first commit

composables/useRoomTimer.ts

@@ -0,0 +1,26 @@
+import { useTimestamp } from '@vueuse/core'
+
+export function useRoomTimer(startedAt: MaybeRefOrGetter<number | null>) {
+  const now = useTimestamp({ interval: 1000 })
+
+  const elapsedMs = computed(() => {
+    const start = toValue(startedAt)
+    if (!start) return 0
+    return Math.max(0, now.value - start)
+  })
+
+  const formatted = computed(() => formatDuration(elapsedMs.value))
+
+  return { elapsedMs, formatted }
+}
+
+export function formatDuration(ms: number) {
+  const totalSec = Math.floor(ms / 1000)
+  const h = Math.floor(totalSec / 3600)
+  const m = Math.floor((totalSec % 3600) / 60)
+  const s = totalSec % 60
+  if (h > 0) {
+    return `${h}:${String(m).padStart(2, '0')}:${String(s).padStart(2, '0')}`
+  }
+  return `${String(m).padStart(2, '0')}:${String(s).padStart(2, '0')}`
+}