:copyright: (c) 2013 RhodeCode GmbH, and others.

:license: GPLv3, see LICENSE.md for more details.

"""

import logging

import re

from webob.exc import HTTPBadRequest

from pylons import request, tmpl_context as c, url

from pylons.controllers.util import redirect

from pylons.i18n.translation import _

from kallithea.lib.vcs.utils.hgcompat import unionrepo

from kallithea.lib import helpers as h

from kallithea.lib.base import BaseRepoController, render

from kallithea.lib.auth import LoginRequired, HasRepoPermissionAnyDecorator

from kallithea.lib import diffs

from kallithea.model.db import Repository

from kallithea.lib.diffs import LimitedDiffContainer

from kallithea.controllers.changeset import _ignorews_url,\

    _context_url, get_line_ctx, get_ignore_ws

from kallithea.lib.graphmod import graph_data

from kallithea.lib.compat import json

log = logging.getLogger(__name__)

class CompareController(BaseRepoController):

    def __before__(self):

        super(CompareController, self).__before__()

    @staticmethod

    def _get_changesets(alias, org_repo, org_rev, other_repo, other_rev):

        """

        Returns lists of changesets that can be merged from org_repo@org_rev

        to other_repo@other_rev

        ... and the other way

        ... and the ancestor that would be used for merge

        :param org_repo: repo object, that is most likely the original repo we forked from

        :param org_rev: the revision we want our compare to be made

        :param other_repo: repo object, most likely the fork of org_repo. It has

            all changesets that we need to obtain

        :param other_rev: revision we want out compare to be made on other_repo

        """

        ancestor = None

            org_changesets = []

            other_changesets = []

            ancestor = org_rev

        elif alias == 'hg':

            #case two independent repos

            if org_repo != other_repo:

                hgrepo = unionrepo.unionrepository(other_repo.baseui,

                                                   other_repo.path,

                                                   org_repo.path)

                # all ancestors of other_rev will be in other_repo and

                # rev numbers from hgrepo can be used in other_repo - org_rev ancestors cannot

            #no remote compare do it on the same repository

            else:

                hgrepo = other_repo._repo

            other_revs = hgrepo.revs("ancestors(id(%s)) and not ancestors(id(%s)) and not id(%s)",

                                     other_rev, org_rev, org_rev)

            other_changesets = [other_repo.get_changeset(rev) for rev in other_revs]

            org_revs = hgrepo.revs("ancestors(id(%s)) and not ancestors(id(%s)) and not id(%s)",

                                   org_rev, other_rev, other_rev)

            org_changesets = [org_repo.get_changeset(hgrepo[rev].hex()) for rev in org_revs]

        elif alias == 'git':

            if org_repo != other_repo:

                from dulwich.repo import Repo

                from dulwich.client import SubprocessGitClient

                gitrepo = Repo(org_repo.path)

                SubprocessGitClient(thin_packs=False).fetch(other_repo.path, gitrepo)

                gitrepo_remote = Repo(other_repo.path)

                SubprocessGitClient(thin_packs=False).fetch(org_repo.path, gitrepo_remote)

                revs = []

                for x in gitrepo_remote.get_walker(include=[other_rev],

                                                   exclude=[org_rev]):

                    revs.append(x.commit.id)

                other_changesets = [other_repo.get_changeset(rev) for rev in reversed(revs)]

                if other_changesets:

                    ancestor = other_changesets[0].parents[0].raw_id

                else:

                    # no changesets from other repo, ancestor is the other_rev

                    ancestor = other_rev

            else:

                so, se = org_repo.run_git_command(

                    'log --reverse --pretty="format: %%H" -s %s..%s'

                        % (org_rev, other_rev)

                )

                other_changesets = [org_repo.get_changeset(cs)

                              for cs in re.findall(r'[0-9a-fA-F]{40}', so)]

                so, se = org_repo.run_git_command(

                    'merge-base %s %s' % (org_rev, other_rev)

                )

                ancestor = re.findall(r'[0-9a-fA-F]{40}', so)[0]

            org_changesets = []

        else:

            raise Exception('Bad alias only git and hg is allowed')