Reply Content Type

Sources/XMTP/CodecRegistry.swift

@@ -25,4 +25,14 @@ struct CodecRegistry {
 
 		return TextCodec()
 	}
+
+	func find(for contentTypeString: String) -> any ContentCodec {
+		for (_, codec) in codecs {
+			if codec.description == contentTypeString {
+				return codec
+			}
+		}
+
+		return TextCodec()
+	}
 }

Sources/XMTP/Codecs/ContentCodec.swift

@@ -85,4 +85,8 @@ public extension ContentCodec {
 	func hash(into hasher: inout Hasher) {
 		hasher.combine(id)
 	}
+
+	var description: String {
+		contentType.description
+	}
 }

Sources/XMTP/Codecs/ContentTypeID.swift

@@ -21,4 +21,33 @@ extension ContentTypeID {
 	var id: String {
 		"\(authorityID):\(typeID)"
 	}
+
+	var description: String {
+		"\(authorityID)/\(typeID):\(versionMajor).\(versionMinor)"
+	}
+}
+
+extension ContentTypeID: Codable {
+    enum CodingKeys: CodingKey {
+        case authorityID, typeID, versionMajor, versionMinor
+    }
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.container(keyedBy: CodingKeys.self)
+
+        try container.encode(authorityID, forKey: .authorityID)
+        try container.encode(typeID, forKey: .typeID)
+        try container.encode(versionMajor, forKey: .versionMajor)
+        try container.encode(versionMinor, forKey: .versionMinor)
+    }
+
+    public init(from decoder: Decoder) throws {
+        self.init()
+
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        authorityID = try container.decode(String.self, forKey: .authorityID)
+        typeID = try container.decode(String.self, forKey: .typeID)
+        versionMajor = try container.decode(UInt32.self, forKey: .versionMajor)
+        versionMinor = try container.decode(UInt32.self, forKey: .versionMinor)
+    }
 }

Sources/XMTP/Codecs/ReplyCodec.swift

@@ -0,0 +1,63 @@
+//
+//  ReplyCodec.swift
+//
+//
+//  Created by Naomi Plasterer on 7/26/23.
+//
+
+import Foundation
+
+
+public let ContentTypeReply = ContentTypeID(authorityID: "xmtp.org", typeID: "reply", versionMajor: 1, versionMinor: 0)
+
+public struct Reply {
+    public var reference: String
+    public var content: Any
+    public var contentType: ContentTypeID
+}
+
+public struct ReplyCodec: ContentCodec {
+  public var contentType = ContentTypeReply
+
+	public init() {}
+
+	public func encode(content reply: Reply) throws -> EncodedContent {
+		var encodedContent = EncodedContent()
+		let replyCodec = Client.codecRegistry.find(for: reply.contentType)
+
+		encodedContent.type = contentType
+		encodedContent.parameters["contentType"] = reply.contentType.description
+		encodedContent.parameters["reference"] = reply.reference
+		encodedContent.content = try encodeReply(codec: replyCodec, content: reply.content).serializedData()
+
+		return encodedContent
+	}
+
+	public func decode(content: EncodedContent) throws -> Reply {
+		guard let contentTypeString = content.parameters["contentType"] else {
+			throw CodecError.codecNotFound
+		}
+
+		guard let reference = content.parameters["reference"] else {
+			throw CodecError.invalidContent
+		}
+
+		let replyEncodedContent = try EncodedContent(serializedData: content.content)
+		let replyCodec = Client.codecRegistry.find(for: contentTypeString)
+		let replyContent = try replyCodec.decode(content: replyEncodedContent)
+
+		return Reply(
+			reference: reference,
+			content: replyContent,
+			contentType: replyCodec.contentType
+		)
+	}
+
+	func encodeReply<Codec: ContentCodec>(codec: Codec, content: Any) throws -> EncodedContent {
+		if let content = content as? Codec.T {
+			return try codec.encode(content: content)
+		} else {
+			throw CodecError.invalidContent
+		}
+	}
+}

Tests/XMTPTests/ReplyTests.swift

@@ -0,0 +1,43 @@
+//
+//  ReplyTests.swift
+//
+//
+//  Created by Naomi Plasterer on 7/26/23.
+//
+import Foundation
+
+import XCTest
+@testable import XMTP
+
+@available(iOS 15, *)
+class ReplyTests: XCTestCase {
+    func testCanUseReplyCodec() async throws {
+        Client.register(codec: ReplyCodec())
+
+        let fixtures = await fixtures()
+        let conversation = try await fixtures.aliceClient.conversations.newConversation(with: fixtures.bobClient.address)
+
+        try await conversation.send(text: "hey alice 2 bob")
+
+        let messageToReply = try await conversation.messages()[0]
+
+        let reply = Reply(
+            reference: messageToReply.id,
+            content: "Hello",
+            contentType: ContentTypeText
+        )
+
+        try await conversation.send(
+            content: reply,
+            options: .init(contentType: ContentTypeReply)
+        )
+
+        let updatedMessages = try await conversation.messages()
+
+        let message = try await conversation.messages()[0]
+        let content: Reply = try message.content()
+        XCTAssertEqual("Hello", content.content as? String)
+        XCTAssertEqual(messageToReply.id, content.reference)
+        XCTAssertEqual(ContentTypeText, content.contentType)
+    }
+}

XMTP.podspec

@@ -16,7 +16,7 @@ Pod::Spec.new do |spec|
   #
 
   spec.name         = "XMTP"
-  spec.version      = "0.4.3-alpha0"
+  spec.version      = "0.4.4-alpha0"
   spec.summary      = "XMTP SDK Cocoapod"
 
   # This description is used to generate tags and improve search results.