Merge pull request 'merge staging to production' (#58) from staging into production

Reviewed-on: #58

.forgejo/workflows/deploy.yaml

@@ -1,5 +1,10 @@
 name: deploy blog
 
+# Create secrets with:
+# KNOWN_HOST=$(ssh-keyscan -H www.berlin.ccc.de | grep ssh-ed25519 | base64 -w0)
+# SSH_PRIVATE_KEY_PRODUCTION=$(agenix -d id_ed25519_www-production.age | base64 -w0)
+# SSH_PRIVATE_KEY_STAGING=$(agenix -d id_ed25519_www-staging.age | base64 -w0)
+
 on:
   workflow_dispatch:
   schedule:

.gitignore

@@ -202,3 +202,8 @@ $RECYCLE.BIN/
 *.lnk
 
 # End of https://www.toptal.com/developers/gitignore/api/windows,linux,macos,hugo,pycharm+all,vim,direnv
+
+### CCCB ###
+# The calendar the site reads its events from is published next to the site and
+# only downloaded here to look at the site locally, see the README.
+/static/calendars/

README.md

@@ -29,20 +29,34 @@ This is the website of the CCCB.
 
 Every change you make on the project will be reflected in your browser as long as `hugo serve` is running.
 
-The *"Nächste Veranstaltungen"* table on the home page is generated by post-processing in `./build.sh`, not by Hugo, so
-it is **not** visible under `hugo serve`. To preview the fully built site (including the home-page calendar), or to
-ready the site for upload, run:
+The *"Nächste Veranstaltungen"* table on the home page and the calendar under `/verein/calendar/` are rendered in the
+browser by `assets/js/upcoming.js` and `assets/js/calendar.js`. Both fetch `/calendars/all.ics`, which is **not**
+generated by Hugo and is not part of this repo — it is published separately on the web server. Without it both tables
+stay empty. Download the published calendar into `static/`, which Hugo serves under the same path, and they work
+locally, under `hugo serve` as well as in a built site:
+
+```shell
+mkdir -p static/calendars
+curl -o static/calendars/all.ics https://berlin.ccc.de/calendars/all.ics
+```
+
+The file is only there to look at the site, it is not checked in. Download it again whenever you want the events that
+are currently published.
+
+Hugo does generate an `.ics` feed per section (for example `/veranstaltungen/index.ics`) from the `dtstart`, `dtend`
+and `rrule` front matter of the pages in `content/veranstaltungen/`, using the `.ics` templates under `layouts/`.
+
+The site must not make the browser load anything from an external server, so third party JavaScript is checked into
+`assets/js/vendor/` and bundled in by Hugo instead of being pulled from a CDN. See the README there before updating it.
+
+To build the site for upload, run:
 
 ```shell
 ./build.sh
-python3 -m http.server -d public 1313
 ```
 
-`build.sh` replaces the `CALENDAR` placeholder in `index.html` with the upcoming-events table. It depends on Python
-with the `icalendar`, `python-dateutil`, and `pytz` packages, plus a `de_DE.UTF-8` locale (used to format weekday
-names). Inside `nix develop` these are provided automatically.
-
-To build with *nix*: `nix build '.?submodules=1#production-content'`
+This deletes `public/` and runs `hugo` with the parameters from `.hugo-params`. To build with *nix* instead:
+`nix build '.?submodules=1#production-content'`
 
 ## Making a change
 
@@ -59,8 +73,7 @@ To build with *nix*: `nix build '.?submodules=1#production-content'`
 
 ## Nix stuff
 
-- After entering the shell with `nix develop`, hugo is available and `hugo serve` should work
-- Python including required packages will be available, so the `build.sh` should work without a venv
+- After entering the shell with `nix develop`, hugo is available and `hugo serve` and `./build.sh` should work
 - You can build the staging and production builds with `nix build .#staging-content` and
   `nix build .#production-content`
 - Do not update the nixpkgs branch - 25.05 contains a newer hugo version that is incompatible with the theme (last

assets/css/calendar.css

@@ -107,6 +107,10 @@
     font-size: 0.9em;
     margin-bottom: 5px;
   }
+  .event-description {
+    /* Descriptions carry their own line breaks, keep them. */
+    white-space: pre-line;
+  }
   .no-events {
     font-style: italic;
     color: var(--color-text-secondary);

assets/css/upcoming.css

@@ -0,0 +1,36 @@
+/* The rows of the table are added by JavaScript and end up as direct children
+   of the table, so the table styling of the theme, which addresses tbody, does
+   not reach them. Separate the date from the name of the event ourselves, and
+   keep the date on one line, it is one piece of information and reads badly
+   broken after the weekday. */
+#upcoming td:first-child {
+  padding-inline-end: 1em;
+  white-space: nowrap;
+}
+
+/* The table stands in a prose column, which the theme limits to 65 characters
+   so that running text stays readable. A date and the name of an event next to
+   each other do not fit into that, so the names were wrapped over several
+   lines. Lift the limit off the column and put it back on everything in it
+   except the table, which leaves the table room to grow while the text around
+   it keeps its width. */
+section.prose:has(> #upcoming) {
+  max-width: none;
+}
+
+section.prose:has(> #upcoming) > :not(#upcoming) {
+  max-width: 65ch;
+  margin-inline: auto;
+}
+
+/* The theme lays a table out as a block, "table { display: block; overflow:
+   auto }", so that a wide one can be scrolled sideways. A block fills its
+   parent instead of shrinking to its content the way a table does, so across
+   the whole width of the page the entries would stay at its left edge.
+   fit-content asks for the width of the content, which the automatic margins
+   then centre, and it never exceeds the column, so a display too narrow for
+   the table still wraps the names instead of overflowing. */
+#upcoming {
+  width: fit-content;
+  margin-inline: auto;
+}

assets/js/calendar.js

@@ -1,449 +1,406 @@
-document.addEventListener('DOMContentLoaded', function() {
-    (function(){
-        let events = [];
-        let eventsByDate = {};
+import { eventUrl, loadCalendar, occurrencesBetween } from "./events.js";
 
-        // Funktion zum Parsen der ICS-Datei
-        function parseICS(icsText) {
-            let events = [];
-            let lines = icsText.split(/\r?\n/);
-            let event = null;
-            lines.forEach(line => {
-                if (line.startsWith("BEGIN:VEVENT")) {
-                    event = {};
-                } else if (line.startsWith("END:VEVENT")) {
-                    if (event) events.push(event);
-                    event = null;
-                } else if (event) {
-                    let colonIndex = line.indexOf(":");
-                    if (colonIndex > -1) {
-                        let key = line.substring(0, colonIndex);
-                        let value = line.substring(colonIndex + 1);
+// The club is in Berlin, so the calendar shows Berlin days and Berlin times,
+// no matter which time zone the browser of the visitor is set to.
+const timeZone = "Europe/Berlin";
 
-                        // Handle properties with parameters (like TZID)
-                        const baseKey = key.split(";")[0];
+const monthNames = [
+  "Januar", "Februar", "März", "April", "Mai", "Juni",
+  "Juli", "August", "September", "Oktober", "November", "Dezember",
+];
 
-                        if (baseKey === "DTSTART") {
-                            event.start = value;
-                            event.startParams = key.includes(";") ? key.substring(key.indexOf(";") + 1) : null;
-                        } else if (baseKey === "DTEND") {
-                            event.end = value;
-                            event.endParams = key.includes(";") ? key.substring(key.indexOf(";") + 1) : null;
-                        } else if (baseKey === "SUMMARY") {
-                            event.summary = value;
-                        } else if (baseKey === "DESCRIPTION") {
-                            event.description = value;
-                        } else if (baseKey === "RRULE") {
-                            event.rrule = value;
-                        }
-                    }
-                }
-            });
-            return events;
-        }
-
-        // Hilfsfunktion: Parst einen ICS-Datum-String ins Format "YYYY-MM-DD"
-        function parseDateString(icsDateStr) {
-            // Handle different date formats
-            if (!icsDateStr) return null;
-
-            // For basic date format: YYYYMMDD
-            if (icsDateStr.length === 8) {
-                let year = icsDateStr.substring(0, 4);
-                let month = icsDateStr.substring(4, 6);
-                let day = icsDateStr.substring(6, 8);
-                return `${year}-${month}-${day}`;
-            }
-            // For datetime formats: YYYYMMDDTHHmmssZ or YYYYMMDDTHHmmss
-            else if (icsDateStr.includes("T")) {
-                let year = icsDateStr.substring(0, 4);
-                let month = icsDateStr.substring(4, 6);
-                let day = icsDateStr.substring(6, 8);
-                return `${year}-${month}-${day}`;
-            }
-            return null;
-        }
-
-        // Extract date components from different date formats
-        function getDateComponents(icsDateStr) {
-            if (!icsDateStr) return null;
-
-            // Basic handling - extract YYYY, MM, DD regardless of format
-            const year = parseInt(icsDateStr.substring(0, 4));
-            const month = parseInt(icsDateStr.substring(4, 6)) - 1; // 0-based months
-            const day = parseInt(icsDateStr.substring(6, 8));
-
-            return { year, month, day };
-        }
-
-        function expandRecurringEvents(event, year, month) {
-            if (!event.rrule) return [event];
-
-            const rruleStr = event.rrule;
-
-            // Get start date components
-            const startComponents = getDateComponents(event.start);
-            if (!startComponents) return [event];
-
-            const startDate = new Date(
-                startComponents.year,
-                startComponents.month,
-                startComponents.day
-            );
-
-            const rangeStart = new Date(year, month, 1);
-            const rangeEnd = new Date(year, month + 1, 0);
-            const expandedEvents = [];
-
-            if (rruleStr.includes("FREQ=WEEKLY") && rruleStr.includes("BYDAY")) {
-                const bydayMatch = rruleStr.match(/BYDAY=([^;]+)/);
-                if (bydayMatch) {
-                    const dayCode = bydayMatch[1];
-                    const dayMap = {
-                        'MO': 1, 'TU': 2, 'WE': 3, 'TH': 4, 'FR': 5, 'SA': 6, 'SU': 0
-                    };
-                    const targetDay = dayMap[dayCode];
-
-                    if (targetDay !== undefined) {
-                        // Create events for each matching day in the month
-                        let day = 1;
-                        while (day <= rangeEnd.getDate()) {
-                            const testDate = new Date(year, month, day);
-                            if (testDate.getDay() === targetDay && testDate >= startDate) {
-                                const newEvent = {...event};
-                                const eventDate = formatDateForICS(testDate);
-
-                                // Preserve time portion from original event
-                                const timePart = event.start.includes('T') ?
-                                    event.start.substring(event.start.indexOf('T')) : '';
-                                const endTimePart = event.end.includes('T') ?
-                                    event.end.substring(event.end.indexOf('T')) : '';
-
-                                newEvent.start = eventDate + timePart;
-                                newEvent.end = eventDate + endTimePart;
-                                expandedEvents.push(newEvent);
-                            }
-                            day++;
-                        }
-                    }
-                }
-            }
-            else if (rruleStr.includes("FREQ=MONTHLY") && rruleStr.includes("BYDAY")) {
-                const bydayMatch = rruleStr.match(/BYDAY=([^;]+)/);
-                if (bydayMatch) {
-                    const intervalMatch = rruleStr.match(/INTERVAL=(\d+)/);
-                    const interval = intervalMatch ? parseInt(intervalMatch[1]) : 1;
-                    const monthsFromStart = (year - startDate.getFullYear()) * 12 + (month - startDate.getMonth());
-                    if (monthsFromStart < 0 || monthsFromStart % interval !== 0) {
-                        return [];
-                    }
-                    const bydays = bydayMatch[1].split(',');
-                    const dayMap = {
-                        'MO': 1, 'TU': 2, 'WE': 3, 'TH': 4, 'FR': 5, 'SA': 6, 'SU': 0
-                    };
-
-                    bydays.forEach(byday => {
-                        const occurrence = parseInt(byday) || 1;
-                        const dayCode = byday.slice(-2);
-                        const dayIndex = dayMap[dayCode];
-
-                        let day = 1;
-                        let count = 0;
-
-                        while (day <= rangeEnd.getDate()) {
-                            const testDate = new Date(year, month, day);
-                            if (testDate.getDay() === dayIndex) {
-                                count++;
-                                if (count === occurrence || (occurrence < 0 && day > rangeEnd.getDate() + occurrence * 7)) {
-                                    const newEvent = {...event};
-                                    const eventDate = new Date(year, month, day);
-
-                                    // Preserve time portion from original event
-                                    const timePart = event.start.includes('T') ?
-                                        event.start.substring(event.start.indexOf('T')) : '';
-                                    const endTimePart = event.end.includes('T') ?
-                                        event.end.substring(event.end.indexOf('T')) : '';
-
-                                    newEvent.start = formatDateForICS(eventDate) + timePart;
-                                    newEvent.end = formatDateForICS(eventDate) + endTimePart;
-                                    expandedEvents.push(newEvent);
-                                }
-                            }
-                            day++;
-                        }
-                    });
-                }
-            }
-
-            return expandedEvents.length > 0 ? expandedEvents : [event];
-        }
-
-        // Kalender initialisieren
-        let currentYear, currentMonth;
-        const currentMonthElem = document.getElementById("current-month");
-        const calendarBody = document.getElementById("calendar-body");
-        const eventPanel = document.getElementById("event-panel");
-        const eventDateElem = document.getElementById("event-date");
-        const eventDetailsElem = document.getElementById("event-details");
-
-        document.getElementById("prev-month").addEventListener("click", function(){
-             currentMonth--;
-             if (currentMonth < 0) {
-                  currentMonth = 11;
-                  currentYear--;
-             }
-             updateEventsForMonth(currentYear, currentMonth);
+const dayKeyFormat = new Intl.DateTimeFormat("en-US", {
+  timeZone,
+  year: "numeric",
+  month: "2-digit",
+  day: "2-digit",
+});
+
+const timeOfDayFormat = new Intl.DateTimeFormat("de-DE", {
+  timeZone,
+  hour: "2-digit",
+  minute: "2-digit",
+});
+
+let calendar = null;
+let eventsByDate = {};
+let currentYear;
+let currentMonth;
+
+let currentMonthElem;
+let calendarBody;
+let eventPanel;
+let eventDateElem;
+let eventDetailsElem;
+
+/**
+ * The day a point in time falls on in Berlin.
+ *
+ * @param {Date} date The point in time
+ * @returns {string} The day as "YYYY-MM-DD"
+ */
+function dayKey(date) {
+  const parts = {};
+
+  for (const part of dayKeyFormat.formatToParts(date)) {
+    parts[part.type] = part.value;
+  }
+
+  return `${parts.year}-${parts.month}-${parts.day}`;
+}
+
+/**
+ * The day an occurrence time falls on in Berlin.
+ *
+ * A date has neither a time nor a zone, its digits are the day itself.
+ * toJSDate() would read them as midnight in the zone of the browser, which
+ * far enough east or west of Berlin lands on the day before or after.
+ *
+ * @param {ICAL.Time} time The time
+ * @returns {string} The day as "YYYY-MM-DD"
+ */
+function timeDayKey(time) {
+  if (time.isDate) {
+    const month = String(time.month).padStart(2, "0");
+    const day = String(time.day).padStart(2, "0");
+
+    return `${time.year}-${month}-${day}`;
+  }
+
+  return dayKey(time.toJSDate());
+}
+
+/**
+ * The days an event covers, so that an event running over several days is
+ * shown on each of them and not only on the day it starts.
+ *
+ * @param {ICAL.Time} start Start of the event
+ * @param {ICAL.Time} end End of the event
+ * @returns {string[]} The days as "YYYY-MM-DD"
+ */
+function daysCovered(start, end) {
+  // The end is not part of the event: one ending at midnight belongs to the day
+  // before, and an all day event ends on the day before its DTEND.
+  const last = end.clone();
+
+  if (end.isDate) {
+    last.adjust(-1, 0, 0, 0);
+  } else {
+    last.adjust(0, 0, 0, -1);
+  }
+
+  const lastKey = timeDayKey(last);
+  const days = [];
+
+  let key = timeDayKey(start);
+
+  // The guard keeps a broken event from looping forever, a year of dots on the
+  // same event is well past the point where the calendar is still useful.
+  while (days.length <= 366) {
+    days.push(key);
+
+    // The keys sort as the days do, so this also stops an event whose end lies
+    // before its start after the day it starts on.
+    if (key >= lastKey) {
+      break;
+    }
+
+    // Step to noon UTC of the next day, which is inside the same Berlin day
+    // whether daylight saving time is in effect or not.
+    const [year, month, day] = key.split("-").map(Number);
+    key = dayKey(new Date(Date.UTC(year, month - 1, day + 1, 12)));
+  }
+
+  return days;
+}
+
+/**
+ * Reduce one occurrence of an event to what the calendar displays.
+ *
+ * @param {ICAL.Event} event The event the occurrence belongs to
+ * @param {ICAL.Time} startDate Start of this occurrence
+ * @param {ICAL.Time} endDate End of this occurrence
+ * @returns {{summary: string, description: string, url: string, start: Date, end: Date, allDay: boolean, days: string[]}}
+ */
+function toOccurrence(event, startDate, endDate) {
+  return {
+    summary: event.summary ?? "",
+    description: event.description ?? "",
+    url: eventUrl(event),
+    start: startDate.toJSDate(),
+    end: endDate.toJSDate(),
+    allDay: startDate.isDate,
+    // Taken from the ICAL times, which still know whether they name a day or a
+    // point in time; the JS dates above no longer do.
+    days: daysCovered(startDate, endDate),
+  };
+}
+
+/**
+ * Collect everything that takes place in the given month, keyed by day.
+ *
+ * @param {number} year The year of the month
+ * @param {number} month The month, January is 0
+ * @returns {Object<string, Array>} The occurrences per "YYYY-MM-DD"
+ */
+function occurrencesOfMonth(year, month) {
+  const byDate = {};
+
+  if (!calendar) {
+    return byDate;
+  }
+
+  // These bounds only limit how far the recurrences have to be expanded, which
+  // day an occurrence ends up on is decided by its Berlin day below. They are
+  // deliberately generous so that no occurrence is cut off at the edge of the
+  // month by a time zone difference.
+  const from = new Date(year, month, 1);
+  const to = new Date(year, month + 1, 1);
+  from.setDate(from.getDate() - 2);
+  to.setDate(to.getDate() + 2);
+
+  const monthPrefix = `${year}-${String(month + 1).padStart(2, "0")}-`;
+
+  const add = (occurrence) => {
+    for (const key of occurrence.days) {
+      if (!key.startsWith(monthPrefix)) {
+        continue;
+      }
+
+      if (!byDate[key]) {
+        byDate[key] = [];
+      }
+
+      byDate[key].push(occurrence);
+    }
+  };
+
+  for (const { event, startDate, endDate } of occurrencesBetween(calendar, from, to)) {
+    add(toOccurrence(event, startDate, endDate));
+  }
+
+  for (const occurrences of Object.values(byDate)) {
+    occurrences.sort((a, b) => {
+      // An all day event has no time of day to sort by, the JS date of its
+      // start is midnight in the zone of the browser. Put it first instead.
+      if (a.allDay !== b.allDay) {
+        return a.allDay ? -1 : 1;
+      }
+
+      return a.start - b.start;
+    });
+  }
+
+  return byDate;
+}
+
+function updateEventsForMonth(year, month) {
+  eventsByDate = occurrencesOfMonth(year, month);
+  renderCalendar(year, month);
+}
+
+function renderCalendar(year, month) {
+  // Setze die Monatsbeschriftung (in Deutsch)
+  currentMonthElem.textContent = monthNames[month] + " " + year;
+  calendarBody.innerHTML = "";
+
+  let firstDay = new Date(year, month, 1);
+  let firstDayIndex = (firstDay.getDay() + 6) % 7; // Montag = 0, Dienstag = 1, etc.
+  let daysInMonth = new Date(year, month + 1, 0).getDate();
+
+  let row = document.createElement("tr");
+  // Leere Zellen vor dem 1. Tag
+  for (let i = 0; i < firstDayIndex; i++) {
+    let cell = document.createElement("td");
+    row.appendChild(cell);
+  }
+
+  // Tage hinzufügen
+  for (let day = 1; day <= daysInMonth; day++) {
+    if (row.children.length === 7) {
+      calendarBody.appendChild(row);
+      row = document.createElement("tr");
+    }
+    let cell = document.createElement("td");
+    cell.innerHTML = "<strong>" + day + "</strong>";
+
+    let dayStr = day < 10 ? "0" + day : day;
+    let monthStr = (month + 1) < 10 ? "0" + (month + 1) : (month + 1);
+    let dateKey = year + "-" + monthStr + "-" + dayStr;
+
+    if (eventsByDate[dateKey]) {
+      let dotsContainer = document.createElement("div");
+      dotsContainer.className = "event-dots-container";
+      cell.classList.add("has-event");
+
+      // Gruppe Events nach Typ
+      const events = eventsByDate[dateKey];
+      const hasMembersOnly = events.some(e => e.summary.toLowerCase().includes("members only"));
+      const hasSubbotnik = events.some(e => e.summary.toLowerCase().includes("subbotnik"));
+      const hasBastelabend = events.some(e => e.summary.toLowerCase().includes("bastelabend"));
+      const hasSpieleabend = events.some(e => e.summary.toLowerCase().includes("spieleabend"));
+      const hasRegular = events.some(e => {
+        const title = e.summary.toLowerCase();
+        return !title.includes("members only") &&
+              !title.includes("subbotnik") &&
+              !title.includes("bastelabend") &&
+              !title.includes("spieleabend");
+      });
+
+      // Füge Dots entsprechend der Event-Typen hinzu
+      if (hasMembersOnly) {
+        let dot = document.createElement("div");
+        dot.className = "event-dot event-dot-red";
+        dotsContainer.appendChild(dot);
+      }
+      if (hasSubbotnik || hasBastelabend || hasSpieleabend) {
+        let dot = document.createElement("div");
+        dot.className = "event-dot event-dot-orange";
+        dotsContainer.appendChild(dot);
+      }
+      if (hasRegular) {
+        let dot = document.createElement("div");
+        dot.className = "event-dot event-dot-greenyellow";
+        dotsContainer.appendChild(dot);
+      }
+
+      cell.appendChild(dotsContainer);
+      cell.dataset.dateKey = dateKey;
+      cell.addEventListener("click", function() {
+        // Clear previous selections
+        document.querySelectorAll('.selected-day').forEach(el => {
+          el.classList.remove('selected-day');
         });
-        document.getElementById("next-month").addEventListener("click", function(){
-             currentMonth++;
-             if (currentMonth > 11) {
-              currentMonth = 0;
-              currentYear++;
-             }
-             updateEventsForMonth(currentYear, currentMonth);
-        });
-
-        function updateEventsForMonth(year, month) {
-            // Clear existing events for this month view
-            eventsByDate = {};
-
-            // Process each event, expanding recurring ones
-            events.forEach(ev => {
-                if (ev.rrule) {
-                    // For recurring events, expand them for current month
-                    const expandedEvents = expandRecurringEvents(ev, year, month);
-                    expandedEvents.forEach(expandedEv => {
-                        let dateKey = parseDateString(expandedEv.start);
-                        if (dateKey) {
-                            if (!eventsByDate[dateKey]) {
-                                eventsByDate[dateKey] = [];
-                            }
-                            eventsByDate[dateKey].push(expandedEv);
-                        }
-                    });
-                } else {
-                    // For regular events, check if they fall in current month
-                    let dateKey = parseDateString(ev.start);
-                    if (dateKey) {
-                        // Check if this event belongs to current month view
-                        const eventYear = parseInt(dateKey.split('-')[0]);
-                        const eventMonth = parseInt(dateKey.split('-')[1]) - 1;
-
-                        if (eventYear === year && eventMonth === month) {
-                            if (!eventsByDate[dateKey]) {
-                                eventsByDate[dateKey] = [];
-                            }
-                            eventsByDate[dateKey].push(ev);
-                        }
-                    }
-                }
-            });
-
-            renderCalendar(year, month);
-        }
-
-        function renderCalendar(year, month) {
-            // Setze die Monatsbeschriftung (in Deutsch)
-            const monthNames = ["Januar", "Februar", "März", "April", "Mai", "Juni", "Juli", "August", "September", "Oktober", "November", "Dezember"];
-            currentMonthElem.textContent = monthNames[month] + " " + year;
-            calendarBody.innerHTML = "";
-
-            let firstDay = new Date(year, month, 1);
-            let firstDayIndex = (firstDay.getDay() + 6) % 7; // Montag = 0, Dienstag = 1, etc.
-            let daysInMonth = new Date(year, month + 1, 0).getDate();
-
-            let row = document.createElement("tr");
-            // Leere Zellen vor dem 1. Tag
-            for (let i = 0; i < firstDayIndex; i++){
-                let cell = document.createElement("td");
-                row.appendChild(cell);
-            }
-
-            // Tage hinzufügen
-            for (let day = 1; day <= daysInMonth; day++){
-                if (row.children.length === 7) {
-                    calendarBody.appendChild(row);
-                    row = document.createElement("tr");
-                }
-                let cell = document.createElement("td");
-                cell.innerHTML = "<strong>" + day + "</strong>";
-
-                let dayStr = day < 10 ? "0" + day : day;
-                let monthStr = (month + 1) < 10 ? "0" + (month + 1) : (month + 1);
-                let dateKey = year + "-" + monthStr + "-" + dayStr;
-
-                if (eventsByDate[dateKey]) {
-                    let dotsContainer = document.createElement("div");
-                    dotsContainer.className = "event-dots-container";
-                    cell.classList.add("has-event");
-
-                    // Gruppe Events nach Typ
-                    const events = eventsByDate[dateKey];
-                    const hasMembersOnly = events.some(e => e.summary.toLowerCase().includes("members only"));
-                    const hasSubbotnik = events.some(e => e.summary.toLowerCase().includes("subbotnik"));
-                    const hasBastelabend = events.some(e => e.summary.toLowerCase().includes("bastelabend"));
-                    const hasSpieleabend = events.some(e => e.summary.toLowerCase().includes("spieleabend"));
-                    const hasRegular = events.some(e => {
-                        const title = e.summary.toLowerCase();
-                        return !title.includes("members only") &&
-                              !title.includes("subbotnik") &&
-                              !title.includes("bastelabend") &&
-                              !title.includes("spieleabend");
-                    });
-
-                    // Füge Dots entsprechend der Event-Typen hinzu
-                    if (hasMembersOnly) {
-                        let dot = document.createElement("div");
-                        dot.className = "event-dot event-dot-red";
-                        dotsContainer.appendChild(dot);
-                    }
-                    if (hasSubbotnik || hasBastelabend || hasSpieleabend) {
-                        let dot = document.createElement("div");
-                        dot.className = "event-dot event-dot-orange";
-                        dotsContainer.appendChild(dot);
-                    }
-                    if (hasRegular) {
-                        let dot = document.createElement("div");
-                        dot.className = "event-dot event-dot-greenyellow";
-                        dotsContainer.appendChild(dot);
-                    }
-
-                    cell.appendChild(dotsContainer);
-                    cell.dataset.dateKey = dateKey;
-                    cell.addEventListener("click", function() {
-                        // Clear previous selections
-                        document.querySelectorAll('.selected-day').forEach(el => {
-                            el.classList.remove('selected-day');
-                        });
-                        cell.classList.add('selected-day');
-                        showEventDetails(dateKey);
-                    });
-                }
-                row.appendChild(cell);
-            }
-            // Falls die letzte Zeile nicht komplett ist
-            while (row.children.length < 7) {
-                let cell = document.createElement("td");
-                row.appendChild(cell);
-            }
-            calendarBody.appendChild(row);
-        }
-
-        function createEventLink(eventTitle) {
-            if (eventTitle.startsWith("Datengarten")) {
-                // Extract the number after "Datengarten "
-                const match = eventTitle.match(/Datengarten\s+(\d+)/i);
-                if (match && match[1]) {
-                    return `https://berlin.ccc.de/datengarten/${match[1]}/`;
-                }
-            }
-
-            // For other titles, convert to lowercase and use as path
-            const slug = eventTitle.toLowerCase().replace(/\s+/g, '-').replace(/[^\w-]/g, '');
-            return `https://berlin.ccc.de/page/${slug}/`;
-        }
-
-        function showEventDetails(dateKey) {
-            const events = eventsByDate[dateKey];
-            eventDateElem.textContent = formatDate(dateKey);
-            eventDetailsElem.innerHTML = "";
-
-            if (events && events.length > 0) {
-                events.forEach(ev => {
-                    let eventItem = document.createElement("div");
-                    eventItem.className = "event-item";
-
-                    let eventTitle = document.createElement("div");
-                    eventTitle.className = "event-title";
-
-                    // Create a link for the event title
-                    let titleLink = document.createElement("h");
-                    titleLink.textContent = ev.summary;
-                    titleLink.target = "_blank";
-                    eventTitle.appendChild(titleLink);
-
-                    eventItem.appendChild(eventTitle);
-
-                    let eventTime = document.createElement("div");
-                    eventTime.className = "event-time";
-                    eventTime.textContent = `Start: ${formatTime(ev.start)}, End: ${formatTime(ev.end)}`;
-                    eventItem.appendChild(eventTime);
-
-                            if (ev.description) {
-                              let eventDescription = document.createElement("div");
-                              eventDescription.className = "event-description";
-
-                              // Check if the description is a URL and make it a clickable link
-                              if (ev.description.trim().startsWith('http')) {
-                                let linkElement = document.createElement("a");
-                                linkElement.href = ev.description.trim();
-                                linkElement.textContent = ev.description.trim();
-                                linkElement.target = "_blank";
-                                eventDescription.innerHTML = '';
-                                eventDescription.appendChild(linkElement);
-                              } else {
-                                eventDescription.textContent = ev.description;
-                              }
-
-                              eventItem.appendChild(eventDescription);
-                            }
-
-                              eventDetailsElem.appendChild(eventItem);
-                });
-            } else {
-                let noEvents = document.createElement("div");
-                noEvents.className = "no-events";
-                noEvents.textContent = "Keine Veranstaltungen an diesem Tag.";
-                eventDetailsElem.appendChild(noEvents);
-            }
-
-            eventPanel.style.display = "block";
-        }
-
-        function formatDate(dateStr) {
-            // Convert YYYY-MM-DD to DD.MM.YYYY
-            const parts = dateStr.split("-");
-            return `${parts[2]}.${parts[1]}.${parts[0]}`;
-        }
-
-        function formatTime(icsTimeStr) {
-            // Format time for display
-            if (!icsTimeStr) return "";
-
-            if (icsTimeStr.length === 8) {
-                // All-day event
-                return "Ganztägig";
-            } else if (icsTimeStr.includes("T")) {
-                // Time-specific event (with or without timezone)
-                const timeStart = icsTimeStr.indexOf("T") + 1;
-                const hour = icsTimeStr.substring(timeStart, timeStart + 2);
-                const minute = icsTimeStr.substring(timeStart + 2, timeStart + 4);
-                return `${hour}:${minute}`;
-            }
-            return icsTimeStr;
-        }
-
-        function formatDateForICS(date) {
-            const year = date.getFullYear();
-            const month = (date.getMonth() + 1).toString().padStart(2, '0');
-            const day = date.getDate().toString().padStart(2, '0');
-            return `${year}${month}${day}`;
-        }
-
-        // ICS-Datei abrufen und Events verarbeiten
-        fetch('/calendars/all.ics')
-        .then(response => response.text())
-        .then(data => {
-            events = parseICS(data);
-
-            // Initialize with current date
-            let today = new Date();
-            currentYear = today.getFullYear();
-            currentMonth = today.getMonth();
-
-            // Process events for current month
-            updateEventsForMonth(currentYear, currentMonth);
-        })
-        .catch(err => console.error('Fehler beim Laden der ICS-Datei:', err));
-    })();
+        cell.classList.add('selected-day');
+        showEventDetails(dateKey);
+      });
+    }
+    row.appendChild(cell);
+  }
+  // Falls die letzte Zeile nicht komplett ist
+  while (row.children.length < 7) {
+    let cell = document.createElement("td");
+    row.appendChild(cell);
+  }
+  calendarBody.appendChild(row);
+}
+
+/**
+ * Build the entry of a single event in the detail panel.
+ *
+ * @param {Object} occurrence The occurrence to show
+ * @returns {HTMLElement} The entry
+ */
+function renderEventItem(occurrence) {
+  const item = document.createElement("div");
+  item.className = "event-item";
+
+  const title = document.createElement("div");
+  title.className = "event-title";
+
+  if (occurrence.url) {
+    const link = document.createElement("a");
+    link.href = occurrence.url;
+    link.textContent = occurrence.summary;
+    title.appendChild(link);
+  } else {
+    title.textContent = occurrence.summary;
+  }
+
+  item.appendChild(title);
+
+  const time = document.createElement("div");
+  time.className = "event-time";
+  time.textContent = formatTimeRange(occurrence);
+  item.appendChild(time);
+
+  if (occurrence.description) {
+    const description = document.createElement("div");
+    description.className = "event-description";
+    description.textContent = occurrence.description;
+    item.appendChild(description);
+  }
+
+  return item;
+}
+
+function showEventDetails(dateKey) {
+  const occurrences = eventsByDate[dateKey];
+  eventDateElem.textContent = formatDate(dateKey);
+  eventDetailsElem.innerHTML = "";
+
+  if (occurrences && occurrences.length > 0) {
+    for (const occurrence of occurrences) {
+      eventDetailsElem.appendChild(renderEventItem(occurrence));
+    }
+  } else {
+    let noEvents = document.createElement("div");
+    noEvents.className = "no-events";
+    noEvents.textContent = "Keine Veranstaltungen an diesem Tag.";
+    eventDetailsElem.appendChild(noEvents);
+  }
+
+  eventPanel.style.display = "block";
+}
+
+function formatDate(dateStr) {
+  // Convert YYYY-MM-DD to DD.MM.YYYY
+  const parts = dateStr.split("-");
+  return `${parts[2]}.${parts[1]}.${parts[0]}`;
+}
+
+/**
+ * Describe when an occurrence takes place, in Berlin time.
+ *
+ * @param {Object} occurrence The occurrence to describe
+ * @returns {string} The description
+ */
+function formatTimeRange(occurrence) {
+  if (occurrence.allDay) {
+    return "Ganztägig";
+  }
+
+  const start = timeOfDayFormat.format(occurrence.start);
+  const end = timeOfDayFormat.format(occurrence.end);
+
+  return `Beginn: ${start}, Ende: ${end}`;
+}
+
+document.addEventListener("DOMContentLoaded", function() {
+  currentMonthElem = document.getElementById("current-month");
+  calendarBody = document.getElementById("calendar-body");
+  eventPanel = document.getElementById("event-panel");
+  eventDateElem = document.getElementById("event-date");
+  eventDetailsElem = document.getElementById("event-details");
+
+  document.getElementById("prev-month").addEventListener("click", function() {
+    currentMonth--;
+    if (currentMonth < 0) {
+      currentMonth = 11;
+      currentYear--;
+    }
+    updateEventsForMonth(currentYear, currentMonth);
+  });
+  document.getElementById("next-month").addEventListener("click", function() {
+    currentMonth++;
+    if (currentMonth > 11) {
+      currentMonth = 0;
+      currentYear++;
+    }
+    updateEventsForMonth(currentYear, currentMonth);
+  });
+
+  // Show the grid of the current month right away, the events are filled in
+  // once the calendar has been loaded.
+  const today = new Date();
+  currentYear = today.getFullYear();
+  currentMonth = today.getMonth();
+  updateEventsForMonth(currentYear, currentMonth);
+
+  loadCalendar()
+    .then(loaded => {
+      calendar = loaded;
+      updateEventsForMonth(currentYear, currentMonth);
+    })
+    .catch(err => console.error("Fehler beim Laden der ICS-Datei:", err));
 });

assets/js/events.js

@@ -0,0 +1,194 @@
+import ICAL from "./vendor/ical.js";
+
+// The calendar is published next to the site and is not built from this
+// repository, see the README.
+const icsUrl = "/calendars/all.ics";
+
+/**
+ * Read the URL of an event.
+ *
+ * ICAL.Event does not expose the URL property, so read it from the component.
+ *
+ * The value ends up in the href of a link, and the calendar is exported from a
+ * CalDAV server, so whoever may write to it decides what that value is. A
+ * "javascript:" URL there would run on our page as soon as a visitor clicks
+ * the event, so hand on nothing but http and https.
+ *
+ * @param {ICAL.Event} event The event to read the URL of
+ * @returns {string} The URL, empty when the event has none or it is not http(s)
+ */
+export function eventUrl(event) {
+  const url = event.component.getFirstPropertyValue("url") ?? "";
+
+  if (!url) {
+    return "";
+  }
+
+  try {
+    // A relative URL is resolved against the page and keeps its scheme.
+    const { protocol } = new URL(url, document.baseURI);
+
+    return protocol === "http:" || protocol === "https:" ? url : "";
+  } catch {
+    // Not a URL at all.
+    return "";
+  }
+}
+
+/**
+ * Group the occurrences that were modified on their own by the UID of the event
+ * they belong to.
+ *
+ * Unless it is told which exceptions belong to an event, ICAL.Event relates
+ * every VEVENT with a RECURRENCE-ID in the file to every recurring event, and
+ * it keys them by the recurrence id alone. Two series that meet at the same
+ * time would therefore take over each other's modifications.
+ *
+ * @param {ICAL.Component[]} components The VEVENTs of the calendar
+ * @returns {Map<string, ICAL.Component[]>} The exceptions per UID
+ */
+function exceptionsByUid(components) {
+  const exceptions = new Map();
+
+  for (const component of components) {
+    if (!component.hasProperty("recurrence-id")) {
+      continue;
+    }
+
+    const uid = component.getFirstPropertyValue("uid");
+    const ofEvent = exceptions.get(uid);
+
+    if (ofEvent) {
+      ofEvent.push(component);
+    } else {
+      exceptions.set(uid, [component]);
+    }
+  }
+
+  return exceptions;
+}
+
+/**
+ * How far the recurrences of an event have to be iterated.
+ *
+ * The iteration walks the unmodified recurrence times, so an occurrence that
+ * was moved to an earlier time is only reached through the time it originally
+ * had, which can lie past the end of the window. Keep going for as long as the
+ * largest move towards the past can still carry an occurrence into it.
+ *
+ * @param {ICAL.Event} event The event whose recurrences are iterated
+ * @param {Date} to End of the window
+ * @returns {Date} The recurrence time to stop at
+ */
+function iterationEnd(event, to) {
+  let last = to.getTime();
+
+  for (const exception of Object.values(event.exceptions)) {
+    const movedBy = exception.recurrenceId.toJSDate().getTime()
+      - exception.startDate.toJSDate().getTime();
+
+    if (movedBy > 0) {
+      last = Math.max(last, to.getTime() + movedBy);
+    }
+  }
+
+  return new Date(last);
+}
+
+/**
+ * Whether an occurrence touches a window.
+ *
+ * @param {ICAL.Time} startDate Start of the occurrence
+ * @param {ICAL.Time} endDate End of the occurrence
+ * @param {Date} from Start of the window
+ * @param {Date} to End of the window
+ * @returns {boolean} True when the two overlap
+ */
+function touches(startDate, endDate, from, to) {
+  return startDate.toJSDate() <= to && endDate.toJSDate() > from;
+}
+
+/**
+ * Load and parse the calendar of the club.
+ *
+ * @returns {Promise<ICAL.Component>} The calendar
+ */
+export async function loadCalendar() {
+  const response = await fetch(icsUrl);
+
+  // Without this an error page would be handed to the parser below, which then
+  // fails with a confusing complaint about the calendar syntax.
+  if (!response.ok) {
+    throw new Error(`${icsUrl}: ${response.status} ${response.statusText}`);
+  }
+
+  return new ICAL.Component(ICAL.parse(await response.text()));
+}
+
+/**
+ * Every occurrence of the calendar that touches the given window.
+ *
+ * A recurring event is expanded, and an occurrence that was modified on its own
+ * is reported with the time, the name and the URL of that modification.
+ *
+ * @param {ICAL.Component} calendar The parsed calendar
+ * @param {Date} from An occurrence has to still be running at this time
+ * @param {Date} to An occurrence has to have started by this time
+ * @yields {{event: ICAL.Event, startDate: ICAL.Time, endDate: ICAL.Time}}
+ */
+export function* occurrencesBetween(calendar, from, to) {
+  const components = calendar.getAllSubcomponents("vevent");
+  const exceptions = exceptionsByUid(components);
+
+  for (const component of components) {
+    // Occurrences modified via RECURRENCE-ID are reached through the event they
+    // belong to, handling them here as well would report them twice.
+    if (component.hasProperty("recurrence-id")) {
+      continue;
+    }
+
+    const event = new ICAL.Event(component, {
+      exceptions: exceptions.get(component.getFirstPropertyValue("uid")) ?? [],
+    });
+
+    if (!event.startDate) {
+      continue;
+    }
+
+    if (!event.isRecurring()) {
+      if (touches(event.startDate, event.endDate, from, to)) {
+        yield { event, startDate: event.startDate, endDate: event.endDate };
+      }
+
+      continue;
+    }
+
+    const iterator = event.iterator();
+    const iterateUntil = iterationEnd(event, to);
+
+    while (true) {
+      const occurrence = iterator.next();
+
+      // Recurrences are chronological, so we are done once one starts after the
+      // window, and after the occurrences a modification can still move back
+      // into it.
+      if (!occurrence || occurrence.toJSDate() > iterateUntil) {
+        break;
+      }
+
+      // Details resolve time, name and URL of an occurrence that was modified
+      // via RECURRENCE-ID.
+      const details = event.getOccurrenceDetails(occurrence);
+
+      // A modification may have moved the occurrence out of the window, so
+      // judge it by the time it really takes place at.
+      if (touches(details.startDate, details.endDate, from, to)) {
+        yield {
+          event: details.item,
+          startDate: details.startDate,
+          endDate: details.endDate,
+        };
+      }
+    }
+  }
+}

assets/js/upcoming.js

@@ -0,0 +1,105 @@
+import { eventUrl, loadCalendar, occurrencesBetween } from "./events.js";
+
+/**
+ * When an occurrence starts, as a point in time.
+ *
+ * A date has no time and no zone, its digits are the day itself. toJSDate()
+ * reads them as midnight in the zone of the browser, which moves an all day
+ * event by the offset that zone has to Berlin and, far enough east or west,
+ * onto the day before or after. Keep the digits and read them as UTC instead,
+ * the table prints an all day event in UTC as well.
+ *
+ * @param {ICAL.Time} time Start of the occurrence
+ * @returns {Date} The point in time to sort and print by
+ */
+function startOf(time) {
+  if (time.isDate) {
+    return new Date(Date.UTC(time.year, time.month - 1, time.day));
+  }
+
+  return time.toJSDate();
+}
+
+/**
+ * The upcoming occurrences of a calendar.
+ *
+ * @param {ICAL.Component} calendar The parsed calendar
+ * @param {Date} now Events must still be running at this date
+ * @param {number} maxEvents Maximum number of events to return
+ * @param {number} maxDays Maximum number of days into the future
+ * @returns {{start: Date, allDay: boolean, name: string, url: string}[]} url is empty when the event has no URL
+ */
+function getUpcomingEvents(calendar, now, maxEvents, maxDays) {
+  const end = new Date(now.getTime());
+  end.setDate(end.getDate() + maxDays);
+
+  const events = [];
+
+  // A running event stays listed until it is over, so the window starts at now
+  // and the walk keeps everything that has not ended yet.
+  for (const { event, startDate } of occurrencesBetween(calendar, now, end)) {
+    events.push({
+      start: startOf(startDate),
+      allDay: startDate.isDate,
+      name: event.summary ?? "",
+      url: eventUrl(event),
+    });
+  }
+
+  // We have occurrences from multiple events, so sort them
+  // before applying the maximum event count.
+  events.sort((a, b) => a.start - b.start);
+
+  return events.slice(0, maxEvents);
+}
+
+document.addEventListener("DOMContentLoaded", () => {
+  const max_days = 20;
+  const max_items = 5;
+
+  const now = new Date();
+
+  const table = document.getElementById("upcoming");
+  loadCalendar()
+    .then(calendar => {
+      getUpcomingEvents(calendar, now, max_items, max_days).forEach(event => {
+        const row = document.createElement("tr");
+
+        const colBegin = document.createElement("td");
+
+        // The events take place in Berlin, so name their time in Berlin time
+        // instead of in the time zone the visitor happens to be in. An all day
+        // event has no time of day and carries its date in UTC, see startOf().
+        const whenFormat = event.allDay
+          ? { timeZone: "UTC" }
+          : { timeZone: "Europe/Berlin", hour: "2-digit", minute: "2-digit" };
+
+        const formattedStart = event.start.toLocaleString("de-DE", {
+          weekday: "long",
+          day: "2-digit",
+          month: "2-digit",
+          ...whenFormat,
+        });
+
+        colBegin.innerText = event.allDay ? formattedStart : `${formattedStart} Uhr`;
+        row.appendChild(colBegin);
+
+        const colName = document.createElement("td");
+
+        if (event.url) {
+          const a = document.createElement("a");
+          a.href = event.url;
+          a.text = event.name;
+
+          colName.appendChild(a);
+        } else {
+          colName.innerText = event.name;
+        }
+
+        row.appendChild(colName);
+
+        table.appendChild(row);
+      });
+    })
+    .catch(err => console.error("Fehler beim Laden der Termine:", err));
+});

assets/js/vendor/README.md

@@ -0,0 +1,19 @@
+# Vendored JavaScript
+
+Third party code is checked in here instead of being loaded from a CDN, so that the website does not make the visitor's
+browser fetch anything from an external server.
+
+Hugo bundles and minifies these files into the scripts that reference them, so the unminified source is checked in.
+
+## ical.js
+
+- Version: 2.2.1
+- Source: <https://unpkg.com/ical.js@2.2.1/dist/ical.js>
+- Upstream: <https://github.com/kewisch/ical.js>
+- License: MPL-2.0 (see the header of `ical.js`)
+
+To update, download the `dist/ical.js` of the wanted release and replace the file, keeping the version above in sync:
+
+```shell
+curl -o assets/js/vendor/ical.js https://unpkg.com/ical.js@<version>/dist/ical.js
+```

content/_index.md

@@ -25,9 +25,6 @@ description: "Startseite CCCB mit Kurzkalender"
 
 ### Nächste Veranstaltungen
 
-<table id="upcoming" class="table table-condensed">
-</table>
+{{< upcoming >}}
 
 Weitere Termine findest du im [Veranstaltungskalender](/verein/calendar/).
-
-<script type="module" src="/js/upcoming.js"></script>

layouts/shortcodes/calendar.html

@@ -1,12 +1,12 @@
-{{ $js := resources.Get "js/calendar.js" }}
-{{ $css := resources.Get "css/calendar.css" }}
+{{ $js := resources.Get "js/calendar.js" | js.Build (dict "minify" true "format" "esm" "target" "es2020") | fingerprint }}
+{{ $css := resources.Get "css/calendar.css" | minify | fingerprint }}
 
 <div class="calendar-container">
   {{ with $css }}
-    <link rel="stylesheet" href="{{ .RelPermalink }}">
+    <link rel="stylesheet" href="{{ .RelPermalink }}" integrity="{{ .Data.Integrity }}">
   {{ end }}
   {{ with $js }}
-    <script src="{{ .RelPermalink }}"></script>
+    <script type="module" src="{{ .RelPermalink }}" integrity="{{ .Data.Integrity }}"></script>
   {{ end }}
   
   <div id="calendar">

layouts/shortcodes/upcoming.html

@@ -0,0 +1,5 @@
+{{- $css := resources.Get "css/upcoming.css" | minify | fingerprint -}}
+{{- $js := resources.Get "js/upcoming.js" | js.Build (dict "minify" true "format" "esm" "target" "es2020") | fingerprint -}}
+<link rel="stylesheet" href="{{ $css.RelPermalink }}" integrity="{{ $css.Data.Integrity }}">
+<table id="upcoming" class="table table-condensed"></table>
+<script type="module" src="{{ $js.RelPermalink }}" integrity="{{ $js.Data.Integrity }}"></script>

static/js/upcoming.js

@@ -1,113 +0,0 @@
-import ICAL from "https://unpkg.com/ical.js/dist/ical.min.js";
-
-/**
- * Parse an ICS calendar and return upcoming event occurrences.
- *
- * @param {string} icsText The contents of the .ics file
- * @param {Date} now Events must start after this date
- * @param {number} maxEvents Maximum number of events to return
- * @param {number} maxDays Maximum number of days into the future
- * @returns {{start: Date, name: string, url: string}[]}
- */
-function getUpcomingEvents(icsText, now, maxEvents, maxDays) {
-  const jcal = ICAL.parse(icsText);
-  const calendar = new ICAL.Component(jcal);
-
-  const end = new Date(now.getTime());
-  end.setDate(end.getDate() + maxDays);
-
-  const events = [];
-
-  for (const component of calendar.getAllSubcomponents("vevent")) {
-    const event = new ICAL.Event(component);
-
-    if (!event.startDate) {
-      continue;
-    }
-
-    if (event.isRecurring()) {
-      const iterator = event.iterator();
-
-      while (true) {
-        const occurrence = iterator.next();
-
-        if (!occurrence) {
-          break;
-        }
-
-        const start = occurrence.toJSDate();
-
-        // Recurrences are chronological, so we're done
-        // once we pass the end of our search window.
-        if (start > end) {
-          break;
-        }
-
-        if (start > now) {
-          events.push({
-            start,
-            name: event.summary ?? "",
-            url: event.url ?? "",
-          });
-        }
-      }
-    } else {
-      const start = event.startDate.toJSDate();
-
-      if (start > now && start <= end) {
-        events.push({
-          start,
-          name: event.summary ?? "",
-          url: event.url ?? "",
-        });
-      }
-    }
-  }
-
-  // We have occurrences from multiple events, so sort them
-  // before applying the maximum event count.
-  events.sort((a, b) => a.start - b.start);
-
-  return events.slice(0, maxEvents);
-}
-
-document.addEventListener("DOMContentLoaded", () => {
-  const ics = "/calendars/all.ics";
-  const max_days = 20;
-  const max_items = 5;
-
-  const now = new Date();
-
-  const table = document.getElementById("upcoming");
-  fetch(ics)
-    .then(response => response.text())
-    .then(icsText => {
-      getUpcomingEvents(icsText, now, max_items, max_days).forEach(event => {
-        const row = document.createElement("tr");
-
-        const colBegin = document.createElement("td");
-
-        const formattedStart = event.start.toLocaleString("de-DE", {
-          weekday: "long",
-          day: "2-digit",
-          month: "2-digit",
-          hour: "2-digit",
-          minute: "2-digit",
-        }).replace(",", "");
-
-        colBegin.innerText = `${formattedStart.replace(" ", ", ")} Uhr`;
-        row.appendChild(colBegin);
-
-        const colName = document.createElement("td");
-
-        const a = document.createElement("a");
-        a.href = event.url;
-        a.text = event.name;
-
-        colName.appendChild(a);
-        row.appendChild(colName);
-
-        table.appendChild(row);
-      });
-    });
-});