refactor: roll mode

* chore: escalate stack trace to console * refactor: event finding in roll * docs: initial roll specification * refactor: call to roll * refactor: normalise index * refactor: roll into next event * refactor: hot reload on waiting to roll * refactor: wait to roll next
2026-08-16 12:53:32 +00:00 · 2024-08-04 21:34:01 +02:00
parent 3012d73285
commit da11ef64c2
21 changed files with 1093 additions and 982 deletions
@@ -0,0 +1,93 @@
+import { dayInMs, getFirstEvent, getLastEvent } from 'ontime-utils';
+import { OntimeEvent, MaybeNumber, PlayableEvent, isPlayableEvent } from 'ontime-types';
+
+import { normaliseEndTime } from './timerUtils.js';
+
+/**
+ * Finds current event in a rolling rundown
+ */
+export function loadRoll(
+  timedEvents: OntimeEvent[],
+  timeNow: number,
+): {
+  event: PlayableEvent | null;
+  index: MaybeNumber;
+  isPending?: boolean;
+} {
+  const { firstEvent } = getFirstEvent(timedEvents);
+  const { lastEvent } = getLastEvent(timedEvents);
+
+  if (!firstEvent || !lastEvent) {
+    return { event: null, index: null };
+  }
+
+  // check that the rundown wraps around midnight
+  const wrapsAroundMidnight = firstEvent.timeStart > lastEvent.timeEnd;
+
+  if (!wrapsAroundMidnight) {
+    // check whether we are before or after the rundown
+    const lastNormalEnd = normaliseEndTime(lastEvent.timeStart, lastEvent.timeEnd);
+    const isAfterRundown = timeNow > lastNormalEnd;
+    const isBeforeRundown = timeNow < firstEvent.timeStart && !isAfterRundown;
+
+    if (isAfterRundown || isBeforeRundown) {
+      return { event: firstEvent, index: 0, isPending: true };
+    }
+  }
+
+  // we know we are in the middle of the rundown and we need to find the current event
+  // account for number of times we went over midnight
+  let daySpan = 0;
+
+  for (let i = 0; i < timedEvents.length; i++) {
+    const event = timedEvents[i];
+
+    if (!isPlayableEvent(event)) {
+      continue;
+    }
+
+    // we check if event crosses midnight
+    if (event.timeStart > event.timeEnd) {
+      daySpan++;
+    }
+
+    const correctedDays = dayInMs * daySpan;
+    const correctedStart = event.timeStart + correctedDays;
+    const correctedEnd = event.timeEnd + correctedDays;
+
+    /**
+     * there are 3 possible states for an event
+     * 1. event is already finished
+     * 2. event is running
+     * 3. event is in the future
+     */
+
+    // 1. event is already finished
+    // when does the event end (handle midnight)
+    const normalEnd = normaliseEndTime(correctedStart, correctedEnd);
+    if (normalEnd <= timeNow) {
+      continue;
+    }
+
+    // 2. event is running and is the first event in our time slot
+    const isFromDayBefore = normalEnd > dayInMs && timeNow < event.timeEnd;
+    const hasStarted = isFromDayBefore || timeNow >= event.timeStart;
+    if (hasStarted) {
+      return { event, index: i };
+    }
+
+    // 3. event will run in the future
+    // we set the isPending flag to indicate that the event is currently playing
+    return { event, index: i, isPending: true };
+  }
+
+  // in case we were unable to find anything, we load the first event
+  return { event: firstEvent, index: 0, isPending: true };
+}
+
+/**
+ * Utility function, checks whether the event start is the day after
+ */
+export function normaliseRollStart(start: number, clock: number) {
+  return start < clock ? start + dayInMs : start;
+}