add script

Author: Gerit Wagner

src/update_calendar.py

@@ -0,0 +1,132 @@
+#!/usr/bin/env python3
+from __future__ import annotations
+
+import uuid
+from pathlib import Path
+from datetime import datetime, timedelta
+
+import yaml
+from dateutil import rrule
+from dateutil.parser import isoparse
+from zoneinfo import ZoneInfo
+
+from icalendar import Calendar, Event
+
+
+BERLIN = ZoneInfo("Europe/Berlin")
+
+
+def parse_dt(value: str) -> datetime:
+    """
+    Accepts:
+      - "YYYY-MM-DD HH:MM"
+      - ISO strings like "2025-01-17T13:00:00Z" / "2025-01-17T13:00:00+01:00"
+    Returns timezone-aware datetime in Europe/Berlin.
+    """
+    value = value.strip()
+    if "T" in value:  # ISO-ish
+        dt = isoparse(value)
+        if dt.tzinfo is None:
+            dt = dt.replace(tzinfo=BERLIN)
+        return dt.astimezone(BERLIN)
+
+    # "YYYY-MM-DD HH:MM"
+    dt = datetime.strptime(value, "%Y-%m-%d %H:%M")
+    return dt.replace(tzinfo=BERLIN)
+
+
+def expand_events(events: list[dict]) -> list[dict]:
+    expanded: list[dict] = []
+
+    for ev in events:
+        start = parse_dt(ev["start"])
+        end = parse_dt(ev["end"])
+        duration = end - start
+
+        if "recurrence" in ev and ev["recurrence"]:
+            # RRULE.parseString equivalent:
+            rule = rrule.rrulestr(ev["recurrence"], dtstart=start)
+
+            for occ_start in rule:
+                occ_end = occ_start + duration
+                expanded.append(
+                    {
+                        "start": occ_start,
+                        "end": occ_end,
+                        "title": ev.get("title", ""),
+                        "location": ev.get("location", ""),
+                        "description": ev.get("description", ""),
+                        "color": ev.get("color", ""),
+                    }
+                )
+        else:
+            expanded.append(
+                {
+                    "start": start,
+                    "end": end,
+                    "title": ev.get("title", ""),
+                    "location": ev.get("location", ""),
+                    "description": ev.get("description", ""),
+                    "color": ev.get("color", ""),
+                }
+            )
+
+    return expanded
+
+
+def generate_ical(events: list[dict]) -> str:
+    cal = Calendar()
+    cal.add("prodid", "-//Digital Work Lab//Calendar Export Tool//EN")
+    cal.add("version", "2.0")
+    cal.add("calscale", "GREGORIAN")
+    cal.add("method", "PUBLISH")
+    # Optional: many clients ignore this, but harmless
+    cal.add("x-published-ttl", "PT1H")
+
+    now_utc = datetime.now(tz=ZoneInfo("UTC"))
+
+    for ev in events:
+        e = Event()
+        e.add("uid", f"{uuid.uuid4()}@digital-work-lab")
+        e.add("dtstamp", now_utc)
+        e.add("summary", ev.get("title", "") or " ")
+        e.add("dtstart", ev["start"])
+        e.add("dtend", ev["end"])
+
+        desc = ev.get("description") or ""
+        loc = ev.get("location") or ""
+        if desc:
+            e.add("description", desc)
+        if loc:
+            e.add("location", loc)
+
+        # NOTE: "color" is not a standard iCalendar VEVENT property.
+        # Some clients support non-standard props like COLOR or CATEGORIES.
+        # If you want to encode it anyway:
+        if ev.get("color"):
+            e.add("x-apple-calendar-color", ev["color"])
+            e.add("color", ev["color"])  # non-standard, but some tools read it
+
+        cal.add_component(e)
+
+    return cal.to_ical().decode("utf-8")
+
+
+def main() -> None:
+    yaml_path = Path("./data/events.yaml")
+    out_path = Path("assets/calendar/fs-ise.ical")
+    out_path.parent.mkdir(parents=True, exist_ok=True)
+
+    raw = yaml.safe_load(yaml_path.read_text(encoding="utf-8"))
+    if not isinstance(raw, list):
+        raise ValueError("Parsed YAML is not a list")
+
+    expanded = expand_events(raw)
+    ical_text = generate_ical(expanded)
+
+    out_path.write_text(ical_text, encoding="utf-8")
+    print(f"Wrote {len(expanded)} events to {out_path}")
+
+
+if __name__ == "__main__":
+    main()