# -*- coding: utf-8 -*-
"""
    rhodecode.model.scm
    ~~~~~~~~~~~~~~~~~~~

    Scm model for RhodeCode

    :created_on: Apr 9, 2010
    :author: marcink
    :copyright: (C) 2009-2011 Marcin Kuzminski <marcin@python-works.com>
    :license: GPLv3, see COPYING for more details.
"""
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# 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 General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
import os
import time
import traceback
import logging

from sqlalchemy.exc import DatabaseError

from vcs import get_backend
from vcs.utils.helpers import get_scm
from vcs.exceptions import RepositoryError, VCSError
from vcs.utils.lazy import LazyProperty
from vcs.nodes import FileNode

from rhodecode import BACKENDS
from rhodecode.lib import helpers as h
from rhodecode.lib import safe_str
from rhodecode.lib.auth import HasRepoPermissionAny
from rhodecode.lib.utils import get_repos as get_filesystem_repos, make_ui, \
    action_logger
from rhodecode.model import BaseModel
from rhodecode.model.user import UserModel
from rhodecode.model.db import Repository, RhodeCodeUi, CacheInvalidation, \
    UserFollowing, UserLog

log = logging.getLogger(__name__)


class UserTemp(object):
    def __init__(self, user_id):
        self.user_id = user_id

    def __repr__(self):
        return "<%s('id:%s')>" % (self.__class__.__name__, self.user_id)


class RepoTemp(object):
    def __init__(self, repo_id):
        self.repo_id = repo_id

    def __repr__(self):
        return "<%s('id:%s')>" % (self.__class__.__name__, self.repo_id)

class CachedRepoList(object):

    def __init__(self, db_repo_list, invalidation_list, repos_path,
                 order_by=None):
        self.db_repo_list = db_repo_list
        self.invalidation_list = invalidation_list
        self.repos_path = repos_path
        self.order_by = order_by
        self.reversed = (order_by or '').startswith('-')

    def __len__(self):
        return len(self.db_repo_list)

    def __repr__(self):
        return '<%s (%s)>' % (self.__class__.__name__, self.__len__())

    def __iter__(self):
        for db_repo in self.db_repo_list:
            dbr = db_repo

            # invalidate the repo cache if needed before getting the 
            # scm instance

            scm_invalidate = False
            if self.invalidation_list is not None:
                scm_invalidate = dbr.repo_name in self.invalidation_list

            if scm_invalidate:
                log.info('invalidating cache for repository %s',
                         dbr.repo_name)
                db_repo.set_invalidate

            scmr = db_repo.scm_instance_cached

            #check permission at this level
            if not HasRepoPermissionAny('repository.read',
                                        'repository.write',
                                        'repository.admin')(dbr.repo_name,
                                                            'get repo check'):
                continue


            if scmr is None:
                log.error('%s this repository is present in database but it '
                          'cannot be created as an scm instance',
                          dbr.repo_name)
                continue


            last_change = scmr.last_change
            tip = h.get_changeset_safe(scmr, 'tip')

            tmp_d = {}
            tmp_d['name'] = dbr.repo_name
            tmp_d['name_sort'] = tmp_d['name'].lower()
            tmp_d['description'] = dbr.description
            tmp_d['description_sort'] = tmp_d['description']
            tmp_d['last_change'] = last_change
            tmp_d['last_change_sort'] = time.mktime(last_change \
                                                    .timetuple())
            tmp_d['tip'] = tip.raw_id
            tmp_d['tip_sort'] = tip.revision
            tmp_d['rev'] = tip.revision
            tmp_d['contact'] = dbr.user.full_contact
            tmp_d['contact_sort'] = tmp_d['contact']
            tmp_d['owner_sort'] = tmp_d['contact']
            tmp_d['repo_archives'] = list(scmr._get_archives())
            tmp_d['last_msg'] = tip.message
            tmp_d['repo'] = scmr
            tmp_d['dbrepo'] = dbr.get_dict()
            tmp_d['dbrepo_fork'] = dbr.fork.get_dict() if dbr.fork \
                                                                    else {}
            yield tmp_d

class ScmModel(BaseModel):
    """Generic Scm Model
    """

    @LazyProperty
    def repos_path(self):
        """Get's the repositories root path from database
        """

        q = self.sa.query(RhodeCodeUi).filter(RhodeCodeUi.ui_key == '/').one()

        return q.ui_value

    def repo_scan(self, repos_path=None):
        """Listing of repositories in given path. This path should not be a
        repository itself. Return a dictionary of repository objects

        :param repos_path: path to directory containing repositories
        """

        log.info('scanning for repositories in %s', repos_path)

        if repos_path is None:
            repos_path = self.repos_path

        baseui = make_ui('db')
        repos_list = {}

        for name, path in get_filesystem_repos(repos_path, recursive=True):
            try:
                if name in repos_list:
                    raise RepositoryError('Duplicate repository name %s '
                                    'found in %s' % (name, path))
                else:

                    klass = get_backend(path[0])

                    if path[0] == 'hg' and path[0] in BACKENDS.keys():

                        # for mercurial we need to have an str path
                        repos_list[name] = klass(safe_str(path[1]),
                                                 baseui=baseui)

                    if path[0] == 'git' and path[0] in BACKENDS.keys():
                        repos_list[name] = klass(path[1])
            except OSError:
                continue

        return repos_list

    def get_repos(self, all_repos=None, sort_key=None):
        """
        Get all repos from db and for each repo create it's
        backend instance and fill that backed with information from database

        :param all_repos: list of repository names as strings
            give specific repositories list, good for filtering
        """
        if all_repos is None:
            all_repos = self.sa.query(Repository)\
                        .filter(Repository.group_id == None)\
                        .order_by(Repository.repo_name).all()

        #get the repositories that should be invalidated
        invalidation_list = [str(x.cache_key) for x in \
                             self.sa.query(CacheInvalidation.cache_key)\
                             .filter(CacheInvalidation.cache_active == False)\
                             .all()]

        repo_iter = CachedRepoList(all_repos, invalidation_list,
                                   repos_path=self.repos_path,
                                   order_by=sort_key)

        return repo_iter

    def mark_for_invalidation(self, repo_name):
        """Puts cache invalidation task into db for
        further global cache invalidation

        :param repo_name: this repo that should invalidation take place
        """

        log.debug('marking %s for invalidation', repo_name)
        cache = self.sa.query(CacheInvalidation)\
            .filter(CacheInvalidation.cache_key == repo_name).scalar()

        if cache:
            #mark this cache as inactive
            cache.cache_active = False
        else:
            log.debug('cache key not found in invalidation db -> creating one')
            cache = CacheInvalidation(repo_name)

        try:
            self.sa.add(cache)
            self.sa.commit()
        except (DatabaseError,):
            log.error(traceback.format_exc())
            self.sa.rollback()

    def toggle_following_repo(self, follow_repo_id, user_id):

        f = self.sa.query(UserFollowing)\
            .filter(UserFollowing.follows_repo_id == follow_repo_id)\
            .filter(UserFollowing.user_id == user_id).scalar()

        if f is not None:

            try:
                self.sa.delete(f)
                self.sa.commit()
                action_logger(UserTemp(user_id),
                              'stopped_following_repo',
                              RepoTemp(follow_repo_id))
                return
            except:
                log.error(traceback.format_exc())
                self.sa.rollback()
                raise

        try:
            f = UserFollowing()
            f.user_id = user_id
            f.follows_repo_id = follow_repo_id
            self.sa.add(f)
            self.sa.commit()
            action_logger(UserTemp(user_id),
                          'started_following_repo',
                          RepoTemp(follow_repo_id))
        except:
            log.error(traceback.format_exc())
            self.sa.rollback()
            raise

    def toggle_following_user(self, follow_user_id, user_id):
        f = self.sa.query(UserFollowing)\
            .filter(UserFollowing.follows_user_id == follow_user_id)\
            .filter(UserFollowing.user_id == user_id).scalar()

        if f is not None:
            try:
                self.sa.delete(f)
                self.sa.commit()
                return
            except:
                log.error(traceback.format_exc())
                self.sa.rollback()
                raise

        try:
            f = UserFollowing()
            f.user_id = user_id
            f.follows_user_id = follow_user_id
            self.sa.add(f)
            self.sa.commit()
        except:
            log.error(traceback.format_exc())
            self.sa.rollback()
            raise

    def is_following_repo(self, repo_name, user_id, cache=False):
        r = self.sa.query(Repository)\
            .filter(Repository.repo_name == repo_name).scalar()

        f = self.sa.query(UserFollowing)\
            .filter(UserFollowing.follows_repository == r)\
            .filter(UserFollowing.user_id == user_id).scalar()

        return f is not None

    def is_following_user(self, username, user_id, cache=False):
        u = UserModel(self.sa).get_by_username(username)

        f = self.sa.query(UserFollowing)\
            .filter(UserFollowing.follows_user == u)\
            .filter(UserFollowing.user_id == user_id).scalar()

        return f is not None

    def get_followers(self, repo_id):
        if not isinstance(repo_id, int):
            repo_id = getattr(Repository.by_repo_name(repo_id), 'repo_id')

        return self.sa.query(UserFollowing)\
                .filter(UserFollowing.follows_repo_id == repo_id).count()

    def get_forks(self, repo_id):
        if not isinstance(repo_id, int):
            repo_id = getattr(Repository.by_repo_name(repo_id), 'repo_id')

        return self.sa.query(Repository)\
                .filter(Repository.fork_id == repo_id).count()

    def pull_changes(self, repo_name, username):
        dbrepo = Repository.by_repo_name(repo_name)
        repo = dbrepo.scm_instance
        try:
            extras = {'ip': '',
                      'username': username,
                      'action': 'push_remote',
                      'repository': repo_name}

            #inject ui extra param to log this action via push logger
            for k, v in extras.items():
                repo._repo.ui.setconfig('rhodecode_extras', k, v)

            repo.pull(dbrepo.clone_uri)
            self.mark_for_invalidation(repo_name)
        except:
            log.error(traceback.format_exc())
            raise


    def commit_change(self, repo, repo_name, cs, user, author, message, content,
                      f_path):

        if repo.alias == 'hg':
            from vcs.backends.hg import MercurialInMemoryChangeset as IMC
        elif repo.alias == 'git':
            from vcs.backends.git import GitInMemoryChangeset as IMC

        # decoding here will force that we have proper encoded values
        # in any other case this will throw exceptions and deny commit
        content = safe_str(content)
        message = safe_str(message)
        path = safe_str(f_path)
        author = safe_str(author)
        m = IMC(repo)
        m.change(FileNode(path, content))
        tip = m.commit(message=message,
                 author=author,
                 parents=[cs], branch=cs.branch)

        new_cs = tip.short_id
        action = 'push_local:%s' % new_cs

        action_logger(user, action, repo_name)

        self.mark_for_invalidation(repo_name)


    def get_unread_journal(self):
        return self.sa.query(UserLog).count()

    def _should_invalidate(self, repo_name):
        """Looks up database for invalidation signals for this repo_name

        :param repo_name:
        """

        ret = self.sa.query(CacheInvalidation)\
            .filter(CacheInvalidation.cache_key == repo_name)\
            .filter(CacheInvalidation.cache_active == False)\
            .scalar()

        return ret

    def _mark_invalidated(self, cache_key):
        """ Marks all occurrences of cache to invalidation as already
        invalidated

        :param cache_key:
        """

        if cache_key:
            log.debug('marking %s as already invalidated', cache_key)
        try:
            cache_key.cache_active = True
            self.sa.add(cache_key)
            self.sa.commit()
        except (DatabaseError,):
            log.error(traceback.format_exc())
            self.sa.rollback()