remindme_caldav.py

@@ -1,4 +1,3 @@
-from pathlib import Path
 from icalendar import Calendar, Event
 import toml, argparse, os, sys, hashlib, json, pytz, glob, os, time
 from dateutil.relativedelta import relativedelta
@@ -10,49 +9,38 @@ from watchdog.events import FileSystemEventHandler
 import email_alert, xmpp_alert
 from pprint import pprint
 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)
+# Parse args
+parser = argparse.ArgumentParser(description="A simple calendar alerting daemon written in Python")
+parser.add_argument('--config', type=str, help='Path to config file. Must be .toml')
+args = parser.parse_args()
 
-def parse_args():
-    """Parse command line arguments."""
-    parser = argparse.ArgumentParser(description="A simple calendar alerting daemon written in Python")
-    parser.add_argument('--config', type=str, help='Path to config file. Must be .toml')
-    parser.add_argument('--loglevel', choices=['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL'], default='INFO', help='Set the logging level')
-    args = parser.parse_args()
-    if args.config is None:
-        raise ValueError("No config file provided")
-    return args
+if not args.config:
+    print("Error: No config file provided.")
+    sys.exit(1)  # Exit with error code
+elif not os.path.isfile(args.config):
+    print("Error: The specified config file does not exist.")
+    sys.exit(1)  # Exit with error code
+else:
+    print("Config file path: ", args.config)
 
-def read_file(filename):                                       
-    try:                                                       
-        return Path(filename).read_text()                      
-    except FileNotFoundError as e:                             
-        print(f"Error: The specified file does not exist. {e}")
-        sys.exit(1)  # Exit with error code                    
-                                                               
-def parse_toml(content):                                       
-    try:                                                       
-        return toml.loads(content)                             
-    except Exception as e:                                     
-        print("Error: Failed to parse TOML file.")             
-        print(e)                                               
-        sys.exit(1)  # Exit with error code                    
+# Get config
+try:
+    with open(args.config, 'r') as f:
+        config = toml.load(f)
+except Exception as e:
+    print("Error: Failed to parse TOML file.")
+    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()
+cal_dir = config["app"]["calendar_dir"]
+# Check if the path is a directory
+if not os.path.isdir(cal_dir):
+    print("The provided path to .ics files does not exist: '{}'".format(cal_dir))
+    exit(1)
+
+# Get all .ics files from your directory
+files = glob.glob(os.path.join(cal_dir, '*.ics'))
 
 class DateTimeEncoder(json.JSONEncoder):
     def default(self, o):
@@ -65,11 +53,29 @@ 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.
-    """
-    def __init__(self, event_list):
-        self.calendar_parser = CalendarParser()  # Create an instance of CalendarParser
-        self.event_list = event_list   
 
+    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 on_modified(self, event):
         print(f"File modified: {event.src_path}")
         if not event.is_directory:    
@@ -81,7 +87,7 @@ class FileChangeHandler(FileSystemEventHandler):
                 return
             
             try:
-                event_dict = self.calendar_parser.parse_calendar(cal_str)  # Use the instance to call parse_calendar method
+                event_dict = calendar_parser(cal_str)
             except Exception as i:
                 print("Failed to parse calendar event at: {}.\n Error:\n{}".format(event.src_path,i))
                 return 
@@ -107,7 +113,7 @@ class FileChangeHandler(FileSystemEventHandler):
                 return
                 
             try:
-                event_dict = self.calendar_parser.parse_calendar(cal_str)  # Use the instance to call parse_calendar method
+                event_dict = calendar_parser(cal_str)
             except Exception as i:
                 print("Failed to parse calendar event at: {}.\n Error:\n{}".format(event.src_path,i))
                 return 
@@ -116,111 +122,175 @@ class FileChangeHandler(FileSystemEventHandler):
     
     def handle_modified(self, old_event, event_dict, remove=False):
         if not remove:
-            for i, old_event in enumerate(self.event_list):
+            for i, old_event in enumerate(event_list):
                 if old_event["uid"] == event_dict["uid"]:  
                     old_hash = old_event["hash"]
                     
-                    new_hash = calculate_event_hash(event_dict)
+                    new_hash = self.calculate_event_hash(event_dict)
                     if new_hash != old_hash:    
                         print("Event with UID {} has been modified or deleted".format(old_event["uid"]))
                         
-                        self.event_list[i] = event_dict
+                        event_list[i] = event_dict
                     else:   
                         print("Event with UID {} hasn't been modified".format(old_event["uid"]))
                     
                     break
             else:    
-                self.event_list.append(event_dict)
+                event_list.append(event_dict)
         else:   # If remove is True, remove the event from the list
-            for i, old_event in enumerate(self.event_list):
+            for i, old_event in enumerate(event_list):
                 if old_event["uid"] == event_dict["uid"]:   
                     print("Event with UID {} has been deleted".format(old_event["uid"]))
                     
-                    del self.event_list[i]
+                    del event_list[i]
                     break
 
+    def calculate_event_hash(self, event):
+        return hashlib.md5(json.dumps(event, sort_keys=True, cls=DateTimeEncoder).encode()).hexdigest()
 
-class RecurringEventGenerator:
-    def __init__(self, dtstart, rrule):
-        self.dtstart = dtstart
-        self.rrule = rrule
-        self.recur_info = {
+def generate_recurring_event_dates(dtstart, rrule):
+    """
+    Generate recurring event dates based on a start date and an RRULE.
+
+    This function takes in a start date (`dtstart`) and an RRULE (`rrule`),
+    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
         }
-        
-    def generate(self):
-        if self.rrule is None:
-            return self.recur_info
-            
-        rule_str = "RRULE:{}".format(self.rrule.to_ical().decode('utf-8'))
-        start_date = self.dtstart
-        infinite_recur = False
-        freq = self.rrule.get('FREQ')[0]
-        count = self.rrule.get("COUNT")
-        interval = self.rrule.get('INTERVAL')[0]
-        current_date = dt.datetime.now().replace(tzinfo=pytz.UTC)
-        
-        if count is 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) 
-        
-        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
+        # Catch errors for missing components
+        for info in event_info:
+            try:
+                event_info[info] = event[info]
+            except Exception:
+                pass
+    
+        uid = str(event_info["uid"])
+        dtstart = event_info["dtstart"].dt
+        exdates = event_info["exdate"]
+        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
+        if isinstance(dtstart, dt.datetime): 
+            dtstart = dtstart.replace(tzinfo=pytz.UTC)
+        else:
+            dtstart = dt.datetime.combine(dtstart, dt.time.min).replace(tzinfo=pytz.UTC)
+         
+        # Get recurring events if they exist
+        recur_info = generate_recurring_event_dates(dtstart, rrule)
+        event_dates = recur_info["recur_dates"]
 
-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"])
+        # Remove exdates
+        event_dates = [i for i in event_dates if i not in exdates]
+    
+        valarms = []
+        for subcomponent in event.walk("valarm"):
+            valarm = Event.from_ical(subcomponent.to_ical())
+            timedelta = valarm["trigger"].dt
+            valarms.append(timedelta)
 
-            valarms = self.process_valarm(event)
-            
-            event_dict = {
-                "uid": str(event_dict["uid"]), 
+        event_dict = {
+                "uid": uid, 
                 "dtstart": dtstart,
-                "summary": event_dict["summary"],
-                "description": event_dict["description"],
-                "location": event_dict["location"],
+                "summary": summary,
+                "description": description,
+                "location": location,
                 "event_dates": event_dates,
                 "recur_info": "Recur freq: {}, Recur interval: {}, N dates left: {}".format(
                     recur_info["recur_freq"], 
@@ -229,76 +299,24 @@ class CalendarParser:
                 ),
                 "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
-    
-    def parse_icalendar(self, cal_str):
-            return Calendar.from_ical(cal_str)
-            
-    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
+        handler = FileChangeHandler()  # Create an instance of the FileChangeHandler class
+        new_hash = handler.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
 
 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 event_dates is None or current_time > event_dates[-1]:
+    if event_dates == [] 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]
     next_alert = min(next_alert_list)
     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.
-    """
+def process_alert(current_time, next_alert, event):
     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"]))
@@ -315,66 +333,38 @@ def process_alert(current_time, next_alert, next_event, event, config):
             f.write(str(event))  # write expects a str not dict
         return
 
-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                                   
+# Create initial event_list using calendar_parser
+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_list.append(event_dict)
 
-    #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.parse_calendar(cal_str)
-        event_list.append(event_dict)
-
-    #Start file handler to detect changes to calendar dir
-    observer = Observer()
-    handler = FileChangeHandler(event_list)  # Pass event_list here
-    observer.schedule(handler, cal_dir, recursive=True)
-    observer.start()
-
-    #Start main loop
-    try:
-        while True:
-            with open("status", 'w') as f:
-                #Refresh the status file
-                f.write("")
-            current_time = dt.datetime.now().replace(tzinfo=pytz.UTC)
-            for event in event_list:
-                next_alert, next_event = get_next_alert(event, current_time)
-                if next_alert == None:
-                    continue
-                event_delta = next_alert-current_time
-                total_seconds = event_delta.total_seconds()
-                human_readable_time = humanfriendly.format_timespan(total_seconds)
-                monitor_status = f"""\
-                    Current time: {current_time}
-                    Monitoring: {event["summary"]}
-                    Event date: {next_event}
-                    Recur Dates: {[str(i) for i in event["event_dates"]]}
-                    Next alert on: {next_alert} in {human_readable_time}
-                    Recur info: {event["recur_info"]}
-                    Alert history: {event["alert_history"]}\n"""
-                monitor_status = textwrap.dedent(monitor_status)
-                with open("status", 'a') as f:
-                    # Write the output to the file
-                    f.write(monitor_status)
-                    f.write("\n")
-                process_alert(current_time, next_alert, next_event, event, config)
-            time.sleep(1)
-    except KeyboardInterrupt:
-        observer.stop()
-        observer.join()
-
-if __name__ == "__main__":
-    main()
+observer = Observer()
+handler = FileChangeHandler()
+observer.schedule(handler, cal_dir, recursive=True)
+observer.start()
+try:
+    while True:
+        with open("status", 'w') as f:
+            #Refresh the status file
+            f.write("")
+        current_time = dt.datetime.now().replace(tzinfo=pytz.UTC)
+        for event in event_list:
+            next_alert, next_event = get_next_alert(event, current_time)
+            if next_alert == None:
+                continue
+            event_delta = next_alert-current_time
+            total_seconds = event_delta.total_seconds()
+            human_readable_time = humanfriendly.format_timespan(total_seconds)
+            monitor_status = "Current time: {}\nMonitoring: {}\nEvent date: {}\nRecur Dates: {}\nNext alert on: {} in {}\nRecur info: {}\nAlert history: {}\n".format(current_time, event["summary"], next_event, [str(i) for i in event["event_dates"]], next_alert, human_readable_time, event["recur_info"], event["alert_history"])
+            with open("status", 'a') as f:
+                # Write the output to the file
+                f.write(monitor_status)
+                f.write("\n")
+            process_alert(current_time, next_alert, event)
+        time.sleep(1)
+except KeyboardInterrupt:
+    observer.stop()
+observer.join()