#!/usr/bin/env python
# encoding: utf-8
# Model for RhodeCode
# Copyright (C) 2009-2010 Marcin Kuzminski <marcin@python-works.com>
# 
# 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.
"""
Created on April 9, 2010
Model for RhodeCode
@author: marcink
"""
from beaker.cache import cache_region, region_invalidate
from mercurial import ui
from rhodecode import BACKENDS
from rhodecode.lib import helpers as h
from rhodecode.lib.auth import HasRepoPermissionAny
from rhodecode.lib.utils import get_repos
from rhodecode.model import meta
from rhodecode.model.db import Repository, User, RhodeCodeUi, CacheInvalidation
from rhodecode.model.caching_query import FromCache
from sqlalchemy.orm import joinedload
from sqlalchemy.orm.session import make_transient
from vcs import get_backend
from vcs.utils.helpers import get_scm
from vcs.exceptions import RepositoryError, VCSError
from vcs.utils.lazy import LazyProperty
import traceback
import logging
import os
import time

log = logging.getLogger(__name__)

class ScmModel(object):
    """
    Mercurial Model
    """

    def __init__(self):
        self.sa = meta.Session()

    @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, baseui, initial=False):
        """
        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
        :param baseui
        :param initial: initial scan
        """
        log.info('scanning for repositories in %s', repos_path)

        if not isinstance(baseui, ui.ui):
            baseui = ui.ui()
        repos_list = {}

        for name, path in get_repos(repos_path):
            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
        """
        if not all_repos:
            all_repos = self.sa.query(Repository)\
                .order_by(Repository.repo_name).all()

        for r in all_repos:

            repo = self.get(r.repo_name)

            if repo is not None:
                last_change = repo.last_change
                tip = h.get_changeset_safe(repo, 'tip')

                tmp_d = {}
                tmp_d['name'] = repo.name
                tmp_d['name_sort'] = tmp_d['name'].lower()
                tmp_d['description'] = repo.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'] = repo.dbrepo.user.full_contact
                tmp_d['contact_sort'] = tmp_d['contact']
                tmp_d['repo_archives'] = list(repo._get_archives())
                tmp_d['last_msg'] = tip.message
                tmp_d['repo'] = repo
                yield tmp_d

    def get_repo(self, repo_name):
        return self.get(repo_name)

    def get(self, repo_name):
        """
        Get's repository from given name, creates BackendInstance and
        propagates it's data from database with all additional information
        :param repo_name:
        """
        if not HasRepoPermissionAny('repository.read', 'repository.write',
                            'repository.admin')(repo_name, 'get repo check'):
            return

        @cache_region('long_term')
        def _get_repo(repo_name):

            repo_path = os.path.join(self.repos_path, repo_name)
            alias = get_scm(repo_path)[0]

            log.debug('Creating instance of %s repository', alias)
            backend = get_backend(alias)

            #TODO: get the baseui from somewhere for this
            if alias == 'hg':
                repo = backend(repo_path, create=False, baseui=None)
                #skip hidden web repository
                if repo._get_hidden():
                    return
            else:
                repo = backend(repo_path, create=False)

            dbrepo = self.sa.query(Repository)\
                .options(joinedload(Repository.fork))\
                .options(joinedload(Repository.user))\
                .filter(Repository.repo_name == repo_name)\
                .scalar()
            make_transient(dbrepo)
            repo.dbrepo = dbrepo
            return repo

        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)

        return _get_repo(repo_name)



    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:
            log.error(traceback.format_exc())
            self.sa.rollback()





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

        ret = self.sa.query(CacheInvalidation)\
            .options(FromCache('sql_cache_short',
                           'get_invalidation_%s' % repo_name))\
            .filter(CacheInvalidation.cache_key == repo_name)\
            .filter(CacheInvalidation.cache_active == False)\
            .scalar()

        return ret

    def _mark_invalidated(self, cache_key):
        """
        Marks all occurences of cache to invaldation as already invalidated
        @param repo_name:
        """
        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:
            log.error(traceback.format_exc())
            self.sa.rollback()