"""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

                                relation_possible, match_form_params)

from cubicweb.interfaces import IWorkflowable

from cubicweb.view import EntityView

from cubicweb.schema import display_name

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

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

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

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

class ChangeStateForm(forms.CompositeEntityForm):

    id = 'changestate'

    form_renderer_id = 'base' # don't want EntityFormRenderer

    form_buttons = [fwdgs.SubmitButton(stdmsgs.YES),

                    fwdgs.Button(stdmsgs.NO, cwaction='cancel')]

class ChangeStateFormView(form.FormViewMixIn, 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)

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

        dest = transition.destination()

        _ = self.req._

        form = self.vreg['forms'].select('changestate', self.req, 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': _(entity.current_state.name),

            'st2': _(dest.name)}

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

        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.form_add_subform(subform)

        self.w(form.form_render(wf_info_for=entity.eid,

                                by_transition=transition.eid))

    def redirectpath(self, entity):

        return entity.rest_path()

class WFHistoryView(EntityView):

    id = 'wfhistory'

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

    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)

class CellView(view.EntityView):

    id = 'cell'

    __select__ = implements('TrInfo')

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

        self.w(self.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)))

class WorkflowPrimaryView(primary.PrimaryView):

    __select__ = implements('Workflow')

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

    def render_entity_attributes(self, entity):

        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)))

# 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.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:'),

                    ' | '.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.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)