add script to create bank holidays

scripts/generate_feiertage.py

@@ -0,0 +1,249 @@
+#!/usr/bin/env python3
+"""Generate Feiertage and Ferien ICS files for all 16 German Bundesländer."""
+
+import argparse
+import hashlib
+import json
+import os
+import urllib.parse
+import urllib.request
+from datetime import date, datetime, timedelta, timezone
+
+
+PRODID = "ics.tools skjerns patch"
+URL = "https://ics.tools"
+FEIERTAGE_API = "https://feiertage-api.de/api/"
+FERIEN_API = "https://openholidaysapi.org/SchoolHolidays"
+MAX_BATCH_DAYS = 1000
+
+# feiertage-api.de land codes
+FEIERTAGE_CODES = {
+    "baden-württemberg":      "BW",
+    "bayern":                 "BY",
+    "berlin":                 "BE",
+    "brandenburg":            "BB",
+    "bremen":                 "HB",
+    "hamburg":                "HH",
+    "hessen":                 "HE",
+    "mecklenburg-vorpommern": "MV",
+    "niedersachsen":          "NI",
+    "nordrhein-westfalen":    "NW",
+    "rheinland-pfalz":        "RP",
+    "saarland":               "SL",
+    "sachsen-anhalt":         "ST",
+    "sachsen":                "SN",
+    "schleswig-holstein":     "SH",
+    "thüringen":              "TH",
+}
+
+# openholidaysapi.org subdivision codes
+SUBDIVISION_CODES = {
+    "baden-württemberg":      "DE-BW",
+    "bayern":                 "DE-BY",
+    "berlin":                 "DE-BE",
+    "brandenburg":            "DE-BB",
+    "bremen":                 "DE-HB",
+    "hamburg":                "DE-HH",
+    "hessen":                 "DE-HE",
+    "mecklenburg-vorpommern": "DE-MV",
+    "niedersachsen":          "DE-NI",
+    "nordrhein-westfalen":    "DE-NW",
+    "rheinland-pfalz":        "DE-RP",
+    "saarland":               "DE-SL",
+    "sachsen-anhalt":         "DE-ST",
+    "sachsen":                "DE-SN",
+    "schleswig-holstein":     "DE-SH",
+    "thüringen":              "DE-TH",
+}
+
+STATES = list(FEIERTAGE_CODES.keys())
+
+
+def fetch_feiertage_api(land_code: str, year: int) -> list[tuple[date, str]]:
+    """Fetch public holidays from feiertage-api.de for a given state and year."""
+    params = urllib.parse.urlencode({"jahr": year, "nur_land": land_code})
+    req = urllib.request.Request(
+        f"{FEIERTAGE_API}?{params}",
+        headers={"Accept": "application/json"},
+    )
+    with urllib.request.urlopen(req) as resp:
+        data = json.loads(resp.read())
+    return sorted(
+        (date.fromisoformat(v["datum"]), name)
+        for name, v in data.items()
+    )
+
+
+def make_uid(summary: str, dtstart: date) -> str:
+    raw = f"{summary}{dtstart.strftime('%Y%m%d')}"
+    return hashlib.sha256(raw.encode()).hexdigest()[:8]
+
+
+def ics_fold(line: str) -> str:
+    """RFC 5545 line folding: max 75 octets per line, continuation with CRLF + space."""
+    encoded = line.encode("utf-8")
+    if len(encoded) <= 75:
+        return line
+    chunks = []
+    pos = 0
+    limit = 75
+    while pos < len(encoded):
+        chunks.append(encoded[pos:pos + limit].decode("utf-8", errors="ignore"))
+        pos += limit
+        limit = 74  # continuation lines have 1 char less (the leading space)
+    return "\r\n ".join(chunks)
+
+
+def vevent(summary: str, dtstart: date, dtend: date, timestamp: str) -> str:
+    uid = make_uid(summary, dtstart)
+    lines = [
+        "BEGIN:VEVENT",
+        f"DTSTART;VALUE=DATE:{dtstart.strftime('%Y%m%d')}",
+        f"DTEND;VALUE=DATE:{dtend.strftime('%Y%m%d')}",
+        f"SUMMARY:{summary}",
+        ics_fold(f"UID:{uid}"),
+        f"URL:{URL}",
+        f"CREATED:{timestamp}",
+        f"LAST-MODIFIED:{timestamp}",
+        f"DTSTAMP:{timestamp}",
+        "TRANSP:TRANSPARENT",
+        "END:VEVENT",
+    ]
+    return "\r\n".join(lines)
+
+
+def write_feiertage(state: str, year_start: int, year_end: int,
+                    output_dir: str, timestamp: str) -> None:
+    cal_name = f"{state.title()} Feiertage"
+    code = FEIERTAGE_CODES[state]
+    events = []
+    for year in range(year_start, year_end + 1):
+        for day, name in fetch_feiertage_api(code, year):
+            dtend = day + timedelta(days=1)
+            events.append(vevent(name, day, dtend, timestamp))
+
+    parts = [
+        "BEGIN:VCALENDAR",
+        "VERSION:2.0",
+        f"PRODID:{PRODID}",
+        *events,
+        f"NAME:{cal_name}",
+        f"X-WR-CALNAME:{cal_name}",
+        "METHOD:PUBLISH",
+        "END:VCALENDAR",
+    ]
+    content = "\r\n".join(parts) + "\r\n"
+
+    os.makedirs(output_dir, exist_ok=True)
+    out_path = os.path.join(output_dir, f"{state}.ics")
+    with open(out_path, "w", encoding="utf-8") as f:
+        f.write(content)
+    print(f"  → {out_path}")
+
+
+def fetch_ferien_api(subdivision_code: str, from_date: date, to_date: date) -> list[dict]:
+    """Fetch school holidays from OpenHolidays API in batches of at most MAX_BATCH_DAYS days."""
+    results = []
+    current = from_date
+    while current <= to_date:
+        batch_end = min(current + timedelta(days=MAX_BATCH_DAYS - 1), to_date)
+        params = urllib.parse.urlencode({
+            "countryIsoCode": "DE",
+            "subdivisionCode": subdivision_code,
+            "validFrom": current.strftime("%Y-%m-%d"),
+            "validTo":   batch_end.strftime("%Y-%m-%d"),
+        })
+        req = urllib.request.Request(
+            f"{FERIEN_API}?{params}",
+            headers={"Accept": "application/json"},
+        )
+        with urllib.request.urlopen(req) as resp:
+            results.extend(json.loads(resp.read()))
+        current = batch_end + timedelta(days=1)
+
+    # Deduplicate entries that appear in overlapping batch windows
+    seen: set[tuple] = set()
+    unique = []
+    for item in results:
+        key = (item["startDate"], item["endDate"])
+        if key not in seen:
+            seen.add(key)
+            unique.append(item)
+    return unique
+
+
+def german_name(name_list: list[dict]) -> str:
+    for entry in name_list:
+        if entry.get("language") == "DE":
+            return entry["text"]
+    return name_list[0]["text"] if name_list else "Ferien"
+
+
+def write_ferien(state: str, year_start: int, year_end: int,
+                 output_dir: str, timestamp: str) -> None:
+    code = SUBDIVISION_CODES[state]
+    state_title = state.title()
+    cal_name = f"{state_title} Ferien"
+
+    print(f"  {state} ({code}) ...", end="", flush=True)
+    holidays = fetch_ferien_api(code, date(year_start, 1, 1), date(year_end, 12, 31))
+    print(f" {len(holidays)} entries")
+
+    events = []
+    for h in sorted(holidays, key=lambda x: x["startDate"]):
+        name = german_name(h["name"])
+        start = date.fromisoformat(h["startDate"])
+        # API endDate is the last inclusive day; ICS DTEND is exclusive
+        end = date.fromisoformat(h["endDate"]) + timedelta(days=1)
+        summary = f"{name} {start.year} {state_title}"
+        events.append(vevent(summary, start, end, timestamp))
+
+    parts = [
+        "BEGIN:VCALENDAR",
+        "VERSION:2.0",
+        f"PRODID:{PRODID}",
+        *events,
+        f"NAME:{cal_name}",
+        f"X-WR-CALNAME:{cal_name}",
+        "METHOD:PUBLISH",
+        "END:VCALENDAR",
+    ]
+    content = "\r\n".join(parts) + "\r\n"
+
+    os.makedirs(output_dir, exist_ok=True)
+    out_path = os.path.join(output_dir, f"{state}.ics")
+    with open(out_path, "w", encoding="utf-8") as f:
+        f.write(content)
+    print(f"  → {out_path}")
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Generate Feiertage and Ferien ICS files for all German Bundesländer."
+    )
+    parser.add_argument("--year_start", type=int, required=True, help="First year (inclusive)")
+    parser.add_argument("--year_end",   type=int, required=True, help="Last year (inclusive)")
+    parser.add_argument("--feiertage_dir", default="Feiertage",
+                        help="Output directory for Feiertage (default: Feiertage/)")
+    parser.add_argument("--ferien_dir", default="Ferien",
+                        help="Output directory for Ferien (default: Ferien/)")
+    args = parser.parse_args()
+
+    if args.year_start > args.year_end:
+        parser.error("year_start must be <= year_end")
+
+    timestamp = datetime.now(timezone.utc).strftime("%Y%m%dT%H%M%SZ")
+
+    print(f"Generating Feiertage {args.year_start}–{args.year_end} → {args.feiertage_dir}/")
+    for state in STATES:
+        write_feiertage(state, args.year_start, args.year_end, args.feiertage_dir, timestamp)
+
+    print(f"\nFetching Ferien {args.year_start}–{args.year_end} → {args.ferien_dir}/")
+    for state in STATES:
+        write_ferien(state, args.year_start, args.year_end, args.ferien_dir, timestamp)
+
+    print("Done.")
+
+
+if __name__ == "__main__":
+    main()