#viewset
class DealViewSet(viewsets.ModelViewSet):
    """
    Get, list, create, update and delete deals with case with `case_id`.
    """
    serializer_class = serializers.DealSerializer
    lookup_field = 'client_generated_id'

    def get_queryset(self):
        case_id = self.kwargs['case_client_generated_id']
        return Deal.objects.filter(case__client_generated_id=case_id)

#models
class Note(models.Model):
    client_generated_id = models.UUIDField(editable=True, unique=True)
    case = models.ForeignKey(Case)
    category = models.ForeignKey(Category)
    party = models.ForeignKey(Party, blank=True, null=True)
    text = models.TextField()
    cancelled = models.BooleanField(default=False)
    private = models.BooleanField(default=False)
    created = models.DateTimeField()

    class Meta:
        verbose_name = _('note')
        verbose_name_plural = _('notes')

    def __str__(self):
        return str(self.id)


class Deal(models.Model):
    client_generated_id = models.UUIDField(editable=True, unique=True)
    case = models.ForeignKey(Case)
    notes = models.ManyToManyField(Note, through='DealNote', through_fields=('deal', 'note'))
    accepted = models.BooleanField()
    created = models.DateTimeField()

    class Meta:
        verbose_name = _('deal')
        verbose_name_plural = _('deals')

    def __str__(self):
        return str(self.id)


class DealNote(models.Model):
    AND = 'and'
    OR = 'or'
    IF = 'if'
    UNLESS = 'unless'
    CONNECTING_WORDS = (
        (AND, 'and'),
        (OR, 'or'),
        (IF, 'if'),
        (UNLESS, 'unless'),
    )
    deal = models.ForeignKey(Deal)
    note = models.ForeignKey(Note)
    connecting_word = models.CharField(max_length=40, choices=CONNECTING_WORDS, blank=True, null=True, default=None)
    parent = models.ForeignKey(Note, related_name='parent', blank=True, null=True, default=None)

#serializers
class DealNoteSerializer(serializers.ModelSerializer):
    note_id = serializers.SlugRelatedField(slug_field='client_generated_id', source='note', queryset=Note.objects.all())
    parent_note_id = serializers.SlugRelatedField(slug_field='client_generated_id', source='parent', queryset=Note.objects.all())

    class Meta:
        model = DealNote
        fields = ('note_id', 'connecting_word', 'parent_note_id')


class DealSerializer(CaseChildSerializer):
    id = serializers.UUIDField(source='client_generated_id')
    case_id = serializers.SlugRelatedField(slug_field='client_generated_id', source='case', queryset=Case.objects.all())
    notes = DealNoteSerializer(many=True, read_only=False)
    created = UnixEpochDateTimeField(required=True)

    class Meta:
        model = Deal
        fields = ('id', 'case_id', 'accepted', 'notes', 'created')

    def create(self, validated_data):
        print('DealSerializer.create()', validated_data)