From 31ad42f637bed44e77c7f3dd28298ec4cff5a783 Mon Sep 17 00:00:00 2001
From: Damocles <damocles@darkest.space>
Date: Thu, 30 Apr 2026 21:09:03 +0200
Subject: [PATCH] matrix read receipts; seed last_shown from stored receipts on
 restart

---
 src/main.rs | 76 +++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 62 insertions(+), 14 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 15f7646..23fd631 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -11,10 +11,15 @@ use matrix_sdk::{
     config::SyncSettings,
     ruma::{
         OwnedEventId, OwnedRoomId, OwnedUserId, UserId,
-        api::client::filter::FilterDefinition,
-        events::room::{
-            member::StrippedRoomMemberEvent,
-            message::{MessageType, OriginalSyncRoomMessageEvent, RoomMessageEventContent},
+        api::client::{
+            filter::FilterDefinition, receipt::create_receipt::v3::ReceiptType as CreateReceiptType,
+        },
+        events::{
+            receipt::ReceiptThread,
+            room::{
+                member::StrippedRoomMemberEvent,
+                message::{MessageType, OriginalSyncRoomMessageEvent, RoomMessageEventContent},
+            },
         },
     },
 };
@@ -434,16 +439,42 @@ async fn process_loop(state: Arc<Mutex<DaemonState>>, client: Client) {
             continue;
         };
 
-        // Snapshot last_shown for this room so we can mark seen vs new
-        let prev_last_shown = {
-            let state = state.lock().await;
-            state.last_shown.get(&room_id).cloned()
-        };
-
         let Some(room) = client.get_room(&room_id) else {
             tracing::warn!(room = %room_id, "room not found in client");
             continue;
         };
+
+        // Snapshot last_shown for this room so we can mark seen vs new.
+        // If we don't have one in memory (e.g. fresh daemon start), seed from
+        // the stored read receipt so we don't reprocess old messages.
+        let in_memory = {
+            let s = state.lock().await;
+            s.last_shown.get(&room_id).cloned()
+        };
+        let prev_last_shown = if let Some(eid) = in_memory {
+            Some(eid)
+        } else {
+            let from_receipt = match room
+                .load_user_receipt(
+                    matrix_sdk::ruma::events::receipt::ReceiptType::Read,
+                    ReceiptThread::Unthreaded,
+                    client.user_id().expect("logged in"),
+                )
+                .await
+            {
+                Ok(Some((eid, _))) => Some(eid),
+                Ok(None) => None,
+                Err(e) => {
+                    tracing::warn!(room = %room_id, "failed to load receipt: {e}");
+                    None
+                }
+            };
+            if let Some(ref eid) = from_receipt {
+                let mut s = state.lock().await;
+                s.last_shown.insert(room_id.clone(), eid.clone());
+            }
+            from_receipt
+        };
         let room_name = room
             .display_name()
             .await
@@ -489,7 +520,7 @@ async fn process_loop(state: Arc<Mutex<DaemonState>>, client: Client) {
                         Ok(_) => {
                             let mut state = state.lock().await;
                             state.rate_budget = state.rate_budget.saturating_sub(1);
-                            if let Some(eid) = new_last_event_id {
+                            if let Some(eid) = new_last_event_id.clone() {
                                 state.last_shown.insert(room_id.clone(), eid);
                             }
                             tracing::info!(
@@ -497,6 +528,8 @@ async fn process_loop(state: Arc<Mutex<DaemonState>>, client: Client) {
                                 "sent response ({} budget remaining)",
                                 state.rate_budget
                             );
+                            drop(state);
+                            send_read_receipt(&room, new_last_event_id.clone()).await;
                         }
                         Err(e) => tracing::error!("failed to send: {e}"),
                     }
@@ -506,10 +539,13 @@ async fn process_loop(state: Arc<Mutex<DaemonState>>, client: Client) {
             }
             Ok(None) => {
                 tracing::debug!(room = %room_id, "claude chose to skip");
-                let mut state = state.lock().await;
-                if let Some(eid) = new_last_event_id {
-                    state.last_shown.insert(room_id.clone(), eid);
+                {
+                    let mut state = state.lock().await;
+                    if let Some(eid) = new_last_event_id.clone() {
+                        state.last_shown.insert(room_id.clone(), eid);
+                    }
                 }
+                send_read_receipt(&room, new_last_event_id.clone()).await;
             }
             Err(e) => {
                 tracing::error!(room = %room_id, "claude invocation failed: {e}");
@@ -518,6 +554,18 @@ async fn process_loop(state: Arc<Mutex<DaemonState>>, client: Client) {
     }
 }
 
+async fn send_read_receipt(room: &Room, event_id: Option<OwnedEventId>) {
+    let Some(eid) = event_id else {
+        return;
+    };
+    if let Err(e) = room
+        .send_single_receipt(CreateReceiptType::Read, ReceiptThread::Unthreaded, eid)
+        .await
+    {
+        tracing::warn!(room = %room.room_id(), "failed to send read receipt: {e}");
+    }
+}
+
 /// Load the last N text messages from the room's persistent event cache.
 /// Returns oldest-first list of (event_id, sender, body, ts_secs).
 async fn load_recent_messages(