From 770dd3b849bfa809e442a58e19f27a0d71c45710 Mon Sep 17 00:00:00 2001
From: Naomi Plasterer <naomi@xmtp.com>
Date: Tue, 1 Aug 2023 12:04:11 -0700
Subject: [PATCH] Reply Content Type (#134)

* add reply content type

* add the public init

* make content type id codable

* trying to make it codecable

* Get reply test passing

* format

* format

* remove codable of content type id

---------

Co-authored-by: Pat Nakajima <patnakajima@gmail.com>
---
 Sources/XMTP/CodecRegistry.swift        | 10 ++++
 Sources/XMTP/Codecs/ContentCodec.swift  |  4 ++
 Sources/XMTP/Codecs/ContentTypeID.swift |  4 ++
 Sources/XMTP/Codecs/ReplyCodec.swift    | 62 +++++++++++++++++++++++++
 Tests/XMTPTests/ReplyTests.swift        | 43 +++++++++++++++++
 XMTP.podspec                            |  2 +-
 6 files changed, 124 insertions(+), 1 deletion(-)
 create mode 100644 Sources/XMTP/Codecs/ReplyCodec.swift
 create mode 100644 Tests/XMTPTests/ReplyTests.swift

diff --git a/Sources/XMTP/CodecRegistry.swift b/Sources/XMTP/CodecRegistry.swift
index 49f6d231..d39f8688 100644
--- a/Sources/XMTP/CodecRegistry.swift
+++ b/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()
+	}
 }
diff --git a/Sources/XMTP/Codecs/ContentCodec.swift b/Sources/XMTP/Codecs/ContentCodec.swift
index c8feac96..8036a5e2 100644
--- a/Sources/XMTP/Codecs/ContentCodec.swift
+++ b/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
+	}
 }
diff --git a/Sources/XMTP/Codecs/ContentTypeID.swift b/Sources/XMTP/Codecs/ContentTypeID.swift
index e55cb16d..bd0457b9 100644
--- a/Sources/XMTP/Codecs/ContentTypeID.swift
+++ b/Sources/XMTP/Codecs/ContentTypeID.swift
@@ -21,4 +21,8 @@ extension ContentTypeID {
 	var id: String {
 		"\(authorityID):\(typeID)"
 	}
+
+	var description: String {
+		"\(authorityID)/\(typeID):\(versionMajor).\(versionMinor)"
+	}
 }
diff --git a/Sources/XMTP/Codecs/ReplyCodec.swift b/Sources/XMTP/Codecs/ReplyCodec.swift
new file mode 100644
index 00000000..10149069
--- /dev/null
+++ b/Sources/XMTP/Codecs/ReplyCodec.swift
@@ -0,0 +1,62 @@
+//
+//  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
+		}
+	}
+}
diff --git a/Tests/XMTPTests/ReplyTests.swift b/Tests/XMTPTests/ReplyTests.swift
new file mode 100644
index 00000000..90a35728
--- /dev/null
+++ b/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)
+	}
+}
diff --git a/XMTP.podspec b/XMTP.podspec
index 11e92b3e..084473c1 100644
--- a/XMTP.podspec
+++ b/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.