Merge pull request 'Refactored PayfastService.GenerateSignature()' (#104) from payments into master

Reviewed-on: #104

LiteCharms.Features.MidrandBooks.Tests/CustomerServiceFeatureTests.cs

@@ -11,20 +11,12 @@ public class CustomerServiceFeatureTests(Fixture fixture) : IClassFixture<Fixtur
     [IntegrationFact]
     public async Task CreateCustomerAsync_ShouldReturn_ResultWithCustomerId()
     {
-        //var request = new CreateCustomer
-        //{
-        //    Company = "Book Lovers",
-        //    Email = "hank@booklovers.com",
-        //    Phone = "555 1245 8577",
-        //    Website = "https://www.booklovers.com"
-        //};
-
         var request = new CreateCustomer
         {
-            //Company = "Book Lovers",
+            Company = "Book Lovers",
             Email = "hank@booklovers.com",
-            //Phone = "555 1245 8577",
-            //Website = "https://www.booklovers.com"
+            Phone = "555 1245 8577",
+            Website = "https://www.booklovers.com"
         };
 
         var result = await customerService.CreateCustomerAsync(request, fixture.CancellationToken);

LiteCharms.Features.MidrandBooks/Payments/PayfastService.cs

@@ -152,11 +152,16 @@ public sealed partial class PayfastService(IDbContextFactory<MidrandBooksDbConte
             if (string.IsNullOrEmpty(kvp.Value))
                 continue;
 
+            if (kvp.Key.Equals("signature", StringComparison.OrdinalIgnoreCase))
+                continue;
+
             string key = kvp.Key;
 
+            // 1. Payfast requires spaces to be '+' signs. HttpUtility does this perfectly.
             string encodedVal = HttpUtility.UrlEncode(kvp.Value.Trim());
 
-            string val = PercentEncodingRegex.Replace(encodedVal, m => m.Value.ToLowerInvariant());
+            // 2. Payfast requires all OTHER percent-encoded hex arrays to be UPPERCASE (e.g., %3A instead of %3a)
+            string val = Regex.Replace(encodedVal, "%[0-9A-Fa-f]{2}", m => m.Value.ToUpperInvariant());
 
             pfOutput.Append($"{key}={val}&");
         }
@@ -167,13 +172,13 @@ public sealed partial class PayfastService(IDbContextFactory<MidrandBooksDbConte
 
         if (!string.IsNullOrWhiteSpace(passPhrase))
         {
+            // Apply the exact same encoding rule to your passphrase
             string encodedPassphrase = HttpUtility.UrlEncode(passPhrase.Trim());
-
-            string safePassphrase = PercentEncodingRegex.Replace(encodedPassphrase, m => m.Value.ToLowerInvariant());
+            string safePassphrase = Regex.Replace(encodedPassphrase, "%[0-9A-Fa-f]{2}", m => m.Value.ToUpperInvariant());
 
             getString += $"&passphrase={safePassphrase}";
         }
 
         return HashService.ToMd5Hash(getString);
-    }    
+    }
 }