"""functions for schema / permissions (de)serialization using RQL

"""

__docformat__ = "restructuredtext en"

import os

from itertools import chain

from logilab.common.shellutils import ProgressBar

from yams import schema as schemamod, buildobjs as ybo

from cubicweb.schema import CONSTRAINTS, ETYPE_NAME_MAP, VIRTUAL_RTYPES

from cubicweb.server import sqlutils

def group_mapping(cursor, interactive=True):

    """create a group mapping from an rql cursor

    A group mapping has standard group names as key (managers, owners at least)

    and the actual CWGroup entity's eid as associated value.

    In interactive mode (the default), missing groups'eid will be prompted

    from the user.

    """

    res = {}

    for eid, name in cursor.execute('Any G, N WHERE G is CWGroup, G name N',

                                    build_descr=False):

        res[name] = eid

    if not interactive:

        return res

    missing = [g for g in ('owners', 'managers', 'users', 'guests') if not g in res]

    if missing:

        print 'some native groups are missing but the following groups have been found:'

        print '\n'.join('* %s (%s)' % (n, eid) for n, eid in res.items())

        print

        print 'enter the eid of a to group to map to each missing native group'

        print 'or just type enter to skip permissions granted to a group'

        for group in missing:

            while True:

                value = raw_input('eid for group %s: ' % group).strip()

                if not value:

                    continue

                try:

                    res[group] = int(value)

                except ValueError:

                    print 'eid should be an integer'

                    continue

    return res

def cstrtype_mapping(cursor):

    """cached constraint types mapping"""

    return dict(cursor.execute('Any T, X WHERE X is CWConstraintType, X name T'))

# schema / perms deserialization ##############################################

def deserialize_schema(schema, session):

    """return a schema according to information stored in an rql database

    as CWRType and CWEType entities

    """

    repo = session.repo

    dbhelper = repo.system_source.dbhelper

    # 3.6 migration

    sqlcu = session.pool['system']

    sqlcu.execute("SELECT * FROM cw_CWRType WHERE cw_name='symetric'")

    if sqlcu.fetchall():

        sql = dbhelper.sql_rename_col('cw_CWRType', 'cw_symetric', 'cw_symmetric',

                                      dbhelper.TYPE_MAPPING['Boolean'], True)

        sqlcu.execute(sql)

        sqlcu.execute("UPDATE cw_CWRType SET cw_name='symmetric' WHERE cw_name='symetric'")

    sidx = {}

    permsdict = deserialize_ertype_permissions(session)

    schema.reading_from_database = True

    for eid, etype, desc in session.execute(

        'Any X, N, D WHERE X is CWEType, X name N, X description D',

        build_descr=False):

        # base types are already in the schema, skip them

        if etype in schemamod.BASE_TYPES:

            # just set the eid

            eschema = schema.eschema(etype)

            eschema.eid = eid

            sidx[eid] = eschema

            continue

        if etype in ETYPE_NAME_MAP:

            netype = ETYPE_NAME_MAP[etype]

            # can't use write rql queries at this point, use raw sql

            session.system_sql('UPDATE %(p)sCWEType SET %(p)sname=%%(n)s WHERE %(p)seid=%%(x)s'

                               % {'p': sqlutils.SQL_PREFIX},

                               {'x': eid, 'n': netype})

            session.system_sql('UPDATE entities SET type=%(n)s WHERE type=%(x)s',

                               {'x': etype, 'n': netype})

            session.commit(False)

            try:

                session.system_sql('UPDATE deleted_entities SET type=%(n)s WHERE type=%(x)s',

                                   {'x': etype, 'n': netype})

            except:

                pass

            tocleanup = [eid]

            tocleanup += (eid for eid, (eidetype, uri, extid) in repo._type_source_cache.items()

                          if etype == eidetype)

            repo.clear_caches(tocleanup)

            session.commit(False)

            etype = netype

        etype = ybo.EntityType(name=etype, description=desc, eid=eid)

        eschema = schema.add_entity_type(etype)

        sidx[eid] = eschema

        set_perms(eschema, permsdict)

    for etype, stype in session.execute(

        'Any XN, ETN WHERE X is CWEType, X name XN, X specializes ET, ET name ETN',

        build_descr=False):

        schema.eschema(etype)._specialized_type = stype

        schema.eschema(stype)._specialized_by.append(etype)

    for eid, rtype, desc, sym, il, ftc in session.execute(

        'Any X,N,D,S,I,FTC WHERE X is CWRType, X name N, X description D, '

        'X symmetric S, X inlined I, X fulltext_container FTC', build_descr=False):

        rtype = ybo.RelationType(name=rtype, description=desc,

                                 symmetric=bool(sym), inlined=bool(il),

                                 fulltext_container=ftc, eid=eid)

        rschema = schema.add_relation_type(rtype)

        sidx[eid] = rschema

    cstrsdict = deserialize_rdef_constraints(session)

    for values in session.execute(

        'Any X,SE,RT,OE,CARD,ORD,DESC,IDX,FTIDX,I18N,DFLT WHERE X is CWAttribute,'

        'X relation_type RT, X cardinality CARD, X ordernum ORD, X indexed IDX,'

        'X description DESC, X internationalizable I18N, X defaultval DFLT,'

        'X fulltextindexed FTIDX, X from_entity SE, X to_entity OE',

        build_descr=False):

        rdefeid, seid, reid, teid, card, ord, desc, idx, ftidx, i18n, default = values

        rdef = ybo.RelationDefinition(sidx[seid].type, sidx[reid].type, sidx[teid].type,

                                      cardinality=card,

                                      constraints=cstrsdict.get(rdefeid, ()),

                                      order=ord, description=desc,

                                      indexed=idx, fulltextindexed=ftidx,

                                      internationalizable=i18n,

                                      default=default, eid=rdefeid)

        rdefs = schema.add_relation_def(rdef)

        # rdefs can be None on duplicated relation definitions (e.g. symmetrics)

        if rdefs is not None:

            set_perms(rdefs, permsdict)

    for values in session.execute(

        'Any X,SE,RT,OE,CARD,ORD,DESC,C WHERE X is CWRelation, X relation_type RT,'

        'X cardinality CARD, X ordernum ORD, X description DESC, '

        'X from_entity SE, X to_entity OE, X composite C', build_descr=False):

        rdefeid, seid, reid, teid, card, ord, desc, c = values

        rdef = ybo.RelationDefinition(sidx[seid].type, sidx[reid].type, sidx[teid].type,

                                      constraints=cstrsdict.get(rdefeid, ()),

                                      cardinality=card, order=ord, description=desc,

                                      composite=c,  eid=rdefeid)

        rdefs = schema.add_relation_def(rdef)

        # rdefs can be None on duplicated relation definitions (e.g. symmetrics)

        if rdefs is not None:

            set_perms(rdefs, permsdict)

    schema.infer_specialization_rules()

    session.commit()

    schema.reading_from_database = False

def deserialize_ertype_permissions(session):

    """return sect action:groups associations for the given

    entity or relation schema with its eid, according to schema's

    permissions stored in the database as [read|add|delete|update]_permission

    relations between CWEType/CWRType and CWGroup entities

    """

    res = {}

    for action in ('read', 'add', 'update', 'delete'):

        rql = 'Any E,N WHERE G is CWGroup, G name N, E %s_permission G' % action

        for eid, gname in session.execute(rql, build_descr=False):

            res.setdefault(eid, {}).setdefault(action, []).append(gname)

        rql = ('Any E,X,EXPR,V WHERE X is RQLExpression, X expression EXPR, '

               'E %s_permission X, X mainvars V' % action)

        for eid, expreid, expr, mainvars in session.execute(rql, build_descr=False):

            # we don't know yet if it's a rql expr for an entity or a relation,

            # so append a tuple to differentiate from groups and so we'll be

            # able to instantiate it later

            res.setdefault(eid, {}).setdefault(action, []).append( (expr, mainvars, expreid) )

    return res

def deserialize_rdef_constraints(session):

    """return the list of relation definition's constraints as instances"""

    res = {}

    for rdefeid, ceid, ct, val in session.execute(

        'Any E, X,TN,V WHERE E constrained_by X, X is CWConstraint, '

        'X cstrtype T, T name TN, X value V', build_descr=False):

        cstr = CONSTRAINTS[ct].deserialize(val)

        cstr.eid = ceid

        res.setdefault(rdefeid, []).append(cstr)

    return res

def set_perms(erschema, permsdict):

    """set permissions on the given erschema according to the permission

    definition dictionary as built by deserialize_ertype_permissions for a

    given erschema's eid

    """

    # reset erschema permissions here to avoid getting yams default anyway

    erschema.permissions = dict((action, ()) for action in erschema.ACTIONS)

    try:

        thispermsdict = permsdict[erschema.eid]

    except KeyError:

        return

    for action, somethings in thispermsdict.iteritems():

        # XXX cw < 3.6.1 bw compat

        if isinstance(erschema, schemamod.RelationDefinitionSchema) and erschema.final and action == 'add':

            action = 'update'

        erschema.permissions[action] = tuple(

            isinstance(p, tuple) and erschema.rql_expression(*p) or p

            for p in somethings)

# schema / perms serialization ################################################

def serialize_schema(cursor, schema):

    """synchronize schema and permissions in the database according to

    current schema

    """

    quiet = os.environ.get('APYCOT_ROOT')

    if not quiet:

        _title = '-> storing the schema in the database '

        print _title,

    execute = cursor.execute

    eschemas = schema.entities()

    if not quiet:

        pb_size = (len(eschemas + schema.relations())

                   + len(CONSTRAINTS)

                   + len([x for x in eschemas if x.specializes()]))

        pb = ProgressBar(pb_size, title=_title)

    else:

        pb = None

    groupmap = group_mapping(cursor, interactive=False)

    # serialize all entity types, assuring CWEType is serialized first for proper

    # is / is_instance_of insertion

    eschemas.remove(schema.eschema('CWEType'))

    eschemas.insert(0, schema.eschema('CWEType'))

    for eschema in eschemas:

        execschemarql(execute, eschema, eschema2rql(eschema, groupmap))

        if pb is not None:

            pb.update()

    # serialize constraint types

    cstrtypemap = {}

    rql = 'INSERT CWConstraintType X: X name %(ct)s'

    for cstrtype in CONSTRAINTS:

        cstrtypemap[cstrtype] = execute(rql, {'ct': unicode(cstrtype)},

                                        build_descr=False)[0][0]

        if pb is not None:

            pb.update()

    # serialize relations

    for rschema in schema.relations():

        # skip virtual relations such as eid, has_text and identity

        if rschema in VIRTUAL_RTYPES:

            if pb is not None:

                pb.update()

            continue

        execschemarql(execute, rschema, rschema2rql(rschema, addrdef=False))

        if rschema.symmetric:

            rdefs = [rdef for k, rdef in rschema.rdefs.iteritems()

                     if (rdef.subject, rdef.object) == k]

        else:

            rdefs = rschema.rdefs.itervalues()

        for rdef in rdefs:

            execschemarql(execute, rdef,

                          rdef2rql(rdef, cstrtypemap, groupmap))

        if pb is not None:

            pb.update()

    for rql, kwargs in specialize2rql(schema):

        execute(rql, kwargs, build_descr=False)

        if pb is not None:

            pb.update()

    if not quiet:

        print

# high level serialization functions

def execschemarql(execute, schema, rqls):

    for rql, kwargs in rqls:

        kwargs['x'] = schema.eid

        rset = execute(rql, kwargs, build_descr=False)

        if schema.eid is None:

            schema.eid = rset[0][0]

        else:

            assert rset

def erschema2rql(erschema, groupmap):

    if isinstance(erschema, schemamod.EntitySchema):

        return eschema2rql(erschema, groupmap=groupmap)

    return rschema2rql(erschema, groupmap=groupmap)

def specialize2rql(schema):

    for eschema in schema.entities():

        if eschema.final:

            continue

        for rql, kwargs in eschemaspecialize2rql(eschema):

            yield rql, kwargs

# etype serialization

def eschema2rql(eschema, groupmap=None):

    """return a list of rql insert statements to enter an entity schema

    in the database as an CWEType entity

    """

    relations, values = eschema_relations_values(eschema)

    # NOTE: 'specializes' relation can't be inserted here since there's no

    # way to make sure the parent type is inserted before the child type

    yield 'INSERT CWEType X: %s' % ','.join(relations) , values

    # entity permissions

    if groupmap is not None:

        for rql, args in _erperms2rql(eschema, groupmap):

            yield rql, args

def eschema_relations_values(eschema):

    values = _ervalues(eschema)

    relations = ['X %s %%(%s)s' % (attr, attr) for attr in sorted(values)]

    return relations, values

def eschemaspecialize2rql(eschema):

    specialized_type = eschema.specializes()

    if specialized_type:

        values = {'x': eschema.eid, 'et': specialized_type.eid}

        yield 'SET X specializes ET WHERE X eid %(x)s, ET eid %(et)s', values

def _ervalues(erschema):

    try:

        type_ = unicode(erschema.type)

    except UnicodeDecodeError, e:

        raise Exception("can't decode %s [was %s]" % (erschema.type, e))

    try:

        desc = unicode(erschema.description) or u''

    except UnicodeDecodeError, e:

        raise Exception("can't decode %s [was %s]" % (erschema.description, e))

    return {

        'name': type_,

        'final': erschema.final,

        'description': desc,

        }

# rtype serialization

def rschema2rql(rschema, cstrtypemap=None, addrdef=True, groupmap=None):

    """return a list of rql insert statements to enter a relation schema

    in the database as an CWRType entity

    """

    if rschema.type == 'has_text':

        return

    relations, values = rschema_relations_values(rschema)

    yield 'INSERT CWRType X: %s' % ','.join(relations), values

    if addrdef:

        assert cstrtypemap

        # sort for testing purpose

        for rdef in sorted(rschema.rdefs.itervalues(),

                           key=lambda x: (x.subject, x.object)):

            for rql, values in rdef2rql(rdef, cstrtypemap, groupmap):

                yield rql, values

def rschema_relations_values(rschema):

    values = _ervalues(rschema)

    values['final'] = rschema.final

    values['symmetric'] = rschema.symmetric