"""workflow views:

* IWorkflowable views and forms

* workflow entities views (State, Transition, TrInfo)

:organization: Logilab

:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

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

"""

__docformat__ = "restructuredtext en"

from logilab.mtconverter import html_escape

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

from cubicweb import Unauthorized, view

from cubicweb.selectors import (implements, has_related_entities,

                                relation_possible, match_form_params)

from cubicweb.interfaces import IWorkflowable

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

from cubicweb.web.formfields import StringField,  RichTextField

from cubicweb.web.formwidgets import HiddenInput

from cubicweb.web.views import TmpFileViewMixin

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

class ChangeStateForm(form.EntityFieldsForm):

    id = 'changestate'

    __method = StringField(name='__method', initial='set_state', widget=HiddenInput)

    state = StringField(widget=HiddenInput, eidparam=True)

    trcomment = RichTextField(eidparam=True)

    def form_buttons(self):

        return [self.button_ok(label=stdmsgs.YES,

                               tabindex=self.req.next_tabindex()),

                self.button_cancel(label=stdmsgs.NO,

                                   tabindex=self.req.next_tabindex())]

class ChangeStateFormView(view.EntityView):

    id = 'statuschange'

    title = _('status change')

    __select__ = implements(IWorkflowable) & match_form_params('treid')

    def cell_call(self, row, col):

        entity = self.entity(row, col)

        state = entity.in_state[0]

        transition = self.req.eid_rset(self.req.form['treid']).get_entity(0, 0)

        dest = transition.destination()

        _ = self.req._

        form = self.vreg.select_object('forms', 'changestate', self.req, self.rset, row=row, col=col,

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

        self.w(form.error_message())

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

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

            'st1': _(state.name),

            'st2': _(dest.name)}

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

        self.w(form.form_render(state=dest.eid, trcomment=u''))

    def redirectpath(self, entity):

        return entity.rest_path()

class WFHistoryVComponent(component.EntityVComponent):

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

    id = 'wfhistory'

    __select__ = (component.EntityVComponent.__select__

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

    context = 'navcontentbottom'

    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('EUser').has_perm(self.req, 'read'):

            sel += ',U,C'

            rql += ', WF owned_by U?'

            displaycols = range(5)

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

                       _('EUser'))            

        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)

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

class CellView(view.EntityView):

    id = 'cell'

    __select__ = implements('TrInfo')

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

        self.w(self.entity(row, col).printable_value('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(html_escape(self.view('textincontext', self.rset,

                                     row=row, col=col)))

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

class ViewWorkflowAction(action.Action):

    id = 'workflow'

    __select__ = implements('EEType') & has_related_entities('state_of', 'object')

    category = 'mainactions'

    title = _('view workflow')

    def url(self):

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

        return entity.absolute_url(vid='workflow')

class EETypeWorkflowView(view.EntityView):

    id = 'workflow'

    __select__ = implements('EEType')

    cache_max_age = 60*60*2 # stay in http cache for 2 hours by default 

    def cell_call(self, row, col, **kwargs):

        entity = self.entity(row, col)

        self.w(u'<h1>%s</h1>' % (self.req._('workflow for %s')

                                 % display_name(self.req, entity.name)))

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

            html_escape(entity.absolute_url(vid='ewfgraph')),

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

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.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.name for g in tr.require_group)))

            if tr.condition:

                descr.append('%s %s'% (self._('condition:'), 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 EETypeWorkflowImageView(TmpFileViewMixin, view.EntityView):

    id = 'ewfgraph'

    content_type = 'image/png'

    __select__ = implements('EEType')

    def _generate(self, tmpfile):

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

        entity = self.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)