# copyright 2003-2012 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr

#

# This file is part of CubicWeb.

#

# CubicWeb is free software: you can redistribute it and/or modify it under the

# terms of the GNU Lesser General Public License as published by the Free

# Software Foundation, either version 2.1 of the License, or (at your option)

# any later version.

#

# CubicWeb 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 Lesser General Public License for more

# details.

#

# You should have received a copy of the GNU Lesser General Public License along

# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.

"""Server subcube of cubicweb : defines objects used only on the server

(repository) side

The server module contains functions to initialize a new repository.

"""

__docformat__ = "restructuredtext en"

import sys

from os.path import join, exists

from glob import glob

from logilab.common.modutils import LazyObject

from logilab.common.textutils import splitstrip

from logilab.common.registry import yes

from yams import BASE_GROUPS

from cubicweb import CW_SOFTWARE_ROOT

from cubicweb.appobject import AppObject

class ShuttingDown(BaseException):

    """raised when trying to access some resources while the repository is

    shutting down. Inherit from BaseException so that `except Exception` won't

    catch it.

    """

# server-side services #########################################################

class Service(AppObject):

    """Base class for services.

    A service is a selectable object that performs an action server-side.

    Use :class:`cubicweb.dbapi.Connection.call_service` to call them from

    the web-side.

    When inheriting this class, do not forget to define at least the __regid__

    attribute (and probably __select__ too).

    """

    __registry__ = 'services'

    __select__ = yes()

    def call(self, **kwargs):

        raise NotImplementedError

# server-side debugging ########################################################

# server debugging flags. They may be combined using binary operators.

#:no debug information

DBG_NONE = 0  #: no debug information

#: rql execution information

DBG_RQL  = 1

#: executed sql

DBG_SQL  = 2

#: repository events

DBG_REPO = 4

#: multi-sources

DBG_MS   = 8

#: hooks

DBG_HOOKS = 16

#: operations

DBG_OPS = 32

#: more verbosity

DBG_MORE = 64

#: all level enabled

DBG_ALL  = DBG_RQL + DBG_SQL + DBG_REPO + DBG_MS + DBG_HOOKS + DBG_OPS + DBG_MORE

#: current debug mode

DEBUG = 0

def set_debug(debugmode):

    """change the repository debugging mode"""

    global DEBUG

    if not debugmode:

        DEBUG = 0

        return

    if isinstance(debugmode, basestring):

        for mode in splitstrip(debugmode, sep='|'):

            DEBUG |= globals()[mode]

    else:

        DEBUG |= debugmode

class debugged(object):

    """Context manager and decorator to help debug the repository.

    It can be used either as a context manager:

    >>> with debugged(server.DBG_RQL | server.DBG_REPO):

    ...     # some code in which you want to debug repository activity,

    ...     # seing information about RQL being executed an repository events.

    or as a function decorator:

    >>> @debugged(server.DBG_RQL | server.DBG_REPO)

    ... def some_function():

    ...     # some code in which you want to debug repository activity,

    ...     # seing information about RQL being executed an repository events

    The debug mode will be reset to its original value when leaving the "with"

    block or the decorated function.

    """

    def __init__(self, debugmode):

        self.debugmode = debugmode

        self._clevel = None

    def __enter__(self):

        """enter with block"""

        self._clevel = DEBUG

        set_debug(self.debugmode)

    def __exit__(self, exctype, exc, traceback):

        """leave with block"""

        set_debug(self._clevel)

        return traceback is None

    def __call__(self, func):

        """decorate function"""

        def wrapped(*args, **kwargs):

            _clevel = DEBUG

            set_debug(self.debugmode)

            try:

                return func(*args, **kwargs)

            finally:

                set_debug(self._clevel)

        return wrapped

# database initialization ######################################################

def create_user(session, login, pwd, *groups):

    # monkey patch this method if you want to customize admin/anon creation

    # (that maybe necessary if you change CWUser's schema)

    user = session.create_entity('CWUser', login=login, upassword=pwd)

    for group in groups:

        session.execute('SET U in_group G WHERE U eid %(u)s, G name %(group)s',

                        {'u': user.eid, 'group': group})

    return user

def init_repository(config, interactive=True, drop=False, vreg=None):

    """initialise a repository database by creating tables add filling them

    with the minimal set of entities (ie at least the schema, base groups and

    a initial user)

    """

    from cubicweb.dbapi import in_memory_repo_cnx

    from cubicweb.server.repository import Repository

    from cubicweb.server.utils import manager_userpasswd

    from cubicweb.server.sqlutils import sqlexec, sqlschema, sql_drop_all_user_tables

    from cubicweb.server.sqlutils import _SQL_DROP_ALL_USER_TABLES_FILTER_FUNCTION as drop_filter

    # configuration to avoid db schema loading and user'state checking

    # on connection

    config.creating = True

    config.consider_user_state = False

    config.cubicweb_appobject_path = set(('hooks', 'entities'))

    config.cube_appobject_path = set(('hooks', 'entities'))

    # only enable the system source at initialization time

    repo = Repository(config, vreg=vreg)

    schema = repo.schema

    sourcescfg = config.sources()

    source = sourcescfg['system']

    driver = source['db-driver']

    sqlcnx = repo.system_source.get_connection()

    sqlcursor = sqlcnx.cursor()

    execute = sqlcursor.execute

    if drop:

        helper = database.get_db_helper(driver)

        dropsql = sql_drop_all_user_tables(helper, sqlcursor)

        # We may fail dropping some tables because of table dependencies, in a first pass.

        # So, we try a second drop sequence to drop remaining tables if needed.

        # Note that 2 passes is an arbitrary choice as it seems enougth for our usecases.

        # (looping may induce infinite recursion when user have no right for example)

        # Here we try to keep code simple and backend independant. That why we don't try to

        # distinguish remaining tables (wrong right, dependencies, ...).

        failed = sqlexec(dropsql, execute, cnx=sqlcnx,

                         pbtitle='-> dropping tables (first pass)')

        if failed:

            failed = sqlexec(failed, execute, cnx=sqlcnx,

                             pbtitle='-> dropping tables (second pass)')

            remainings = filter(drop_filter, helper.list_tables(sqlcursor))

            assert not remainings, 'Remaining tables: %s' % ', '.join(remainings)

    _title = '-> creating tables '

    print _title,

    # schema entities and relations tables

    # can't skip entities table even if system source doesn't support them,

    # they are used sometimes by generated sql. Keeping them empty is much

    # simpler than fixing this...

    schemasql = sqlschema(schema, driver)

    #skip_entities=[str(e) for e in schema.entities()

    #               if not repo.system_source.support_entity(str(e))])

    sqlexec(schemasql, execute, pbtitle=_title, delimiter=';;')

    sqlcursor.close()

    sqlcnx.commit()

    sqlcnx.close()

    session = repo.internal_session()

    # insert entity representing the system source

    ssource = session.create_entity('CWSource', type=u'native', name=u'system')

    repo.system_source.eid = ssource.eid

    session.execute('SET X cw_source X WHERE X eid %(x)s', {'x': ssource.eid})

    # insert base groups and default admin

    print '-> inserting default user and default groups.'

    try:

        login = unicode(sourcescfg['admin']['login'])

        pwd = sourcescfg['admin']['password']

    except KeyError:

        if interactive:

            msg = 'enter login and password of the initial manager account'

            login, pwd = manager_userpasswd(msg=msg, confirm=True)

        else:

            login, pwd = unicode(source['db-user']), source['db-password']

    # sort for eid predicatability as expected in some server tests

    for group in sorted(BASE_GROUPS):

        session.create_entity('CWGroup', name=unicode(group))

    admin = create_user(session, login, pwd, 'managers')

    session.execute('SET X owned_by U WHERE X is IN (CWGroup,CWSource), U eid %(u)s',

                    {'u': admin.eid})

    session.commit()

    session.close()

    repo.shutdown()

    # reloging using the admin user

    config._cubes = None # avoid assertion error

    repo, cnx = in_memory_repo_cnx(config, login, password=pwd)

    repo.system_source.eid = ssource.eid # redo this manually

    assert len(repo.sources) == 1, repo.sources

    handler = config.migration_handler(schema, interactive=False,

                                       cnx=cnx, repo=repo)

    # install additional driver specific sql files

    handler.cmd_install_custom_sql_scripts()

    for cube in reversed(config.cubes()):

        handler.cmd_install_custom_sql_scripts(cube)

    # serialize the schema

    initialize_schema(config, schema, handler)

    # yoo !

    cnx.commit()

    repo.system_source.init_creating()

    cnx.commit()

    cnx.close()

    repo.shutdown()

    # restore initial configuration

    config.creating = False

    config.consider_user_state = True

    # (drop instance attribute to get back to class attribute)

    del config.cubicweb_appobject_path

    del config.cube_appobject_path

    print '-> database for instance %s initialized.' % config.appid

def initialize_schema(config, schema, mhandler, event='create'):

    from cubicweb.server.schemaserial import serialize_schema

    session = mhandler.session

    cubes = config.cubes()

    # deactivate every hooks but those responsible to set metadata

    # so, NO INTEGRITY CHECKS are done, to have quicker db creation.

    # Active integrity is kept else we may pb such as two default

    # workflows for one entity type.

    with session.deny_all_hooks_but('metadata', 'activeintegrity'):

        # execute cubicweb's pre<event> script

        mhandler.cmd_exec_event_script('pre%s' % event)

        # execute cubes pre<event> script if any

        for cube in reversed(cubes):

            mhandler.cmd_exec_event_script('pre%s' % event, cube)

        # execute instance's pre<event> script (useful in tests)

        mhandler.cmd_exec_event_script('pre%s' % event, apphome=True)

        # enter instance'schema into the database

        session.set_cnxset()

        serialize_schema(session, schema)

        # execute cubicweb's post<event> script

        mhandler.cmd_exec_event_script('post%s' % event)

        # execute cubes'post<event> script if any

        for cube in reversed(cubes):

            mhandler.cmd_exec_event_script('post%s' % event, cube)

        # execute instance's post<event> script (useful in tests)

        mhandler.cmd_exec_event_script('post%s' % event, apphome=True)

# sqlite'stored procedures have to be registered at connection opening time

from logilab.database import SQL_CONNECT_HOOKS

# add to this set relations which should have their add security checking done

# *BEFORE* adding the actual relation (done after by default)

BEFORE_ADD_RELATIONS = set(('owned_by',))

# add to this set relations which should have their add security checking done

# *at COMMIT TIME* (done after by default)

ON_COMMIT_ADD_RELATIONS = set(())

# available sources registry

SOURCE_TYPES = {'native': LazyObject('cubicweb.server.sources.native', 'NativeSQLSource'),

                'datafeed': LazyObject('cubicweb.server.sources.datafeed', 'DataFeedSource'),

                'ldapfeed': LazyObject('cubicweb.server.sources.ldapfeed', 'LDAPFeedSource'),

                'pyrorql': LazyObject('cubicweb.server.sources.pyrorql', 'PyroRQLSource'),

                'zmqrql': LazyObject('cubicweb.server.sources.zmqrql', 'ZMQRQLSource'),

                }