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

"""

__docformat__ = "restructuredtext en"

_ = unicode

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

from yams.schema2dot import CARD_MAP

from yams.schema import RelationDefinitionSchema

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['views'].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 = [Link(self.req.build_url('cwgroup/%s' % group), self.req._(group))

                    for group in schema.get_groups(access_type)]

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

            acls = [n for _n in acls for n in (_n, Text(', '))][:-1]

            data.append(Span(children=acls))

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

                       klass='acl')

    def visit_schema(self, schema, display_relations=0, skiptypes=()):

        """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)

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

                    if not (eschema.final or eschema in skiptypes)]

        for eschema in sorted(eschemas):

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

        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.final or rschema.type in skiptypes)]

            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():

            rdef = eschema.rdef(rschema)

            if not rdef.may_have_permission('read', self.req):

                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 rdef.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('cwetype/%s' % eschema)

    def rschema_link_url(self, rschema):

        return self.req.build_url('cwrtype/%s' % 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, skiptypes=()):

        """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)

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

        table = Table(cols=4, rheaders=1, klass='listing',

                      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, role in eschema.relation_definitions():

            if rschema.type in skiptypes:

                continue

            rschemaurl = self.rschema_link_url(rschema)

            for oeschema in targetschemas:

                rdef = rschema.role_rdef(eschema, oeschema, role)

                if not rdef.may_have_permission('read', self.req):

                    continue

                label = rschema.type

                if role == '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, role),

                                           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.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._

        if title:

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

            stereotypes = []

            if rschema.meta:

                stereotypes.append('meta')

            if rschema.symmetric:

                stereotypes.append('symmetric')

            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')

        else:

            layout = Section(klass='schema')

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

        schema = rschema.schema

        rschema_objects = rschema.objects()

        if rschema_objects:

            # might be empty

            properties = [p for p in RelationDefinitionSchema.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.symmetric:

                    done.add((objtype, subjtype))

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

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

                rdef = rschema.rdef(subjtype, objtype)

                for prop in properties:

                    val = getattr(rdef, 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, klass='listing')

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

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

        #    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)