#!/usr/bin/env python3

from ansible.module_utils.basic import AnsibleModule
from caldav import DAVClient
import vobject
import requests
from urllib.parse import urlparse
import logging

# Logging für Debugging einrichten
logging.basicConfig(level=logging.WARNING)

def fetch_ics_events(url, user=None, password=None):
    try:
        response = requests.get(url, auth=(user, password) if user else None)
        response.raise_for_status()
        events = []
        ics_data = response.text
        
        # Debug-Ausgabe für ungültige Daten
        if not ics_data.strip():
            logging.warning("Leere ICS-Daten empfangen")
            return events

        try:
            for calendar in vobject.readComponents(ics_data):
                for component in calendar.components():
                    if component.name == 'VEVENT':
                        if hasattr(component, 'uid') and component.uid.value:
                            events.append(component)
                        else:
                            logging.warning("VEVENT ohne UID übersprungen")
        except vobject.base.ParseError as e:
            logging.error(f"Parse-Fehler in ICS-Daten: {str(e)}")
        return events
    except Exception as e:
        raise Exception(f"ICS-Fehler: {str(e)}")

def connect_caldav(url, user=None, password=None, verify_ssl=False):
    try:
        client = DAVClient(
            url,
            username=user,
            password=password,
            ssl_verify_cert=verify_ssl
        )
        principal = client.principal()
        target_path = urlparse(url).path

        # 1. Direkt versuchen mit bekannter Kalender-URL
        try:
            return principal.calendar(url)
        except Exception as direct_err:
            logging.warning(f"Direkter Zugriff auf Kalender fehlgeschlagen: {direct_err}")

        # 2. Fallback: Durch alle bekannten Kalender iterieren
        for calendar in principal.calendars():
            if target_path in str(calendar.url):
                return calendar

        raise Exception(f"Kalender mit Pfad '{target_path}' nicht gefunden")

    except Exception as e:
        raise Exception(f"CalDAV-Fehler: {str(e)}")

def safe_caldav_event_processing(event):
    try:
        if event is None or not hasattr(event, 'data') or not event.data:
            return None
            
        for calendar in vobject.readComponents(event.data):
            for component in calendar.components():
                if component.name == 'VEVENT' and hasattr(component, 'uid'):
                    return {
                        'uid': str(component.uid),
                        'event_object': event,
                        'data': event.data
                    }
        return None
    except vobject.base.ParseError:
        logging.warning("Parse-Fehler in CalDAV-Event, überspringe")
        return None
    except Exception as e:
        logging.error(f"Fehler bei Event-Verarbeitung: {str(e)}")
        return None

def sync_ics_to_caldav(module):
    ics_events = fetch_ics_events(
        module.params['source_url'],
        module.params['source_user'],
        module.params['source_password']
    )

    target_cal = connect_caldav(
        module.params['target_url'],
        module.params['target_user'],
        module.params['target_password'],
        module.params['verify_ssl']
    )

    existing_events = {}
    for event in target_cal.events():
        processed = safe_caldav_event_processing(event)
        if processed:
            existing_events[processed['uid']] = processed

    changed = False
    results = {'added': [], 'updated': [], 'removed': []}

    for vevent in ics_events:
        uid = str(vevent.uid)
        try:
            ical_data = vevent.serialize()
        except Exception as e:
            logging.error(f"Serialisierungsfehler für UID {uid}: {str(e)}")
            continue

        if not ical_data.strip():
            logging.warning(f"Leere iCal-Daten für UID {uid}, überspringe")
            continue

        if uid not in existing_events:
            try:
                target_cal.add_event(ical_data)
                results['added'].append(uid)
                changed = True
            except Exception as e:
                logging.error(f"Hinzufügen fehlgeschlagen für UID {uid}: {str(e)}")
        else:
            existing_data = existing_events[uid]['data']
            if ical_data != existing_data:
                try:
                    event_obj = existing_events[uid]['event_object']
                    event_obj.data = ical_data
                    event_obj.save()
                    results['updated'].append(uid)
                    changed = True
                except Exception as e:
                    logging.error(f"Aktualisieren fehlgeschlagen für UID {uid}: {str(e)}")

    if module.params['purge']:
        current_uids = {str(e.uid) for e in ics_events}
        for uid, event_info in existing_events.items():
            if uid not in current_uids:
                try:
                    event_info['event_object'].delete()
                    results['removed'].append(uid)
                    changed = True
                except Exception as e:
                    logging.error(f"Löschen fehlgeschlagen für UID {uid}: {str(e)}")

    return changed, results

def run_module():
    module_args = dict(
        source_url=dict(type='str', required=True),
        source_user=dict(type='str', required=False, default=None),
        source_password=dict(type='str', required=False, no_log=True, default=None),
        target_url=dict(type='str', required=True),
        target_user=dict(type='str', required=False, default=None),
        target_password=dict(type='str', required=False, no_log=True, default=None),
        verify_ssl=dict(type='bool', default=False),
        purge=dict(type='bool', default=False)
    )

    module = AnsibleModule(argument_spec=module_args, supports_check_mode=False)

    try:
        changed, results = sync_ics_to_caldav(module)
        module.exit_json(changed=changed, **results)
    except Exception as e:
        module.fail_json(msg=str(e))

if __name__ == '__main__':
    run_module()