from rest_framework import serializers
from .models import Enseignant, Specialite, Classe
from N3wtSchool import settings
from django.utils import timezone
import pytz

class SpecialiteSerializer(serializers.ModelSerializer):
    dateCreation_formattee = serializers.SerializerMethodField()
    class Meta:
        model = Specialite
        fields = '__all__'
    
    def get_dateCreation_formattee(self, obj):
        utc_time = timezone.localtime(obj.dateCreation) # Convertir en heure locale
        local_tz = pytz.timezone(settings.TZ_APPLI)
        local_time = utc_time.astimezone(local_tz)

        return local_time.strftime("%d-%m-%Y %H:%M")

class ClasseSerializer(serializers.ModelSerializer):
    specialites = SpecialiteSerializer(many=True, read_only=True)
    specialites_ids = serializers.PrimaryKeyRelatedField(queryset=Specialite.objects.all(), many=True, source='specialites')
    dateCreation_formattee = serializers.SerializerMethodField()
    enseignant_principal = serializers.SerializerMethodField()
    enseignant_principal_id = serializers.PrimaryKeyRelatedField(queryset=Enseignant.objects.all(), source='enseignant_principal', write_only=False, read_only=False)

    class Meta:
        model = Classe
        fields = ['id', 'nom_ambiance', 'tranche_age', 'nombre_eleves', 'langue_enseignement', 'specialites', 'specialites_ids', 'enseignant_principal', 'enseignant_principal_id', 'annee_scolaire', 'dateCreation', 'dateCreation_formattee']

    def get_enseignant_principal(self, obj):
        from .serializers import EnseignantDetailSerializer
        if obj.enseignant_principal:
            return EnseignantDetailSerializer(obj.enseignant_principal).data
        return None

    def create(self, validated_data):
        specialites_data = validated_data.pop('specialites', [])
        classe = Classe.objects.create(**validated_data)
        classe.specialites.set(specialites_data)
        return classe

    def update(self, instance, validated_data):
        specialites_data = validated_data.pop('specialites', [])
        instance.nom_ambiance = validated_data.get('nom_ambiance', instance.nom_ambiance)
        instance.tranche_age = validated_data.get('tranche_age', instance.tranche_age)
        instance.nombre_eleves = validated_data.get('nombre_eleves', instance.nombre_eleves)
        instance.langue_enseignement = validated_data.get('langue_enseignement', instance.langue_enseignement)
        instance.annee_scolaire = validated_data.get('annee_scolaire', instance.annee_scolaire)
        instance.enseignant_principal = validated_data.get('enseignant_principal', instance.enseignant_principal)
        instance.save()
        instance.specialites.set(specialites_data)
        return instance

    def get_dateCreation_formattee(self, obj):
        utc_time = timezone.localtime(obj.dateCreation) # Convertir en heure locale
        local_tz = pytz.timezone(settings.TZ_APPLI)
        local_time = utc_time.astimezone(local_tz)

        return local_time.strftime("%d-%m-%Y %H:%M")

class EnseignantSerializer(serializers.ModelSerializer):
    specialite = SpecialiteSerializer(read_only=True)
    specialite_id = serializers.PrimaryKeyRelatedField(queryset=Specialite.objects.all(), source='specialite', write_only=False, read_only=False)
    classes_principal = ClasseSerializer(many=True, read_only=True)

    class Meta:
        model = Enseignant
        fields = ['id', 'nom', 'prenom', 'mail', 'specialite', 'specialite_id', 'classes_principal']
    
    def create(self, validated_data):
        specialite = validated_data.pop('specialite', None)
        enseignant = Enseignant.objects.create(**validated_data)
        enseignant.specialite = specialite
        enseignant.save()
        return enseignant

class EnseignantDetailSerializer(serializers.ModelSerializer):
    specialite = SpecialiteSerializer(read_only=True)

    class Meta:
        model = Enseignant
        fields = ['id', 'nom', 'prenom', 'mail', 'specialite']