From a82d33f7a815d1a1ba596c37a1465a27a20983ae Mon Sep 17 00:00:00 2001
From: Peter Cai <peter@typeblog.net>
Date: Sun, 17 Jan 2021 10:18:20 +0800
Subject: [PATCH] forwarder: implement reply on IRC side

---
 forwarder.js | 29 ++++++++++++++++++++++++++---
 index.js     |  4 +++-
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/forwarder.js b/forwarder.js
index 432c8df..92e75f7 100644
--- a/forwarder.js
+++ b/forwarder.js
@@ -102,7 +102,7 @@ module.exports = class Forwarder {
     }
   }
 
-  onMatrixMessage(event, room, toStartOfTimeline) {
+  async onMatrixMessage(event, room, toStartOfTimeline) {
     this.clientMatrix.sendReadReceipt(event);
     if (toStartOfTimeline) {
       return; // Ignore pagniation
@@ -124,6 +124,28 @@ module.exports = class Forwarder {
       }
     }
 
+    let replyUsername = null;
+    if (content['m.relates_to'] && content['m.relates_to']['m.in_reply_to']) {
+      let replyEvId = content['m.relates_to']['m.in_reply_to']['event_id'];
+      try {
+        let tl = await this.clientMatrix.getEventTimeline(room.getUnfilteredTimelineSet(), replyEvId);
+        let replyEv = tl.getEvents().filter((v) => v.getId() == replyEvId);
+        if (replyEv.length > 0) {
+          replyUsername = replyEv[0].sender.name;
+          if (replyEv[0].getContent()['net.typeblog.i2m.irc_nick']) {
+            replyUsername = replyEv[0].getContent()['net.typeblog.i2m.irc_nick'];
+          }
+        }
+      } catch (err) {
+        console.log(err);
+      }
+    }
+
+    let replyTxt = "";
+    if (replyUsername) {
+      replyTxt = replyUsername + ": "
+    }
+
     let msgTxt = null;
     switch (event.getType()) {
       case "m.sticker":
@@ -138,7 +160,8 @@ module.exports = class Forwarder {
             msgTxt = `${content.body} ${this.clientMatrix.mxcUrlToHttp(content.url)}`;
             break;
           default:
-            msgTxt = content.body;
+            // Get rid of the reply quote generated by Element client
+            msgTxt = content.body.replace(/> <@(.*):(.*)> (.*)\n\n/, "");
             break;
         }
         break;
@@ -154,7 +177,7 @@ module.exports = class Forwarder {
         // Special format for emote
         this.clientIRC.say(this.mappingM2I[room.roomId], `* ${name} ${msgTxt}`);
       } else {
-        this.clientIRC.say(this.mappingM2I[room.roomId], `[${name}] ${msgTxt}`);
+        this.clientIRC.say(this.mappingM2I[room.roomId], `[${name}] ${replyTxt}${msgTxt}`);
       }
     }
   }
diff --git a/index.js b/index.js
index c3c1f22..26248d8 100644
--- a/index.js
+++ b/index.js
@@ -33,7 +33,9 @@ function connectIrc(config, callback) {
 }
 
 function connectMatrix(config, callback) {
-  let client = matrix.createClient(config.matrix);
+  let client = matrix.createClient(Object.assign(config.matrix, {
+    timelineSupport: true
+  }));
   let myCallback = (state) => {
     switch (state) {
       case "PREPARED":