#!/usr/bin/env python3

from ansible.module_utils.basic import AnsibleModule
import subprocess
import sys

# Auto-Install, falls caldav fehlt
try:
    from caldav import DAVClient
    import vobject
except ImportError:
    subprocess.check_call([sys.executable, "-m", "pip", "install", "caldav", "vobject"])
    from caldav import DAVClient
    import vobject


def connect_calendar(url, user=None, password=None):
    client = DAVClient(url, username=user, password=password) if user else DAVClient(url)
    principal = client.principal()
    calendars = principal.calendars()
    if not calendars:
        raise Exception(f"Kein Kalender gefunden unter {url}")
    return calendars[0]


def get_event_uid_map(calendar):
    uid_map = {}
    for event in calendar.events():
        try:
            cal = vobject.readOne(event.data)
            uid = cal.vevent.uid.value
            uid_map[uid] = event
        except Exception:
            continue
    return uid_map


def sync_calendars(source_cal, target_cal):
    src_events = get_event_uid_map(source_cal)
    tgt_events = get_event_uid_map(target_cal)

    changed = False
    added, updated, removed = [], [], []

    for uid, src_event in src_events.items():
        src_data = src_event.data
        if uid not in tgt_events:
            target_cal.add_event(src_data)
            added.append(uid)
            changed = True
        elif src_data != tgt_events[uid].data:
            tgt_events[uid].delete()
            target_cal.add_event(src_data)
            updated.append(uid)
            changed = True

    for uid in set(tgt_events.keys()) - set(src_events.keys()):
        tgt_events[uid].delete()
        removed.append(uid)
        changed = True

    return changed, added, updated, removed


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, default=None, no_log=True),
        target_url=dict(type='str', required=True),
        target_user=dict(type='str', required=True),
        target_password=dict(type='str', required=True, no_log=True),
    )

    result = dict(
        changed=False,
        added=[],
        updated=[],
        removed=[],
    )

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

    try:
        source_cal = connect_calendar(
            module.params['source_url'],
            module.params['source_user'],
            module.params['source_password']
        )
        target_cal = connect_calendar(
            module.params['target_url'],
            module.params['target_user'],
            module.params['target_password']
        )
        changed, added, updated, removed = sync_calendars(source_cal, target_cal)

        result['changed'] = changed
        result['added'] = added
        result['updated'] = updated
        result['removed'] = removed

        module.exit_json(**result)
    except Exception as e:
        module.fail_json(msg=str(e), **result)


def main():
    run_module()


if __name__ == '__main__':
    main()