from rest_framework import serializers
from .models import *
from muscle.models import ExerciseMuscle
from equipment.models import WorkoutEquipment
from equipment.serializers import WorkoutEquipmentSerializer

class ExerciseMuscleSerializer(serializers.ModelSerializer):
    name = serializers.SerializerMethodField()

    class Meta:
        model = ExerciseMuscle
        fields = '__all__'

    def get_name(self, obj):
        return obj.muscle.name

class ExerciseSerializer(serializers.ModelSerializer):
    muscles = serializers.SerializerMethodField()
    equipment = serializers.SerializerMethodField()
    audio_url = serializers.ReadOnlyField()
    video_url = serializers.ReadOnlyField()
    transition_url = serializers.ReadOnlyField()

    class Meta:
        model = Exercise
        fields = '__all__'

    def get_muscles(self, obj):
        # Use prefetched data if available, avoiding N+1 queries
        if hasattr(obj, '_prefetched_objects_cache') and 'exercise_muscle_exercise' in obj._prefetched_objects_cache:
            return [{'muscle': em.muscle_id, 'name': em.muscle.name} for em in obj.exercise_muscle_exercise.all()]
        return list(obj.exercise_muscle_exercise.values('muscle', name=models.F('muscle__name')))

    def get_equipment(self, obj):
        # Use prefetched data if available, avoiding N+1 queries
        if hasattr(obj, '_prefetched_objects_cache') and 'workout_exercise_workout' in obj._prefetched_objects_cache:
            return [{'equipment': we.equipment_id, 'name': we.equipment.name} for we in obj.workout_exercise_workout.all()]
        return list(obj.workout_exercise_workout.values('equipment', name=models.F('equipment__name')))