# copyright 2003-2011 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/>.

"""SQL utilities functions and classes."""

__docformat__ = "restructuredtext en"

import os

import subprocess

from datetime import datetime, date

from logilab import database as db, common as lgc

from logilab.common.shellutils import ProgressBar

from logilab.common.date import todate, todatetime, utcdatetime, utctime

from logilab.database.sqlgen import SQLGenerator

from cubicweb import Binary, ConfigurationError

from cubicweb.uilib import remove_html_tags

from cubicweb.schema import PURE_VIRTUAL_RTYPES

from cubicweb.server import SQL_CONNECT_HOOKS

from cubicweb.server.utils import crypt_password

from rql.utils import RQL_FUNCTIONS_REGISTRY

lgc.USE_MX_DATETIME = False

SQL_PREFIX = 'cw_'

def _run_command(cmd):

    """backup/restore command are string w/ lgc < 0.47, lists with earlier versions

    """

    if isinstance(cmd, basestring):

        print '->', cmd

        return subprocess.call(cmd, shell=True)

    print ' '.join(cmd)

    return subprocess.call(cmd)

def sqlexec(sqlstmts, cursor_or_execute, withpb=not os.environ.get('APYCOT_ROOT'),

            pbtitle='', delimiter=';'):

    """execute sql statements ignoring DROP/ CREATE GROUP or USER statements

    error. If a cnx is given, commit at each statement

    """

    if hasattr(cursor_or_execute, 'execute'):

        execute = cursor_or_execute.execute

    else:

        execute = cursor_or_execute

    sqlstmts = sqlstmts.split(delimiter)

    if withpb:

        pb = ProgressBar(len(sqlstmts), title=pbtitle)

    for sql in sqlstmts:

        sql = sql.strip()

        if withpb:

            pb.update()

        if not sql:

            continue

        # some dbapi modules doesn't accept unicode for sql string

        execute(str(sql))

    if withpb:

        print

def sqlgrants(schema, driver, user,

              text_index=True, set_owner=True,

              skip_relations=(), skip_entities=()):

    """return sql to give all access privileges to the given user on the system

    schema

    """

    from yams.schema2sql import grant_schema

    from cubicweb.server.sources import native

    output = []

    w = output.append

    w(native.grant_schema(user, set_owner))

    w('')

    if text_index:

        dbhelper = db.get_db_helper(driver)

        w(dbhelper.sql_grant_user_on_fti(user))

        w('')

    w(grant_schema(schema, user, set_owner, skip_entities=skip_entities, prefix=SQL_PREFIX))

    return '\n'.join(output)

def sqlschema(schema, driver, text_index=True,

              user=None, set_owner=False,

              skip_relations=PURE_VIRTUAL_RTYPES, skip_entities=()):

    """return the system sql schema, according to the given parameters"""

    from yams.schema2sql import schema2sql

    from cubicweb.server.sources import native

    if set_owner:

        assert user, 'user is argument required when set_owner is true'

    output = []

    w = output.append

    w(native.sql_schema(driver))

    w('')

    dbhelper = db.get_db_helper(driver)

    if text_index:

        w(dbhelper.sql_init_fti().replace(';', ';;'))

        w('')

    w(schema2sql(dbhelper, schema, prefix=SQL_PREFIX,

                 skip_entities=skip_entities,

                 skip_relations=skip_relations).replace(';', ';;'))

    if dbhelper.users_support and user:

        w('')

        w(sqlgrants(schema, driver, user, text_index, set_owner,

                    skip_relations, skip_entities).replace(';', ';;'))

    return '\n'.join(output)

def sqldropschema(schema, driver, text_index=True,

                  skip_relations=PURE_VIRTUAL_RTYPES, skip_entities=()):

    """return the sql to drop the schema, according to the given parameters"""

    from yams.schema2sql import dropschema2sql

    from cubicweb.server.sources import native

    output = []

    w = output.append

    if text_index:

        dbhelper = db.get_db_helper(driver)

        w(dbhelper.sql_drop_fti())

        w('')

    w(dropschema2sql(schema, prefix=SQL_PREFIX,

                     skip_entities=skip_entities,

                     skip_relations=skip_relations))

    w('')

    w(native.sql_drop_schema(driver))

    return '\n'.join(output)

class SQLAdapterMixIn(object):

    """Mixin for SQL data sources, getting a connection from a configuration

    dictionary and handling connection locking

    """

    def __init__(self, source_config):

        try:

            self.dbdriver = source_config['db-driver'].lower()

            dbname = source_config['db-name']

        except KeyError:

            raise ConfigurationError('missing some expected entries in sources file')

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

        port = source_config.get('db-port')

        dbport = port and int(port) or None

        dbuser = source_config.get('db-user')

        dbpassword = source_config.get('db-password')

        dbencoding = source_config.get('db-encoding', 'UTF-8')

        dbextraargs = source_config.get('db-extra-arguments')

        self.dbhelper = db.get_db_helper(self.dbdriver)

        self.dbhelper.record_connection_info(dbname, dbhost, dbport, dbuser,

                                             dbpassword, dbextraargs,

                                             dbencoding)

        self.sqlgen = SQLGenerator()

        # copy back some commonly accessed attributes

        dbapi_module = self.dbhelper.dbapi_module

        self.OperationalError = dbapi_module.OperationalError

        self.InterfaceError = dbapi_module.InterfaceError

        self.DbapiError = dbapi_module.Error

        self._binary = self.dbhelper.binary_value

        self._process_value = dbapi_module.process_value

        self._dbencoding = dbencoding

    def get_connection(self):

        """open and return a connection to the database"""

        return self.dbhelper.get_connection()

    def backup_to_file(self, backupfile, confirm):

        for cmd in self.dbhelper.backup_commands(backupfile,

                                                 keepownership=False):

            if _run_command(cmd):

                if not confirm('   [Failed] Continue anyway?', default='n'):

                    raise Exception('Failed command: %s' % cmd)

    def restore_from_file(self, backupfile, confirm, drop=True):

        for cmd in self.dbhelper.restore_commands(backupfile,

                                                  keepownership=False,

                                                  drop=drop):

            if _run_command(cmd):

                if not confirm('   [Failed] Continue anyway?', default='n'):

                    raise Exception('Failed command: %s' % cmd)

    def merge_args(self, args, query_args):

        if args is not None:

            newargs = {}

            for key, val in args.iteritems():

                # convert cubicweb binary into db binary

                if isinstance(val, Binary):

                    val = self._binary(val.getvalue())

                newargs[key] = val

            # should not collide

            newargs.update(query_args)

            return newargs

        return query_args

    def process_result(self, cursor, column_callbacks=None, session=None):

        """return a list of CubicWeb compliant values from data in the given cursor

        """

        return list(self.iter_process_result(cursor, column_callbacks, session))

    def iter_process_result(self, cursor, column_callbacks=None, session=None):

        """return a iterator on tuples of CubicWeb compliant values from data

        in the given cursor

        """

        # use two different implementations to avoid paying the price of

        # callback lookup for each *cell* in results when there is nothing to

        # lookup

        if not column_callbacks:

            return self._process_result(cursor)

        assert session

        return self._cb_process_result(cursor, column_callbacks, session)

    def _process_result(self, cursor):

        # begin bind to locals for optimization

        descr = cursor.description

        encoding = self._dbencoding

        process_value = self._process_value

        binary = Binary

        # /end

        cursor.arraysize = 100

        while True:

            results = cursor.fetchmany()

            if not results:

                break

            for line in results:

                result = []

                for col, value in enumerate(line):

                    if value is None:

                        result.append(value)

                        continue

                    result.append(process_value(value, descr[col], encoding, binary))

                yield result

    def _cb_process_result(self, cursor, column_callbacks, session):

        # begin bind to locals for optimization

        descr = cursor.description

        encoding = self._dbencoding

        process_value = self._process_value

        binary = Binary

        # /end

        cursor.arraysize = 100

        while True:

            results = cursor.fetchmany()

            if not results:

                break

            for line in results:

                result = []

                for col, value in enumerate(line):

                    if value is None:

                        result.append(value)

                        continue

                    cbstack = column_callbacks.get(col, None)

                    if cbstack is None:

                        value = process_value(value, descr[col], encoding, binary)

                    else:

                        for cb in cbstack:

                            value = cb(self, session, value)

                    result.append(value)

                yield result

    def preprocess_entity(self, entity):

        """return a dictionary to use as extra argument to cursor.execute

        to insert/update an entity into a SQL database

        """

        attrs = {}

        eschema = entity.e_schema

        for attr, value in entity.cw_edited.iteritems():

            if value is not None and eschema.subjrels[attr].final:

                atype = str(entity.e_schema.destination(attr))

                if atype == 'Boolean':

                    value = self.dbhelper.boolean_value(value)

                elif atype == 'Password':

                    # if value is a Binary instance, this mean we got it

                    # from a query result and so it is already encrypted

                    if isinstance(value, Binary):

                        value = value.getvalue()

                    else:

                        value = crypt_password(value)

                    value = self._binary(value)

                # XXX needed for sqlite but I don't think it is for other backends

                # Note: use is __class__ since issubclass(datetime, date)

                elif atype in ('Datetime', 'TZDatetime') and type(value) is date:

                    value = todatetime(value)

                elif atype == 'Date' and isinstance(value, datetime):

                    value = todate(value)

                elif atype == 'TZDatetime' and getattr(value, 'tzinfo', None):

                    value = utcdatetime(value)

                elif atype == 'TZTime' and getattr(value, 'tzinfo', None):

                    value = utctime(value)

                elif isinstance(value, Binary):

                    value = self._binary(value.getvalue())

            attrs[SQL_PREFIX+str(attr)] = value

        attrs[SQL_PREFIX+'eid'] = entity.eid

        return attrs

    # these are overridden by set_log_methods below

    # only defining here to prevent pylint from complaining

    info = warning = error = critical = exception = debug = lambda msg,*a,**kw: None

from logging import getLogger

from cubicweb import set_log_methods

set_log_methods(SQLAdapterMixIn, getLogger('cubicweb.sqladapter'))

def init_sqlite_connexion(cnx):

    class group_concat(object):

        def __init__(self):

            self.values = []

        def step(self, value):

            if value is not None:

                self.values.append(value)

        def finalize(self):

            return ', '.join(self.values)

    cnx.create_aggregate("GROUP_CONCAT", 1, group_concat)

    def _limit_size(text, maxsize, format='text/plain'):

        if len(text) < maxsize:

            return text

        if format in ('text/html', 'text/xhtml', 'text/xml'):

            text = remove_html_tags(text)

        if len(text) > maxsize:

            text = text[:maxsize] + '...'

        return text

    def limit_size3(text, format, maxsize):

        return _limit_size(text, maxsize, format)

    cnx.create_function("LIMIT_SIZE", 3, limit_size3)

    def limit_size2(text, maxsize):

        return _limit_size(text, maxsize)

    cnx.create_function("TEXT_LIMIT_SIZE", 2, limit_size2)

    import yams.constraints

    yams.constraints.patch_sqlite_decimal()

sqlite_hooks = SQL_CONNECT_HOOKS.setdefault('sqlite', [])

sqlite_hooks.append(init_sqlite_connexion)

def init_postgres_connexion(cnx):

    cnx.cursor().execute('SET TIME ZONE UTC')

    # commit is needed, else setting are lost if the connection is first

    # rollbacked

    cnx.commit()

postgres_hooks = SQL_CONNECT_HOOKS.setdefault('postgres', [])

postgres_hooks.append(init_postgres_connexion)