[ACL-196] Add support for SchemeSelection in Payouts

src/TrueLayer/Payouts/Model/CreatePayoutRequest.cs

@@ -5,6 +5,7 @@
 namespace TrueLayer.Payouts.Model
 {
     using BeneficiaryUnion = OneOf<PaymentSource, ExternalAccount, BusinessAccount>;
+    using SchemeSelectionUnion = OneOf<SchemeSelection.InstantPreferred, SchemeSelection.InstantOnly, SchemeSelection.Preselected>;
 
     /// <summary>
     /// Represents a request for payout
@@ -19,18 +20,21 @@ public record CreatePayoutRequest
         /// <param name="currency">The three-letter ISO alpha currency code</param>
         /// <param name="beneficiary">The payout beneficiary details</param>
         /// <param name="metadata">Metadata</param>
+        /// <param name="schemeSelection">Metadata</param>
         public CreatePayoutRequest(
             string merchantAccountId,
             long amountInMinor,
             string currency,
             BeneficiaryUnion beneficiary,
-            Dictionary<string, string>? metadata = null)
+            Dictionary<string, string>? metadata = null,
+            SchemeSelectionUnion? schemeSelection = null)
         {
             MerchantAccountId = merchantAccountId;
             AmountInMinor = amountInMinor.GreaterThan(0, nameof(amountInMinor));
             Currency = currency.NotNullOrWhiteSpace(nameof(currency));
             Beneficiary = beneficiary;
             Metadata = metadata;
+            SchemeSelection = schemeSelection;
         }
 
         /// <summary>
@@ -54,6 +58,14 @@ public CreatePayoutRequest(
         /// </summary>
         public BeneficiaryUnion Beneficiary { get; }
 
+        /// <summary>
+        /// Gets the metadata
+        /// </summary>
         public Dictionary<string, string>? Metadata { get; }
+
+        /// <summary>
+        /// Gets the scheme selection
+        /// </summary>
+        public SchemeSelectionUnion? SchemeSelection { get; }
     }
 }

src/TrueLayer/Payouts/Model/SchemeSelection.cs

@@ -0,0 +1,55 @@
+using TrueLayer.Serialization;
+
+namespace TrueLayer.Payouts.Model;
+
+/// <summary>
+/// Payout scheme selection types
+/// </summary>
+public static class SchemeSelection
+{
+    /// <summary>
+    /// Automatically select a payment scheme that supports instant payments based on currency and geography.
+    /// </summary>
+    [JsonDiscriminator("instant_only")]
+    public record InstantOnly : IDiscriminated
+    {
+        /// <summary>
+        /// Gets the scheme selection type
+        /// </summary>
+        public string Type => "instant_only";
+    }
+
+    /// <summary>
+    /// Automatically select a payment scheme that supports instant payments based on currency and geography,
+    /// with a fallback to a non-instant scheme if instant payment is unavailable.
+    /// The payout_executed webhook will specify the actual scheme used.
+    /// This is optimal when slow settlement is not a concern. This is used by default if no scheme_selection is provided.
+    /// </summary>
+    [JsonDiscriminator("instant_preferred")]
+    public record InstantPreferred : IDiscriminated
+    {
+        /// <summary>
+        /// Gets the scheme selection type
+        /// </summary>
+        public string Type => "instant_preferred";
+    }
+
+
+    /// <summary>
+    /// Represents that the scheme for the payout is preselected.
+    /// </summary>
+    [JsonDiscriminator("preselected")]
+    public record Preselected : IDiscriminated
+    {
+        /// <summary>
+        /// Gets the scheme selection type
+        /// </summary>
+        public string Type => "preselected";
+
+        /// <summary>
+        /// Select a payment scheme compatible with the currency and geographic region to avoid payout failures after submission.
+        /// This helps with payouts by selecting the better-performing scheme between two similar options in a region, based on various criteria
+        /// </summary>
+        public string? SchemeId { get; init; }
+    }
+}

test/TrueLayer.AcceptanceTests/PayoutTests.cs

@@ -23,8 +23,7 @@ public async Task Can_create_payout()
         {
             CreatePayoutRequest payoutRequest = CreatePayoutRequest();
 
-            var response = await _fixture.TlClients[0].Payouts.CreatePayout(
-                payoutRequest, idempotencyKey: Guid.NewGuid().ToString());
+            var response = await _fixture.TlClients[0].Payouts.CreatePayout(payoutRequest);
 
             response.StatusCode.Should().Be(HttpStatusCode.Accepted);
             response.Data.Should().NotBeNull();
@@ -81,8 +80,8 @@ private CreatePayoutRequest CreatePayoutRequest()
                     new AccountIdentifier.Iban("GB33BUKB20201555555555"),
                     dateOfBirth: new DateTime(1970, 12, 31),
                     address: new Address("London", "England", "EC1R 4RB", "GB", "1 Hardwick St")),
-                metadata: new() { { "a", "b" } }
+                metadata: new() { { "a", "b" } },
+                schemeSelection: new SchemeSelection.InstantOnly()
             );
-
     }
 }

test/TrueLayer.Tests/Payouts/PayoutsApiTests.cs

@@ -107,7 +107,8 @@ private static CreatePayoutRequest CreatePayoutRequest(PayoutBeneficiary benefic
                 100,
                 Currencies.GBP,
                 beneficiary,
-                metadata: new() { { "a", "b" } });
+                metadata: new() { { "a", "b" } },
+                schemeSelection: new SchemeSelection.InstantPreferred());
 
         public static IEnumerable<object[]> TestData =>
             new List<object[]>