1 files changed, 28 insertions, 18 deletions

diff --git a/jb-ui/src/models/grlEventsSlice.ts b/jb-ui/src/models/grlEventsSlice.ts
index f77bbc1..912c4ca 100644
--- a/jb-ui/src/models/grlEventsSlice.ts
+++ b/jb-ui/src/models/grlEventsSlice.ts
@@ -1,32 +1,25 @@
 import { EventEnvelope } from "@/api_fsb";
 import { RootState } from "@/store";
-import { createEntityAdapter, createSlice, PayloadAction } from '@reduxjs/toolkit';
+import { createEntityAdapter, createSelector, createSlice } from '@reduxjs/toolkit';
 
 const eventAdapter = createEntityAdapter({
     selectId: (model: EventEnvelope) => model.event_uuid!,
     sortComparer: (a, b) => {
-        return b.timestamp!.localeCompare(a.timestamp!);
+        // ASC by timestamp
+        return a.timestamp!.localeCompare(b.timestamp!);
     },
 });
 
 
 const grlEventsSlice = createSlice({
     name: 'grlEvents',
-    // initialState: eventAdapter.getInitialState(),
-    initialState: eventAdapter.getInitialState({ latestEvent: null as EventEnvelope | null }),
+    initialState: eventAdapter.getInitialState(),
 
     reducers: {
+        addEvent: eventAdapter.addOne,
         addEvents: eventAdapter.addMany,
-        upsertEvent: eventAdapter.upsertOne,  // add or update
-
-        // addEvent: eventAdapter.addOne,
-        addEvent: (state, action: PayloadAction<EventEnvelope>) => {
-            eventAdapter.addOne(state, action.payload);
-            const incoming = action.payload.timestamp!;
-            if (!state.latestEvent || incoming.localeCompare(state.latestEvent.timestamp!) > 0) {
-                state.latestEvent = action.payload;
-            }
-        },
+        upsertEvent: eventAdapter.upsertOne,  // Add or Update
+
     }
 })
 
@@ -35,14 +28,31 @@ export const {
     addEvent, addEvents, upsertEvent
 } = grlEventsSlice.actions;
 
-// Add this after the slice, before exports
+
 export const eventSelectors = eventAdapter.getSelectors(
     (state: RootState) => state.events
 );
 
-export const selectLatestEvents = (count: number) => (state: RootState) =>
-    eventSelectors.selectAll(state).slice(0, count);
+export const selectAllEvents = (state: RootState): EventEnvelope[] => eventSelectors.selectAll(state);
+
+const BASE_SPEED = 40;  // px/sec at idle
+const MAX_SPEED = 380;  // px/sec at surge
+
+const RATE_WINDOW_MS = 10_000;  // ms window to measure message frequency
+const RATE_TO_SPEED = 55;  // px/sec added per msg/sec
 
-export const selectLatestEvent = (state: RootState) => state.events.latestEvent;
+
+// --- Speed: derived from arrival rate of recent items --- 
+export const selectCurrentSpeed = createSelector(selectAllEvents, (items) => {
+    const now = Date.now();
+
+    const recentCount = items.filter((m) => {
+        const ts = new Date(m.timestamp!).getTime();
+        return now - ts < RATE_WINDOW_MS;
+    }).length;
+
+    const rate = recentCount / (RATE_WINDOW_MS / 1_000);  // msgs/sec
+    return Math.min(BASE_SPEED + rate * RATE_TO_SPEED, MAX_SPEED);
+});
 
 export default grlEventsSlice.reducer