# -*- 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; version 2
# of the License or (at your opinion) any later version of the license.
# 
# 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, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA  02110-1301, USA.
import os
import time
import traceback
import logging

from mercurial import ui

from sqlalchemy.exc import DatabaseError
from sqlalchemy.orm import make_transient

from beaker.cache import cache_region, region_invalidate

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 rhodecode import BACKENDS
from rhodecode.lib import helpers as h
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.repo import RepoModel
from rhodecode.model.db import Repository, RhodeCodeUi, CacheInvalidation, \
    UserFollowing, UserLog
from rhodecode.model.caching_query import FromCache

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 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 repos_list.has_key(name):
                    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():
                        repos_list[name] = klass(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):
        """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: give specific repositories list, good for filtering
            this have to be a list of  just the repository names
        """
        if all_repos is None:
            all_repos = [r.repo_name for r in self.sa.query(Repository)\
                .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()]
        for r_name in all_repos:
            r_dbr = self.get(r_name, invalidation_list)
            if r_dbr is not None:
                repo, dbrepo = r_dbr

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

                tmp_d = {}
                tmp_d['name'] = dbrepo.repo_name
                tmp_d['name_sort'] = tmp_d['name'].lower()
                tmp_d['description'] = dbrepo.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'] = dbrepo.user.full_contact
                tmp_d['contact_sort'] = tmp_d['contact']
                tmp_d['owner_sort'] = tmp_d['contact']
                tmp_d['repo_archives'] = list(repo._get_archives())
                tmp_d['last_msg'] = tip.message
                tmp_d['repo'] = repo
                tmp_d['dbrepo'] = dbrepo.get_dict()
                tmp_d['dbrepo_fork'] = dbrepo.fork.get_dict() if dbrepo.fork else {}
                yield tmp_d

    def get(self, repo_name, invalidation_list=None, retval='all'):
        """Returns a tuple of Repository,DbRepository,
        Get's repository from given name, creates BackendInstance and
        propagates it's data from database with all additional information
        
        :param repo_name:
        :param invalidation_list: if a invalidation list is given the get
            method should not manually check if this repository needs 
            invalidation and just invalidate the repositories in list
        :param retval: string specifing what to return one of 'repo','dbrepo',
            'all'if repo or dbrepo is given it'll just lazy load chosen type
            and return None as the second
        """
        if not HasRepoPermissionAny('repository.read', 'repository.write',
                            'repository.admin')(repo_name, 'get repo check'):
            return

        #======================================================================
        # CACHE FUNCTION
        #======================================================================
        @cache_region('long_term')
        def _get_repo(repo_name):

            repo_path = os.path.join(self.repos_path, repo_name)

            try:
                alias = get_scm(repo_path)[0]
                log.debug('Creating instance of %s repository', alias)
                backend = get_backend(alias)
            except VCSError:
                log.error(traceback.format_exc())
                log.error('Perhaps this repository is in db and not in '
                          'filesystem run rescan repositories with '
                          '"destroy old data " option from admin panel')
                return

            if alias == 'hg':
                repo = backend(repo_path, create=False, baseui=make_ui('db'))
                #skip hidden web repository
                if repo._get_hidden():
                    return
            else:
                repo = backend(repo_path, create=False)

            return repo

        pre_invalidate = True
        dbinvalidate = False

        if invalidation_list is not None:
            pre_invalidate = repo_name in invalidation_list

        if pre_invalidate:
            #this returns object to invalidate
            invalidate = self._should_invalidate(repo_name)
            if invalidate:
                log.info('invalidating cache for repository %s', repo_name)
                region_invalidate(_get_repo, None, repo_name)
                self._mark_invalidated(invalidate)
                dbinvalidate = True

        r, dbr = None, None
        if retval == 'repo' or 'all':
            r = _get_repo(repo_name)
        if retval == 'dbrepo' or 'all':
            dbr = RepoModel().get_full(repo_name, cache=True,
                                          invalidate=dbinvalidate)


        return r, dbr



    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 isinstance(repo_id, int):
            return self.sa.query(UserFollowing)\
                    .filter(UserFollowing.follows_repo_id == repo_id).count()
        else:
            return self.sa.query(UserFollowing)\
                    .filter(UserFollowing.follows_repository \
                            == RepoModel().get_by_repo_name(repo_id)).count()

    def get_forks(self, repo_id):
        if isinstance(repo_id, int):
            return self.sa.query(Repository)\
                .filter(Repository.fork_id == repo_id).count()
        else:
            return self.sa.query(Repository)\
                .filter(Repository.fork \
                        == RepoModel().get_by_repo_name(repo_id)).count()


    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()