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from __future__ import annotations

import json
from collections.abc import Sequence
from tempfile import NamedTemporaryFile
from typing import TYPE_CHECKING, Any

from airflow.providers.google.cloud.hooks.gcs import GCSHook
from airflow.providers.google.suite.hooks.calendar import GoogleCalendarHook
from airflow.providers.google.version_compat import BaseOperator

if TYPE_CHECKING:
    from datetime import datetime


class GoogleCalendarToGCSOperator(BaseOperator):
    """
    Writes Google Calendar data into Google Cloud Storage.

    .. seealso::
        For more information on how to use this operator, take a look at the guide:
        :ref:`howto/operator:GoogleCalendarToGCSOperator`

    :param calendar_id: The Google Calendar ID to interact with.
    :param i_cal_uid: Optional. Specifies event ID in the ``iCalendar`` format in the response.
    :param max_attendees: Optional. If there are more than the specified number of attendees,
        only the participant is returned.
    :param max_results: Optional. Maximum number of events returned on one result page.
        Incomplete pages can be detected by a non-empty ``nextPageToken`` field in the response.
        By default the value is 250 events. The page size can never be larger than 2500 events
    :param order_by: Optional. Acceptable values are ``"startTime"`` or "updated"
    :param private_extended_property: Optional. Extended properties constraint specified as
        ``propertyName=value``. Matches only private properties. This parameter might be repeated
        multiple times to return events that match all given constraints.
    :param text_search_query: Optional. Free text search.
    :param shared_extended_property: Optional. Extended properties constraint specified as
        ``propertyName=value``. Matches only shared properties. This parameter might be repeated
        multiple times to return events that match all given constraints.
    :param show_deleted: Optional. False by default
    :param show_hidden_invitation: Optional. False by default
    :param single_events: Optional. False by default
    :param sync_token: Optional. Token obtained from the ``nextSyncToken`` field returned
    :param time_max: Optional. Upper bound (exclusive) for an event's start time to filter by.
        Default is no filter
    :param time_min: Optional. Lower bound (exclusive) for an event's end time to filter by.
        Default is no filter
    :param time_zone: Optional. Time zone used in response. Default is calendars time zone.
    :param updated_min: Optional. Lower bound for an event's last modification time
    :param destination_bucket: The destination Google Cloud Storage bucket where the
        report should be written to. (templated)
    :param destination_path: The Google Cloud Storage URI array for the object created by the operator.
        For example: ``path/to/my/files``.
    :param gcp_conn_id: The connection ID to use when fetching connection info.
    :param impersonation_chain: Optional service account to impersonate using short-term
        credentials, or chained list of accounts required to get the access_token
        of the last account in the list, which will be impersonated in the request.
        If set as a string, the account must grant the originating account
        the Service Account Token Creator IAM role.
        If set as a sequence, the identities from the list must grant
        Service Account Token Creator IAM role to the directly preceding identity, with first
        account from the list granting this role to the originating account (templated).
    :param unwrap_single: If True (default), returns a single URI string when there's only one file.
        If False, always returns a list of URIs. Default will change to False in a future release.
    :param return_gcs_uri: If True, returns the full GCS URI (e.g., ``gs://bucket/path/to/file``).
        If False (default), returns the destination file name only (e.g., ``bucket/path/to/file``).
        This parameter is deprecated and will be removed in a future release.
        When this parameter's value is False, it cannot be used altogether with ``unwrap_single=False``.
    """

    template_fields = [
        "calendar_id",
        "destination_bucket",
        "destination_path",
        "impersonation_chain",
    ]

    def __init__(
        self,
        *,
        destination_bucket: str,
        api_version: str,
        calendar_id: str = "primary",
        i_cal_uid: str | None = None,
        max_attendees: int | None = None,
        max_results: int | None = None,
        order_by: str | None = None,
        private_extended_property: str | None = None,
        text_search_query: str | None = None,
        shared_extended_property: str | None = None,
        show_deleted: bool | None = None,
        show_hidden_invitation: bool | None = None,
        single_events: bool | None = None,
        sync_token: str | None = None,
        time_max: datetime | None = None,
        time_min: datetime | None = None,
        time_zone: str | None = None,
        updated_min: datetime | None = None,
        destination_path: str | None = None,
        gcp_conn_id: str = "google_cloud_default",
        impersonation_chain: str | Sequence[str] | None = None,
        unwrap_single: bool | None = None,
        return_gcs_uri: bool | None = None,
        **kwargs,
    ) -> None:
        super().__init__(**kwargs)
        self.gcp_conn_id = gcp_conn_id
        self.calendar_id = calendar_id
        self.api_version = api_version
        self.i_cal_uid = i_cal_uid
        self.max_attendees = max_attendees
        self.max_results = max_results
        self.order_by = order_by
        self.private_extended_property = private_extended_property
        self.text_search_query = text_search_query
        self.shared_extended_property = shared_extended_property
        self.show_deleted = show_deleted
        self.show_hidden_invitation = show_hidden_invitation
        self.single_events = single_events
        self.sync_token = sync_token
        self.time_max = time_max
        self.time_min = time_min
        self.time_zone = time_zone
        self.updated_min = updated_min
        self.destination_bucket = destination_bucket
        self.destination_path = destination_path
        self.impersonation_chain = impersonation_chain

        import warnings

        if unwrap_single is None:
            self.unwrap_single = True
            warnings.warn(
                "The default value of unwrap_single will change from True to False in a future release. "
                "Please set unwrap_single explicitly to avoid this warning.",
                FutureWarning,
                stacklevel=2,
            )
        else:
            self.unwrap_single = unwrap_single

        if return_gcs_uri is None:
            self.return_gcs_uri = False
            warnings.warn(
                "The return_gcs_uri parameter is deprecated and will be removed in a future release. "
                "In the future, operators will always return full GCS URIs.",
                FutureWarning,
                stacklevel=2,
            )
        else:
            self.return_gcs_uri = return_gcs_uri

        # Validate that the combination is valid: we cannot have both unwrap_single=False
        # and return_gcs_uri=False as this combination is backward-incompatible with the
        # future behavior of always returning lists of URIs.
        # Note: After None handling above, both values are guaranteed to be bool (not None).
        if not self.unwrap_single and not self.return_gcs_uri:
            raise ValueError(
                "return_gcs_uri cannot be False together with unwrap_single=False. "
                "In the future, all operators will return list of URIs, so please set "
                "return_gcs_uri=True when using unwrap_single=False.",
            )

    def _upload_data(
        self,
        events: list[Any],
    ) -> tuple[str, str]:
        gcs_hook = GCSHook(
            gcp_conn_id=self.gcp_conn_id,
            impersonation_chain=self.impersonation_chain,
        )

        # Construct destination file path
        file_name = f"{self.calendar_id}.json".replace(" ", "_")
        dest_file_name = (
            f"{self.destination_path.strip('/')}/{file_name}" if self.destination_path else file_name
        )

        with NamedTemporaryFile("w+") as temp_file:
            # Write data
            json.dump(events, temp_file)
            temp_file.flush()

            # Upload to GCS
            gcs_hook.upload(
                bucket_name=self.destination_bucket,
                object_name=dest_file_name,
                filename=temp_file.name,
            )
        gcs_uri = f"gs://{self.destination_bucket}/{dest_file_name}"
        return dest_file_name, gcs_uri

    def execute(self, context) -> str | list[str]:
        calendar_hook = GoogleCalendarHook(
            api_version=self.api_version,
            gcp_conn_id=self.gcp_conn_id,
            impersonation_chain=self.impersonation_chain,
        )

        events = calendar_hook.get_events(
            calendar_id=self.calendar_id,
            i_cal_uid=self.i_cal_uid,
            max_attendees=self.max_attendees,
            max_results=self.max_results,
            order_by=self.order_by,
            private_extended_property=self.private_extended_property,
            q=self.text_search_query,
            shared_extended_property=self.shared_extended_property,
            show_deleted=self.show_deleted,
            show_hidden_invitation=self.show_hidden_invitation,
            single_events=self.single_events,
            sync_token=self.sync_token,
            time_max=self.time_max,
            time_min=self.time_min,
            time_zone=self.time_zone,
            updated_min=self.updated_min,
        )
        dest_file_name, gcs_uri = self._upload_data(events)

        # Determine what to return based on flags
        if self.return_gcs_uri:
            result = [gcs_uri]
        else:
            # For backward compatibility, return dest_file_name when unwrap_single=False
            # and return_gcs_uri=False (default behavior)
            result = [dest_file_name]

        if self.unwrap_single:
            return result[0]
        return result
