created CalendarParser class

remindme_caldav.py

@@ -13,6 +13,18 @@ import humanfriendly
 from pathlib import Path
 import argparse
 import textwrap
+import logging
+
+def setup_logger(loglevel):
+    """Setup basic logging."""
+    loglevel = getattr(logging, loglevel.upper(), None)
+    
+    if not isinstance(loglevel, int):
+        raise ValueError('Invalid log level: %s' % loglevel)
+        
+    logging.basicConfig(filename='app.log', filemode='w', format='%(name)s - %(levelname)s - %(message)s')
+    logger = logging.getLogger()
+    logger.setLevel(loglevel)
 
 def parse_args():
     """Parse command line arguments."""
@@ -39,6 +51,9 @@ def parse_toml(content):
         print(e)                                               
         sys.exit(1)  # Exit with error code                    
 
+def calculate_event_hash(event):
+    return hashlib.md5(json.dumps(event, sort_keys=True, cls=DateTimeEncoder).encode()).hexdigest()
+
 class DateTimeEncoder(json.JSONEncoder):
     def default(self, o):
         if isinstance(o, (dt.datetime, dt.timedelta)):
@@ -50,29 +65,11 @@ class FileChangeHandler(FileSystemEventHandler):
     `FileChangeHandler` is a custom event handler for the
     `watchdog.observers.Observer` class that handles file system events such as
     file modifications, deletions and creations.
-
-    It inherits from `watchdog.events.FileSystemEventHandler` providing methods
-    to handle these events: `on_modified`, `on_deleted`, and `on_created`. Each
-    method is overridden for specific functionality when a file system event
-    occurs.
-
-    The class also includes a method `calculate_event_hash` that generates an
-    MD5 hash for each event dictionary based on its contents. This is used to
-    track changes in the events and determine if they have been modified or
-    deleted.
-    
-    For example, when a file is modified:
-    - It reads the content of the file, parses it into an event dictionary
-      using `calendar_parser`.
-    - Calculates the hash for the event and checks if there's already an
-      existing event with the same UID in `event_list`.
-    - If there is one, it compares the new hash with the old hash. If they
-      differ, it prints that the event has been modified or deleted. Otherwise,
-      it prints that the event hasn't been modified.
-    
-    For file deletion and creation, similar operations are performed but
-    without comparison of hashes.
     """
+    def __init__(self, event_list):
+        self.calendar_parser = CalendarParser()  # Create an instance of CalendarParser
+        self.event_list = event_list   
+
     def on_modified(self, event):
         print(f"File modified: {event.src_path}")
         if not event.is_directory:    
@@ -84,7 +81,7 @@ class FileChangeHandler(FileSystemEventHandler):
                 return
             
             try:
-                event_dict = calendar_parser(cal_str)
+                event_dict = self.calendar_parser.parse_calendar(cal_str)  # Use the instance to call parse_calendar method
             except Exception as i:
                 print("Failed to parse calendar event at: {}.\n Error:\n{}".format(event.src_path,i))
                 return 
@@ -110,7 +107,7 @@ class FileChangeHandler(FileSystemEventHandler):
                 return
                 
             try:
-                event_dict = calendar_parser(cal_str)
+                event_dict = self.calendar_parser.parse_calendar(cal_str)  # Use the instance to call parse_calendar method
             except Exception as i:
                 print("Failed to parse calendar event at: {}.\n Error:\n{}".format(event.src_path,i))
                 return 
@@ -119,175 +116,111 @@ class FileChangeHandler(FileSystemEventHandler):
     
     def handle_modified(self, old_event, event_dict, remove=False):
         if not remove:
-            for i, old_event in enumerate(event_list):
+            for i, old_event in enumerate(self.event_list):
                 if old_event["uid"] == event_dict["uid"]:  
                     old_hash = old_event["hash"]
                     
-                    new_hash = self.calculate_event_hash(event_dict)
+                    new_hash = calculate_event_hash(event_dict)
                     if new_hash != old_hash:    
                         print("Event with UID {} has been modified or deleted".format(old_event["uid"]))
                         
-                        event_list[i] = event_dict
+                        self.event_list[i] = event_dict
                     else:   
                         print("Event with UID {} hasn't been modified".format(old_event["uid"]))
                     
                     break
             else:    
-                event_list.append(event_dict)
+                self.event_list.append(event_dict)
         else:   # If remove is True, remove the event from the list
-            for i, old_event in enumerate(event_list):
+            for i, old_event in enumerate(self.event_list):
                 if old_event["uid"] == event_dict["uid"]:   
                     print("Event with UID {} has been deleted".format(old_event["uid"]))
                     
-                    del event_list[i]
+                    del self.event_list[i]
                     break
 
-    def calculate_event_hash(self, event):
-        return hashlib.md5(json.dumps(event, sort_keys=True, cls=DateTimeEncoder).encode()).hexdigest()
 
-def generate_recurring_event_dates(dtstart, rrule):
+class RecurringEventGenerator:
-    """
+    def __init__(self, dtstart, rrule):
-    Generate recurring event dates based on a start date and an RRULE.
+        self.dtstart = dtstart
-
+        self.rrule = rrule
-    This function takes in a start date (`dtstart`) and an RRULE (`rrule`),
+        self.recur_info = {
-    which is used to generate future dates according to the rules specified by
-    the RRULE.
-
-    If no count rule is present, it generates a date array from `dtstart` to
-    the current datetime, then adds an arbitrary number of dates into the
-    future (here it's 10). This is done because generating a date array using
-    the rrulestr function without a count rule will return a very large number
-    of elements.
-
-    The function returns a dictionary containing information about the
-    recurring event:
-      - `recur_dates`: A list of future dates generated by the RRULE.
-      - `infinite_recur`: Boolean indicating whether the recurrence is infinite.
-      - `recur_freq`: The frequency of the recurrence (e.g., 'DAILY').
-      - `recur_interval`: The interval between each occurrence of the event.
-      - `n_recur_dates_left`: The number of future dates left.
-
-    Parameters:
-        dtstart (datetime): The start date of the recurring event.
-        rrule (rrule): The RRULE object specifying the recurrence rules.
-
-    Returns:
-        dict: A dictionary containing information about the recurring event
-        dates, frequency, interval and count.
-    """
-    recur_info = {
             "recur_dates": [dtstart], 
             "infinite_recur": False,
             "recur_freq": None,
             "recur_interval": None,
             "n_recur_dates_left": None
-    }
-    if rrule is None:
-        return recur_info
-    rule_str = "RRULE:{}".format(rrule.to_ical().decode('utf-8'))
-    start_date = dtstart
-    infinite_recur = False
-    freq = rrule.get('FREQ')[0]
-    count = rrule.get("COUNT")
-    interval = rrule.get('INTERVAL')[0]
-    current_date = dt.datetime.now().replace(tzinfo=pytz.UTC)
-
-    if count is None:# or until is not None:
-            
-        delta = None
-    
-        if freq == "DAILY":
-            delta = relativedelta(days=interval)
-        elif freq == "MONTHLY":
-            delta = relativedelta(months=interval)
-        elif freq == "YEARLY":
-            delta = relativedelta(years=interval)
-        
-        count = 0
-        origin_date = start_date
-        while origin_date < current_date:
-            count += interval
-            origin_date += delta*interval
-           
-        rule_str += ";COUNT={}".format(count+10)
-        infinite_recur = True
-        
-    ruleset = rrulestr(rule_str, dtstart=start_date)
-    
-    recur_dates = [None]
-    n_recur = None
-    dates = list(ruleset) # Generate future dates according to the rules
-    recur_dates = [i for i in dates if i >= current_date]
-    n_recur = "inf" if infinite_recur is True else len(recur_dates) 
-
-    recur_info["recur_dates"] = recur_dates
-    recur_info["infinite_recur"] = infinite_recur
-    recur_info["recur_freq"] = freq
-    recur_info["recur_interval"] = interval
-    recur_info["n_recur_dates_left"] = n_recur
-    return recur_info
-
-def calendar_parser(cal_str):
-    # Parse the calendar
-    cal = Calendar.from_ical(cal_str)
-
-    # Iterate over each event in the calendar
-    for event in cal.walk('vevent'):
-    
-        event_info = {
-                "uid": None,
-                "dtstart": "",
-                "exdate": [],
-                "summary": None,
-                "description": None,
-                "location": None,
-                "rrule": None
         }
-        # Catch errors for missing components
-        for info in event_info:
-            try:
-                event_info[info] = event[info]
-            except Exception:
-                pass
         
-        uid = str(event_info["uid"])
+    def generate(self):
-        dtstart = event_info["dtstart"].dt
+        if self.rrule is None:
-        exdates = event_info["exdate"]
+            return self.recur_info
-        if exdates is not []:
-            if isinstance(exdates, list):
-                exdates = [i.dts.dt.replace(tzinfo=pytz.UTC) for i in exdates]
-            else:
-                exdates = [exdates.dts[0].dt.replace(tzinfo=pytz.UTC)]
-        summary = event["summary"]
-        description = event_info["description"]
-        location = event_info["location"]
-        rrule = event_info["rrule"]
             
-        # Ensure dates are always as datetime
+        rule_str = "RRULE:{}".format(self.rrule.to_ical().decode('utf-8'))
-        if isinstance(dtstart, dt.datetime): 
+        start_date = self.dtstart
-            dtstart = dtstart.replace(tzinfo=pytz.UTC)
+        infinite_recur = False
-        else:
+        freq = self.rrule.get('FREQ')[0]
-            dtstart = dt.datetime.combine(dtstart, dt.time.min).replace(tzinfo=pytz.UTC)
+        count = self.rrule.get("COUNT")
+        interval = self.rrule.get('INTERVAL')[0]
+        current_date = dt.datetime.now().replace(tzinfo=pytz.UTC)
         
-        # Get recurring events if they exist
+        if count is None:
-        recur_info = generate_recurring_event_dates(dtstart, rrule)
+            delta = None
-        event_dates = recur_info["recur_dates"]
             
-        # Remove exdates
+            if freq == "DAILY":
-        event_dates = [i for i in event_dates if i not in exdates]
+                delta = relativedelta(days=interval)
+            elif freq == "MONTHLY":
+                delta = relativedelta(months=interval)
+            elif freq == "YEARLY":
+                delta = relativedelta(years=interval)
                 
-        valarms = []
+            count = 0
-        for subcomponent in event.walk("valarm"):
+            origin_date = start_date
-            valarm = Event.from_ical(subcomponent.to_ical())
+            while origin_date < current_date:
-            timedelta = valarm["trigger"].dt
+                count += interval
-            valarms.append(timedelta)
+                origin_date += delta*interval
             
-        event_dict = {
+            rule_str += ";COUNT={}".format(count+10)
-                "uid": uid, 
+            infinite_recur = True
+        
+        ruleset = rrulestr(rule_str, dtstart=start_date)
+        
+        recur_dates = [None]
+        n_recur = None
+        dates = list(ruleset) # Generate future dates according to the rules
+        recur_dates = [i for i in dates if i >= current_date]
+        n_recur = "inf" if infinite_recur is True else len(recur_dates) 
+        
+        self.recur_info["recur_dates"] = recur_dates
+        self.recur_info["infinite_recur"] = infinite_recur
+        self.recur_info["recur_freq"] = freq
+        self.recur_info["recur_interval"] = interval
+        self.recur_info["n_recur_dates_left"] = n_recur
+        
+        return self.recur_info
+
+class CalendarParser:
+    def parse_calendar(self, cal_str):
+        # Parse the calendar
+        cal = self.parse_icalendar(cal_str)
+        
+        # Iterate over each event in the calendar
+        for event in cal.walk('vevent'):
+            event_dict = self.process_event(event)
+            dtstart = self.dtstart_to_datetime(event_dict["dtstart"].dt)
+            
+            generator = RecurringEventGenerator(dtstart, event_dict["rrule"])
+            recur_info = generator.generate() 
+            event_dates = self.remove_exdates(event_dict["exdate"], recur_info["recur_dates"])
+
+            valarms = self.process_valarm(event)
+            
+            event_dict = {
+                "uid": str(event_dict["uid"]), 
                 "dtstart": dtstart,
-                "summary": summary,
+                "summary": event_dict["summary"],
-                "description": description,
+                "description": event_dict["description"],
-                "location": location,
+                "location": event_dict["location"],
                 "event_dates": event_dates,
                 "recur_info": "Recur freq: {}, Recur interval: {}, N dates left: {}".format(
                     recur_info["recur_freq"], 
@@ -296,17 +229,66 @@ def calendar_parser(cal_str):
                 ),
                 "valarms": valarms,
                 "alert_history": []
-        }
+            }
+            new_hash = calculate_event_hash(event_dict)  # Calculate the hash of the event dictionary
+            event_dict["hash"] = new_hash  # Store the hash in the event dictionary
+            return event_dict
     
-        handler = FileChangeHandler()  # Create an instance of the FileChangeHandler class
+    def parse_icalendar(self, cal_str):
-        new_hash = handler.calculate_event_hash(event_dict)  # Calculate the hash of the event dictionary
+            return Calendar.from_ical(cal_str)
-        event_dict["hash"] = new_hash  # Store the hash in the event dictionary
+            
-        return event_dict
+    def process_event(self, event):
+        # Catch errors for missing components
+        event_info = {
+                 "uid": None,
+                 "dtstart": "",
+                 "exdate": [],
+                 "summary": None,
+                 "description": None,
+                 "location": None,
+                 "rrule": None
+         }
+         
+        for info in event_info:
+            try:
+                event_info[info] = event[info]
+            except Exception:
+                pass
+            
+        return event_info
+    
+    def dtstart_to_datetime(self, dtstart):
+        # Ensure dates are always as datetime
+        if isinstance(dtstart, dt.datetime): 
+            return dtstart.replace(tzinfo=pytz.UTC)
+        else:
+            return dt.datetime.combine(dtstart, dt.time.min).replace(tzinfo=pytz.UTC)
+
+    def remove_exdates(self, exdates, recur_dates):
+        if exdates != []:
+            if isinstance(exdates, list):
+                exdates = [i.dts[0].dt.replace(tzinfo=pytz.UTC) for i in exdates]
+            else:
+                exdates = [exdates.dts[0].dt.replace(tzinfo=pytz.UTC)]
+            return [i for i in recur_dates if i not in exdates]
+        else: 
+            return recur_dates
+
+    def process_valarm(self, event):
+        valarms = []
+        for subcomponent in event.walk("valarm"):
+            valarm = Event.from_ical(subcomponent.to_ical())
+            timedelta = valarm["trigger"].dt
+            valarms.append(timedelta)
+        return valarms
 
 def get_next_alert(event, current_time):
+    """
+    This function returns the next alert that should be processed based on the current time.
+    """
     event_dates = event["event_dates"]
     valarm_deltas = event["valarms"]
-    if event_dates == [] or current_time > event_dates[-1]:
+    if event_dates == [] or event_dates is None or current_time > event_dates[-1]:
         return None, None
     next_event = [i for i in event_dates if i >= current_time][0]
     next_alert_list = [next_event + i for i in valarm_deltas]
@@ -314,6 +296,9 @@ def get_next_alert(event, current_time):
     return next_alert - dt.timedelta(seconds=5), next_event
 
 def process_alert(current_time, next_alert, next_event, event, config):
+    """
+    This function processes a given alert and passes it to a messaging client.
+    """
     if current_time >= next_alert and next_alert < next_alert + dt.timedelta(seconds=15):
         if len(event["alert_history"]) == 0:
             print("First alert for '{}' detected".format(event["summary"]))
@@ -330,24 +315,35 @@ def process_alert(current_time, next_alert, next_event, event, config):
             f.write(str(event))  # write expects a str not dict
         return
 
-def create_event_list(files):
+def main():
+    # Parse args and config
+    args = parse_args()
+    content = read_file(args.config)
+    config = parse_toml(content)
+   
+    # Get calendar dir
+    cal_dir = Path(config["app"]["calendar_dir"])
+    if not cal_dir.is_dir():                                                  
+        print(f"The provided path to .ics files does not exist: '{cal_dir}'") 
+        sys.exit(1)  # Exit with error code                                   
+
+    #Parse calendar events
+    calendar_parser = CalendarParser()
+    files = list(cal_dir.glob('*.ics'))                        
     event_list = []  # List to hold dictionaries for each event
     for file in files:
         with open(file, 'r') as f:
             cal_str = f.read()
-        event_dict = calendar_parser(cal_str)
+        event_dict = calendar_parser.parse_calendar(cal_str)
         event_list.append(event_dict)
-    return event_list
 
-def start_observer(cal_dir):
+    #Start file handler to detect changes to calendar dir
     observer = Observer()
-    handler = FileChangeHandler()
+    handler = FileChangeHandler(event_list)  # Pass event_list here
     observer.schedule(handler, cal_dir, recursive=True)
     observer.start()
-    return observer
 
-def main_loop(event_list, config, cal_dir):
+    #Start main loop
-    observer = start_observer(cal_dir)
     try:
         while True:
             with open("status", 'w') as f:
@@ -380,21 +376,5 @@ def main_loop(event_list, config, cal_dir):
         observer.stop()
         observer.join()
 
-# Main script execution starts here
-def main():
-    args = parse_args()
-    print(args)
-    content = read_file(args.config)
-    config = parse_toml(content)
-    
-    cal_dir = Path(config["app"]["calendar_dir"])
-    if not cal_dir.is_dir():                                                  
-        print(f"The provided path to .ics files does not exist: '{cal_dir}'") 
-        sys.exit(1)  # Exit with error code                                   
-
-    files = list(cal_dir.glob('*.ics'))                        
-    event_list = create_event_list(files)
-    main_loop(event_list, config, cal_dir)
-
 if __name__ == "__main__":
     main()