import datetime

import mercurial.context

import mercurial.node

from kallithea.lib.vcs.backends.base import BaseInMemoryChangeset

from kallithea.lib.vcs.exceptions import RepositoryError

from kallithea.lib.vcs.utils import ascii_str, safe_bytes

class MercurialInMemoryChangeset(BaseInMemoryChangeset):

    def commit(self, message, author, parents=None, branch=None, date=None,

        """

        Performs in-memory commit (doesn't check workdir in any way) and

        returns newly created ``Changeset``. Updates repository's

        ``revisions``.

        :param message: message of the commit

        :param author: full username, i.e. "Joe Doe <joe.doe@example.com>"

        :param parents: single parent or sequence of parents from which commit

          would be derived

        :param date: ``datetime.datetime`` instance. Defaults to

          ``datetime.datetime.now()``.

        :param branch: branch name, as string. If none given, default backend's

          branch would be used.

        :raises ``CommitError``: if any error occurs while committing

        """

        self.check_integrity(parents)

        from .repository import MercurialRepository

        if not isinstance(message, unicode) or not isinstance(author, unicode):

            raise RepositoryError('Given message and author needs to be '

                                  'an <unicode> instance got %r & %r instead'

                                  % (type(message), type(author)))

        if branch is None:

            branch = MercurialRepository.DEFAULT_BRANCH_NAME

        kwargs[b'branch'] = branch

            """

            """

            # check if this path is removed

            if path in (node.path for node in self.removed):

                return None

            # check if this path is added

            for node in self.added:

                if node.path == path:

                        data=node.content,

                        islink=False,

                        isexec=node.is_executable,

                        copysource=False)

            # or changed

            for node in self.changed:

                if node.path == path:

                        data=node.content,

                        islink=False,

                        isexec=node.is_executable,

                        copysource=False)

                                  "changed or removed (%s)" % path)

        parents = [None, None]

        for i, parent in enumerate(self.parents):

            if parent is not None:

                parents[i] = parent._ctx.node()

        if date and isinstance(date, datetime.datetime):

            date = date.strftime('%a, %d %b %Y %H:%M:%S')

        commit_ctx = mercurial.context.memctx(

            repo=self.repository._repo,

            parents=parents,

            text=b'',

            files=self.get_paths(),

            filectxfn=filectxfn,

            user=author,

            date=date,

            extra=kwargs)

        # injecting given _repo params

        commit_ctx._text = safe_bytes(message)

        commit_ctx._user = safe_bytes(author)

        commit_ctx._date = date

        # TODO: Catch exceptions!

        n = self.repository._repo.commitctx(commit_ctx)

        # Returns mercurial node

        self._commit_ctx = commit_ctx  # For reference

        # Update vcs repository object & recreate mercurial _repo

        # new_ctx = self.repository._repo[node]

        # new_tip = ascii_str(self.repository.get_changeset(new_ctx.hex()))

        self.repository.revisions.append(ascii_str(mercurial.node.hex(n)))

        self._repo = self.repository._get_repo(create=False)

        self.repository.branches = self.repository._get_branches()

        tip = self.repository.get_changeset()

        self.reset()

        return tip