support building a timetable without untis specifying the lesson's periods

Move all untis related configuration into the webuntis section.

1 files changed, 100 insertions, 30 deletions

diff --git a/lessons.py b/lessons.py
index 71a90e6..6ac20ea 100755
--- a/lessons.py
+++ b/lessons.py
@@ -17,8 +17,21 @@ import toml
 import webuntis
 
 
+def die(msg: str, status=1) -> t.NoReturn:
+    """print a message and exit"""
+    print(msg, file=sys.stderr)
+    sys.exit(status)
+
+
+@dataclass
+class Period:
+    """Data representing a period where a lesson could take place"""
+    start: datetime.datetime
+    code = None
+
+
 @dataclass
-class SessionCredentials:
+class WebuntisSessionCredentials:
     """Data required to create a new webuntis session"""
     school: str
     server: str
@@ -142,6 +155,46 @@ def filter_periods(timetable: webuntis.objects.PeriodList,
     ]
 
 
+DAYS_MAP = {'Mo': 1, 'Di': 2, 'Mi': 3, 'Do': 4, 'Fr': 5}
+
+TIME_SLOTS = {
+    '1': datetime.timedelta(hours=8),
+    '2': datetime.timedelta(hours=8, minutes=45),
+    '3': datetime.timedelta(hours=9, minutes=45),
+    '4': datetime.timedelta(hours=10, minutes=30),
+    '5': datetime.timedelta(hours=11, minutes=30),
+    '6': datetime.timedelta(hours=12, minutes=15),
+    '7': datetime.timedelta(hours=13),
+    '8': datetime.timedelta(hours=13, minutes=45),
+    '9': datetime.timedelta(hours=14, minutes=30),
+    '10': datetime.timedelta(hours=15, minutes=20),
+    '11': datetime.timedelta(hours=16),
+    '12': datetime.timedelta(hours=16, minutes=45),
+}
+
+
+def build_periods(config: str, start: datetime.datetime,
+                  end: datetime.datetime) -> list[Period]:
+    """Build a list of periods from a configuration string"""
+
+    periods = []
+    week = start.isocalendar().week
+    while True:
+        year = start.year if week >= start.isocalendar().week else end.year
+        for period in config.split(';'):
+            weekday, slot = period.split(':')
+            period_day = datetime.datetime.fromisocalendar(
+                year=year, week=week, day=DAYS_MAP[weekday])
+            period_start = period_day + TIME_SLOTS[slot]
+            periods.append(Period(period_start))
+
+        week = week % 52 + 1
+        if week > end.isocalendar().week and year == end.isocalendar().year:
+            break
+
+    return periods
+
+
 def main():
     """Programm entry point loading data from webuntis and printing the remaining lessons"""
     parser = argparse.ArgumentParser()
@@ -156,6 +209,10 @@ def main():
     parser.add_argument('--subject',
                         help='The subject abbreviation used in webuntis')
     parser.add_argument('--class', help='The class name')
+    parser.add_argument('--periods',
+                        help=('The periods when you teach the class.'
+                              'Format: <Day>:<Slot>[;<Day><Slot>]*'),
+                        type=str)
     parser.add_argument('--show-events',
                         action='store_true',
                         help='Show ICS calendar events during the lessons')
@@ -168,35 +225,48 @@ def main():
     config.update({k: v for k, v in args.__dict__.items() if v})
 
     if 'class' not in config or 'subject' not in config:
-        print('Class and subject must be provided')
-        sys.exit(1)
-
-    # use the webuntis username as teacher fallback
-    if 'teacher' not in config:
-        config['teacher'] = config['username']
-
-    session_info = SessionCredentials(config)
-    with webuntis.Session(useragent="muhq's avail-lessons script",
-                          **session_info.__dict__).login() as session:
-
-        # Unfortunately pylint does not understand the type (_itemclass)
-        # of the webuntis ListResults, therfore we supress the errors when
-        # accessing members of the _itemclass.
-        year = [
-            y for y in session.schoolyears()
-            if y.start <= config['start'] <= y.end  # pylint: disable=no-member
-        ][0]
-
-        if 'end' not in config:
-            config['end'] = year.end
-
-        klasse = session.klassen().filter(name=config['class'])[0]  # pylint: disable=no-member
-
-        timetable = session.timetable_extended(klasse=klasse,
-                                               start=config['start'],
-                                               end=config['end'])
-
-        periods = filter_periods(timetable, config)
+        die('Class and subject must be provided')
+
+    periods = None
+    if 'webuntis' in config:
+        # use the webuntis username as teacher fallback
+        if 'teacher' not in config:
+            config['teacher'] = config['webuntis']['username']
+
+        session_info = WebuntisSessionCredentials(config['webuntis'])
+        with webuntis.Session(useragent="muhq's avail-lessons script",
+                              **session_info.__dict__).login() as session:
+
+            # Unfortunately pylint does not understand the type (_itemclass)
+            # of the webuntis ListResults, therfore we supress the errors when
+            # accessing members of the _itemclass.
+            year = [
+                y for y in session.schoolyears()
+                if y.start <= config['start'] <= y.end  # pylint: disable=no-member
+            ]
+            if not year:
+                die('No school year is active')
+            year = year[0]
+
+            if 'end' not in config:
+                config['end'] = year.end
+
+            klasse = session.klassen().filter(name=config['class'])[0]  # pylint: disable=no-member
+
+            timetable = session.timetable_extended(klasse=klasse,
+                                                   start=config['start'],
+                                                   end=config['end'])
+
+            periods = filter_periods(timetable, config)
+    elif args.periods:
+        start = config.setdefault(
+            'start', datetime.datetime.fromisocalendar(2023, 37, 2))
+        end = config.setdefault('end',
+                                datetime.datetime.fromisocalendar(2024, 30, 5))
+        periods = build_periods(args.periods, start, end)
+
+    if not periods:
+        die('Webuntis credentials or manual periods must be provided')
 
     # load ICS events
     evs = load_events(config)