from kallithea.model import BaseModel

from kallithea.model.db import ChangesetStatus, PullRequest

from kallithea.lib.exceptions import StatusChangeOnClosedPullRequestError

log = logging.getLogger(__name__)

class ChangesetStatusModel(BaseModel):

    cls = ChangesetStatus

    def __get_changeset_status(self, changeset_status):

        return self._get_instance(ChangesetStatus, changeset_status)

    def __get_pull_request(self, pull_request):

        return self._get_instance(PullRequest, pull_request)

    def _get_status_query(self, repo, revision, pull_request,

                          with_revisions=False):

        repo = self._get_repo(repo)

        q = ChangesetStatus.query() \

            .filter(ChangesetStatus.repo == repo)

        if not with_revisions:

            q = q.filter(ChangesetStatus.version == 0)

        if revision:

            q = q.filter(ChangesetStatus.revision == revision)

        elif pull_request:

            pull_request = self.__get_pull_request(pull_request)

            q = q.filter(ChangesetStatus.pull_request == pull_request)

        else:

            raise Exception('Please specify revision or pull_request')

        q = q.order_by(ChangesetStatus.version.asc())

        return q

    def _calculate_status(self, statuses):

        """

        Given a list of statuses, calculate the resulting status, according to

        the policy: approve if consensus, reject when at least one reject.

        """

        if not statuses:

            return ChangesetStatus.STATUS_UNDER_REVIEW

        if all(st and st.status == ChangesetStatus.STATUS_APPROVED for st in statuses):

            return ChangesetStatus.STATUS_APPROVED