import six
from rest_framework import serializers
from taggit_serializer.serializers import (TagListSerializerField,
                                           TaggitSerializer)

from rp.models import Article


class ArticleTagListSerializerField(TagListSerializerField):
    # We need this to fix a serializer issue:
    # https://stackoverflow.com/questions/52695298/using-django-taggit-and-django-taggit-serializer-with-issue
    def to_internal_value(self, value):
        if isinstance(value, six.string_types):
            value = value.split(',')

        if not isinstance(value, list):
            self.fail('Not a list', input_type=(value).__name__)

        for s in value:
            if not isinstance(s, six.string_types):
                self.fail('Not a string')

            self.child.run_validation(s)
        return value

    def to_representation(self, obj):
        if not isinstance(obj, list):
            return [tag.name for tag in obj.all()]
        return obj


class ArticleSerializer(TaggitSerializer, serializers.ModelSerializer):
    #: List of short tags to describe the article (eg. "Privacy", "Copyright")
    tags = TagListSerializerField(help_text="""
        List of short tags to describe the article (eg."Privacy", "Copyright").
        It must be a valid JSON list of tags.

        For instance ["Privacy", "Copyright"}]
        """, required=False)

    class Meta:
        model = Article
        fields = ('id', 'url', 'title', 'tags', 'extracts',
                  'status', 'score', 'priority',
                  'archive', 'quote', 'speak')

    def create(self, validated_data):
        article = Article.add_new_url(**validated_data)
        if article is not None:
            article.save()
        return article

    def update(self, instance, validated_data):
        tags = validated_data.pop("tags", None)

        # Let's update the classic fields of the
        # instance first
        for (k, v) in validated_data.items():
            setattr(instance, k, v)

        # Let's set the tags to what's provided
        if tags:
            instance.tags.set(*tags)
        instance.save()
        return instance