from __future__ import absolute_import, unicode_literals

from django import forms
from django.forms.formsets import formset_factory
from django.utils.translation import ugettext_lazy as _

from .models import Workflow, WorkflowState, WorkflowTransition


class WorkflowForm(forms.ModelForm):
    class Meta:
        fields = ('label', 'internal_name')
        model = Workflow


class WorkflowStateForm(forms.ModelForm):
    class Meta:
        fields = ('initial', 'label', 'completion')
        model = WorkflowState


class WorkflowTransitionForm(forms.ModelForm):
    def __init__(self, *args, **kwargs):
        workflow = kwargs.pop('workflow')
        super(WorkflowTransitionForm, self).__init__(*args, **kwargs)
        self.fields[
            'origin_state'
        ].queryset = self.fields[
            'origin_state'
        ].queryset.filter(workflow=workflow)

        self.fields[
            'destination_state'
        ].queryset = self.fields[
            'destination_state'
        ].queryset.filter(workflow=workflow)

    class Meta:
        fields = ('label', 'origin_state', 'destination_state')
        model = WorkflowTransition


class WorkflowTransitionTriggerEventRelationshipForm(forms.Form):
    label = forms.CharField(
        label=_('Label'), required=False,
        widget=forms.TextInput(attrs={'readonly': 'readonly'})
    )
    relationship = forms.ChoiceField(
        label=_('Enabled'),
        widget=forms.RadioSelect(), choices=(
            ('no', _('No')),
            ('yes', _('Yes')),
        )
    )

    def __init__(self, *args, **kwargs):
        super(WorkflowTransitionTriggerEventRelationshipForm, self).__init__(
            *args, **kwargs
        )

        self.fields['label'].initial = self.initial['event_type'].label

        relationship = self.initial['transition'].trigger_events.filter(
            event_type=self.initial['event_type'],
        )

        if relationship.exists():
            self.fields['relationship'].initial = 'yes'
        else:
            self.fields['relationship'].initial = 'no'

    def save(self):
        relationship = self.initial['transition'].trigger_events.filter(
            event_type=self.initial['event_type'],
        )

        if self.cleaned_data['relationship'] == 'no':
            relationship.delete()
        elif self.cleaned_data['relationship'] == 'yes':
            if not relationship.exists():
                self.initial['transition'].trigger_events.create(
                    event_type=self.initial['event_type'],
                )


WorkflowTransitionTriggerEventRelationshipFormSet = formset_factory(
    WorkflowTransitionTriggerEventRelationshipForm, extra=0
)


class WorkflowInstanceTransitionForm(forms.Form):
    def __init__(self, *args, **kwargs):
        user = kwargs.pop('user')
        workflow_instance = kwargs.pop('workflow_instance')
        super(WorkflowInstanceTransitionForm, self).__init__(*args, **kwargs)
        self.fields[
            'transition'
        ].queryset = workflow_instance.get_transition_choices(_user=user)

    transition = forms.ModelChoiceField(
        label=_('Transition'), queryset=WorkflowTransition.objects.none()
    )
    comment = forms.CharField(
        label=_('Comment'), required=False, widget=forms.widgets.Textarea()
    )