"""workflow views:

* IWorkflowable views and forms

* workflow entities views (State, Transition, TrInfo)

:organization: Logilab

:copyright: 2001-2009 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

"""

__docformat__ = "restructuredtext en"

_ = unicode

from logilab.mtconverter import xml_escape

from logilab.common.graph import escape, GraphGenerator, DotBackend

from cubicweb import Unauthorized, view

from cubicweb.selectors import (implements, has_related_entities, one_line_rset,

                                relation_possible, match_form_params,

                                entity_implements, score_entity)

from cubicweb.interfaces import IWorkflowable

from cubicweb.view import EntityView

from cubicweb.schema import display_name

from cubicweb.web import uicfg, stdmsgs, action, component, form, action

from cubicweb.web import formfields as ff, formwidgets as fwdgs

from cubicweb.web.views import TmpFileViewMixin, forms, primary, autoform

# IWorkflowable views #########################################################

class ChangeStateForm(forms.CompositeEntityForm):

    id = 'changestate'

    form_renderer_id = 'base' # don't want EntityFormRenderer

    form_buttons = [fwdgs.SubmitButton(),

                    fwdgs.Button(stdmsgs.BUTTON_CANCEL, cwaction='cancel')]

class ChangeStateFormView(form.FormViewMixIn, view.EntityView):

    id = 'statuschange'

    title = _('status change')

    __select__ = (one_line_rset() & implements(IWorkflowable)

                  & match_form_params('treid'))

    def cell_call(self, row, col):

        entity = self.rset.get_entity(row, col)

        transition = self.req.entity_from_eid(self.req.form['treid'])

        form = self.get_form(entity, transition)

        self.w(form.error_message())

        self.w(u'<h4>%s %s</h4>\n' % (self.req._(transition.name),

                                      entity.view('oneline')))

        msg = _('status will change from %(st1)s to %(st2)s') % {

            'st1': entity.printable_state,

            'st2': self.req._(transition.destination().name)}

        self.w(u'<p>%s</p>\n' % msg)

        self.w(form.render(formvalues=dict(wf_info_for=entity.eid,

                                           by_transition=transition.eid)))

    def redirectpath(self, entity):

        return entity.rest_path()

    def get_form(self, entity, transition, **kwargs):

        # XXX used to specify both rset/row/col and entity in case implements

        # selector (and not entity_implements) is used on custom form

        form = self.vreg['forms'].select(

            'changestate', self.req, entity=entity, transition=transition,

            redirect_path=self.redirectpath(entity), **kwargs)

        trinfo = self.vreg['etypes'].etype_class('TrInfo')(self.req)

        self.initialize_varmaker()

        trinfo.eid = self.varmaker.next()

        subform = self.vreg['forms'].select('edition', self.req, entity=trinfo,

                                            mainform=False)

        subform.field_by_name('by_transition').widget = fwdgs.HiddenInput()

        form.add_subform(subform)

        return form

class WFHistoryView(EntityView):

    id = 'wfhistory'

    __select__ = relation_possible('wf_info_for', role='object') & \

                 score_entity(lambda x: x.workflow_history)

    title = _('Workflow history')

    def cell_call(self, row, col, view=None):

        _ = self.req._

        eid = self.rset[row][col]

        sel = 'Any FS,TS,WF,D'

        rql = ' ORDERBY D DESC WHERE WF wf_info_for X,'\

              'WF from_state FS, WF to_state TS, WF comment C,'\

              'WF creation_date D'

        if self.vreg.schema.eschema('CWUser').has_perm(self.req, 'read'):

            sel += ',U,C'

            rql += ', WF owned_by U?'

            displaycols = range(5)

            headers = (_('from_state'), _('to_state'), _('comment'), _('date'),

                       _('CWUser'))

        else:

            sel += ',C'

            displaycols = range(4)

            headers = (_('from_state'), _('to_state'), _('comment'), _('date'))

        rql = '%s %s, X eid %%(x)s' % (sel, rql)

        try:

            rset = self.req.execute(rql, {'x': eid}, 'x')

        except Unauthorized:

            return

        if rset:

            self.wview('table', rset, title=_(self.title), displayactions=False,

                       displaycols=displaycols, headers=headers)

class WFHistoryVComponent(component.EntityVComponent):

    """display the workflow history for entities supporting it"""

    id = 'wfhistory'

    __select__ = WFHistoryView.__select__ & component.EntityVComponent.__select__

    context = 'navcontentbottom'

    title = _('Workflow history')

    def cell_call(self, row, col, view=None):

        self.wview('wfhistory', self.rset, row=row, col=col, view=view)

# workflow actions #############################################################

class WorkflowActions(action.Action):

    """fill 'workflow' sub-menu of the actions box"""

    id = 'workflow'

    __select__ = (action.Action.__select__ & one_line_rset() &

                  relation_possible('in_state'))

    submenu = _('workflow')

    order = 10

    def fill_menu(self, box, menu):

        entity = self.rset.get_entity(self.row or 0, self.col or 0)

        menu.label = u'%s: %s' % (self.req._('state'), entity.printable_state)

        menu.append_anyway = True

        super(WorkflowActions, self).fill_menu(box, menu)

    def actual_actions(self):

        entity = self.rset.get_entity(self.row or 0, self.col or 0)

        hastr = False

        for tr in entity.possible_transitions():

            url = entity.absolute_url(vid='statuschange', treid=tr.eid)

            yield self.build_action(self.req._(tr.name), url)

            hastr = True

        # don't propose to see wf if user can't pass any transition

        if hastr:

            wfurl = entity.current_workflow.absolute_url()

            yield self.build_action(self.req._('view workflow'), wfurl)

        if entity.workflow_history:

            wfurl = entity.absolute_url(vid='wfhistory')

            yield self.build_action(self.req._('view history'), wfurl)

# workflow entity types views ##################################################

_pvs = uicfg.primaryview_section

_pvs.tag_subject_of(('Workflow', 'initial_state', '*'), 'hidden')

_pvs.tag_object_of(('*', 'state_of', 'Workflow'), 'hidden')

_pvs.tag_object_of(('*', 'transition_of', 'Workflow'), 'hidden')

_abaa = uicfg.actionbox_appearsin_addmenu

_abaa.tag_subject_of(('BaseTransition', 'condition', 'RQLExpression'), False)

_abaa.tag_subject_of(('State', 'allowed_transition', 'BaseTransition'), False)

_abaa.tag_object_of(('SubWorkflowExitPoint', 'destination_state', 'State'),

                    False)

_abaa.tag_object_of(('State', 'state_of', 'Workflow'), True)

_abaa.tag_object_of(('BaseTransition', 'transition_of', 'Workflow'), False)

_abaa.tag_object_of(('Transition', 'transition_of', 'Workflow'), True)

_abaa.tag_object_of(('WorkflowTransition', 'transition_of', 'Workflow'), True)

class WorkflowPrimaryView(primary.PrimaryView):

    __select__ = implements('Workflow')

    def render_entity_attributes(self, entity):

        self.w(entity.view('reledit', rtype='description'))

        self.w(u'<img src="%s" alt="%s"/>' % (

            xml_escape(entity.absolute_url(vid='wfgraph')),

            xml_escape(self.req._('graphical workflow for %s') % entity.name)))

class CellView(view.EntityView):

    id = 'cell'

    __select__ = implements('TrInfo')

    def cell_call(self, row, col, cellvid=None):

        self.w(self.rset.get_entity(row, col).view('reledit', rtype='comment'))

class StateInContextView(view.EntityView):

    """convenience trick, State's incontext view should not be clickable"""

    id = 'incontext'

    __select__ = implements('State')

    def cell_call(self, row, col):

        self.w(xml_escape(self.view('textincontext', self.rset,

                                     row=row, col=col)))

# workflow entity types edition ################################################

_afs = uicfg.autoform_section

_afs.tag_subject_of(('TrInfo', 'to_state', '*'), 'generated')

_afs.tag_subject_of(('TrInfo', 'from_state', '*'), 'generated')

_afs.tag_object_of(('State', 'allowed_transition', '*'), 'primary')

_afs.tag_subject_of(('State', 'allowed_transition', '*'), 'primary')

def workflow_items_for_relation(req, wfeid, wfrelation, targetrelation):

    wf = req.entity_from_eid(wfeid)

    rschema = req.vreg.schema[targetrelation]

    return sorted((e.view('combobox'), e.eid)

                  for e in getattr(wf, 'reverse_%s' % wfrelation)

                  if rschema.has_perm(req, 'add', toeid=e.eid))

class TransitionEditionForm(autoform.AutomaticEntityForm):

    __select__ = entity_implements('Transition')

    def workflow_states_for_relation(self, targetrelation):

        eids = self.edited_entity.linked_to('transition_of', 'subject')

        if eids:

            return workflow_items_for_relation(self.req, eids[0], 'state_of',

                                               targetrelation)

        return []

    def subject_destination_state_vocabulary(self, rtype, limit=None):

        if not self.edited_entity.has_eid():

            return self.workflow_states_for_relation('destination_state')

        return self.subject_relation_vocabulary(rtype, limit)

    def object_allowed_transition_vocabulary(self, rtype, limit=None):

        if not self.edited_entity.has_eid():

            return self.workflow_states_for_relation('allowed_transition')

        return self.object_relation_vocabulary(rtype, limit)

class StateEditionForm(autoform.AutomaticEntityForm):

    __select__ = entity_implements('State')

    def subject_allowed_transition_vocabulary(self, rtype, limit=None):

        if not self.edited_entity.has_eid():

            eids = self.edited_entity.linked_to('state_of', 'subject')

            if eids:

                return workflow_items_for_relation(self.req, eids[0], 'transition_of',

                                                   'allowed_transition')

        return []

# workflow images ##############################################################

class WorkflowDotPropsHandler(object):

    def __init__(self, req):

        self._ = req._

    def node_properties(self, stateortransition):

        """return default DOT drawing options for a state or transition"""

        props = {'label': stateortransition.printable_value('name'),

                 'fontname': 'Courier'}

        if hasattr(stateortransition, 'state_of'):

            props['shape'] = 'box'

            props['style'] = 'filled'

            if stateortransition.reverse_initial_state:

                props['color'] = '#88CC88'

        else:

            props['shape'] = 'ellipse'

            descr = []

            tr = stateortransition

            if tr.require_group:

                descr.append('%s %s'% (

                    self._('groups:'),

                    ','.join(g.printable_value('name') for g in tr.require_group)))

            if tr.condition:

                descr.append('%s %s'% (

                    self._('condition:'),

                    ' | '.join(e.expression for e in tr.condition)))

            if descr:

                props['label'] += escape('\n'.join(descr))

        return props

    def edge_properties(self, transition, fromstate, tostate):

        return {'label': '', 'dir': 'forward',

                'color': 'black', 'style': 'filled'}

class WorkflowVisitor:

    def __init__(self, entity):

        self.entity = entity

    def nodes(self):

        for state in self.entity.reverse_state_of:

            state.complete()

            yield state.eid, state

        for transition in self.entity.reverse_transition_of:

            transition.complete()

            yield transition.eid, transition

    def edges(self):

        for transition in self.entity.reverse_transition_of:

            for incomingstate in transition.reverse_allowed_transition:

                yield incomingstate.eid, transition.eid, transition

            yield transition.eid, transition.destination().eid, transition

class WorkflowImageView(TmpFileViewMixin, view.EntityView):

    id = 'wfgraph'

    content_type = 'image/png'

    __select__ = implements('Workflow')

    def _generate(self, tmpfile):

        """display schema information for an entity"""

        entity = self.rset.get_entity(self.row, self.col)

        visitor = WorkflowVisitor(entity)

        prophdlr = WorkflowDotPropsHandler(self.req)

        generator = GraphGenerator(DotBackend('workflow', 'LR',

                                              ratio='compress', size='30,12'))

        return generator.generate(visitor, prophdlr, tmpfile)