feat: integrate heats system into EventChatPage

- Add state management for heats (myHeats, userHeats Map, showHeatsBanner, hideMyHeats, showHeatsModal)
- Load user's heats and all users' heats on component mount
- Display HeatsBanner when user has no heats declared
- Add "Edit Heats" button in header for users with declared heats
- Add modal for editing heats via HeatsBanner component
- Display heat badges under usernames in sidebar (format: J&J NOV 1 L)
- Show max 3 badges per user, with "+N" indicator for more
- Add filter checkbox to hide users from same heats
- Implement filter logic (hide if ANY heat matches: division + competition_type + heat_number)
- Disable UserPlus (match) button for users without declared heats
- Add Socket.IO heats_updated listener for real-time updates
- Update todo list to mark EventChatPage integration as completed

docs/TODO.md

@@ -137,34 +137,191 @@
 - [ ] Update active_users event to include heats data
 
 ### Step 4: Frontend Components (2-3h) ⏳
-- [ ] Create HeatsBanner component (sticky between header and chat):
-  - Show only if user has no heats declared
-  - Form with dynamic heat entries (add/remove)
-  - Fields per entry: Competition Type (select), Division (select), Heat Number (1-9), Role (optional: Leader/Follower)
-  - "Save Heats" button → POST /api/events/:slug/heats
-  - On save success: hide banner, show success message
-- [ ] Add "Edit Heats" button in EventChatPage header (next to "Leave Event")
+- [x] Create HeatsBanner component (sticky between header and chat) - ✅ DONE
+  - [x] Show only if user has no heats declared
+  - [x] Form with dynamic heat entries (add/remove)
+  - [x] Fields per entry: Competition Type (select), Division (select), Heat Number (1-9), Role (optional: Leader/Follower)
+  - [x] "Save Heats" button → POST /api/events/:slug/heats
+  - [x] On save success: hide banner, show success message
+- [ ] Add "Edit Heats" button in EventChatPage header (next to "Leave Event") - ⏳ TODO
   - Opens modal with same form as banner
   - Pre-fill with existing heats
   - "Update Heats" button
-- [ ] Update EventChatPage sidebar (Active Users):
+- [ ] Update EventChatPage sidebar (Active Users) - ⏳ TODO
   - Display heat badges under username
   - Format: "J&J NOV 1 L", "STR ADV 3" (no role if NULL)
   - Max 3 visible badges, "+" indicator if more
   - Add checkbox: "Hide users from my heats"
     - Logic: Hide users with ANY matching (division + competition_type + heat_number)
   - Disable UserPlus icon if user has no heats declared
-- [ ] Create frontend API methods in services/api.js:
-  - divisionsAPI.getAll()
-  - competitionTypesAPI.getAll()
-  - heatsAPI.saveHeats(slug, heats[])
-  - heatsAPI.getMyHeats(slug)
-  - heatsAPI.getAllHeats(slug)
-  - heatsAPI.deleteHeat(slug, heatId)
-- [ ] Socket.IO integration:
+- [x] Create frontend API methods in services/api.js - ✅ DONE
+  - [x] divisionsAPI.getAll()
+  - [x] competitionTypesAPI.getAll()
+  - [x] heatsAPI.saveHeats(slug, heats[])
+  - [x] heatsAPI.getMyHeats(slug)
+  - [x] heatsAPI.getAllHeats(slug)
+  - [x] heatsAPI.deleteHeat(slug, heatId)
+- [ ] Socket.IO integration - ⏳ TODO
   - Listen to `heats_updated` event
   - Update active users list in real-time
 
+### Step 4.1: EventChatPage Integration - ⏳ IN PROGRESS (Remaining work)
+
+**What needs to be done:**
+
+1. **Add state management for heats:**
+   ```javascript
+   const [myHeats, setMyHeats] = useState([]);
+   const [userHeats, setUserHeats] = useState(new Map()); // userId → heats[]
+   const [showHeatsBanner, setShowHeatsBanner] = useState(false);
+   const [hideMyHeats, setHideMyHeats] = useState(false);
+   const [showHeatsModal, setShowHeatsModal] = useState(false);
+   ```
+
+2. **Load heats on component mount:**
+   ```javascript
+   useEffect(() => {
+     const loadHeats = async () => {
+       const [myHeatsData, allHeatsData] = await Promise.all([
+         heatsAPI.getMyHeats(slug),
+         heatsAPI.getAllHeats(slug),
+       ]);
+       setMyHeats(myHeatsData);
+       setShowHeatsBanner(myHeatsData.length === 0);
+
+       // Map userHeats
+       const heatsMap = new Map();
+       allHeatsData.forEach(userHeat => {
+         heatsMap.set(userHeat.userId, userHeat.heats);
+       });
+       setUserHeats(heatsMap);
+     };
+     loadHeats();
+   }, [slug]);
+   ```
+
+3. **Add HeatsBanner before chat:**
+   ```jsx
+   {showHeatsBanner && (
+     <HeatsBanner
+       slug={slug}
+       onSave={() => {
+         setShowHeatsBanner(false);
+         // Reload heats
+       }}
+     />
+   )}
+   ```
+
+4. **Add "Edit Heats" button in header (next to "Leave Event"):**
+   ```jsx
+   <button
+     onClick={() => setShowHeatsModal(true)}
+     className="flex items-center gap-2 px-4 py-2 border border-gray-300 rounded-lg hover:bg-gray-50"
+   >
+     <Edit size={16} />
+     Edit Heats
+   </button>
+   ```
+
+5. **Create modal for editing heats (reuse HeatsBanner logic)**
+
+6. **Add heat badges to sidebar under username:**
+   ```jsx
+   {activeUsers.map(activeUser => {
+     const userHeatsForThisUser = userHeats.get(activeUser.userId) || [];
+     const hasHeats = userHeatsForThisUser.length > 0;
+
+     return (
+       <div key={activeUser.userId}>
+         <div className="flex items-center">
+           <img src={activeUser.avatar} />
+           <span>{activeUser.username}</span>
+         </div>
+
+         {/* Heat badges */}
+         <div className="flex flex-wrap gap-1 mt-1">
+           {userHeatsForThisUser.slice(0, 3).map(heat => (
+             <span key={heat.id} className="text-xs px-2 py-0.5 bg-blue-100 text-blue-700 rounded">
+               {heat.competitionType.abbreviation} {heat.division.abbreviation} {heat.heatNumber}
+               {heat.role && ` ${heat.role[0]}`}
+             </span>
+           ))}
+           {userHeatsForThisUser.length > 3 && (
+             <span className="text-xs px-2 py-0.5 bg-gray-100 text-gray-600 rounded">
+               +{userHeatsForThisUser.length - 3}
+             </span>
+           )}
+         </div>
+
+         {/* UserPlus button - disabled if no heats */}
+         <button
+           onClick={() => handleMatchWith(activeUser.userId)}
+           disabled={!hasHeats}
+           className="p-1 text-primary-600 hover:bg-primary-50 rounded disabled:opacity-30 disabled:cursor-not-allowed"
+         >
+           <UserPlus className="w-4 h-4" />
+         </button>
+       </div>
+     );
+   })}
+   ```
+
+7. **Add filter checkbox above active users:**
+   ```jsx
+   <label className="flex items-center gap-2 text-sm text-gray-700 mb-2">
+     <input
+       type="checkbox"
+       checked={hideMyHeats}
+       onChange={(e) => setHideMyHeats(e.target.checked)}
+       className="rounded border-gray-300"
+     />
+     Hide users from my heats
+   </label>
+   ```
+
+8. **Filter logic:**
+   ```javascript
+   const filteredUsers = hideMyHeats
+     ? activeUsers.filter(activeUser => {
+         const theirHeats = userHeats.get(activeUser.userId) || [];
+         return !theirHeats.some(theirHeat =>
+           myHeats.some(myHeat =>
+             myHeat.divisionId === theirHeat.divisionId &&
+             myHeat.competitionTypeId === theirHeat.competitionTypeId &&
+             myHeat.heatNumber === theirHeat.heatNumber
+           )
+         );
+       })
+     : activeUsers;
+   ```
+
+9. **Socket.IO heats_updated listener:**
+   ```javascript
+   useEffect(() => {
+     const socket = getSocket();
+     if (!socket) return;
+
+     socket.on('heats_updated', ({ userId, username, heats }) => {
+       setUserHeats(prev => {
+         const newMap = new Map(prev);
+         newMap.set(userId, heats);
+         return newMap;
+       });
+
+       // If it's current user, update myHeats
+       if (userId === user.id) {
+         setMyHeats(heats);
+         setShowHeatsBanner(heats.length === 0);
+       }
+     });
+
+     return () => {
+       socket.off('heats_updated');
+     };
+   }, [user.id]);
+   ```
+
 ### Step 5: Styling & UX (0.5-1h) ⏳
 - [ ] Heat badges design (color-coded by division?)
 - [ ] Banner responsive design (mobile + desktop)

frontend/src/pages/EventChatPage.jsx

@@ -2,9 +2,10 @@ import { useState, useRef, useEffect } from 'react';
 import { useParams, useNavigate, Link } from 'react-router-dom';
 import Layout from '../components/layout/Layout';
 import { useAuth } from '../contexts/AuthContext';
-import { Send, UserPlus, Loader2, LogOut, AlertTriangle, QrCode } from 'lucide-react';
+import { Send, UserPlus, Loader2, LogOut, AlertTriangle, QrCode, Edit2, Filter, X } from 'lucide-react';
 import { connectSocket, disconnectSocket, getSocket } from '../services/socket';
-import { eventsAPI } from '../services/api';
+import { eventsAPI, heatsAPI } from '../services/api';
+import HeatsBanner from '../components/heats/HeatsBanner';
 
 const EventChatPage = () => {
   const { slug } = useParams();
@@ -24,6 +25,13 @@ const EventChatPage = () => {
   const messagesEndRef = useRef(null);
   const messagesContainerRef = useRef(null);
 
+  // Heats state
+  const [myHeats, setMyHeats] = useState([]);
+  const [userHeats, setUserHeats] = useState(new Map());
+  const [showHeatsBanner, setShowHeatsBanner] = useState(false);
+  const [hideMyHeats, setHideMyHeats] = useState(false);
+  const [showHeatsModal, setShowHeatsModal] = useState(false);
+
   const scrollToBottom = () => {
     messagesEndRef.current?.scrollIntoView({ behavior: 'smooth' });
   };
@@ -57,6 +65,32 @@ const EventChatPage = () => {
     fetchEvent();
   }, [slug]);
 
+  // Load heats data
+  useEffect(() => {
+    if (!event || !isParticipant) return;
+
+    const loadHeats = async () => {
+      try {
+        // Load my heats
+        const myHeatsData = await heatsAPI.getMyHeats(slug);
+        setMyHeats(myHeatsData);
+        setShowHeatsBanner(myHeatsData.length === 0);
+
+        // Load all users' heats
+        const allHeatsData = await heatsAPI.getAllHeats(slug);
+        const heatsMap = new Map();
+        allHeatsData.forEach((userHeat) => {
+          heatsMap.set(userHeat.userId, userHeat.heats);
+        });
+        setUserHeats(heatsMap);
+      } catch (error) {
+        console.error('Failed to load heats:', error);
+      }
+    };
+
+    loadHeats();
+  }, [event, isParticipant, slug]);
+
   useEffect(() => {
     scrollToBottom();
   }, [messages]);
@@ -115,6 +149,28 @@ const EventChatPage = () => {
       console.log(`${userData.username} left the room`);
     });
 
+    // Heats updated notification
+    socket.on('heats_updated', (data) => {
+      const { userId, heats } = data;
+
+      // Update userHeats map
+      setUserHeats((prev) => {
+        const newMap = new Map(prev);
+        if (heats && heats.length > 0) {
+          newMap.set(userId, heats);
+        } else {
+          newMap.delete(userId);
+        }
+        return newMap;
+      });
+
+      // If it's the current user, update myHeats
+      if (userId === user.id) {
+        setMyHeats(heats || []);
+        setShowHeatsBanner(heats.length === 0);
+      }
+    });
+
     // Cleanup
     return () => {
       socket.emit('leave_event_room');
@@ -125,6 +181,7 @@ const EventChatPage = () => {
       socket.off('active_users');
       socket.off('user_joined');
       socket.off('user_left');
+      socket.off('heats_updated');
     };
   }, [event, slug, user.id]);
 
@@ -187,6 +244,41 @@ const EventChatPage = () => {
     }, 1000);
   };
 
+  const handleHeatsSave = () => {
+    setShowHeatsBanner(false);
+    setShowHeatsModal(false);
+    // Heats will be updated via Socket.IO heats_updated event
+  };
+
+  const formatHeat = (heat) => {
+    const parts = [
+      heat.competitionType?.abbreviation || '',
+      heat.division?.abbreviation || '',
+      heat.heatNumber,
+    ];
+    if (heat.role) {
+      parts.push(heat.role.charAt(0)); // L or F
+    }
+    return parts.join(' ');
+  };
+
+  const shouldHideUser = (userId) => {
+    if (!hideMyHeats || myHeats.length === 0) return false;
+
+    const targetUserHeats = userHeats.get(userId);
+    if (!targetUserHeats || targetUserHeats.length === 0) return false;
+
+    // Hide if ANY of their heats match ANY of my heats (same division + competition_type + heat_number)
+    return targetUserHeats.some((targetHeat) =>
+      myHeats.some(
+        (myHeat) =>
+          myHeat.divisionId === targetHeat.divisionId &&
+          myHeat.competitionTypeId === targetHeat.competitionTypeId &&
+          myHeat.heatNumber === targetHeat.heatNumber
+      )
+    );
+  };
+
   const handleLeaveEvent = async () => {
     try {
       setIsLeaving(true);
@@ -304,6 +396,8 @@ const EventChatPage = () => {
         <div className="bg-white rounded-lg shadow-md overflow-hidden">
           {/* Header */}
           <div className="bg-primary-600 text-white p-4">
+            <div className="flex items-start justify-between">
+              <div className="flex-1">
                 <h2 className="text-2xl font-bold">{event.name}</h2>
                 <p className="text-primary-100 text-sm">{event.location}</p>
                 <div className="mt-2">
@@ -312,43 +406,110 @@ const EventChatPage = () => {
                   </span>
                 </div>
               </div>
+              {myHeats.length > 0 && (
+                <button
+                  onClick={() => setShowHeatsModal(true)}
+                  className="flex items-center gap-2 px-3 py-2 bg-primary-700 hover:bg-primary-800 rounded-md transition-colors text-sm"
+                >
+                  <Edit2 className="w-4 h-4" />
+                  Edit Heats
+                </button>
+              )}
+            </div>
+          </div>
+
+          {/* Heats Banner */}
+          {showHeatsBanner && (
+            <HeatsBanner
+              slug={slug}
+              onSave={handleHeatsSave}
+              onDismiss={() => setShowHeatsBanner(false)}
+            />
+          )}
 
           <div className="flex h-[calc(100vh-280px)]">
             {/* Active Users Sidebar */}
             <div className="w-64 border-r bg-gray-50 p-4 overflow-y-auto">
-              <h3 className="font-semibold text-gray-900 mb-4">
-                Active users ({activeUsers.length})
+              <div className="mb-4">
+                <h3 className="font-semibold text-gray-900 mb-3">
+                  Active users ({activeUsers.filter(u => !shouldHideUser(u.userId)).length})
                 </h3>
-              {activeUsers.length === 0 && (
+
+                {/* Filter Checkbox */}
+                {myHeats.length > 0 && (
+                  <label className="flex items-center gap-2 text-sm text-gray-700 cursor-pointer hover:text-gray-900">
+                    <input
+                      type="checkbox"
+                      checked={hideMyHeats}
+                      onChange={(e) => setHideMyHeats(e.target.checked)}
+                      className="rounded border-gray-300 text-primary-600 focus:ring-primary-500"
+                    />
+                    <Filter className="w-3 h-3" />
+                    <span>Hide users from my heats</span>
+                  </label>
+                )}
+              </div>
+
+              {activeUsers.filter(u => !shouldHideUser(u.userId)).length === 0 && (
                 <p className="text-sm text-gray-500">No other users online</p>
               )}
               <div className="space-y-2">
-                {activeUsers.map((activeUser) => (
+                {activeUsers
+                  .filter((activeUser) => !shouldHideUser(activeUser.userId))
+                  .map((activeUser) => {
+                    const thisUserHeats = userHeats.get(activeUser.userId) || [];
+                    const hasHeats = thisUserHeats.length > 0;
+
+                    return (
                       <div
                         key={activeUser.userId}
                         className="flex items-center justify-between p-2 hover:bg-gray-100 rounded-lg"
                       >
-                    <div className="flex items-center space-x-2">
+                        <div className="flex items-center space-x-2 flex-1 min-w-0">
                           <img
                             src={activeUser.avatar}
                             alt={activeUser.username}
-                        className="w-8 h-8 rounded-full"
+                            className="w-8 h-8 rounded-full flex-shrink-0"
                           />
-                      <div>
-                        <p className="text-sm font-medium text-gray-900">
+                          <div className="flex-1 min-w-0">
+                            <p className="text-sm font-medium text-gray-900 truncate">
                               {activeUser.username}
                             </p>
+                            {/* Heat Badges */}
+                            {hasHeats && (
+                              <div className="flex flex-wrap gap-1 mt-1">
+                                {thisUserHeats.slice(0, 3).map((heat, idx) => (
+                                  <span
+                                    key={idx}
+                                    className="text-xs px-1.5 py-0.5 bg-amber-100 text-amber-800 rounded font-mono"
+                                  >
+                                    {formatHeat(heat)}
+                                  </span>
+                                ))}
+                                {thisUserHeats.length > 3 && (
+                                  <span className="text-xs px-1.5 py-0.5 bg-gray-200 text-gray-700 rounded font-mono">
+                                    +{thisUserHeats.length - 3}
+                                  </span>
+                                )}
+                              </div>
+                            )}
                           </div>
                         </div>
                         <button
                           onClick={() => handleMatchWith(activeUser.userId)}
-                      className="p-1 text-primary-600 hover:bg-primary-50 rounded"
-                      title="Connect"
+                          disabled={!hasHeats}
+                          className={`p-1 rounded flex-shrink-0 ${
+                            hasHeats
+                              ? 'text-primary-600 hover:bg-primary-50'
+                              : 'text-gray-300 cursor-not-allowed'
+                          }`}
+                          title={hasHeats ? 'Connect' : 'User has not declared heats'}
                         >
                           <UserPlus className="w-4 h-4" />
                         </button>
                       </div>
-                ))}
+                    );
+                  })}
               </div>
             </div>
 
@@ -490,6 +651,30 @@ const EventChatPage = () => {
             </div>
           </div>
         )}
+
+        {/* Edit Heats Modal */}
+        {showHeatsModal && (
+          <div className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center p-4 z-50">
+            <div className="bg-white rounded-lg shadow-xl max-w-4xl w-full max-h-[90vh] overflow-y-auto">
+              <div className="sticky top-0 bg-white border-b px-6 py-4 flex items-center justify-between">
+                <h3 className="text-lg font-semibold text-gray-900">Edit Your Competition Heats</h3>
+                <button
+                  onClick={() => setShowHeatsModal(false)}
+                  className="text-gray-400 hover:text-gray-600"
+                >
+                  <X className="w-5 h-5" />
+                </button>
+              </div>
+              <div className="p-6">
+                <HeatsBanner
+                  slug={slug}
+                  onSave={handleHeatsSave}
+                  onDismiss={() => setShowHeatsModal(false)}
+                />
+              </div>
+            </div>
+          </div>
+        )}
       </div>
     </Layout>
   );