# 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/>.

"""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 BadSchemaDefinition, schema as schemamod, buildobjs as ybo

from cubicweb import CW_SOFTWARE_ROOT, typed_eid

from cubicweb.schema import (CONSTRAINTS, ETYPE_NAME_MAP,

                             VIRTUAL_RTYPES, PURE_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:

                    eid = typed_eid(value)

                except ValueError:

                    print 'eid should be an integer'

                    continue

                for eid_ in res.values():

                    if eid == eid_:

                        break

                else:

                    print 'eid is not a group eid'

                    continue

                res[name] = eid

                break

    return res

def cstrtype_mapping(cursor):

    """cached constraint types mapping"""

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

    if not 'BoundConstraint' in map:

        map['BoundConstraint'] = map['BoundaryConstraint']

    return map

# 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

    # XXX bw compat (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'")

    ertidx = {}

    copiedeids = set()

    permsidx = 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

            ertidx[eid] = etype

            continue

        if etype in ETYPE_NAME_MAP:

            needcopy = False

            netype = ETYPE_NAME_MAP[etype]

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

            sqlexec = session.system_sql

            if sqlexec('SELECT 1 FROM %(p)sCWEType WHERE %(p)sname=%%(n)s'

                       % {'p': sqlutils.SQL_PREFIX}, {'n': netype}).fetchone():

                # the new type already exists, we should copy (eg make existing

                # instances of the old type instances of the new type)

                assert etype.lower() != netype.lower()

                needcopy = True

            else:

                # the new type doesn't exist, we should rename

                sqlexec('UPDATE %(p)sCWEType SET %(p)sname=%%(n)s WHERE %(p)seid=%%(x)s'

                        % {'p': sqlutils.SQL_PREFIX}, {'x': eid, 'n': netype})

                if etype.lower() != netype.lower():

                    sqlexec('ALTER TABLE %s%s RENAME TO %s%s' % (

                        sqlutils.SQL_PREFIX, etype, sqlutils.SQL_PREFIX, netype))

            sqlexec('UPDATE entities SET type=%(n)s WHERE type=%(x)s',

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

            session.commit(False)

            try:

                sqlexec('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)

            if needcopy:

                ertidx[eid] = netype

                copiedeids.add(eid)

                # copy / CWEType entity removal expected to be done through

                # rename_entity_type in a migration script

                continue

            etype = netype

        ertidx[eid] = etype

        eschema = schema.add_entity_type(

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

        set_perms(eschema, permsidx)

    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):

        etype = ETYPE_NAME_MAP.get(etype, etype)

        stype = ETYPE_NAME_MAP.get(stype, stype)

        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):

        ertidx[eid] = rtype

        rschema = schema.add_relation_type(

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

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

                             fulltext_container=ftc, eid=eid))

    cstrsidx = deserialize_rdef_constraints(session)

    pendingrdefs = []

    # closure to factorize common code of attribute/relation rdef addition

    def _add_rdef(rdefeid, seid, reid, oeid, **kwargs):

        rdef = ybo.RelationDefinition(ertidx[seid], ertidx[reid], ertidx[oeid],

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

                                      eid=rdefeid, **kwargs)

        if seid in copiedeids or oeid in copiedeids:

            # delay addition of this rdef. We'll insert them later if needed. We

            # have to do this because:

            #

            # * on etype renaming, we want relation of the old entity type being

            #   redirected to the new type during migration

            #

            # * in the case of a copy, we've to take care that rdef already

            #   existing in the schema are not overwritten by a redirected one,

            #   since we want correct eid on them (redirected rdef will be

            #   removed in rename_entity_type)

            pendingrdefs.append(rdef)

        else:

            # add_relation_def return a RelationDefinitionSchema if it has been

            # actually added (can be None on duplicated relation definitions,

            # e.g. if the relation type is marked as beeing symmetric)

            rdefs = schema.add_relation_def(rdef)

            if rdefs is not None:

                set_perms(rdefs, permsidx)

    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, oeid, card, ord, desc, idx, ftidx, i18n, default = values

        _add_rdef(rdefeid, seid, reid, oeid,

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

                  indexed=idx, fulltextindexed=ftidx, internationalizable=i18n,

                  default=default)

    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, oeid, card, ord, desc, comp = values

        _add_rdef(rdefeid, seid, reid, oeid,

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

                  composite=comp)

    for rdef in pendingrdefs:

        try:

            rdefs = schema.add_relation_def(rdef)

        except BadSchemaDefinition:

            continue

        if rdefs is not None:

            set_perms(rdefs, permsidx)

    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, permsidx):

    """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 = permsidx[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:

        if cstrtype == 'BoundConstraint':

            continue # XXX deprecated in yams 0.29 / cw 3.8.1

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

                                        build_descr=False)[0][0]

        if pb is not None:

            pb.update()

    cstrtypemap['BoundConstraint'] = cstrtypemap['BoundaryConstraint']

    # 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