from typing import Any, cast, Dict, Optional, TYPE_CHECKING, Union

from gitlab import exceptions as exc
from gitlab import types
from gitlab.base import RequiredOptional, RESTManager, RESTObject
from gitlab.mixins import (
    CreateMixin,
    CRUDMixin,
    DeleteMixin,
    ListMixin,
    ObjectDeleteMixin,
    SaveMixin,
    UpdateMixin,
)

from .events import GroupEpicResourceLabelEventManager  # noqa: F401

__all__ = [
    "GroupEpic",
    "GroupEpicManager",
    "GroupEpicIssue",
    "GroupEpicIssueManager",
]


class GroupEpic(ObjectDeleteMixin, SaveMixin, RESTObject):
    _id_attr = "iid"

    issues: "GroupEpicIssueManager"
    resourcelabelevents: GroupEpicResourceLabelEventManager


class GroupEpicManager(CRUDMixin, RESTManager):
    _path = "/groups/{group_id}/epics"
    _obj_cls = GroupEpic
    _from_parent_attrs = {"group_id": "id"}
    _list_filters = ("author_id", "labels", "order_by", "sort", "search")
    _create_attrs = RequiredOptional(
        required=("title",),
        optional=("labels", "description", "start_date", "end_date"),
    )
    _update_attrs = RequiredOptional(
        optional=("title", "labels", "description", "start_date", "end_date"),
    )
    _types = {"labels": types.ListAttribute}

    def get(self, id: Union[str, int], lazy: bool = False, **kwargs: Any) -> GroupEpic:
        return cast(GroupEpic, super().get(id=id, lazy=lazy, **kwargs))


class GroupEpicIssue(ObjectDeleteMixin, SaveMixin, RESTObject):
    _id_attr = "epic_issue_id"
    # Define type for 'manager' here So mypy won't complain about
    # 'self.manager.update()' call in the 'save' method.
    manager: "GroupEpicIssueManager"

    def save(self, **kwargs: Any) -> None:
        """Save the changes made to the object to the server.

        The object is updated to match what the server returns.

        Args:
            **kwargs: Extra options to send to the server (e.g. sudo)

        Raise:
            GitlabAuthenticationError: If authentication is not correct
            GitlabUpdateError: If the server cannot perform the request
        """
        updated_data = self._get_updated_data()
        # Nothing to update. Server fails if sent an empty dict.
        if not updated_data:
            return

        # call the manager
        obj_id = self.get_id()
        self.manager.update(obj_id, updated_data, **kwargs)


class GroupEpicIssueManager(
    ListMixin, CreateMixin, UpdateMixin, DeleteMixin, RESTManager
):
    _path = "/groups/{group_id}/epics/{epic_iid}/issues"
    _obj_cls = GroupEpicIssue
    _from_parent_attrs = {"group_id": "group_id", "epic_iid": "iid"}
    _create_attrs = RequiredOptional(required=("issue_id",))
    _update_attrs = RequiredOptional(optional=("move_before_id", "move_after_id"))

    @exc.on_http_error(exc.GitlabCreateError)
    def create(
        self, data: Optional[Dict[str, Any]] = None, **kwargs: Any
    ) -> GroupEpicIssue:
        """Create a new object.

        Args:
            data: Parameters to send to the server to create the
                         resource
            **kwargs: Extra options to send to the server (e.g. sudo)

        Raises:
            GitlabAuthenticationError: If authentication is not correct
            GitlabCreateError: If the server cannot perform the request

        Returns:
            A new instance of the manage object class build with
                the data sent by the server
        """
        if TYPE_CHECKING:
            assert data is not None
        CreateMixin._check_missing_create_attrs(self, data)
        path = f"{self.path}/{data.pop('issue_id')}"
        server_data = self.gitlab.http_post(path, **kwargs)
        if TYPE_CHECKING:
            assert isinstance(server_data, dict)
        # The epic_issue_id attribute doesn't exist when creating the resource,
        # but is used everywhere elese. Let's create it to be consistent client
        # side
        server_data["epic_issue_id"] = server_data["id"]
        return self._obj_cls(self, server_data)