"""Calendar is a dictionary like Python object that can render itself as VCAL files according to RFC 5545. These are the defined components. """ from __future__ import annotations from datetime import datetime, timedelta from icalendar.caselessdict import CaselessDict from icalendar.parser import Contentline from icalendar.parser import Contentlines from icalendar.parser import Parameters from icalendar.parser import q_join from icalendar.parser import q_split from icalendar.parser_tools import DEFAULT_ENCODING from icalendar.prop import TypesFactory from icalendar.prop import vText, vDDDLists from icalendar.timezone import tzp from typing import Tuple, List import dateutil.rrule import dateutil.tz import os def get_example(component_directory: str, example_name: str) -> bytes: """Return an example and raise an error if it is absent.""" here = os.path.dirname(__file__) examples = os.path.join(here, "tests", component_directory) if not example_name.endswith(".ics"): example_name = example_name + ".ics" example_file = os.path.join(examples, example_name) if not os.path.isfile(example_file): raise ValueError(f"Example {example_name} for {component_directory} not found. You can use one of {', '.join(os.listdir(examples))}") with open(example_file, "rb") as f: return f.read() ###################################### # The component factory class ComponentFactory(CaselessDict): """All components defined in RFC 5545 are registered in this factory class. To get a component you can use it like this. """ def __init__(self, *args, **kwargs): """Set keys to upper for initial dict. """ super().__init__(*args, **kwargs) self['VEVENT'] = Event self['VTODO'] = Todo self['VJOURNAL'] = Journal self['VFREEBUSY'] = FreeBusy self['VTIMEZONE'] = Timezone self['STANDARD'] = TimezoneStandard self['DAYLIGHT'] = TimezoneDaylight self['VALARM'] = Alarm self['VCALENDAR'] = Calendar # These Properties have multiple property values inlined in one propertyline # seperated by comma. Use CaselessDict as simple caseless set. INLINE = CaselessDict({ 'CATEGORIES': 1, 'RESOURCES': 1, 'FREEBUSY': 1, }) _marker = [] class Component(CaselessDict): """Component is the base object for calendar, Event and the other components defined in RFC 5545. Normally you will not use this class directly, but rather one of the subclasses. """ name = None # should be defined in each component required = () # These properties are required singletons = () # These properties must only appear once multiple = () # may occur more than once exclusive = () # These properties are mutually exclusive inclusive = () # if any occurs the other(s) MUST occur # ('duration', 'repeat') ignore_exceptions = False # if True, and we cannot parse this # component, we will silently ignore # it, rather than let the exception # propagate upwards # not_compliant = [''] # List of non-compliant properties. def __init__(self, *args, **kwargs): """Set keys to upper for initial dict. """ super().__init__(*args, **kwargs) # set parameters here for properties that use non-default values self.subcomponents = [] # Components can be nested. self.errors = [] # If we ignored exception(s) while # parsing a property, contains error strings # def is_compliant(self, name): # """Returns True is the given property name is compliant with the # icalendar implementation. # # If the parser is too strict it might prevent parsing erroneous but # otherwise compliant properties. So the parser is pretty lax, but it is # possible to test for non-compliance by calling this method. # """ # return name in not_compliant def __bool__(self): """Returns True, CaselessDict would return False if it had no items. """ return True # python 2 compatibility __nonzero__ = __bool__ def is_empty(self): """Returns True if Component has no items or subcomponents, else False. """ return True if not (list(self.values()) + self.subcomponents) else False # noqa ############################# # handling of property values @staticmethod def _encode(name, value, parameters=None, encode=1): """Encode values to icalendar property values. :param name: Name of the property. :type name: string :param value: Value of the property. Either of a basic Python type of any of the icalendar's own property types. :type value: Python native type or icalendar property type. :param parameters: Property parameter dictionary for the value. Only available, if encode is set to True. :type parameters: Dictionary :param encode: True, if the value should be encoded to one of icalendar's own property types (Fallback is "vText") or False, if not. :type encode: Boolean :returns: icalendar property value """ if not encode: return value if isinstance(value, types_factory.all_types): # Don't encode already encoded values. obj = value else: klass = types_factory.for_property(name) obj = klass(value) if parameters: if not hasattr(obj, "params"): obj.params = Parameters() for key, item in parameters.items(): if item is None: if key in obj.params: del obj.params[key] else: obj.params[key] = item return obj def add(self, name, value, parameters=None, encode=1): """Add a property. :param name: Name of the property. :type name: string :param value: Value of the property. Either of a basic Python type of any of the icalendar's own property types. :type value: Python native type or icalendar property type. :param parameters: Property parameter dictionary for the value. Only available, if encode is set to True. :type parameters: Dictionary :param encode: True, if the value should be encoded to one of icalendar's own property types (Fallback is "vText") or False, if not. :type encode: Boolean :returns: None """ if isinstance(value, datetime) and\ name.lower() in ('dtstamp', 'created', 'last-modified'): # RFC expects UTC for those... force value conversion. value = tzp.localize_utc(value) # encode value if encode and isinstance(value, list) \ and name.lower() not in ['rdate', 'exdate', 'categories']: # Individually convert each value to an ical type except rdate and # exdate, where lists of dates might be passed to vDDDLists. value = [self._encode(name, v, parameters, encode) for v in value] else: value = self._encode(name, value, parameters, encode) # set value if name in self: # If property already exists, append it. oldval = self[name] if isinstance(oldval, list): if isinstance(value, list): value = oldval + value else: oldval.append(value) value = oldval else: value = [oldval, value] self[name] = value def _decode(self, name, value): """Internal for decoding property values. """ # TODO: Currently the decoded method calls the icalendar.prop instances # from_ical. We probably want to decode properties into Python native # types here. But when parsing from an ical string with from_ical, we # want to encode the string into a real icalendar.prop property. if isinstance(value, vDDDLists): # TODO: Workaround unfinished decoding return value decoded = types_factory.from_ical(name, value) # TODO: remove when proper decoded is implemented in every prop.* class # Workaround to decode vText properly if isinstance(decoded, vText): decoded = decoded.encode(DEFAULT_ENCODING) return decoded def decoded(self, name, default=_marker): """Returns decoded value of property. """ # XXX: fail. what's this function supposed to do in the end? # -rnix if name in self: value = self[name] if isinstance(value, list): return [self._decode(name, v) for v in value] return self._decode(name, value) else: if default is _marker: raise KeyError(name) else: return default ######################################################################## # Inline values. A few properties have multiple values inlined in in one # property line. These methods are used for splitting and joining these. def get_inline(self, name, decode=1): """Returns a list of values (split on comma). """ vals = [v.strip('" ') for v in q_split(self[name])] if decode: return [self._decode(name, val) for val in vals] return vals def set_inline(self, name, values, encode=1): """Converts a list of values into comma separated string and sets value to that. """ if encode: values = [self._encode(name, value, encode=1) for value in values] self[name] = types_factory['inline'](q_join(values)) ######################### # Handling of components def add_component(self, component): """Add a subcomponent to this component. """ self.subcomponents.append(component) def _walk(self, name, select): """Walk to given component. """ result = [] if (name is None or self.name == name) and select(self): result.append(self) for subcomponent in self.subcomponents: result += subcomponent._walk(name, select) return result def walk(self, name=None, select=lambda c: True): """Recursively traverses component and subcomponents. Returns sequence of same. If name is passed, only components with name will be returned. :param name: The name of the component or None such as ``VEVENT``. :param select: A function that takes the component as first argument and returns True/False. :returns: A list of components that match. :rtype: list[Component] """ if name is not None: name = name.upper() return self._walk(name, select) ##################### # Generation def property_items(self, recursive=True, sorted=True): """Returns properties in this component and subcomponents as: [(name, value), ...] """ vText = types_factory['text'] properties = [('BEGIN', vText(self.name).to_ical())] if sorted: property_names = self.sorted_keys() else: property_names = self.keys() for name in property_names: values = self[name] if isinstance(values, list): # normally one property is one line for value in values: properties.append((name, value)) else: properties.append((name, values)) if recursive: # recursion is fun! for subcomponent in self.subcomponents: properties += subcomponent.property_items(sorted=sorted) properties.append(('END', vText(self.name).to_ical())) return properties @classmethod def from_ical(cls, st, multiple=False): """Populates the component recursively from a string. """ stack = [] # a stack of components comps = [] for line in Contentlines.from_ical(st): # raw parsing if not line: continue try: name, params, vals = line.parts() except ValueError as e: # if unable to parse a line within a component # that ignores exceptions, mark the component # as broken and skip the line. otherwise raise. component = stack[-1] if stack else None if not component or not component.ignore_exceptions: raise component.errors.append((None, str(e))) continue uname = name.upper() # check for start of component if uname == 'BEGIN': # try and create one of the components defined in the spec, # otherwise get a general Components for robustness. c_name = vals.upper() c_class = component_factory.get(c_name, Component) # If component factory cannot resolve ``c_name``, the generic # ``Component`` class is used which does not have the name set. # That's opposed to the usage of ``cls``, which represents a # more concrete subclass with a name set (e.g. VCALENDAR). component = c_class() if not getattr(component, 'name', ''): # undefined components component.name = c_name stack.append(component) # check for end of event elif uname == 'END': # we are done adding properties to this component # so pop it from the stack and add it to the new top. if not stack: # The stack is currently empty, the input must be invalid raise ValueError('END encountered without an accompanying BEGIN!') component = stack.pop() if not stack: # we are at the end comps.append(component) else: stack[-1].add_component(component) if vals == 'VTIMEZONE' and 'TZID' in component: tzp.cache_timezone_component(component) # we are adding properties to the current top of the stack else: factory = types_factory.for_property(name) component = stack[-1] if stack else None if not component: # only accept X-COMMENT at the end of the .ics file # ignore these components in parsing if uname == 'X-COMMENT': break else: raise ValueError(f'Property "{name}" does not have a parent component.') datetime_names = ('DTSTART', 'DTEND', 'RECURRENCE-ID', 'DUE', 'RDATE', 'EXDATE') try: if name == 'FREEBUSY': vals = vals.split(',') if 'TZID' in params: parsed_components = [factory(factory.from_ical(val, params['TZID'])) for val in vals] else: parsed_components = [factory(factory.from_ical(val)) for val in vals] elif name in datetime_names and 'TZID' in params: parsed_components = [factory(factory.from_ical(vals, params['TZID']))] else: parsed_components = [factory(factory.from_ical(vals))] except ValueError as e: if not component.ignore_exceptions: raise component.errors.append((uname, str(e))) else: for parsed_component in parsed_components: parsed_component.params = params component.add(name, parsed_component, encode=0) if multiple: return comps if len(comps) > 1: raise ValueError(cls._format_error( 'Found multiple components where only one is allowed', st)) if len(comps) < 1: raise ValueError(cls._format_error( 'Found no components where exactly one is required', st)) return comps[0] def _format_error(error_description, bad_input, elipsis='[...]'): # there's three character more in the error, ie. ' ' x2 and a ':' max_error_length = 100 - 3 if len(error_description) + len(bad_input) + len(elipsis) > max_error_length: truncate_to = max_error_length - len(error_description) - len(elipsis) return f'{error_description}: {bad_input[:truncate_to]} {elipsis}' else: return f'{error_description}: {bad_input}' def content_line(self, name, value, sorted=True): """Returns property as content line. """ params = getattr(value, 'params', Parameters()) return Contentline.from_parts(name, params, value, sorted=sorted) def content_lines(self, sorted=True): """Converts the Component and subcomponents into content lines. """ contentlines = Contentlines() for name, value in self.property_items(sorted=sorted): cl = self.content_line(name, value, sorted=sorted) contentlines.append(cl) contentlines.append('') # remember the empty string in the end return contentlines def to_ical(self, sorted=True): ''' :param sorted: Whether parameters and properties should be lexicographically sorted. ''' content_lines = self.content_lines(sorted=sorted) return content_lines.to_ical() def __repr__(self): """String representation of class with all of it's subcomponents. """ subs = ', '.join(str(it) for it in self.subcomponents) return f"{self.name or type(self).__name__}({dict(self)}{', ' + subs if subs else ''})" def __eq__(self, other): if len(self.subcomponents) != len(other.subcomponents): return False properties_equal = super().__eq__(other) if not properties_equal: return False # The subcomponents might not be in the same order, # neither there's a natural key we can sort the subcomponents by nor # are the subcomponent types hashable, so we cant put them in a set to # check for set equivalence. We have to iterate over the subcomponents # and look for each of them in the list. for subcomponent in self.subcomponents: if subcomponent not in other.subcomponents: return False return True ####################################### # components defined in RFC 5545 class Event(Component): name = 'VEVENT' canonical_order = ( 'SUMMARY', 'DTSTART', 'DTEND', 'DURATION', 'DTSTAMP', 'UID', 'RECURRENCE-ID', 'SEQUENCE', 'RRULE', 'RDATE', 'EXDATE', ) required = ('UID', 'DTSTAMP',) singletons = ( 'CLASS', 'CREATED', 'DESCRIPTION', 'DTSTART', 'GEO', 'LAST-MODIFIED', 'LOCATION', 'ORGANIZER', 'PRIORITY', 'DTSTAMP', 'SEQUENCE', 'STATUS', 'SUMMARY', 'TRANSP', 'URL', 'RECURRENCE-ID', 'DTEND', 'DURATION', 'UID', 'CATEGORIES', ) exclusive = ('DTEND', 'DURATION',) multiple = ( 'ATTACH', 'ATTENDEE', 'COMMENT', 'CONTACT', 'EXDATE', 'RSTATUS', 'RELATED', 'RESOURCES', 'RDATE', 'RRULE' ) ignore_exceptions = True @classmethod def example(cls, name) -> Event: """Return the calendar example with the given name.""" return cls.from_ical(get_example("events", name)) class Todo(Component): name = 'VTODO' required = ('UID', 'DTSTAMP',) singletons = ( 'CLASS', 'COMPLETED', 'CREATED', 'DESCRIPTION', 'DTSTAMP', 'DTSTART', 'GEO', 'LAST-MODIFIED', 'LOCATION', 'ORGANIZER', 'PERCENT-COMPLETE', 'PRIORITY', 'RECURRENCE-ID', 'SEQUENCE', 'STATUS', 'SUMMARY', 'UID', 'URL', 'DUE', 'DURATION', ) exclusive = ('DUE', 'DURATION',) multiple = ( 'ATTACH', 'ATTENDEE', 'CATEGORIES', 'COMMENT', 'CONTACT', 'EXDATE', 'RSTATUS', 'RELATED', 'RESOURCES', 'RDATE', 'RRULE' ) class Journal(Component): name = 'VJOURNAL' required = ('UID', 'DTSTAMP',) singletons = ( 'CLASS', 'CREATED', 'DTSTART', 'DTSTAMP', 'LAST-MODIFIED', 'ORGANIZER', 'RECURRENCE-ID', 'SEQUENCE', 'STATUS', 'SUMMARY', 'UID', 'URL', ) multiple = ( 'ATTACH', 'ATTENDEE', 'CATEGORIES', 'COMMENT', 'CONTACT', 'EXDATE', 'RELATED', 'RDATE', 'RRULE', 'RSTATUS', 'DESCRIPTION', ) class FreeBusy(Component): name = 'VFREEBUSY' required = ('UID', 'DTSTAMP',) singletons = ( 'CONTACT', 'DTSTART', 'DTEND', 'DTSTAMP', 'ORGANIZER', 'UID', 'URL', ) multiple = ('ATTENDEE', 'COMMENT', 'FREEBUSY', 'RSTATUS',) class Timezone(Component): name = 'VTIMEZONE' canonical_order = ('TZID',) required = ('TZID',) # it also requires one of components DAYLIGHT and STANDARD singletons = ('TZID', 'LAST-MODIFIED', 'TZURL',) @classmethod def example(cls, name) -> Calendar: """Return the calendar example with the given name.""" return cls.from_ical(get_example("timezones", name)) @staticmethod def _extract_offsets(component, tzname): """extract offsets and transition times from a VTIMEZONE component :param component: a STANDARD or DAYLIGHT component :param tzname: the name of the zone """ offsetfrom = component['TZOFFSETFROM'].td offsetto = component['TZOFFSETTO'].td dtstart = component['DTSTART'].dt # offsets need to be rounded to the next minute, we might loose up # to 30 seconds accuracy, but it can't be helped (datetime # supposedly cannot handle smaller offsets) offsetto_s = int((offsetto.seconds + 30) / 60) * 60 offsetto = timedelta(days=offsetto.days, seconds=offsetto_s) offsetfrom_s = int((offsetfrom.seconds + 30) / 60) * 60 offsetfrom = timedelta(days=offsetfrom.days, seconds=offsetfrom_s) # expand recurrences if 'RRULE' in component: # to be paranoid about correct weekdays # evaluate the rrule with the current offset tzi = dateutil.tz.tzoffset ("(offsetfrom)", offsetfrom) rrstart = dtstart.replace (tzinfo=tzi) rrulestr = component['RRULE'].to_ical().decode('utf-8') rrule = dateutil.rrule.rrulestr(rrulestr, dtstart=rrstart) tzp.fix_rrule_until(rrule, component['RRULE']) # constructing the timezone requires UTC transition times. # here we construct local times without tzinfo, the offset to UTC # gets subtracted in to_tz(). transtimes = [dt.replace (tzinfo=None) for dt in rrule] # or rdates elif 'RDATE' in component: if not isinstance(component['RDATE'], list): rdates = [component['RDATE']] else: rdates = component['RDATE'] transtimes = [dtstart] + [leaf.dt for tree in rdates for leaf in tree.dts] else: transtimes = [dtstart] transitions = [(transtime, offsetfrom, offsetto, tzname) for transtime in set(transtimes)] if component.name == 'STANDARD': is_dst = 0 elif component.name == 'DAYLIGHT': is_dst = 1 return is_dst, transitions @staticmethod def _make_unique_tzname(tzname, tznames): """ :param tzname: Candidate tzname :param tznames: Other tznames """ # TODO better way of making sure tznames are unique while tzname in tznames: tzname += '_1' tznames.add(tzname) return tzname def to_tz(self, tzp=tzp): """convert this VTIMEZONE component to a timezone object """ return tzp.create_timezone(self) @property def tz_name(self) -> str: """Return the name of the timezone component. Please note that the names of the timezone are different from this name and may change with winter/summer time. """ try: return str(self['TZID']) except UnicodeEncodeError: return self['TZID'].encode('ascii', 'replace') def get_transitions(self) -> Tuple[List[datetime], List[Tuple[timedelta, timedelta, str]]]: """Return a tuple of (transition_times, transition_info) - transition_times = [datetime, ...] - transition_info = [(TZOFFSETTO, dts_offset, tzname)] """ zone = self.tz_name transitions = [] dst = {} tznames = set() for component in self.walk(): if type(component) == Timezone: continue assert isinstance(component['DTSTART'].dt, datetime), ( "VTIMEZONEs sub-components' DTSTART must be of type datetime, not date" ) try: tzname = str(component['TZNAME']) except UnicodeEncodeError: tzname = component['TZNAME'].encode('ascii', 'replace') tzname = self._make_unique_tzname(tzname, tznames) except KeyError: # for whatever reason this is str/unicode tzname = f"{zone}_{component['DTSTART'].to_ical().decode('utf-8')}_" + \ f"{component['TZOFFSETFROM'].to_ical()}_" + \ f"{component['TZOFFSETTO'].to_ical()}" tzname = self._make_unique_tzname(tzname, tznames) dst[tzname], component_transitions = self._extract_offsets( component, tzname ) transitions.extend(component_transitions) transitions.sort() transition_times = [ transtime - osfrom for transtime, osfrom, _, _ in transitions ] # transition_info is a list with tuples in the format # (utcoffset, dstoffset, name) # dstoffset = 0, if current transition is to standard time # = this_utcoffset - prev_standard_utcoffset, otherwise transition_info = [] for num, (transtime, osfrom, osto, name) in enumerate(transitions): dst_offset = False if not dst[name]: dst_offset = timedelta(seconds=0) else: # go back in time until we find a transition to dst for index in range(num - 1, -1, -1): if not dst[transitions[index][3]]: # [3] is the name dst_offset = osto - transitions[index][2] # [2] is osto # noqa break # when the first transition is to dst, we didn't find anything # in the past, so we have to look into the future if not dst_offset: for index in range(num, len(transitions)): if not dst[transitions[index][3]]: # [3] is the name dst_offset = osto - transitions[index][2] # [2] is osto # noqa break assert dst_offset is not False transition_info.append((osto, dst_offset, name)) return transition_times, transition_info class TimezoneStandard(Component): name = 'STANDARD' required = ('DTSTART', 'TZOFFSETTO', 'TZOFFSETFROM') singletons = ('DTSTART', 'TZOFFSETTO', 'TZOFFSETFROM',) multiple = ('COMMENT', 'RDATE', 'TZNAME', 'RRULE', 'EXDATE') class TimezoneDaylight(Component): name = 'DAYLIGHT' required = TimezoneStandard.required singletons = TimezoneStandard.singletons multiple = TimezoneStandard.multiple class Alarm(Component): name = 'VALARM' # some properties MAY/MUST/MUST NOT appear depending on ACTION value required = ('ACTION', 'TRIGGER',) singletons = ( 'ATTACH', 'ACTION', 'DESCRIPTION', 'SUMMARY', 'TRIGGER', 'DURATION', 'REPEAT', ) inclusive = (('DURATION', 'REPEAT',), ('SUMMARY', 'ATTENDEE',)) multiple = ('ATTENDEE', 'ATTACH') class Calendar(Component): """This is the base object for an iCalendar file. """ name = 'VCALENDAR' canonical_order = ('VERSION', 'PRODID', 'CALSCALE', 'METHOD',) required = ('PRODID', 'VERSION', ) singletons = ('PRODID', 'VERSION', 'CALSCALE', 'METHOD') @classmethod def example(cls, name) -> Calendar: """Return the calendar example with the given name.""" return cls.from_ical(get_example("calendars", name)) # These are read only singleton, so one instance is enough for the module types_factory = TypesFactory() component_factory = ComponentFactory() __all__ = ["Alarm", "Calendar", "Component", "ComponentFactory", "Event", "FreeBusy", "INLINE", "Journal", "Timezone", "TimezoneDaylight", "TimezoneStandard", "Todo", "component_factory", "get_example"]