add CancellationDetails to Offering (#103)

Sources/tbDEX/Protocol/DevTools.swift

@@ -35,7 +35,8 @@ enum DevTools {
                     )
                 ]
             ),
-            requiredClaims: nil
+            requiredClaims: nil,
+            cancellation: .init(enabled: false)
         )
 
         if let `protocol` = `protocol` {

Sources/tbDEX/Protocol/Models/Resources/Offering.swift

@@ -22,8 +22,11 @@ public struct OfferingData: ResourceData {
     /// Details and options associated to the payout currency
     public let payout: PayoutDetails
 
-    /// Articulates the claim(s) required when submitting an RFQ for this offering.
+    /// Articulates the claim(s) required when submitting an RFQ for this offering
     public let requiredClaims: PresentationDefinitionV2?
+
+    /// Details about PFI's cancellation policy
+    public let cancellation: CancellationDetails
 
     /// Returns the ResourceKind of offering
     public func kind() -> ResourceKind {
@@ -203,3 +206,29 @@ public struct PayoutMethod: Codable, Equatable {
         self.max = max
     }
 }
+
+/// Details about cancellation within an Offering
+///
+/// [Specification Reference](https://github.com/TBD54566975/tbdex/tree/main/specs/protocol#cancellationdetails)
+public struct CancellationDetails: Codable, Equatable {
+
+    /// Whether cancellation is enabled for this offering
+    public let enabled: Bool
+
+    /// A link to a page that describes the terms of cancellation
+    public let termsUrl: URL?
+
+    /// A human-readable description of the terms of cancellation in plaintext
+    public let terms: String?
+
+    /// Default initializer
+    init(
+        enabled: Bool,
+        termsUrl: URL? = nil,
+        terms: String? = nil
+    ) {
+        self.enabled = enabled
+        self.termsUrl = termsUrl
+        self.terms = terms
+    }
+}