from rest_framework import serializers
from apps.quiz.models import Quiz, Question, QuizParticipant, ParticipantAnswer
from apps.course.models import Course, CourseLesson
from apps.account.models import User
from apps.course.models.course import get_localized_field

def get_request_lang(serializer_instance):
    request = serializer_instance.context.get('request')
    return getattr(request, 'LANGUAGE_CODE', None) or 'en'


class AdminCourseSerializer(serializers.ModelSerializer):
    class Meta:
        model = Course
        fields = ['id', 'title']

    def to_representation(self, instance):
        ret = super().to_representation(instance)
        lang = get_request_lang(self)
        ret['title'] = get_localized_field(lang, instance.title)
        return ret


class AdminCourseLessonSerializer(serializers.ModelSerializer):
    title = serializers.SerializerMethodField()

    class Meta:
        model = CourseLesson
        fields = ['id', 'title']
        ref_name = 'QuizAdminCourseLesson'

    def get_title(self, obj):
        lang = get_request_lang(self)
        raw_title = obj.title or (obj.lesson.title if obj.lesson else [])
        return get_localized_field(lang, raw_title)


class AdminQuizListSerializer(serializers.ModelSerializer):
    questions_count = serializers.SerializerMethodField()
    participants_count = serializers.SerializerMethodField()
    course_title = serializers.SerializerMethodField()
    lesson_title = serializers.SerializerMethodField()

    class Meta:
        model = Quiz
        fields = [
            'id', 
            'title', 
            'description', 
            'each_question_timing', 
            'status', 
            'course', 
            'course_title', 
            'lesson', 
            'lesson_title', 
            'questions_count', 
            'participants_count'
        ]

    def get_questions_count(self, obj):
        return obj.questions.count()

    def get_participants_count(self, obj):
        return obj.participants.count()

    def get_course_title(self, obj):
        if not obj.course:
            return None
        lang = get_request_lang(self)
        return get_localized_field(lang, obj.course.title)

    def get_lesson_title(self, obj):
        if not obj.lesson:
            return None
        lang = get_request_lang(self)
        raw_title = obj.lesson.title or (obj.lesson.lesson.title if obj.lesson.lesson else None)
        return get_localized_field(lang, raw_title)


class AdminQuizDetailSerializer(serializers.ModelSerializer):
    questions_count = serializers.SerializerMethodField()
    participants_count = serializers.SerializerMethodField()
    course_title = serializers.SerializerMethodField()
    lesson_title = serializers.SerializerMethodField()

    class Meta:
        model = Quiz
        fields = [
            'id', 
            'title', 
            'description', 
            'each_question_timing', 
            'status', 
            'course', 
            'course_title', 
            'lesson', 
            'lesson_title', 
            'questions_count', 
            'participants_count'
        ]
        read_only_fields = ['course', 'course_title', 'lesson_title', 'questions_count', 'participants_count']

    def get_questions_count(self, obj):
        return obj.questions.count()

    def get_participants_count(self, obj):
        return obj.participants.count()

    def get_course_title(self, obj):
        if not obj.course:
            return None
        lang = get_request_lang(self)
        return get_localized_field(lang, obj.course.title)

    def get_lesson_title(self, obj):
        if not obj.lesson:
            return None
        lang = get_request_lang(self)
        raw_title = obj.lesson.title or (obj.lesson.lesson.title if obj.lesson.lesson else None)
        return get_localized_field(lang, raw_title)


class AdminQuestionSerializer(serializers.ModelSerializer):
    class Meta:
        model = Question
        fields = [
            'id', 
            'quiz', 
            'question', 
            'option1', 
            'option2', 
            'option3', 
            'option4', 
            'correct_answer', 
            'priority'
        ]


class AdminParticipantAnswerSerializer(serializers.ModelSerializer):
    class Meta:
        model = ParticipantAnswer
        fields = ['id', 'question', 'option_num', 'at_time', 'answer_timing']


class AdminQuizParticipantSerializer(serializers.ModelSerializer):
    user_name = serializers.CharField(source='user.fullname', read_only=True)
    user_email = serializers.EmailField(source='user.email', read_only=True)
    answers = AdminParticipantAnswerSerializer(many=True, read_only=True)

    class Meta:
        model = QuizParticipant
        fields = [
            'id', 
            'user_id', 
            'user_name', 
            'user_email', 
            'started_at', 
            'ended_at', 
            'total_timing', 
            'question_score', 
            'timing_score', 
            'total_score',
            'answers'
        ]


class AdminQuizAbsenteeSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = ['id', 'fullname', 'email']