Fix the way Reply Codecs work (#99)

* add api client with grpc kotlin

* fix up the way reply codec is sent

* fix up lint spacing

Author: nplasterer

library/src/main/java/org/xmtp/android/library/CodecRegistry.kt

@@ -20,4 +20,13 @@ data class CodecRegistry(val codecs: MutableMap<String, ContentCodec<*>> = mutab
         }
         return TextCodec()
     }
+
+    fun findFromId(contentTypeString: String): ContentCodec<*> {
+        for ((_, codec) in codecs) {
+            if (codec.contentType.id == contentTypeString) {
+                return codec
+            }
+        }
+        return TextCodec()
+    }
 }

library/src/main/java/org/xmtp/android/library/codecs/ReplyCodec.kt

@@ -1,7 +1,7 @@
 package org.xmtp.android.library.codecs
 
-import com.google.gson.GsonBuilder
-import com.google.protobuf.kotlin.toByteStringUtf8
+import org.xmtp.android.library.Client
+import org.xmtp.android.library.XMTPException
 
 val ContentTypeReply = ContentTypeIdBuilder.builderFromAuthorityId(
     "xmtp.org",
@@ -19,16 +19,42 @@ data class Reply(
 data class ReplyCodec(override var contentType: ContentTypeId = ContentTypeReply) :
     ContentCodec<Reply> {
 
-    override fun encode(content: Reply): EncodedContent {
-        val gson = GsonBuilder().create()
+    override fun encode(reply: Reply): EncodedContent {
+        val replyCodec = Client.codecRegistry.find(reply.contentType)
+
         return EncodedContent.newBuilder().also {
             it.type = ContentTypeReply
-            it.content = gson.toJson(content).toByteStringUtf8()
+            it.putParameters("contentType", reply.contentType.id)
+            it.putParameters("reference", reply.reference)
+            it.content = encodeReply(replyCodec, reply.content).toByteString()
         }.build()
     }
 
     override fun decode(content: EncodedContent): Reply {
-        val gson = GsonBuilder().create()
-        return gson.fromJson(content.content.toStringUtf8(), Reply::class.java)
+        val contentTypeIdString =
+            content.getParametersOrThrow("contentType") ?: throw XMTPException("Codec Not Found")
+        val reference =
+            content.getParametersOrThrow("reference") ?: throw XMTPException("Invalid Content")
+        val replyEncodedContent = EncodedContent.parseFrom(content.content)
+        val replyCodec = Client.codecRegistry.findFromId(contentTypeIdString)
+        val replyContent = replyCodec.decode(content = replyEncodedContent)
+            ?: throw XMTPException("Invalid Content")
+        return Reply(
+            reference = reference,
+            content = replyContent,
+            contentType = replyCodec.contentType
+        )
+    }
+
+    private fun <Codec : ContentCodec<T>, T> encodeReply(
+        codec: Codec,
+        content: Any,
+    ): EncodedContent {
+        val reply = content as? T
+        if (reply != null) {
+            return codec.encode(content = reply)
+        } else {
+            throw XMTPException("Invalid Content")
+        }
     }
 }