models.py

from django.conf import settings
from django.contrib.postgres.fields import JSONField
from django.db import models
from django.db.models.signals import post_save
from django.dispatch import receiver
from django.urls import reverse

from opentech.apply.activity.models import Activity
from opentech.apply.users.models import User

NO = 0
MAYBE = 1
YES = 2

RECOMMENDATION_CHOICES = (
    (NO, 'No'),
    (MAYBE, 'Maybe'),
    (YES, 'Yes'),
)


class ReviewQuerySet(models.QuerySet):
    def published(self):
        return self.filter(is_draft=False)

    def by_staff(self):
        return self.published().filter(author__in=User.objects.staff())

    def by_reviewers(self):
        return self.published().filter(author__in=User.objects.reviewers())

    def staff_score(self):
        return self.by_staff().score()

    def staff_recommendation(self):
        return self.by_staff().recommendation()

    def reviewers_score(self):
        return self.by_reviewers().score()

    def reviewers_recommendation(self):
        return self.by_reviewers().recommendation()

    def score(self):
        return self.aggregate(models.Avg('score'))['score__avg']

    def recommendation(self):
        recommendations = self.values_list('recommendation', flat=True)
        try:
            recommendation = sum(recommendations) / len(recommendations)
        except ZeroDivisionError:
            return -1

        if recommendation == YES or recommendation == NO:
            # If everyone in agreement return Yes/No
            return recommendation
        else:
            return MAYBE


class Review(models.Model):
    submission = models.ForeignKey('funds.ApplicationSubmission', on_delete=models.CASCADE, related_name='reviews')
    author = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.PROTECT,
    )
    review = JSONField()
    recommendation = models.IntegerField(verbose_name="Recommendation", choices=RECOMMENDATION_CHOICES, default=0)
    score = models.DecimalField(max_digits=10, decimal_places=1, default=0)
    is_draft = models.BooleanField(default=False, verbose_name="Draft")

    objects = ReviewQuerySet.as_manager()

    class Meta:
        unique_together = ('author', 'submission')

    def get_absolute_url(self):
        return reverse('apply:reviews:review', args=(self.id,))

    def __str__(self):
        return f'Review for {self.submission.title} by {self.author!s}'

    def __repr__(self):
        return f'<{self.__class__.__name__}: {str(self.review)}>'


@receiver(post_save, sender=Review)
def update_submission_reviewers_list(sender, **kwargs):
    review = kwargs.get('instance')

    if not review.submission.reviewers.filter(id=review.author.id).exists():
        review.submission.reviewers.add(review.author)

    if kwargs.get('created', False):
        Activity.actions.create(
            user=review.author,
            submission=review.submission,
            message=f'Created a review for {review.submission.title}'
        )