"""SQL utilities functions and classes.

:organization: Logilab

:copyright: 2001-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.

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

:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses

"""

__docformat__ = "restructuredtext en"

import os

import subprocess

from os.path import exists

from warnings import warn

from datetime import datetime, date, timedelta

import logilab.common as lgc

from logilab.common import db

from logilab.common.shellutils import ProgressBar

from logilab.common.adbh import get_adv_func_helper

from logilab.common.sqlgen import SQLGenerator

from logilab.common.date import todate, todatetime

from indexer import get_indexer

from cubicweb import Binary, ConfigurationError

from cubicweb.uilib import remove_html_tags

from cubicweb.toolsutils import restrict_perms_to_user

from cubicweb.schema import PURE_VIRTUAL_RTYPES

from cubicweb.server import SQL_CONNECT_HOOKS

from cubicweb.server.utils import crypt_password

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:

        indexer = get_indexer(driver)

        w(indexer.sql_grant_user(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('')

    if text_index:

        indexer = get_indexer(driver)

        w(indexer.sql_init_fti())

        w('')

    dbhelper = get_adv_func_helper(driver)

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

                 skip_entities=skip_entities, skip_relations=skip_relations))

    if dbhelper.users_support and user:

        w('')

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

                    skip_relations, skip_entities))

    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

    w(native.sql_drop_schema(driver))

    w('')

    if text_index:

        indexer = get_indexer(driver)

        w(indexer.sql_drop_fti())

        w('')

    w(dropschema2sql(schema, prefix=SQL_PREFIX,

                     skip_entities=skip_entities,

                     skip_relations=skip_relations))

    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()

            self.dbname = source_config['db-name']

        except KeyError:

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

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

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

        self.dbport = port and int(port) or None

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

        self.dbpasswd = source_config.get('db-password')

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

        self.dbapi_module = db.get_dbapi_compliant_module(self.dbdriver)

        self.dbdriver_extra_args = source_config.get('db-extra-arguments')

        self.binary = self.dbapi_module.Binary

        self.dbhelper = self.dbapi_module.adv_func_helper

        self.sqlgen = SQLGenerator()

    def get_connection(self, user=None, password=None):

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

        if user or self.dbuser:

            self.info('connecting to %s@%s for user %s', self.dbname,

                      self.dbhost or 'localhost', user or self.dbuser)

        else:

            self.info('connecting to %s@%s', self.dbname,

                      self.dbhost or 'localhost')

        extra = {}

        if self.dbdriver_extra_args:

            extra = {'extra_args': self.dbdriver_extra_args}

        cnx = self.dbapi_module.connect(self.dbhost, self.dbname,

                                        user or self.dbuser,

                                        password or self.dbpasswd,

                                        port=self.dbport,

                                        **extra)

        init_cnx(self.dbdriver, cnx)

        #self.dbapi_module.type_code_test(cnx.cursor())

        return cnx

    def backup_to_file(self, backupfile):

        for cmd in self.dbhelper.backup_commands(self.dbname, self.dbhost,

                                                 self.dbuser, 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(self.dbname, self.dbhost,

                                                  self.dbuser, backupfile,

                                                  self.encoding,

                                                  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):

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

        """

        descr = cursor.description

        encoding = self.encoding

        process_value = self.dbapi_module.process_value

        binary = Binary

        results = cursor.fetchall()

        for i, line in enumerate(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))

            results[i] = result

        return results

    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.items():

            rschema = eschema.subjrels[attr]

            if rschema.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

                elif atype == 'Datetime' and isinstance(value, date):

                    value = todatetime(value)

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

                    value = todate(value)

                elif isinstance(value, Binary):

                    value = self.binary(value.getvalue())

            attrs[SQL_PREFIX+str(attr)] = value

        return attrs

from logging import getLogger

from cubicweb import set_log_methods

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

def init_sqlite_connexion(cnx):

    # XXX should not be publicly exposed

    #def comma_join(strings):

    #    return ', '.join(strings)

    #cnx.create_function("COMMA_JOIN", 1, comma_join)

    class concat_strings(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)

    # renamed to GROUP_CONCAT in cubicweb 2.45, keep old name for bw compat for

    # some time

    cnx.create_aggregate("CONCAT_STRINGS", 1, concat_strings)

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

    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

    if hasattr(yams.constraints, 'patch_sqlite_decimal'):

        yams.constraints.patch_sqlite_decimal()

    def fspath(eid, etype, attr):

        try:

            cu = cnx.cursor()

            cu.execute('SELECT X.cw_%s FROM cw_%s as X '

                       'WHERE X.cw_eid=%%(eid)s' % (attr, etype),

                       {'eid': eid})

            return cu.fetchone()[0]

        except:

            import traceback

            traceback.print_exc()

            raise

    cnx.create_function('fspath', 3, fspath)

    def _fsopen(fspath):

        if fspath:

            try:

                return buffer(file(fspath).read())

            except:

                import traceback

                traceback.print_exc()

                raise

    cnx.create_function('_fsopen', 1, _fsopen)

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

sqlite_hooks.append(init_sqlite_connexion)

def init_cnx(driver, cnx):

    for hook in SQL_CONNECT_HOOKS.get(driver, ()):

        hook(cnx)