From 407ba8224b02efc1089d738337cc565da8eae186 Mon Sep 17 00:00:00 2001
From: vikingowl <christian@nachtigall.dev>
Date: Sun, 28 Dec 2025 05:39:51 +0100
Subject: [PATCH] fix: sync refresh rate from frontend to backend on SSE
 connect
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When container restarts, backend resets to default 5s interval but
frontend still shows the user's stored preference from localStorage.

Now on SSE connect, frontend pushes its stored refresh rate to the
backend, ensuring they stay in sync after container rebuilds.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 frontend/src/lib/api/sse.ts         |  3 +++
 frontend/src/lib/stores/settings.ts | 30 ++++++++++++++++++-----------
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/frontend/src/lib/api/sse.ts b/frontend/src/lib/api/sse.ts
index 5ace487..119a193 100644
--- a/frontend/src/lib/api/sse.ts
+++ b/frontend/src/lib/api/sse.ts
@@ -1,4 +1,5 @@
 import { metrics, connected, historyData } from '$lib/stores/metrics';
+import { settings } from '$lib/stores/settings';
 import { browser } from '$app/environment';
 import type { AllMetrics, HistoryData } from '$lib/types/metrics';
 
@@ -35,6 +36,8 @@ export function connectSSE() {
 	eventSource.onopen = () => {
 		connected.set(true);
 		console.log('SSE connected');
+		// Sync stored settings to backend (in case container was restarted)
+		settings.syncToBackend();
 	};
 
 	eventSource.onmessage = (event) => {
diff --git a/frontend/src/lib/stores/settings.ts b/frontend/src/lib/stores/settings.ts
index 8ab2fbe..b04e856 100644
--- a/frontend/src/lib/stores/settings.ts
+++ b/frontend/src/lib/stores/settings.ts
@@ -15,21 +15,29 @@ function createSettingsStore() {
 
 	const { subscribe, set, update } = writable<Settings>(initial);
 
+	// Helper to push refresh rate to backend
+	async function pushRefreshRate(rate: number) {
+		try {
+			await fetch('/api/v1/settings/refresh', {
+				method: 'POST',
+				headers: { 'Content-Type': 'application/json' },
+				body: JSON.stringify({ interval: rate })
+			});
+		} catch (e) {
+			console.error('Failed to update refresh rate:', e);
+		}
+	}
+
 	return {
 		subscribe,
 		setRefreshRate: async (rate: number) => {
 			update((s) => ({ ...s, refreshRate: rate }));
-
-			// Notify backend
-			try {
-				await fetch('/api/v1/settings/refresh', {
-					method: 'POST',
-					headers: { 'Content-Type': 'application/json' },
-					body: JSON.stringify({ interval: rate })
-				});
-			} catch (e) {
-				console.error('Failed to update refresh rate:', e);
-			}
+			await pushRefreshRate(rate);
+		},
+		// Sync stored settings to backend (call on SSE connect)
+		syncToBackend: async () => {
+			const current = stored ? JSON.parse(stored) : defaultSettings;
+			await pushRefreshRate(current.refreshRate);
 		}
 	};
 }