from odoo import models, fields, api
import uuid
import logging

_logger = logging.getLogger(__name__)


class RecurrenceRule(models.Model):
    _inherit = "calendar.recurrence"

    caldav_uid = fields.Char(
        readonly=True,
        copy=False,
    )
    _sql_constraints = [
        ("caldav_uid_unique", "UNIQUE (caldav_uid)", "caldav_uid must be unique")
    ]

    @api.model_create_multi
    def create(self, vals_list):
        for vals in vals_list:
            vals["caldav_uid"] = str(uuid.uuid4())
        return super().create(vals_list)

    @api.model
    def _detach_events(self, events):
        """When events are detached from a recurrence, their CalDAV UID and recurrence-id
        are no longer going to be valid, so we remove them from the server. They may then
        be re-written to the server with their new IDs later, but we don't care about
        that here."""
        detached_events = super()._detach_events(events)
        for event in detached_events:
            event._sync_unlink_to_caldav()
        return detached_events