From 76983ce76b224ae043dc6bc65a94b0c24f6262f7 Mon Sep 17 00:00:00 2001
From: cameronvoell <cameronvoell@users.noreply.github.com>
Date: Fri, 10 Jan 2025 16:19:35 -0800
Subject: [PATCH] json deserialization for legacy reactions

---
 Cargo.lock                         |  2 ++
 xmtp_content_types/Cargo.toml      |  2 ++
 xmtp_content_types/src/reaction.rs | 16 ++++++++++++++++
 xmtp_mls/src/groups/mod.rs         | 20 +++++++++++++++++---
 4 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index fce55ab9e..3ff761b54 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -7380,6 +7380,8 @@ version = "0.1.0"
 dependencies = [
  "prost",
  "rand",
+ "serde",
+ "serde_json",
  "thiserror 2.0.6",
  "tonic",
  "xmtp_common",
diff --git a/xmtp_content_types/Cargo.toml b/xmtp_content_types/Cargo.toml
index 2b7c506d1..c3800557f 100644
--- a/xmtp_content_types/Cargo.toml
+++ b/xmtp_content_types/Cargo.toml
@@ -8,6 +8,8 @@ license.workspace = true
 thiserror = { workspace = true }
 prost = { workspace = true, features = ["prost-derive"] }
 rand = { workspace = true }
+serde = { workspace = true, features = ["derive"] }
+serde_json = { workspace = true }
 
 # XMTP/Local
 xmtp_proto = { workspace = true, features = ["convert"] }
diff --git a/xmtp_content_types/src/reaction.rs b/xmtp_content_types/src/reaction.rs
index f70b925bc..efd2a5c31 100644
--- a/xmtp_content_types/src/reaction.rs
+++ b/xmtp_content_types/src/reaction.rs
@@ -3,6 +3,7 @@ use std::collections::HashMap;
 use crate::{CodecError, ContentCodec};
 use prost::Message;
 
+use serde::{Deserialize, Serialize};
 use xmtp_proto::xmtp::mls::message_contents::{
     content_types::ReactionV2, ContentTypeId, EncodedContent,
 };
@@ -47,6 +48,21 @@ impl ContentCodec<ReactionV2> for ReactionCodec {
     }
 }
 
+#[derive(Debug, Serialize, Deserialize)]
+pub struct LegacyReaction {
+    /// The message ID for the message that is being reacted to
+    pub reference: String,
+    /// The inbox ID of the user who sent the message that is being reacted to
+    #[serde(rename = "referenceInboxId", skip_serializing_if = "Option::is_none")]
+    pub reference_inbox_id: Option<String>,
+    /// The action of the reaction ("added" or "removed")
+    pub action: String,
+    /// The content of the reaction
+    pub content: String,
+    /// The schema of the content ("unicode", "shortcode", or "custom")
+    pub schema: String,
+}
+
 #[cfg(test)]
 pub(crate) mod tests {
     #[cfg(target_arch = "wasm32")]
diff --git a/xmtp_mls/src/groups/mod.rs b/xmtp_mls/src/groups/mod.rs
index d8c4487f8..5d69e9713 100644
--- a/xmtp_mls/src/groups/mod.rs
+++ b/xmtp_mls/src/groups/mod.rs
@@ -33,9 +33,10 @@ use openmls::{
 };
 use openmls_traits::OpenMlsProvider;
 use prost::Message;
+use serde::{Deserialize, Serialize};
 use thiserror::Error;
 use tokio::sync::Mutex;
-use xmtp_content_types::reaction::ReactionCodec;
+use xmtp_content_types::reaction::{LegacyReaction, ReactionCodec};
 
 use self::device_sync::DeviceSyncError;
 pub use self::group_permissions::PreconfiguredPolicies;
@@ -357,8 +358,21 @@ impl TryFrom<EncodedContent> for QueryableContentFields {
                 hex::decode(reaction.reference).ok()
             }
             (ReactionCodec::TYPE_ID, _) => {
-                // TODO: Implement JSON deserialization for legacy reaction format
-                None
+                // Try to decode the content as UTF-8 string first
+                if let Ok(decoded_content) = String::from_utf8(content.content) {
+                    tracing::info!("attempting legacy json deserialization: {}", decoded_content);
+                    // Try parsing as canonical JSON format first
+                    if let Ok(reaction) = serde_json::from_str::<LegacyReaction>(&decoded_content) {
+                        hex::decode(reaction.reference).ok()
+                    } else {
+                        tracing::error!("legacy json deserialization failed");
+                        // If canonical format fails, try legacy format using parameters
+                        None
+                    }
+                } else {
+                    tracing::error!("utf-8 deserialization failed");
+                    None
+                }
             }
             _ => None,
         };