"""an helper class to display CubicWeb schema using ureports

:organization: Logilab

:copyright: 2001-2008 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

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

"""

__docformat__ = "restructuredtext en"

from logilab.common.ureports import Section, Title, Table, Link, Span, Text

from yams.schema2dot import CARD_MAP    

_ = unicode

I18NSTRINGS = [_('read'), _('add'), _('delete'), _('update'), _('order')]

class SchemaViewer(object):

    """return an ureport layout for some part of a schema"""

    def __init__(self, req=None, encoding=None):

        self.req = req

        if req is not None:

            self.req.add_css('cubicweb.schema.css')

            self._possible_views = req.vreg.possible_views

            if not encoding:

                encoding = req.encoding

        else:

            self._possible_views = lambda x: ()

        self.encoding = encoding

    def format_acls(self, schema, access_types):

        """return a layout displaying access control lists"""

        data = [self.req._('access type'), self.req._('groups')]

        for access_type in access_types:

            data.append(self.req._(access_type))

            acls = [self.req._(group) for group in schema.get_groups(access_type)]

            acls += (rqlexp.expression for rqlexp in schema.get_rqlexprs(access_type))

            data.append(', '.join(acls))

        return Section(children=(Table(cols=2, cheaders=1, rheaders=1, children=data),),

                       klass='acl')

    def visit_schema(self, schema, display_relations=0,

                     skiprels=(), skipmeta=True):

        """get a layout for a whole schema"""

        title = Title(self.req._('Schema %s') % schema.name,

                      klass='titleUnderline')

        layout = Section(children=(title,))

        esection = Section(children=(Title(self.req._('Entities'),

                                           klass='titleUnderline'),))

        layout.append(esection)

        entities = [eschema for eschema in schema.entities()

                    if not eschema.is_final()]

        if skipmeta:

            entities = [eschema for eschema in entities

                        if not eschema.meta]

        keys = [(eschema.type, eschema) for eschema in entities]

        for key, eschema in sorted(keys):

            esection.append(self.visit_entityschema(eschema, skiprels))

        if display_relations:

            title = Title(self.req._('Relations'), klass='titleUnderline')

            rsection = Section(children=(title,)) 

            layout.append(rsection)

            relations = [rschema for rschema in schema.relations()

                         if not (rschema.is_final() or rschema.type in skiprels)]

            if skipmeta:

                relations = [rschema for rschema in relations

                             if not rschema.meta]

            keys = [(rschema.type, rschema) for rschema in relations]

            for key, rschema in sorted(keys):

                relstr = self.visit_relationschema(rschema)

                rsection.append(relstr)

        return layout

    def _entity_attributes_data(self, eschema):

        _ = self.req._

        data = [_('attribute'), _('type'), _('default'), _('constraints')]

        for rschema, aschema in eschema.attribute_definitions():

            if not (rschema.has_local_role('read') or rschema.has_perm(self.req, 'read')):

                continue

            aname = rschema.type

            if aname == 'eid':

                continue            

            data.append('%s (%s)' % (aname, _(aname)))

            data.append(_(aschema.type))

            defaultval = eschema.default(aname)

            if defaultval is not None:

                default = self.to_string(defaultval)

            elif eschema.rproperty(rschema, 'cardinality')[0] == '1':

                default = _('required field')

            else:

                default = ''

            data.append(default)

            constraints = rschema.rproperty(eschema.type, aschema.type,

                                            'constraints')

            data.append(', '.join(str(constr) for constr in constraints))

        return data

    def eschema_link_url(self, eschema):

        return self.req.build_url('eetype/%s?vid=eschema' % eschema)

    def rschema_link_url(self, rschema):

        return self.req.build_url('ertype/%s?vid=eschema' % rschema)

    def possible_views(self, etype):

        rset = self.req.etype_rset(etype)

        return [v for v in self._possible_views(self.req, rset)

                if v.category != 'startupview']

    def stereotype(self, name):

        return Span((' <<%s>>' % name,), klass='stereotype')

    def visit_entityschema(self, eschema, skiprels=()):

        """get a layout for an entity schema"""

        etype = eschema.type

        layout = Section(children=' ', klass='clear')

        layout.append(Link(etype,' ' , id=etype)) # anchor

        title = Link(self.eschema_link_url(eschema), etype)

        if eschema.meta:

            stereotype = self.stereotype('meta')

            boxchild = [Section(children=(title, ' (%s)'%eschema.display_name(self.req), stereotype), klass='title')]

        else:

            boxchild = [Section(children=(title, ' (%s)'%eschema.display_name(self.req)), klass='title')]

        table = Table(cols=4, rheaders=1, 

                      children=self._entity_attributes_data(eschema))

        boxchild.append(Section(children=(table,), klass='body'))

        data = []

        data.append(Section(children=boxchild, klass='box'))

        data.append(Section(children='', klass='vl'))

        data.append(Section(children='', klass='hl'))

        t_vars = []

        rels = []

        first = True

        for rschema, targetschemas, x in eschema.relation_definitions():

            if rschema.type in skiprels:

                continue

            if not (rschema.has_local_role('read') or rschema.has_perm(self.req, 'read')):

                continue

            rschemaurl = self.rschema_link_url(rschema)

            for oeschema in targetschemas:

                label = rschema.type

                if x == 'subject':

                    cards = rschema.rproperty(eschema, oeschema, 'cardinality')

                else:

                    cards = rschema.rproperty(oeschema, eschema, 'cardinality')

                    cards = cards[::-1]

                label = '%s %s (%s) %s' % (CARD_MAP[cards[1]], label, display_name(self.req, label, x), CARD_MAP[cards[0]])

                rlink = Link(rschemaurl, label)

                elink = Link(self.eschema_link_url(oeschema), oeschema.type)

                if first:

                    t_vars.append(Section(children=(elink,), klass='firstvar'))

                    rels.append(Section(children=(rlink,), klass='firstrel'))

                    first = False

                else:

                    t_vars.append(Section(children=(elink,), klass='var'))

                    rels.append(Section(children=(rlink,), klass='rel'))

        data.append(Section(children=rels, klass='rels'))

        data.append(Section(children=t_vars, klass='vars'))

        layout.append(Section(children=data, klass='entityAttributes'))

        if eschema.is_final(): # stop here for final entities

            return layout

        _ = self.req._

        if self.req.user.matching_groups('managers'):

            layout.append(self.format_acls(eschema, ('read', 'add', 'delete', 'update')))

            # possible views for this entity type

            views = [_(view.title) for view in self.possible_views(etype)]

            layout.append(Section(children=(Table(cols=1, rheaders=1,

                                                  children=[_('views')]+views),),

                                  klass='views'))

        return layout

    def visit_relationschema(self, rschema, title=True):

        """get a layout for a relation schema"""

        _ = self.req._

        title = Link(self.rschema_link_url(rschema), rschema.type)

        stereotypes = []

        if rschema.meta:

            stereotypes.append('meta')

        if rschema.symetric:

            stereotypes.append('symetric')

        if rschema.inlined:

            stereotypes.append('inlined')

        title = Section(children=(title, ' (%s)'%rschema.display_name(self.req)), klass='title')

        if stereotypes:

            title.append(self.stereotype(','.join(stereotypes)))

        layout = Section(children=(title,), klass='schema')

        data = [_('from'), _('to')]

        schema = rschema.schema

        rschema_objects = rschema.objects()

        if rschema_objects:

            # might be empty

            properties = [p for p in rschema.rproperty_defs(rschema_objects[0])

                          if not p in ('cardinality', 'composite', 'eid')]

        else:

            properties = []

        data += [_(prop) for prop in properties]

        cols = len(data)

        done = set()

        for subjtype, objtypes in rschema.associations():

            for objtype in objtypes:

                if (subjtype, objtype) in done:

                    continue

                done.add((subjtype, objtype))

                if rschema.symetric:

                    done.add((objtype, subjtype))

                data.append(Link(self.eschema_link_url(schema[subjtype]), subjtype))

                data.append(Link(self.eschema_link_url(schema[objtype]), objtype))

                for prop in properties:

                    val = rschema.rproperty(subjtype, objtype, prop)

                    if val is None:

                        val = ''

                    elif isinstance(val, (list, tuple)):

                        val = ', '.join(str(v) for v in val)

                    elif val and isinstance(val, basestring):

                        val = _(val)

                    else:

                        val = str(val)

                    data.append(Text(val))

        table = Table(cols=cols, rheaders=1, children=data)

        layout.append(Section(children=(table,), klass='relationDefinition'))

        if not self.req.cnx.anonymous_connection:

            layout.append(self.format_acls(rschema, ('read', 'add', 'delete')))

        layout.append(Section(children='', klass='clear'))

        return layout

    def to_string(self, value):

        """used to converte arbitrary values to encoded string"""

        if isinstance(value, unicode):

            return value.encode(self.encoding, 'replace')

        return str(value)