"""Check integrity of a CubicWeb repository. Hum actually only the system database

is checked.

: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

"""

from __future__ import with_statement

__docformat__ = "restructuredtext en"

import sys

from datetime import datetime

from logilab.common.shellutils import ProgressBar

from cubicweb.schema import PURE_VIRTUAL_RTYPES

from cubicweb.server.sqlutils import SQL_PREFIX

from cubicweb.server.session import security_enabled

def has_eid(sqlcursor, eid, eids):

    """return true if the eid is a valid eid"""

    if eids.has_key(eid):

        return eids[eid]

    sqlcursor.execute('SELECT type, source FROM entities WHERE eid=%s' % eid)

    try:

        etype, source = sqlcursor.fetchone()

    except:

        eids[eid] = False

        return False

    if source and source != 'system':

        # XXX what to do...

        eids[eid] = True

        return True

    sqlcursor.execute('SELECT * FROM %s%s WHERE %seid=%s' % (SQL_PREFIX, etype,

                                                             SQL_PREFIX, eid))

    result = sqlcursor.fetchall()

    if len(result) == 0:

        eids[eid] = False

        return False

    elif len(result) > 1:

        msg = '  More than one entity with eid %s exists in source !'

        print >> sys.stderr, msg % eid

        print >> sys.stderr, '  WARNING : Unable to fix this, do it yourself !'

    eids[eid] = True

    return True

# XXX move to yams?

def etype_fti_containers(eschema, _done=None):

    if _done is None:

        _done = set()

    _done.add(eschema)

    containers = tuple(eschema.fulltext_containers())

    if containers:

        for rschema, target in containers:

            if target == 'object':

                targets = rschema.objects(eschema)

            else:

                targets = rschema.subjects(eschema)

            for targeteschema in targets:

                if targeteschema in _done:

                    continue

                _done.add(targeteschema)

                for container in etype_fti_containers(targeteschema, _done):

                    yield container

    else:

        yield eschema

def reindex_entities(schema, session, withpb=True):

    """reindex all entities in the repository"""

    # deactivate modification_date hook since we don't want them

    # to be updated due to the reindexation

    repo = session.repo

    cursor = session.pool['system']

    if not repo.system_source.dbhelper.has_fti_table(cursor):

        print 'no text index table'

        dbhelper.init_fti(cursor)

    repo.system_source.do_fti = True  # ensure full-text indexation is activated

    etypes = set()

    for eschema in schema.entities():

        if eschema.final:

            continue

        indexable_attrs = tuple(eschema.indexable_attributes()) # generator

        if not indexable_attrs:

            continue

        for container in etype_fti_containers(eschema):

            etypes.add(container)

    print 'Reindexing entities of type %s' % \

          ', '.join(sorted(str(e) for e in etypes))

    if withpb:

        pb = ProgressBar(len(etypes) + 1)

    # first monkey patch Entity.check to disable validation

    # clear fti table first

    session.system_sql('DELETE FROM %s' % session.repo.system_source.dbhelper.fti_table)

    if withpb:

        pb.update()

    # reindex entities by generating rql queries which set all indexable

    # attribute to their current value

    source = repo.system_source

    for eschema in etypes:

        for entity in session.execute('Any X WHERE X is %s' % eschema).entities():

            source.fti_index_entity(session, entity)

        if withpb:

            pb.update()

def check_schema(schema, session, eids, fix=1):

    """check serialized schema"""

    print 'Checking serialized schema'

    unique_constraints = ('SizeConstraint', 'FormatConstraint',

                          'VocabularyConstraint', 'RQLConstraint',

                          'RQLVocabularyConstraint')

    rql = ('Any COUNT(X),RN,EN,ECTN GROUPBY RN,EN,ECTN ORDERBY 1 '

           'WHERE X is CWConstraint, R constrained_by X, '

           'R relation_type RT, R from_entity ET, RT name RN, '

           'ET name EN, X cstrtype ECT, ECT name ECTN')

    for count, rn, en, cstrname in session.execute(rql):

        if count == 1:

            continue

        if cstrname in unique_constraints:

            print "ERROR: got %s %r constraints on relation %s.%s" % (

                count, cstrname, en, rn)

def check_text_index(schema, session, eids, fix=1):

    """check all entities registered in the text index"""

    print 'Checking text index'

    cursor = session.system_sql('SELECT uid FROM appears;')

    for row in cursor.fetchall():

        eid = row[0]

        if not has_eid(cursor, eid, eids):

            msg = '  Entity with eid %s exists in the text index but in no source'

            print >> sys.stderr, msg % eid,

            if fix:

                session.system_sql('DELETE FROM appears WHERE uid=%s;' % eid)

                print >> sys.stderr, ' [FIXED]'

            else:

                print >> sys.stderr

def check_entities(schema, session, eids, fix=1):

    """check all entities registered in the repo system table"""

    print 'Checking entities system table'

    cursor = session.system_sql('SELECT eid FROM entities;')

    for row in cursor.fetchall():

        eid = row[0]

        if not has_eid(cursor, eid, eids):

            msg = '  Entity with eid %s exists in the system table but in no source'

            print >> sys.stderr, msg % eid,

            if fix:

                session.system_sql('DELETE FROM entities WHERE eid=%s;' % eid)

                print >> sys.stderr, ' [FIXED]'

            else:

                print >> sys.stderr

    print 'Checking entities tables'

    for eschema in schema.entities():

        if eschema.final:

            continue

        table = SQL_PREFIX + eschema.type

        column = SQL_PREFIX +  'eid'

        cursor = session.system_sql('SELECT %s FROM %s;' % (column, table))

        for row in cursor.fetchall():

            eid = row[0]

            # eids is full since we have fetched everyting from the entities table,

            # no need to call has_eid

            if not eid in eids or not eids[eid]:

                msg = '  Entity with eid %s exists in the %s table but not in the system table'

                print >> sys.stderr, msg % (eid, eschema.type),

                if fix:

                    session.system_sql('DELETE FROM %s WHERE %s=%s;' % (table, column, eid))

                    print >> sys.stderr, ' [FIXED]'

                else:

                    print >> sys.stderr

def bad_related_msg(rtype, target, eid, fix):

    msg = '  A relation %s with %s eid %s exists but no such entity in sources'

    print >> sys.stderr, msg % (rtype, target, eid),

    if fix:

        print >> sys.stderr, ' [FIXED]'

    else:

        print >> sys.stderr

def check_relations(schema, session, eids, fix=1):

    """check all relations registered in the repo system table"""

    print 'Checking relations'

    for rschema in schema.relations():

        if rschema.final or rschema in PURE_VIRTUAL_RTYPES:

            continue

        if rschema.inlined:

            for subjtype in rschema.subjects():

                table = SQL_PREFIX + str(subjtype)

                column = SQL_PREFIX +  str(rschema)

                sql = 'SELECT %s FROM %s WHERE %s IS NOT NULL;' % (

                    column, table, column)

                cursor = session.system_sql(sql)

                for row in cursor.fetchall():

                    eid = row[0]

                    if not has_eid(cursor, eid, eids):

                        bad_related_msg(rschema, 'object', eid, fix)

                        if fix:

                            sql = 'UPDATE %s SET %s=NULL WHERE %s=%s;' % (

                                table, column, column, eid)

                            session.system_sql(sql)

            continue

        cursor = session.system_sql('SELECT eid_from FROM %s_relation;' % rschema)

        for row in cursor.fetchall():

            eid = row[0]

            if not has_eid(cursor, eid, eids):

                bad_related_msg(rschema, 'subject', eid, fix)

                if fix:

                    sql = 'DELETE FROM %s_relation WHERE eid_from=%s;' % (

                        rschema, eid)

                    session.system_sql(sql)

        cursor = session.system_sql('SELECT eid_to FROM %s_relation;' % rschema)

        for row in cursor.fetchall():

            eid = row[0]

            if not has_eid(cursor, eid, eids):

                bad_related_msg(rschema, 'object', eid, fix)

                if fix:

                    sql = 'DELETE FROM %s_relation WHERE eid_to=%s;' % (

                        rschema, eid)

                    session.system_sql(sql)

def check_metadata(schema, session, eids, fix=1):

    """check entities has required metadata

    FIXME: rewrite using RQL queries ?

    """

    print 'Checking metadata'

    cursor = session.system_sql("SELECT DISTINCT type FROM entities;")

    eidcolumn = SQL_PREFIX + 'eid'

    for etype, in cursor.fetchall():

        table = SQL_PREFIX + etype

        for rel, default in ( ('creation_date', datetime.now()),

                              ('modification_date', datetime.now()), ):

            column = SQL_PREFIX + rel

            cursor = session.system_sql("SELECT %s FROM %s WHERE %s is NULL"

                                        % (eidcolumn, table, column))

            for eid, in cursor.fetchall():

                msg = '  %s with eid %s has no %s'

                print >> sys.stderr, msg % (etype, eid, rel),

                if fix:

                    session.system_sql("UPDATE %s SET %s=%%(v)s WHERE %s=%s ;"

                                       % (table, column, eidcolumn, eid),

                                       {'v': default})

                    print >> sys.stderr, ' [FIXED]'

                else:

                    print >> sys.stderr

    cursor = session.system_sql('SELECT MIN(%s) FROM %sCWUser;' % (eidcolumn,

                                                                  SQL_PREFIX))

    default_user_eid = cursor.fetchone()[0]

    assert default_user_eid is not None, 'no user defined !'

    for rel, default in ( ('owned_by', default_user_eid), ):

        cursor = session.system_sql("SELECT eid, type FROM entities "

                                    "WHERE NOT EXISTS "

                                    "(SELECT 1 FROM %s_relation WHERE eid_from=eid);"

                                    % rel)

        for eid, etype in cursor.fetchall():

            msg = '  %s with eid %s has no %s relation'

            print >> sys.stderr, msg % (etype, eid, rel),

            if fix:

                session.system_sql('INSERT INTO %s_relation VALUES (%s, %s) ;'

                                   % (rel, eid, default))

                print >> sys.stderr, ' [FIXED]'

            else:

                print >> sys.stderr

def check(repo, cnx, checks, reindex, fix, withpb=True):

    """check integrity of instance's repository,

    using given user and password to locally connect to the repository

    (no running cubicweb server needed)

    """

    session = repo._get_session(cnx.sessionid, setpool=True)

    # yo, launch checks

    if checks:

        eids_cache = {}

        with security_enabled(session, read=False): # ensure no read security

            for check in checks:

                check_func = globals()['check_%s' % check]

                check_func(repo.schema, session, eids_cache, fix=fix)

        if fix:

            cnx.commit()

        else:

            print

        if not fix:

            print 'WARNING: Diagnostic run, nothing has been corrected'

    if reindex:

        cnx.rollback()

        session.set_pool()

        reindex_entities(repo.schema, session, withpb=withpb)

        cnx.commit()