from drf_spectacular.utils import extend_schema_field
from rest_framework import serializers

from .models import Grade


# ---- Grades ----

class GradeSerializer(serializers.ModelSerializer):
    class Meta:
        model = Grade
        fields = ['id', 'title', 'icon', 'color']


class GradesListResponseSerializer(serializers.Serializer):
    grades = GradeSerializer(many=True)


# ---- Home (skill map + stats) ----

class NodeStatusSerializer(serializers.Serializer):
    id = serializers.CharField()
    title = serializers.CharField()
    status = serializers.ChoiceField(choices=['locked', 'unlocked', 'completed'])
    # شناسه‌ی درس‌های همین گره تا کلاینت بدونه با کلیک روی گره کدوم درس رو
    # باز کنه (endpointهای lessons/{id}/... مستقیم با همین id کار می‌کنن).
    lessonIds = serializers.ListField(child=serializers.IntegerField())


class UnitWithNodesSerializer(serializers.Serializer):
    id = serializers.CharField()
    title = serializers.CharField()
    nodes = NodeStatusSerializer(many=True)


class StatsSerializer(serializers.Serializer):
    progressPercent = serializers.FloatField()
    xp = serializers.IntegerField()
    coins = serializers.IntegerField()


class HomeResponseSerializer(serializers.Serializer):
    units = UnitWithNodesSerializer(many=True)
    stats = StatsSerializer()


# ---- Lesson intro ----

class LessonIntroResponseSerializer(serializers.Serializer):
    lessonId = serializers.CharField()
    title = serializers.CharField()
    introText = serializers.CharField()
    mascotAnimation = serializers.CharField()


# ---- Lesson questions ----

class ChoiceOptionSerializer(serializers.Serializer):
    id = serializers.CharField()
    value = serializers.CharField()


class QuestionSerializer(serializers.Serializer):
    id = serializers.CharField()
    type = serializers.CharField()
    prompt = serializers.CharField()
    options = ChoiceOptionSerializer(many=True)


class LessonQuestionsResponseSerializer(serializers.Serializer):
    questions = QuestionSerializer(many=True)


# ---- Answer submission ----

class AnswerRequestSerializer(serializers.Serializer):
    selectedOptionId = serializers.IntegerField()


class AnswerResponseSerializer(serializers.Serializer):
    correct = serializers.BooleanField()
    correctOptionId = serializers.CharField()
    xpEarned = serializers.IntegerField()
    heartsRemaining = serializers.IntegerField()
    # حالتِ انیمیشنِ ماسکوت («رُبو») برای فرانت: جوابِ درست → happy، غلط →
    # encourage. هم‌خوان با RobotMood در MathApp_frontend.
    mascotMood = serializers.CharField()


# ---- Lesson completion ----

class LessonCompleteRequestSerializer(serializers.Serializer):
    # 🔒 اصلاح امنیتی: قبلاً هیچ محدودیتی روی این دو فیلد نبود؛ کلاینت
    # می‌تونست correctCount منفی یا totalQuestions صفر/منفی بفرسته.
    # min_value ها فقط شرطِ ساده‌ی «غیرمنفی/مثبت» رو تضمین می‌کنن؛ چکِ
    # اصلیِ «correctCount نباید از تعدادِ واقعیِ سوال‌های درس بیشتر باشه»
    # در LessonCompleteView (جایی که به Lesson دسترسی داریم) انجام می‌شه.
    correctCount = serializers.IntegerField(min_value=0)
    totalQuestions = serializers.IntegerField(min_value=1)


class LessonCompleteResponseSerializer(serializers.Serializer):
    stars = serializers.IntegerField()
    xpEarned = serializers.IntegerField()
    coinsEarned = serializers.IntegerField()
    stats = StatsSerializer()


# ---- Node progress (تکمیل‌شده / نصفه‌رها / در حال انجام) ----

class NodeProgressSerializer(serializers.Serializer):
    nodeId = serializers.CharField(source='node_id')
    nodeTitle = serializers.CharField(source='node.title')
    unitId = serializers.CharField(source='node.unit_id')
    status = serializers.ChoiceField(
        choices=['not_started', 'in_progress', 'completed', 'abandoned'],
    )
    lessonsCompleted = serializers.IntegerField(source='lessons_completed_count')
    lessonsTotal = serializers.SerializerMethodField()
    startedAt = serializers.DateTimeField(source='started_at', allow_null=True)
    completedAt = serializers.DateTimeField(source='completed_at', allow_null=True)
    lastActivityAt = serializers.DateTimeField(source='last_activity_at', allow_null=True)

    @extend_schema_field(serializers.IntegerField)
    def get_lessonsTotal(self, obj):
        return obj.node.lessons.count()


class NodeProgressListResponseSerializer(serializers.Serializer):
    progress = NodeProgressSerializer(many=True)