update: octane calendar link that each user can add

src/lib/icsFeed.js

@@ -0,0 +1,56 @@
+// Builds a text/calendar feed of rehearsals for subscription (webcal://) in
+// external calendar apps. Timestamps are emitted in UTC (`...Z`) so no
+// VTIMEZONE block is needed — every client renders them in its own zone.
+function formatDateUTC(date) {
+  return new Date(date).toISOString().replace(/[-:]/g, '').split('.')[0] + 'Z';
+}
+
+// Per RFC 5545 §3.3.11: backslash-escape commas, semicolons and backslashes,
+// and turn newlines into the literal `\n` escape sequence.
+function escapeText(text) {
+  return String(text)
+    .replace(/\\/g, '\\\\')
+    .replace(/;/g, '\\;')
+    .replace(/,/g, '\\,')
+    .replace(/\r?\n/g, '\\n');
+}
+
+function rehearsalStatus(rehearsal) {
+  const hasReject = rehearsal.votes.some((v) => v.vote === 'reject');
+  const hasAccept = rehearsal.votes.some((v) => v.vote === 'accept');
+  if (hasAccept && !hasReject) return 'CONFIRMED';
+  return 'TENTATIVE';
+}
+
+function rehearsalToEvent(rehearsal) {
+  const status = rehearsalStatus(rehearsal);
+  const summary = status === 'CONFIRMED' ? 'Répétition' : 'Répétition (proposition)';
+  const lines = [
+    'BEGIN:VEVENT',
+    `UID:rehearsal-${rehearsal.id}@octane`,
+    `DTSTAMP:${formatDateUTC(rehearsal.created_at || new Date())}`,
+    `DTSTART:${formatDateUTC(rehearsal.starts_at)}`,
+    `DTEND:${formatDateUTC(rehearsal.ends_at)}`,
+    `SUMMARY:${escapeText(summary)}`,
+    `STATUS:${status}`,
+  ];
+  if (rehearsal.location) lines.push(`LOCATION:${escapeText(rehearsal.location)}`);
+  lines.push('END:VEVENT');
+  return lines;
+}
+
+function buildRehearsalsFeed(rehearsals) {
+  const lines = [
+    'BEGIN:VCALENDAR',
+    'VERSION:2.0',
+    'PRODID:-//Octane//Rehearsals//FR',
+    'CALSCALE:GREGORIAN',
+    'METHOD:PUBLISH',
+    'X-WR-CALNAME:Répétitions Octane',
+    ...rehearsals.flatMap(rehearsalToEvent),
+    'END:VCALENDAR',
+  ];
+  return lines.join('\r\n');
+}
+
+module.exports = { buildRehearsalsFeed };