# copyright 2003-2010 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/>.

"""cubicweb-ctl commands and command handlers specific to the repository"""

__docformat__ = 'restructuredtext en'

# *ctl module should limit the number of import to be imported as quickly as

# possible (for cubicweb-ctl reactivity, necessary for instance for usable bash

# completion). So import locally in command helpers.

import sys

import os

from logilab.common import nullobject

from logilab.common.configuration import Configuration

from logilab.common.shellutils import ASK

from cubicweb import AuthenticationError, ExecutionError, ConfigurationError

from cubicweb.toolsutils import Command, CommandHandler, underline_title

from cubicweb.cwctl import CWCTL

from cubicweb.server import SOURCE_TYPES

from cubicweb.server.serverconfig import (

    USER_OPTIONS, ServerConfiguration, SourceConfiguration,

    ask_source_config, generate_source_config)

# utility functions ###########################################################

def source_cnx(source, dbname=None, special_privs=False, verbose=True):

    """open and return a connection to the system database defined in the

    given server.serverconfig

    """

    from getpass import getpass

    from logilab.database import get_connection, get_db_helper

    dbhost = source.get('db-host')

    if dbname is None:

        dbname = source['db-name']

    driver = source['db-driver']

    dbhelper = get_db_helper(driver)

    if verbose:

        print '-> connecting to %s database' % driver,

        if dbhost:

            print '%s@%s' % (dbname, dbhost),

        else:

            print dbname,

    if dbhelper.users_support:

        if not special_privs and source.get('db-user'):

            user = source['db-user']

            if verbose:

                print 'as', user

            password = source.get('db-password')

        else:

            if verbose:

                print

            if special_privs:

                print 'WARNING'

                print ('the user will need the following special access rights '

                       'on the database:')

                print special_privs

                print

            default_user = source.get('db-user', os.environ.get('USER', ''))

            user = raw_input('Connect as user ? [%r]: ' % default_user)

            user = user.strip() or default_user

            if user == source.get('db-user'):

                password = source['db-password']

            else:

                password = getpass('password: ')

    else:

        user = password = None

    extra_args = source.get('db-extra-arguments')

    extra = extra_args and {'extra_args': extra_args} or {}

    cnx = get_connection(driver, dbhost, dbname, user, password=password,

                         port=source.get('db-port'),

                         **extra)

    try:

        cnx.logged_user = user

    except AttributeError:

        # C object, __slots__

        from logilab.database import _SimpleConnectionWrapper

        cnx = _SimpleConnectionWrapper(cnx)

        cnx.logged_user = user

    return cnx

def system_source_cnx(source, dbms_system_base=False,

                      special_privs='CREATE/DROP DATABASE', verbose=True):

    """shortcut to get a connextion to the instance system database

    defined in the given config. If <dbms_system_base> is True,

    connect to the dbms system database instead (for task such as

    create/drop the instance database)

    """

    if dbms_system_base:

        from logilab.database import get_db_helper

        system_db = get_db_helper(source['db-driver']).system_database()

        return source_cnx(source, system_db, special_privs=special_privs, verbose=verbose)

    return source_cnx(source, special_privs=special_privs, verbose=verbose)

def _db_sys_cnx(source, special_privs, verbose=True):

    """return a connection on the RDMS system table (to create/drop a user or a

    database)

    """

    import logilab.common as lgp

    from logilab.database import get_db_helper

    lgp.USE_MX_DATETIME = False

    driver = source['db-driver']

    helper = get_db_helper(driver)

    # connect on the dbms system base to create our base

    cnx = system_source_cnx(source, True, special_privs=special_privs,

                            verbose=verbose)

    # disable autocommit (isolation_level(1)) because DROP and

    # CREATE DATABASE can't be executed in a transaction

    try:

        cnx.set_isolation_level(0)

    except AttributeError:

        # set_isolation_level() is psycopg specific

        pass

    return cnx

def repo_cnx(config):

    """return a in-memory repository and a db api connection it"""

    from cubicweb.dbapi import in_memory_cnx

    from cubicweb.server.utils import manager_userpasswd

    try:

        login = config.sources()['admin']['login']

        pwd = config.sources()['admin']['password']

    except KeyError:

        login, pwd = manager_userpasswd()

    while True:

        try:

            return in_memory_cnx(config, login, password=pwd)

        except AuthenticationError:

            print '-> Error: wrong user/password.'

            # reset cubes else we'll have an assertion error on next retry

            config._cubes = None

        login, pwd = manager_userpasswd()

# repository specific command handlers ########################################

class RepositoryCreateHandler(CommandHandler):

    cmdname = 'create'

    cfgname = 'repository'

    def bootstrap(self, cubes, inputlevel=0):

        """create an instance by copying files from the given cube and by asking

        information necessary to build required configuration files

        """

        config = self.config

        print underline_title('Configuring the repository')

        config.input_config('email', inputlevel)

        # ask for pyro configuration if pyro is activated and we're not using a

        # all-in-one config, in which case this is done by the web side command

        # handler

        if config.pyro_enabled() and config.name != 'all-in-one':

            config.input_config('pyro', inputlevel)

        print '\n'+underline_title('Configuring the sources')

        sourcesfile = config.sources_file()

        # XXX hack to make Method('default_instance_id') usable in db option

        # defs (in native.py)

        sconfig = SourceConfiguration(config,

                                      options=SOURCE_TYPES['native'].options)

        sconfig.input_config(inputlevel=inputlevel)

        sourcescfg = {'system': sconfig}

        print

        sconfig = Configuration(options=USER_OPTIONS)

        sconfig.input_config(inputlevel=inputlevel)

        sourcescfg['admin'] = sconfig

        config.write_sources_file(sourcescfg)

        # remember selected cubes for later initialization of the database

        config.write_bootstrap_cubes_file(cubes)

    def postcreate(self):

        if ASK.confirm('Run db-create to create the system database ?'):

            verbosity = (self.config.mode == 'installed') and 'y' or 'n'

            CWCTL.run(['db-create', self.config.appid, '--verbose=%s' % verbosity])

        else:

            print ('-> nevermind, you can do it later with '

                   '"cubicweb-ctl db-create %s".' % self.config.appid)

ERROR = nullobject()

def confirm_on_error_or_die(msg, func, *args, **kwargs):

    try:

        return func(*args, **kwargs)

    except Exception, ex:

        print 'ERROR', ex

        if not ASK.confirm('An error occurred while %s. Continue anyway?' % msg):

            raise ExecutionError(str(ex))

    return ERROR

class RepositoryDeleteHandler(CommandHandler):

    cmdname = 'delete'

    cfgname = 'repository'

    def cleanup(self):

        """remove instance's configuration and database"""

        from logilab.database import get_db_helper

        source = self.config.sources()['system']

        dbname = source['db-name']

        helper = get_db_helper(source['db-driver'])

        if ASK.confirm('Delete database %s ?' % dbname):

            if source['db-driver'] == 'sqlite':

                if confirm_on_error_or_die(

                    'deleting database file %s' % dbname,

                    os.unlink, source['db-name']) is not ERROR:

                    print '-> database %s dropped.' % dbname

                return

            user = source['db-user'] or None

            cnx = confirm_on_error_or_die('connecting to database %s' % dbname,

                                          _db_sys_cnx, source, 'DROP DATABASE', user=user)

            if cnx is ERROR:

                return

            cursor = cnx.cursor()

            try:

                if confirm_on_error_or_die(

                    'dropping database %s' % dbname,

                    cursor.execute, 'DROP DATABASE "%s"' % dbname) is not ERROR:

                    print '-> database %s dropped.' % dbname

                # XXX should check we are not connected as user

                if user and helper.users_support and \

                       ASK.confirm('Delete user %s ?' % user, default_is_yes=False):

                    if confirm_on_error_or_die(

                        'dropping user %s' % user,

                        cursor.execute, 'DROP USER %s' % user) is not ERROR:

                        print '-> user %s dropped.' % user

                cnx.commit()

            except:

                cnx.rollback()

                raise

class RepositoryStartHandler(CommandHandler):

    cmdname = 'start'

    cfgname = 'repository'

    def start_server(self, config):

        command = ['cubicweb-ctl start-repository ']

        if config.debugmode:

            command.append('--debug')

        command.append('--loglevel %s' % config['log-threshold'].lower())

        command.append(config.appid)

        os.system(' '.join(command))

        return 1

class RepositoryStopHandler(CommandHandler):

    cmdname = 'stop'

    cfgname = 'repository'

    def poststop(self):

        """if pyro is enabled, ensure the repository is correctly unregistered

        """

        if self.config.pyro_enabled():

            from cubicweb.server.repository import pyro_unregister

            pyro_unregister(self.config)

# repository specific commands ################################################

def createdb(helper, source, dbcnx, cursor, **kwargs):

    if dbcnx.logged_user != source['db-user']:

        helper.create_database(cursor, source['db-name'], source['db-user'],

                               source['db-encoding'], **kwargs)

    else:

        helper.create_database(cursor, source['db-name'],

                               dbencoding=source['db-encoding'], **kwargs)

class CreateInstanceDBCommand(Command):

    """Create the system database of an instance (run after 'create').

    You will be prompted for a login / password to use to connect to

    the system database.  The given user should have almost all rights

    on the database (ie a super user on the DBMS allowed to create

    database, users, languages...).

    <instance>

      the identifier of the instance to initialize.

    """

    name = 'db-create'

    arguments = '<instance>'

    min_args = max_args = 1

    options = (

        ('create-db',

         {'short': 'c', 'type': 'yn', 'metavar': '<y or n>',

          'default': True,

          'help': 'create the database (yes by default)'}),

        ('verbose',

         {'short': 'v', 'type' : 'yn', 'metavar': '<verbose>',

          'default': 'n',

          'help': 'verbose mode: will ask all possible configuration questions',

          }

         ),

        ('automatic',

         {'short': 'a', 'type' : 'yn', 'metavar': '<auto>',

          'default': 'n',

          'help': 'automatic mode: never ask and use default answer to every question',

          }

         ),

        )

    def run(self, args):

        """run the command with its specific arguments"""

        from logilab.database import get_db_helper

        verbose = self.get('verbose')

        automatic = self.get('automatic')

        appid = args.pop()

        config = ServerConfiguration.config_for(appid)

        source = config.sources()['system']

        dbname = source['db-name']

        driver = source['db-driver']

        helper = get_db_helper(driver)

        if driver == 'sqlite':

            if os.path.exists(dbname) and (

                automatic or

                ASK.confirm('Database %s already exists. Drop it?' % dbname)):

                os.unlink(dbname)

        elif self.config.create_db:

            print '\n'+underline_title('Creating the system database')

            # connect on the dbms system base to create our base

            dbcnx = _db_sys_cnx(source, 'CREATE/DROP DATABASE and / or USER', verbose=verbose)

            cursor = dbcnx.cursor()

            try:

                if helper.users_support:

                    user = source['db-user']

                    if not helper.user_exists(cursor, user) and (automatic or \

                           ASK.confirm('Create db user %s ?' % user, default_is_yes=False)):

                        helper.create_user(source['db-user'], source['db-password'])

                        print '-> user %s created.' % user

                if dbname in helper.list_databases(cursor):

                    if automatic or ASK.confirm('Database %s already exists -- do you want to drop it ?' % dbname):

                        cursor.execute('DROP DATABASE %s' % dbname)

                    else:

                        return

                createdb(helper, source, dbcnx, cursor)

                dbcnx.commit()

                print '-> database %s created.' % dbname

            except:

                dbcnx.rollback()

                raise

        cnx = system_source_cnx(source, special_privs='CREATE LANGUAGE',

                                verbose=verbose)

        cursor = cnx.cursor()

        helper.init_fti_extensions(cursor)

        # postgres specific stuff

        if driver == 'postgres':

            # install plpythonu/plpgsql language if not installed by the cube

            langs = sys.platform == 'win32' and ('plpgsql',) or ('plpythonu', 'plpgsql')

            for extlang in langs:

                helper.create_language(cursor, extlang)

        cursor.close()

        cnx.commit()

        print '-> database for instance %s created and necessary extensions installed.' % appid

        print

        if automatic or ASK.confirm('Run db-init to initialize the system database ?'):

            CWCTL.run(['db-init', config.appid])

        else:

            print ('-> nevermind, you can do it later with '

                   '"cubicweb-ctl db-init %s".' % config.appid)

class InitInstanceCommand(Command):

    """Initialize the system database of an instance (run after 'db-create').

    Notice this will be done using user specified in the sources files, so this

    user should have the create tables grant permissions on the database.

    <instance>

      the identifier of the instance to initialize.

    """

    name = 'db-init'

    arguments = '<instance>'