# Copyright (C) 2010-2020 RhodeCode GmbH
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License, version 3
# (only), as published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# This program is dual-licensed. If you wish to learn more about the
# RhodeCode Enterprise Edition, including its added features, Support services,
# and proprietary license terms, please see https://rhodecode.com/licenses/


import logging

from pyramid.httpexceptions import HTTPNotFound, HTTPFound

from pyramid.renderers import render
from pyramid.response import Response

from rhodecode.apps._base import RepoAppView
import rhodecode.lib.helpers as h
from rhodecode.lib import ext_json
from rhodecode.lib.auth import (
    LoginRequired, HasRepoPermissionAnyDecorator)

from rhodecode.lib.graphmod import _colored, _dagwalker
from rhodecode.lib.helpers import RepoPage
from rhodecode.lib.utils2 import str2bool
from rhodecode.lib.str_utils import safe_int, safe_str
from rhodecode.lib.vcs.exceptions import (
    RepositoryError, CommitDoesNotExistError,
    CommitError, NodeDoesNotExistError, EmptyRepositoryError)

log = logging.getLogger(__name__)

DEFAULT_CHANGELOG_SIZE = 20


class RepoChangelogView(RepoAppView):

    def _get_commit_or_redirect(self, commit_id, redirect_after=True):
        """
        This is a safe way to get commit. If an error occurs it redirects to
        tip with proper message

        :param commit_id: id of commit to fetch
        :param redirect_after: toggle redirection
        """
        _ = self.request.translate

        try:
            return self.rhodecode_vcs_repo.get_commit(commit_id)
        except EmptyRepositoryError:
            if not redirect_after:
                return None

            h.flash(h.literal(
                _('There are no commits yet')), category='warning')
            raise HTTPFound(
                h.route_path('repo_summary', repo_name=self.db_repo_name))

        except (CommitDoesNotExistError, LookupError):
            msg = _('No such commit exists for this repository')
            h.flash(msg, category='error')
            raise HTTPNotFound()
        except RepositoryError as e:
            h.flash(h.escape(safe_str(e)), category='error')
            raise HTTPNotFound()

    def _graph(self, repo, commits, prev_data=None, next_data=None):
        """
        Generates a DAG graph for repo

        :param repo: repo instance
        :param commits: list of commits
        """
        if not commits:
            return ext_json.str_json([]), ext_json.str_json([])

        def serialize(commit, parents=True):
            data = dict(
                raw_id=commit.raw_id,
                idx=commit.idx,
                branch=None,
            )
            if parents:
                data['parents'] = [
                    serialize(x, parents=False) for x in commit.parents]
            return data

        prev_data = prev_data or []
        next_data = next_data or []

        current = [serialize(x) for x in commits]

        commits = prev_data + current + next_data

        dag = _dagwalker(repo, commits)

        data = [[commit_id, vtx, edges, branch]
                for commit_id, vtx, edges, branch in _colored(dag)]
        return ext_json.str_json(data), ext_json.str_json(current)

    def _check_if_valid_branch(self, branch_name, repo_name, f_path):
        if branch_name not in self.rhodecode_vcs_repo.branches_all:
            h.flash(u'Branch {} is not found.'.format(h.escape(safe_str(branch_name))),
                    category='warning')
            redirect_url = h.route_path(
                'repo_commits_file', repo_name=repo_name,
                commit_id=branch_name, f_path=f_path or '')
            raise HTTPFound(redirect_url)

    def _load_changelog_data(
            self, c, collection, page, chunk_size, branch_name=None,
            dynamic=False, f_path=None, commit_id=None):

        def url_generator(page_num):
            query_params = {
                'page': page_num
            }

            if branch_name:
                query_params.update({
                    'branch': branch_name
                })

            if f_path:
                # changelog for file
                return h.route_path(
                    'repo_commits_file',
                    repo_name=c.rhodecode_db_repo.repo_name,
                    commit_id=commit_id, f_path=f_path,
                    _query=query_params)
            else:
                return h.route_path(
                    'repo_commits',
                    repo_name=c.rhodecode_db_repo.repo_name, _query=query_params)

        c.total_cs = len(collection)
        c.showing_commits = min(chunk_size, c.total_cs)
        c.pagination = RepoPage(collection, page=page, item_count=c.total_cs,
                                items_per_page=chunk_size, url_maker=url_generator)

        c.next_page = c.pagination.next_page
        c.prev_page = c.pagination.previous_page

        if dynamic:
            if self.request.GET.get('chunk') != 'next':
                c.next_page = None
            if self.request.GET.get('chunk') != 'prev':
                c.prev_page = None

        page_commit_ids = [x.raw_id for x in c.pagination]
        c.comments = c.rhodecode_db_repo.get_comments(page_commit_ids)
        c.statuses = c.rhodecode_db_repo.statuses(page_commit_ids)

    def load_default_context(self):
        c = self._get_local_tmpl_context(include_app_defaults=True)

        c.rhodecode_repo = self.rhodecode_vcs_repo

        return c

    @LoginRequired()
    @HasRepoPermissionAnyDecorator(
        'repository.read', 'repository.write', 'repository.admin')
    def repo_changelog(self):
        c = self.load_default_context()

        commit_id = self.request.matchdict.get('commit_id')
        f_path = self._get_f_path(self.request.matchdict)
        show_hidden = str2bool(self.request.GET.get('evolve'))

        chunk_size = 20

        c.branch_name = branch_name = self.request.GET.get('branch') or ''
        c.book_name = book_name = self.request.GET.get('bookmark') or ''
        c.f_path = f_path
        c.commit_id = commit_id
        c.show_hidden = show_hidden

        hist_limit = safe_int(self.request.GET.get('limit')) or None

        p = safe_int(self.request.GET.get('page', 1), 1)

        c.selected_name = branch_name or book_name
        if not commit_id and branch_name:
            self._check_if_valid_branch(branch_name, self.db_repo_name, f_path)

        c.changelog_for_path = f_path
        pre_load = self.get_commit_preload_attrs()

        partial_xhr = self.request.environ.get('HTTP_X_PARTIAL_XHR')

        try:
            if f_path:
                log.debug('generating changelog for path %s', f_path)
                # get the history for the file !
                base_commit = self.rhodecode_vcs_repo.get_commit(commit_id)

                try:
                    collection = base_commit.get_path_history(
                        f_path, limit=hist_limit, pre_load=pre_load)
                    if collection and partial_xhr:
                        # for ajax call we remove first one since we're looking
                        # at it right now in the context of a file commit
                        collection.pop(0)
                except (NodeDoesNotExistError, CommitError):
                    # this node is not present at tip!
                    try:
                        commit = self._get_commit_or_redirect(commit_id)
                        collection = commit.get_path_history(f_path)
                    except RepositoryError as e:
                        h.flash(safe_str(e), category='warning')
                        redirect_url = h.route_path(
                            'repo_commits', repo_name=self.db_repo_name)
                        raise HTTPFound(redirect_url)
                collection = list(reversed(collection))
            else:
                collection = self.rhodecode_vcs_repo.get_commits(
                    branch_name=branch_name, show_hidden=show_hidden,
                    pre_load=pre_load, translate_tags=False)

            self._load_changelog_data(
                c, collection, p, chunk_size, c.branch_name,
                f_path=f_path, commit_id=commit_id)

        except EmptyRepositoryError as e:
            h.flash(h.escape(safe_str(e)), category='warning')
            raise HTTPFound(
                h.route_path('repo_summary', repo_name=self.db_repo_name))
        except HTTPFound:
            raise
        except (RepositoryError, CommitDoesNotExistError, Exception) as e:
            log.exception(safe_str(e))
            h.flash(h.escape(safe_str(e)), category='error')

            if commit_id:
                # from single commit page, we redirect to main commits
                raise HTTPFound(
                    h.route_path('repo_commits', repo_name=self.db_repo_name))
            else:
                # otherwise we redirect to summary
                raise HTTPFound(
                    h.route_path('repo_summary', repo_name=self.db_repo_name))



        if partial_xhr or self.request.environ.get('HTTP_X_PJAX'):
            # case when loading dynamic file history in file view
            # loading from ajax, we don't want the first result, it's popped
            # in the code above
            html = render(
                'rhodecode:templates/commits/changelog_file_history.mako',
                self._get_template_context(c), self.request)
            return Response(html)

        commit_ids = []
        if not f_path:
            # only load graph data when not in file history mode
            commit_ids = c.pagination

        c.graph_data, c.graph_commits = self._graph(
            self.rhodecode_vcs_repo, commit_ids)

        return self._get_template_context(c)

    @LoginRequired()
    @HasRepoPermissionAnyDecorator(
        'repository.read', 'repository.write', 'repository.admin')
    def repo_commits_elements(self):
        c = self.load_default_context()
        commit_id = self.request.matchdict.get('commit_id')
        f_path = self._get_f_path(self.request.matchdict)
        show_hidden = str2bool(self.request.GET.get('evolve'))

        chunk_size = 20
        hist_limit = safe_int(self.request.GET.get('limit')) or None

        def wrap_for_error(err):
            html = '<tr>' \
                   '<td colspan="9" class="alert alert-error">ERROR: {}</td>' \
                   '</tr>'.format(err)
            return Response(html)

        c.branch_name = branch_name = self.request.GET.get('branch') or ''
        c.book_name = book_name = self.request.GET.get('bookmark') or ''
        c.f_path = f_path
        c.commit_id = commit_id
        c.show_hidden = show_hidden

        c.selected_name = branch_name or book_name
        if branch_name and branch_name not in self.rhodecode_vcs_repo.branches_all:
            return wrap_for_error(
                safe_str('Branch: {} is not valid'.format(branch_name)))

        pre_load = self.get_commit_preload_attrs()

        if f_path:
            try:
                base_commit = self.rhodecode_vcs_repo.get_commit(commit_id)
            except (RepositoryError, CommitDoesNotExistError, Exception) as e:
                log.exception(safe_str(e))
                raise HTTPFound(
                    h.route_path('repo_commits', repo_name=self.db_repo_name))

            collection = base_commit.get_path_history(
                f_path, limit=hist_limit, pre_load=pre_load)
            collection = list(reversed(collection))
        else:
            collection = self.rhodecode_vcs_repo.get_commits(
                branch_name=branch_name, show_hidden=show_hidden, pre_load=pre_load,
                translate_tags=False)

        p = safe_int(self.request.GET.get('page', 1), 1)
        try:
            self._load_changelog_data(
                c, collection, p, chunk_size, dynamic=True,
                f_path=f_path, commit_id=commit_id)
        except EmptyRepositoryError as e:
            return wrap_for_error(safe_str(e))
        except (RepositoryError, CommitDoesNotExistError, Exception) as e:
            log.exception('Failed to fetch commits')
            return wrap_for_error(safe_str(e))

        prev_data = None
        next_data = None

        try:
            prev_graph = ext_json.json.loads(self.request.POST.get('graph') or '{}')
        except ext_json.json.JSONDecodeError:
            prev_graph = {}

        if self.request.GET.get('chunk') == 'prev':
            next_data = prev_graph
        elif self.request.GET.get('chunk') == 'next':
            prev_data = prev_graph

        commit_ids = []
        if not f_path:
            # only load graph data when not in file history mode
            commit_ids = c.pagination

        c.graph_data, c.graph_commits = self._graph(
            self.rhodecode_vcs_repo, commit_ids,
            prev_data=prev_data, next_data=next_data)

        return self._get_template_context(c)