from rest_framework import serializers
from .models import *
from exercise.models import Exercise
from exercise.serializers import ExerciseSerializer

class SupersetExerciseSerializer(serializers.ModelSerializer):
    exercise = serializers.SerializerMethodField()
    unique_id = serializers.SerializerMethodField()

    class Meta:
        model = SupersetExercise
        fields = '__all__'

    def get_exercise(self, obj):
        try:
            exercise = obj.exercise
        except (Exercise.DoesNotExist, AttributeError):
            return None
        if exercise is None:
            return None
        return ExerciseSerializer(exercise, many=False).data

    def get_unique_id(self, obj):
        return f"{obj.pk}-{obj.superset_id}" if hasattr(obj, 'superset_id') else str(obj.pk)

class SupersetSerializer(serializers.ModelSerializer):
    """Serializer for Superset with nested exercises.

    For optimal performance, callers should prefetch related data:
        Superset.objects.prefetch_related(
            'superset_exercises__exercise__exercise_muscle_exercise__muscle',
            'superset_exercises__exercise__workout_exercise_workout__equipment',
        )
    """
    exercises = serializers.SerializerMethodField()

    class Meta:
        model = Superset
        fields = '__all__'

    def get_exercises(self, obj):
        if obj.pk is None:
            return []
        # Use prefetched data if available via superset_exercises related manager
        objs = obj.superset_exercises.all().order_by('order')
        return SupersetExerciseSerializer(objs, many=True).data