forms.py

from django import forms
from django.contrib import messages
from django.utils.text import mark_safe
from django.utils.translation import ugettext_lazy as _

from django_select2.forms import Select2Widget

from opentech.apply.users.models import User

from .models import ApplicationSubmission, AssignedReviewers, ReviewerRole
from .widgets import Select2MultiCheckboxesWidget, Select2IconWidget


class ProgressSubmissionForm(forms.ModelForm):
    action = forms.ChoiceField(label='Take action')

    class Meta:
        model = ApplicationSubmission
        fields: list = []

    def __init__(self, *args, **kwargs):
        self.user = kwargs.pop('user')
        super().__init__(*args, **kwargs)
        choices = list(self.instance.get_actions_for_user(self.user))
        action_field = self.fields['action']
        action_field.choices = choices
        self.should_show = bool(choices)


class ScreeningSubmissionForm(forms.ModelForm):

    class Meta:
        model = ApplicationSubmission
        fields = ('screening_status',)

    def __init__(self, *args, **kwargs):
        self.user = kwargs.pop('user')
        super().__init__(*args, **kwargs)
        self.should_show = False
        if (self.instance.active and self.user.is_apply_staff) or self.user.is_superuser:
            self.should_show = True


class UpdateSubmissionLeadForm(forms.ModelForm):
    class Meta:
        model = ApplicationSubmission
        fields = ('lead',)

    def __init__(self, *args, **kwargs):
        kwargs.pop('user')
        super().__init__(*args, **kwargs)
        lead_field = self.fields['lead']
        lead_field.label = f'Update lead from { self.instance.lead } to'
        lead_field.queryset = lead_field.queryset.exclude(id=self.instance.lead.id)


class UpdateReviewersForm(forms.ModelForm):
    reviewer_reviewers = forms.ModelMultipleChoiceField(
        queryset=User.objects.reviewers().exclude(id__in=User.objects.staff()),
        widget=Select2MultiCheckboxesWidget(attrs={'data-placeholder': 'Reviewers'}),
        label='Reviewers',
        required=False,
    )

    class Meta:
        model = ApplicationSubmission
        fields: list = []

    def __init__(self, *args, **kwargs):
        self.user = kwargs.pop('user')
        self.request = kwargs.pop('request', None)
        super().__init__(*args, **kwargs)

        reviewers = self.instance.reviewers.all()
        self.submitted_reviewers = User.objects.filter(id__in=self.instance.reviews.values('author'))

        if self.can_alter_external_reviewers(self.instance, self.user):
            self.prepare_field('reviewer_reviewers', reviewers, self.submitted_reviewers)
        else:
            self.fields.pop('reviewer_reviewers')

        staff_reviewers = User.objects.staff()
        for role in ReviewerRole.objects.all().order_by('order'):
            field_name = 'reviewer_' + str(role.pk)
            self.fields[field_name] = forms.ModelChoiceField(
                queryset=staff_reviewers,
                widget=Select2IconWidget(attrs={
                    'data-placeholder': 'Select a reviewer', 'role': role}),
                required=False,
                label=f'{role.name} Reviewer',
            )
            # Pre-populate form field
            existing_submission_reviewer = AssignedReviewers.objects.filter(submission=self.instance, role=role)
            if existing_submission_reviewer:
                self.fields[field_name].initial = existing_submission_reviewer[0].reviewer

    def prepare_field(self, field_name, initial, excluded):
        field = self.fields[field_name]
        field.queryset = field.queryset.exclude(id__in=excluded)
        field.initial = initial

    def can_alter_external_reviewers(self, instance, user):
        return instance.stage.has_external_review and (user == instance.lead or user.is_superuser)

    def clean(self):
        cleaned_data = super().clean()
        role_reviewers = cleaned_data.copy()
        role_reviewers.pop('reviewer_reviewers')
        role_reviewer_users_list =  [value for value in role_reviewers.values()]

        if len(role_reviewer_users_list) != len(set(role_reviewer_users_list)):  # If any of the users match
            error_message = _('Users cannot be assigned to multiple roles.')
            messages.error(self.request, mark_safe(error_message + self.errors.as_ul()))
            raise forms.ValidationError(error_message)

        return cleaned_data

    def save(self, *args, **kwargs):
        instance = super().save(*args, **kwargs)
        if self.can_alter_external_reviewers(self.instance, self.user):
            reviewers = self.cleaned_data.get('reviewer_reviewers')
        else:
            reviewers = instance.reviewers_not_reviewed

        current_reviewers = set(reviewers | self.submitted_reviewers)
        for reviewer in current_reviewers:
            AssignedReviewers.objects.get_or_create(
                submission=instance,
                reviewer=reviewer,
                )
        AssignedReviewers.objects.filter(
            submission=instance).exclude(
            reviewer__in=current_reviewers).delete()

        return instance


class BatchUpdateReviewersForm(forms.Form):
    staff_reviewers = forms.ModelMultipleChoiceField(
        queryset=User.objects.staff(),
        widget=Select2MultiCheckboxesWidget(attrs={'data-placeholder': 'Staff'}),
    )
    submission_ids = forms.CharField(widget=forms.HiddenInput())

    def clean_submission_ids(self):
        value = self.cleaned_data['submission_ids']
        return [int(submission) for submission in value.split(',')]