>
+        bytes is null ? null : Convert.ToHexString(SHA256.HashData(bytes));
+
+    public static Result<string> ToMd5Hash(string input)
+    {
+        if (string.IsNullOrEmpty(input))
+            return Result.Fail<string>("Input content cannot be null or empty for MD5 processing.");
+
+        byte[] bytes = MD5.HashData(Encoding.UTF8.GetBytes(input));
+        return Result.Ok(Convert.ToHexString(bytes).ToLowerInvariant());
+    }
+
+    public Result<bool> VerifyPayfastWebhookSignature(PayfastWebhookPayload payload, string incomingSignature)
+    {
+        try
+        {
+            if (string.IsNullOrWhiteSpace(incomingSignature))
+                return Result.Fail<bool>("Validation failed: Missing signature string parameter.");
+
+            var parameters = new List<string>();
+
+            if (!string.IsNullOrWhiteSpace(payload.Amount))
+                parameters.Add($"amount={WebUtility.UrlEncode(payload.Amount)}");
+
+            if (!string.IsNullOrWhiteSpace(payload.ItemName))
+                parameters.Add($"item_name={WebUtility.UrlEncode(payload.ItemName)}");
+
+            if (!string.IsNullOrWhiteSpace(payload.MPaymentId))
+                parameters.Add($"m_payment_id={WebUtility.UrlEncode(payload.MPaymentId)}");
+
+            string signatureString = string.Join("&", parameters);
+
+            if (!string.IsNullOrWhiteSpace(settings.PayfastPassphrase))
+                signatureString += $"&passphrase={WebUtility.UrlEncode(settings.PayfastPassphrase)}";
+
+            var localHashResult = ToMd5Hash(signatureString);
+
+            if (!localHashResult.IsSuccess)
+                return Result.Fail<bool>(localHashResult.Errors);
+
+            bool isValid = string.Equals(localHashResult.Value, incomingSignature, StringComparison.OrdinalIgnoreCase);
+
+            return Result.Ok(isValid);
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail<bool>(new Error("An error occurred during Payfast MD5 verification.").CausedBy(ex));
+        }
+    }
+
+    public Result<string> HashEncodeHex(string input) => string.IsNullOrWhiteSpace(input) || !HexHashRegex.IsMatch(input)
+            ? Result.Fail<string>("Input must be a valid hexadecimal string.")
+            : Result.Ok(hasher.EncodeHex(input));
+
+    public Result<string> HashEncodeIntId(int id) => id < 0
+        ? Result.Fail<string>("Id cannot be negative.")
+        : Result.Ok(hasher.Encode(id));
+
+    public Result<string> HashEncodeLongId(long id) => id < 0
+        ? Result.Fail<string>("Id cannot be negative.")
+        : Result.Ok(hasher.EncodeLong(id));
+
+    public Result<int> DecodeIntIdHash(string hash)
+    {
+        if (string.IsNullOrWhiteSpace(hash)) return Result.Fail<int>("Invalid token layout.");
+
+        int[] decoded = hasher.Decode(hash);
+
+        return decoded.Length == 1 ? Result.Ok(decoded[0]) : Result.Fail<int>("Invalid or modified Int hash token.");
+    }
+
+    public Result<long> DecodeLongIdHash(string hash)
+    {
+        if (string.IsNullOrWhiteSpace(hash)) return Result.Fail<long>("Invalid token layout.");
+
+        long[] decoded = hasher.DecodeLong(hash);
+
+        return decoded.Length == 1 ? Result.Ok(decoded[0]) : Result.Fail<long>("Invalid or modified Long hash token.");
+    }
+
+    public Result<string> DecodeHexHash(string hex)
+    {
+        try
+        {
+            string decoded = hasher.DecodeHex(hex);
+
+            return string.IsNullOrEmpty(decoded)
+                ? Result.Fail<string>("Invalid or corrupted hex hash.")
+                : Result.Ok(decoded);
+        }
+        catch (FormatException fex)
+        {
+            return Result.Fail<string>(new Error("Invalid hash structure.").CausedBy(fex));
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail<string>(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+}

LiteCharms.Features/LiteCharms.Features.csproj

@@ -31,6 +31,7 @@
 
   <!-- Quartz Scheduler-->
   <ItemGroup>    
+    <PackageReference Include="Hashids.net" Version="1.7.0" />    
     <PackageReference Include="Meziantou.Analyzer" Version="3.0.96">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
@@ -146,6 +147,9 @@
 
   <!-- Shared Usings -->
   <ItemGroup>
+    <Using Include="HashidsNet" />
+    <Using Include="System.Net" />
+    <Using Include="System.Text.RegularExpressions" />
     <Using Include="System.Globalization" />
     <Using Include="Microsoft.AspNetCore.Builder" />
     <Using Include="Microsoft.Extensions.Hosting" />

LiteCharms.Features/Models/PayfastWebhookPayload.cs

@@ -0,0 +1,8 @@
+namespace LiteCharms.Features.Models;
+
+public sealed class PayfastWebhookPayload
+{
+    public string? Amount { get; set; }
+    public string? ItemName { get; set; }
+    public string? MPaymentId { get; set; }
+}

LiteCharms.Features/S3/Abstractions/S3ServiceBase.cs

@@ -1,4 +1,4 @@
-using static LiteCharms.Features.Extensions.Hash;
+using LiteCharms.Features.Hasher;
 
 namespace LiteCharms.Features.S3.Abstractions;
 
@@ -26,7 +26,7 @@ public abstract class S3ServiceBase(IAmazonS3 amazonS3)
 
             stream.Seek(0, SeekOrigin.Begin);
 
-            var fileHash = StreamToSha256Hash(stream);
+            var fileHash = HashService.StreamToSha256Hash(stream);
 
             if(string.IsNullOrWhiteSpace(fileHash))
                 return Result.Fail<string>("Failed to compute file hash.");
@@ -39,7 +39,7 @@ public abstract class S3ServiceBase(IAmazonS3 amazonS3)
                 Key = fileKey,
                 InputStream = stream,
                 ContentType = contentType,
-                UseChunkEncoding = false
+                UseChunkEncoding = false,
             };
 
             stream.Seek(0, SeekOrigin.Begin);