from rest_framework import serializers

from .models import Example, ExampleState, Comment


class CommentSerializer(serializers.ModelSerializer):

    class Meta:
        model = Comment
        fields = ('id', 'user', 'username', 'example', 'text', 'created_at', )
        read_only_fields = ('user', 'example')


class ExampleSerializer(serializers.ModelSerializer):
    annotation_approver = serializers.SerializerMethodField()
    is_confirmed = serializers.SerializerMethodField()

    @classmethod
    def get_annotation_approver(cls, instance):
        approver = instance.annotations_approved_by
        return approver.username if approver else None

    def get_is_confirmed(self, instance):
        user = self.context.get('request').user
        if instance.project.collaborative_annotation:
            states = instance.states.all()
        else:
            states = instance.states.filter(confirmed_by_id=user.id)
        return states.count() > 0

    class Meta:
        model = Example
        fields = [
            'id',
            'filename',
            'meta',
            'annotation_approver',
            'comment_count',
            'text',
            'is_confirmed'
        ]
        read_only_fields = ['filename', 'is_confirmed']


class ExampleStateSerializer(serializers.ModelSerializer):

    class Meta:
        model = ExampleState
        fields = ('id', 'example', 'confirmed_by')
        read_only_fields = ('id', 'example', 'confirmed_by')