fix: timezone-safe streak continuity with 48h elapsed-time window

Use local dates instead of UTC for day boundaries, and store an epoch timestamp alongside the date string. Streak alive check uses real elapsed time (<48h) which covers dateline crossings. Old data without timestamps falls back to date-string comparison so existing streaks are preserved.
2026-04-06 00:36:02 +02:00
parent 082202b71c
commit c5710ff72d
6 changed files with 141 additions and 49 deletions
--- a/src/lib/stores/angelusStreak.svelte.ts
+++ b/src/lib/stores/angelusStreak.svelte.ts
@@ -1,12 +1,14 @@
 import { browser } from '$app/environment';

 const STORAGE_KEY = 'angelus_streak';
+const STREAK_WINDOW_MS = 48 * 60 * 60 * 1000; // 48 hours — covers dateline crossings

 interface AngelusStreakData {
 	streak: number;
-	lastComplete: string | null; // YYYY-MM-DD
+	lastComplete: string | null; // local YYYY-MM-DD
+	lastCompleteTs?: number | null; // epoch ms for timezone-safe streak checks
 	todayPrayed: number; // bitmask: 1=morning, 2=noon, 4=evening
-	todayDate: string | null; // YYYY-MM-DD
+	todayDate: string | null; // local YYYY-MM-DD
 }

 export type TimeSlot = 'morning' | 'noon' | 'evening';
@@ -18,13 +20,29 @@ const TIME_BITS: Record<TimeSlot, number> = {
 };

 function getToday(): string {
-	return new Date().toISOString().split('T')[0];
+	const d = new Date();
+	return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
 }

-function isYesterday(dateStr: string): boolean {
+// Legacy fallback for old data without timestamp
+function isYesterdayByDate(dateStr: string): boolean {
 	const yesterday = new Date();
 	yesterday.setDate(yesterday.getDate() - 1);
-	return dateStr === yesterday.toISOString().split('T')[0];
+	const ys = `${yesterday.getFullYear()}-${String(yesterday.getMonth() + 1).padStart(2, '0')}-${String(yesterday.getDate()).padStart(2, '0')}`;
+	return dateStr === ys;
+}
+
+function isStreakAlive(data: AngelusStreakData): boolean {
+	if (!data.lastComplete) return false;
+	if (data.lastComplete === getToday()) return true;
+
+	// Prefer real elapsed time (handles timezone/dateline changes)
+	if (data.lastCompleteTs) {
+		return (Date.now() - data.lastCompleteTs) < STREAK_WINDOW_MS;
+	}
+
+	// Legacy fallback
+	return isYesterdayByDate(data.lastComplete);
 }

 export function getCurrentTimeSlot(): TimeSlot {
@@ -81,30 +99,47 @@ function mergeStreakData(local: AngelusStreakData, server: AngelusStreakData | n
 	// Take the higher streak or more recent lastComplete
 	let bestStreak: number;
 	let bestLastComplete: string | null;
+	let bestLastCompleteTs: number | null;

 	if (localEffective.lastComplete === serverEffective.lastComplete) {
 		bestStreak = Math.max(localEffective.streak, serverEffective.streak);
 		bestLastComplete = localEffective.lastComplete;
+		bestLastCompleteTs = localEffective.lastCompleteTs ?? serverEffective.lastCompleteTs ?? null;
 	} else if (!localEffective.lastComplete) {
 		bestStreak = serverEffective.streak;
 		bestLastComplete = serverEffective.lastComplete;
+		bestLastCompleteTs = serverEffective.lastCompleteTs ?? null;
 	} else if (!serverEffective.lastComplete) {
 		bestStreak = localEffective.streak;
 		bestLastComplete = localEffective.lastComplete;
+		bestLastCompleteTs = localEffective.lastCompleteTs ?? null;
 	} else {
-		// Take whichever has more recent lastComplete
-		if (localEffective.lastComplete > serverEffective.lastComplete) {
+		// Prefer timestamp comparison when available
+		if (localEffective.lastCompleteTs && serverEffective.lastCompleteTs) {
+			if (localEffective.lastCompleteTs > serverEffective.lastCompleteTs) {
+				bestStreak = localEffective.streak;
+				bestLastComplete = localEffective.lastComplete;
+				bestLastCompleteTs = localEffective.lastCompleteTs;
+			} else {
+				bestStreak = serverEffective.streak;
+				bestLastComplete = serverEffective.lastComplete;
+				bestLastCompleteTs = serverEffective.lastCompleteTs;
+			}
+		} else if (localEffective.lastComplete > serverEffective.lastComplete) {
 			bestStreak = localEffective.streak;
 			bestLastComplete = localEffective.lastComplete;
+			bestLastCompleteTs = localEffective.lastCompleteTs ?? null;
 		} else {
 			bestStreak = serverEffective.streak;
 			bestLastComplete = serverEffective.lastComplete;
+			bestLastCompleteTs = serverEffective.lastCompleteTs ?? null;
 		}
 	}

 	return {
 		streak: bestStreak,
 		lastComplete: bestLastComplete,
+		lastCompleteTs: bestLastCompleteTs,
 		todayPrayed: mergedTodayPrayed,
 		todayDate: mergedTodayPrayed > 0 ? today : null
 	};
@@ -119,6 +154,7 @@ function isPWA(): boolean {
 class AngelusStreakStore {
 	#streak = $state(0);
 	#lastComplete = $state<string | null>(null);
+	#lastCompleteTs = $state<number | null>(null);
 	#todayPrayed = $state(0);
 	#todayDate = $state<string | null>(null);
 	#isLoggedIn = $state(false);
@@ -148,6 +184,7 @@ class AngelusStreakStore {

 		this.#streak = data.streak;
 		this.#lastComplete = data.lastComplete;
+		this.#lastCompleteTs = data.lastCompleteTs ?? null;
 		this.#todayPrayed = data.todayPrayed;
 		this.#todayDate = data.todayDate;
 		this.#initialized = true;
@@ -193,9 +230,15 @@ class AngelusStreakStore {
 	}

 	get streak() {
-		// If lastComplete is stale (not today, not yesterday), streak is broken
-		if (this.#lastComplete && this.#lastComplete !== getToday() && !isYesterday(this.#lastComplete)) {
-			// But if today has some prayers, streak might still be valid from today's completion
+		const data: AngelusStreakData = {
+			streak: this.#streak,
+			lastComplete: this.#lastComplete,
+			lastCompleteTs: this.#lastCompleteTs,
+			todayPrayed: this.#todayPrayed,
+			todayDate: this.#todayDate
+		};
+		if (!isStreakAlive(data)) {
+			// But if today is complete, streak might still be valid
 			if (this.#todayDate !== getToday() || this.#todayPrayed !== 7) {
 				return 0;
 			}
@@ -239,17 +282,14 @@ class AngelusStreakStore {
 		const merged = mergeStreakData(localData, serverData);

 		// Check if streak is expired
-		const isExpired =
-			merged.lastComplete !== null &&
-			merged.lastComplete !== getToday() &&
-			!isYesterday(merged.lastComplete) &&
-			merged.todayPrayed !== 7;
+		const isExpired = !isStreakAlive(merged) && merged.todayPrayed !== 7;
 		const effective: AngelusStreakData = isExpired
-			? { streak: 0, lastComplete: null, todayPrayed: merged.todayPrayed, todayDate: merged.todayDate }
+			? { streak: 0, lastComplete: null, lastCompleteTs: null, todayPrayed: merged.todayPrayed, todayDate: merged.todayDate }
 			: merged;

 		this.#streak = effective.streak;
 		this.#lastComplete = effective.lastComplete;
+		this.#lastCompleteTs = effective.lastCompleteTs ?? null;
 		this.#todayPrayed = effective.todayPrayed;
 		this.#todayDate = effective.todayDate;
 		saveToStorage(effective);
@@ -271,6 +311,7 @@ class AngelusStreakStore {
 			const data: AngelusStreakData = {
 				streak: this.#streak,
 				lastComplete: this.#lastComplete,
+				lastCompleteTs: this.#lastCompleteTs,
 				todayPrayed: this.#todayPrayed,
 				todayDate: this.#todayDate
 			};
@@ -306,23 +347,28 @@ class AngelusStreakStore {
 		let dayCompleted = false;
 		if (this.#todayPrayed === 7) {
 			dayCompleted = true;
+			const now = Date.now();

 			// Update streak
-			if (this.#lastComplete && (this.#lastComplete === today || isYesterday(this.#lastComplete))) {
-				// lastComplete is today (shouldn't happen) or yesterday → continue streak
-				if (this.#lastComplete !== today) {
-					this.#streak += 1;
-				}
-			} else {
-				// Gap or first time → start new streak
+			const alive = isStreakAlive({
+				streak: this.#streak,
+				lastComplete: this.#lastComplete,
+				lastCompleteTs: this.#lastCompleteTs,
+				todayPrayed: 0, todayDate: null
+			});
+			if (alive && this.#lastComplete !== today) {
+				this.#streak += 1;
+			} else if (!alive) {
 				this.#streak = 1;
 			}
 			this.#lastComplete = today;
+			this.#lastCompleteTs = now;
 		}

 		const data: AngelusStreakData = {
 			streak: this.#streak,
 			lastComplete: this.#lastComplete,
+			lastCompleteTs: this.#lastCompleteTs,
 			todayPrayed: this.#todayPrayed,
 			todayDate: this.#todayDate
 		};
--- a/src/lib/stores/rosaryStreak.svelte.ts
+++ b/src/lib/stores/rosaryStreak.svelte.ts
@@ -1,20 +1,39 @@
 import { browser } from '$app/environment';

 const STORAGE_KEY = 'rosary_streak';
+const STREAK_WINDOW_MS = 48 * 60 * 60 * 1000; // 48 hours — covers dateline crossings

 interface StreakData {
 	length: number;
-	lastPrayed: string | null; // ISO date string (YYYY-MM-DD)
+	lastPrayed: string | null;    // local YYYY-MM-DD (same-day dedup)
+	lastPrayedTs?: number | null; // epoch ms (streak continuity across timezones)
 }

 function getToday(): string {
-	return new Date().toISOString().split('T')[0];
+	const d = new Date();
+	return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
 }

-function isYesterday(dateStr: string): boolean {
+// Legacy fallback: date-string comparison for old data without timestamp
+function isYesterdayByDate(dateStr: string): boolean {
 	const yesterday = new Date();
 	yesterday.setDate(yesterday.getDate() - 1);
-	return dateStr === yesterday.toISOString().split('T')[0];
+	const ys = `${yesterday.getFullYear()}-${String(yesterday.getMonth() + 1).padStart(2, '0')}-${String(yesterday.getDate()).padStart(2, '0')}`;
+	return dateStr === ys;
+}
+
+// Check if streak is still alive: use timestamp if available, fall back to date string
+function isStreakAlive(data: StreakData): boolean {
+	if (!data.lastPrayed) return false;
+	if (data.lastPrayed === getToday()) return true;
+
+	// Prefer real elapsed time (handles timezone/dateline changes)
+	if (data.lastPrayedTs) {
+		return (Date.now() - data.lastPrayedTs) < STREAK_WINDOW_MS;
+	}
+
+	// Legacy fallback for old data without timestamp
+	return isYesterdayByDate(data.lastPrayed);
 }

 function loadFromStorage(): StreakData {
@@ -53,15 +72,21 @@ async function saveToServer(data: StreakData): Promise<boolean> {
 function mergeStreakData(local: StreakData, server: StreakData | null): StreakData {
 	if (!server) return local;

-	// If same lastPrayed date, take the higher length
+	// If same lastPrayed date, take the higher length, keep best timestamp
 	if (local.lastPrayed === server.lastPrayed) {
-		return local.length >= server.length ? local : server;
+		const winner = local.length >= server.length ? local : server;
+		return { ...winner, lastPrayedTs: local.lastPrayedTs ?? server.lastPrayedTs ?? null };
 	}

 	// Otherwise take whichever was prayed more recently
 	if (!local.lastPrayed) return server;
 	if (!server.lastPrayed) return local;

+	// Prefer timestamp comparison when available
+	if (local.lastPrayedTs && server.lastPrayedTs) {
+		return local.lastPrayedTs > server.lastPrayedTs ? local : server;
+	}
+
 	return local.lastPrayed > server.lastPrayed ? local : server;
 }

@@ -75,6 +100,7 @@ function isPWA(): boolean {
 class RosaryStreakStore {
 	#length = $state(0);
 	#lastPrayed = $state<string | null>(null);
+	#lastPrayedTs = $state<number | null>(null);
 	#isLoggedIn = $state(false);
 	#initialized = false;
 	#syncing = $state(false);
@@ -94,6 +120,7 @@ class RosaryStreakStore {
 		const data = loadFromStorage();
 		this.#length = data.length;
 		this.#lastPrayed = data.lastPrayed;
+		this.#lastPrayedTs = data.lastPrayedTs ?? null;
 		this.#initialized = true;
 	}

@@ -141,7 +168,7 @@ class RosaryStreakStore {
 	}

 	get length() {
-		if (this.#lastPrayed && this.#lastPrayed !== getToday() && !isYesterday(this.#lastPrayed)) {
+		if (!isStreakAlive({ length: this.#length, lastPrayed: this.#lastPrayed, lastPrayedTs: this.#lastPrayedTs })) {
 			return 0;
 		}
 		return this.#length;
@@ -176,15 +203,14 @@ class RosaryStreakStore {

 		// If the best data we have is still expired, reset to zero so the next
 		// SSR load won't flash a stale streak count.
-		const isExpired =
-			merged.lastPrayed !== null &&
-			merged.lastPrayed !== getToday() &&
-			!isYesterday(merged.lastPrayed);
-		const effective: StreakData = isExpired ? { length: 0, lastPrayed: null } : merged;
+		const effective: StreakData = isStreakAlive(merged)
+			? merged
+			: { length: 0, lastPrayed: null, lastPrayedTs: null };

 		// Update local state
 		this.#length = effective.length;
 		this.#lastPrayed = effective.lastPrayed;
+		this.#lastPrayedTs = effective.lastPrayedTs ?? null;
 		saveToStorage(effective);

 		// Push to server if anything changed (newer local data, or expired streak reset)
@@ -198,7 +224,7 @@ class RosaryStreakStore {
 		this.#syncing = true;

 		try {
-			const data: StreakData = { length: this.#length, lastPrayed: this.#lastPrayed };
+			const data: StreakData = { length: this.#length, lastPrayed: this.#lastPrayed, lastPrayedTs: this.#lastPrayedTs };
 			const success = await saveToServer(data);
 			this.#pendingSync = !success;
 		} catch {
@@ -217,19 +243,21 @@ class RosaryStreakStore {
 		}

 		// Determine new streak length
+		const now = Date.now();
 		let newLength: number;
-		if (this.#lastPrayed && isYesterday(this.#lastPrayed)) {
-			// Continuing streak from yesterday
+		if (isStreakAlive({ length: this.#length, lastPrayed: this.#lastPrayed, lastPrayedTs: this.#lastPrayedTs })) {
+			// Continuing streak
 			newLength = this.#length + 1;
 		} else {
-			// Starting new streak (either first time or gap > 1 day)
+			// Starting new streak (either first time or gap too large)
 			newLength = 1;
 		}

 		this.#length = newLength;
 		this.#lastPrayed = today;
+		this.#lastPrayedTs = now;

-		const data: StreakData = { length: newLength, lastPrayed: today };
+		const data: StreakData = { length: newLength, lastPrayed: today, lastPrayedTs: now };
 		saveToStorage(data);

 		// Sync to server if logged in
--- a/src/models/AngelusStreak.ts
+++ b/src/models/AngelusStreak.ts
@@ -4,9 +4,10 @@ const AngelusStreakSchema = new mongoose.Schema(
  {
    username: { type: String, required: true, unique: true },
    streak: { type: Number, required: true, default: 0 },
-    lastComplete: { type: String, default: null }, // YYYY-MM-DD of last fully-completed day
+    lastComplete: { type: String, default: null }, // local YYYY-MM-DD of last fully-completed day
+    lastCompleteTs: { type: Number, default: null }, // epoch ms for timezone-safe streak checks
    todayPrayed: { type: Number, required: true, default: 0 }, // bitmask: 1=morning, 2=noon, 4=evening
-    todayDate: { type: String, default: null } // YYYY-MM-DD
+    todayDate: { type: String, default: null } // local YYYY-MM-DD
  },
  { timestamps: true }
 );
@@ -15,6 +16,7 @@ interface IAngelusStreak {
  username: string;
  streak: number;
  lastComplete: string | null;
+  lastCompleteTs: number | null;
  todayPrayed: number;
  todayDate: string | null;
 }
--- a/src/models/RosaryStreak.ts
+++ b/src/models/RosaryStreak.ts
@@ -4,7 +4,8 @@ const RosaryStreakSchema = new mongoose.Schema(
  {
    username: { type: String, required: true, unique: true },
    length: { type: Number, required: true, default: 0 },
-    lastPrayed: { type: String, default: null } // ISO date string (YYYY-MM-DD)
+    lastPrayed: { type: String, default: null }, // local YYYY-MM-DD
+    lastPrayedTs: { type: Number, default: null } // epoch ms for timezone-safe streak checks
  },
  { timestamps: true }
 );
@@ -13,6 +14,7 @@ interface IRosaryStreak {
  username: string;
  length: number;
  lastPrayed: string | null;
+  lastPrayedTs: number | null;
 }

 let _model: mongoose.Model<IRosaryStreak>;
--- a/src/routes/api/glaube/angelus-streak/+server.ts
+++ b/src/routes/api/glaube/angelus-streak/+server.ts
@@ -19,6 +19,7 @@ export const GET: RequestHandler = async ({ locals }) => {
    return json({
      streak: streak?.streak ?? 0,
      lastComplete: streak?.lastComplete ?? null,
+      lastCompleteTs: streak?.lastCompleteTs ?? null,
      todayPrayed: streak?.todayPrayed ?? 0,
      todayDate: streak?.todayDate ?? null
    });
@@ -34,7 +35,7 @@ export const POST: RequestHandler = async ({ request, locals }) => {
    throw error(401, 'Authentication required');
  }

-  const { streak, lastComplete, todayPrayed, todayDate } = await request.json();
+  const { streak, lastComplete, lastCompleteTs, todayPrayed, todayDate } = await request.json();

  if (typeof streak !== 'number' || streak < 0) {
    throw error(400, 'Valid streak required');
@@ -55,15 +56,21 @@ export const POST: RequestHandler = async ({ request, locals }) => {
  await dbConnect();

  try {
+    const updateFields: Record<string, unknown> = { streak, lastComplete, todayPrayed, todayDate };
+    if (typeof lastCompleteTs === 'number') {
+      updateFields.lastCompleteTs = lastCompleteTs;
+    }
+
    const updated = await AngelusStreak.findOneAndUpdate(
      { username: session.user.nickname },
-      { streak, lastComplete, todayPrayed, todayDate },
+      updateFields,
      { upsert: true, new: true }
    ).lean() as any;

    return json({
      streak: updated?.streak ?? 0,
      lastComplete: updated?.lastComplete ?? null,
+      lastCompleteTs: updated?.lastCompleteTs ?? null,
      todayPrayed: updated?.todayPrayed ?? 0,
      todayDate: updated?.todayDate ?? null
    });
--- a/src/routes/api/glaube/rosary-streak/+server.ts
+++ b/src/routes/api/glaube/rosary-streak/+server.ts
@@ -18,7 +18,8 @@ export const GET: RequestHandler = async ({ locals }) => {

    return json({
      length: streak?.length ?? 0,
-      lastPrayed: streak?.lastPrayed ?? null
+      lastPrayed: streak?.lastPrayed ?? null,
+      lastPrayedTs: streak?.lastPrayedTs ?? null
    });
  } catch (e) {
    throw error(500, 'Failed to fetch rosary streak');
@@ -32,7 +33,7 @@ export const POST: RequestHandler = async ({ request, locals }) => {
    throw error(401, 'Authentication required');
  }

-  const { length, lastPrayed } = await request.json();
+  const { length, lastPrayed, lastPrayedTs } = await request.json();

  if (typeof length !== 'number' || length < 0) {
    throw error(400, 'Valid streak length required');
@@ -45,15 +46,21 @@ export const POST: RequestHandler = async ({ request, locals }) => {
  await dbConnect();

  try {
+    const updateFields: Record<string, unknown> = { length, lastPrayed };
+    if (typeof lastPrayedTs === 'number') {
+      updateFields.lastPrayedTs = lastPrayedTs;
+    }
+
    const updated = await RosaryStreak.findOneAndUpdate(
      { username: session.user.nickname },
-      { length, lastPrayed },
+      updateFields,
      { upsert: true, new: true }
    ).lean() as any;

    return json({
      length: updated?.length ?? 0,
-      lastPrayed: updated?.lastPrayed ?? null
+      lastPrayed: updated?.lastPrayed ?? null,
+      lastPrayedTs: updated?.lastPrayedTs ?? null
    });
  } catch (e) {
    throw error(500, 'Failed to update rosary streak');