feat(messages): group message feed by channel and thread sections

services/frontend/src/features/messages/components/MessageFeed.tsx

@@ -1,5 +1,7 @@
 import { motion } from "framer-motion";
+import { Hash } from "lucide-react";
 import { useEffect, useMemo, useRef } from "react";
+import { parseMetadata } from "../../../entities/message/types";
 import type { MessageRecord } from "../../../shared/api/client";
 import { cardItem, cardStagger } from "../../../shared/hooks/useFramerStagger";
 import { ScrollArea, EmptyStateMascot } from "../../../shared/ui";
@@ -18,12 +20,12 @@ export interface MessageFeedProps {
 /** Messages from the same user within 5 minutes are visually grouped. */
 const GROUP_WINDOW_MS = 5 * 60 * 1000;
 
-interface MessageGroup {
+interface UserMessageGroup {
   messages: MessageRecord[];
 }
 
-function groupMessages(messages: MessageRecord[]): MessageGroup[] {
+function groupByUser(messages: MessageRecord[]): UserMessageGroup[] {
-  const groups: MessageGroup[] = [];
+  const groups: UserMessageGroup[] = [];
   for (const msg of messages) {
     const lastGroup = groups[groups.length - 1];
     if (
@@ -41,6 +43,57 @@ function groupMessages(messages: MessageRecord[]): MessageGroup[] {
   return groups;
 }
 
+interface ChannelSection {
+  key: string;
+  channelId: string;
+  threadId: string | null;
+  label: string;
+  groups: UserMessageGroup[];
+}
+
+function computeChannelSections(messages: MessageRecord[]): ChannelSection[] {
+  if (messages.length === 0) return [];
+
+  // Group by (channel_id, thread_id)
+  const map = new Map<string, MessageRecord[]>();
+  for (const msg of messages) {
+    const key = msg.thread_id
+      ? `${msg.channel_id}:t:${msg.thread_id}`
+      : msg.channel_id;
+    const list = map.get(key);
+    if (list) list.push(msg);
+    else map.set(key, [msg]);
+  }
+
+  const sections: ChannelSection[] = [];
+  for (const [key, channelMessages] of map) {
+    const first = channelMessages[0];
+    const meta = parseMetadata(first.metadata);
+    const ch = meta?.channel;
+
+    let label: string;
+    if (ch?.threadName && ch?.channelName) {
+      label = `# ${ch.channelName} › ${ch.threadName}`;
+    } else if (ch?.channelName) {
+      label = `# ${ch.channelName}`;
+    } else if (first.thread_id) {
+      label = `thread:${first.thread_id.slice(0, 8)}`;
+    } else {
+      label = `# ${first.channel_id.slice(0, 8)}`;
+    }
+
+    sections.push({
+      key,
+      channelId: first.channel_id,
+      threadId: first.thread_id,
+      label,
+      groups: groupByUser(channelMessages),
+    });
+  }
+
+  return sections;
+}
+
 export function MessageFeed({
   messages,
   onReanalyze,
@@ -62,13 +115,13 @@ export function MessageFeed({
       (entries) => {
         if (entries[0]?.isIntersecting) onLoadMore();
       },
-      { rootMargin: "400px" }, // preload before user reaches bottom
+      { rootMargin: "400px" },
     );
     observer.observe(el);
     return () => observer.disconnect();
   }, [onLoadMore, hasMore]);
 
-  const groupedMessages = useMemo(() => groupMessages(messages), [messages]);
+  const sections = useMemo(() => computeChannelSections(messages), [messages]);
 
   if (loading) {
     return (
@@ -94,7 +147,18 @@ export function MessageFeed({
         initial="initial"
         animate="animate"
       >
-        {groupedMessages.map((group) => (
+        {sections.map((section) => (
+          <div key={section.key} className="space-y-2">
+            {/* Channel/Thread section header */}
+            <div className="sticky top-0 z-10 -mx-1 rounded-lg bg-muted/80 backdrop-blur-sm px-3 py-1.5 flex items-center gap-1.5">
+              <Hash className="h-3.5 w-3.5 text-primary/60" />
+              <span className="text-xs font-medium text-muted-foreground">
+                {section.label}
+              </span>
+            </div>
+
+            <div className="space-y-3">
+              {section.groups.map((group) => (
                 <motion.div key={group.messages[0].id} variants={cardItem}>
                   <MessageCard
                     messages={group.messages}
@@ -102,6 +166,9 @@ export function MessageFeed({
                   />
                 </motion.div>
               ))}
+            </div>
+          </div>
+        ))}
 
         {/* Infinite-scroll sentinel */}
         {hasMore && (