from typing import List

from rest_framework import serializers
from django.utils.translation import gettext as _

from labs.models import LabQuizSubmission as DBLabQuizSubmission


class LabQuizSubmissionGetSerializer(serializers.ModelSerializer):
    answers = serializers.SerializerMethodField(method_name="get_answers")

    class Meta:
        model = DBLabQuizSubmission
        fields = ["answers", "created_at", "updated_at"]

    def get_answers(self, obj):
        quiz = self.context["lab_quiz"]
        data = []
        for _answer in obj.answers:
            _data = {
                "user_answer": _answer["user_answer"],
            }
            if quiz.evaluate_immediately:
                _data["is_correct"] = _answer["is_correct"]

                if quiz.show_correct_answer:
                    _data["correct_answer"] = _answer["correct_answer"]
                    _data["explanation"] = _answer["explanation"]
            data.append(_data)
        return data


class LabQuizSubmissionPostSerializer(serializers.Serializer):
    answers = serializers.ListField(
        child=serializers.ListField(
            child=serializers.IntegerField(),
        ),
        allow_empty=False,
    )

    def validate_answers(self, answers: List[List[int]]):
        quiz = self.context["lab_quiz"]
        if len(answers) != len(quiz.questions):
            raise serializers.ValidationError(
                _("The number of answers does not match the number of quiz questions.")
            )

        self.quiz_result = []
        self.score = 0
        for idx, (user_answer, question) in enumerate(zip(answers, quiz.questions)):
            user_answer = set(user_answer)
            option_ids = set()
            correct_option_ids = set()
            for option in question["options"]:
                option_ids.add(option["id"])
                if option["correct"]:
                    correct_option_ids.add(option["id"])

            if not user_answer.issubset(option_ids):
                raise serializers.ValidationError(
                    _("Answer [{idx}] options are invalid.").format(idx=idx)
                )

            if user_answer == correct_option_ids:
                is_correct = True
                self.score += 1
            else:
                is_correct = False

            self.quiz_result.append(
                {
                    "is_correct": is_correct,
                    "user_answer": list(user_answer),
                    "correct_answer": list(correct_option_ids),
                    "explanation": question["explanation"],
                }
            )
        return answers

    def validate(self, attrs):
        quiz = self.context["lab_quiz"]
        quiz_submission = self.instance
        if not quiz.allow_repeat_submission and quiz_submission:
            raise serializers.ValidationError(
                _(
                    "This quiz has already been submitted before and cannot be submitted again."
                )
            )
        return attrs

    def create(self, validated_data):
        return DBLabQuizSubmission.objects.create(
            lab_instance=self.context["lab_instance"],
            lab_quiz=self.context["lab_quiz"],
            user=self.context["request"].user,
            answers=self.quiz_result,
            score=self.score,
        )

    def update(self, instance, validated_data):
        instance.answers = self.quiz_result
        instance.score = self.score
        instance.save()
        return instance