from .models import Mroom, MroomBooking, MroomSlot
from apps.utils.serializers import CustomModelSerializer
from rest_framework import serializers
from django.db import transaction
from rest_framework.exceptions import ParseError
from apps.utils.constants import EXCLUDE_FIELDS


class MroomSerializer(CustomModelSerializer):
    class Meta:
        model = Mroom
        fields = '__all__'


class MroomBookingSerializer(CustomModelSerializer):
    mroom = serializers.PrimaryKeyRelatedField(queryset=Mroom.objects.all(), write_only=True, label="会议室")
    mdate = serializers.DateField(write_only=True, label="预订日期")
    slots = serializers.ListField(child=serializers.IntegerField(), write_only=True, label="时段索引")
    create_by_name = serializers.CharField(source='create_by.username', read_only=True)
    class Meta:
        model = MroomBooking
        fields = '__all__'
        read_only_fields = EXCLUDE_FIELDS
    
    @transaction.atomic
    def create(self, validated_data):
        mroom = validated_data.pop('mroom')
        slots = validated_data.pop('slots')
        mdate = validated_data.pop('mdate')
        booking = MroomBooking.objects.create(**validated_data)
        MroomSlot.objects.filter(booking=booking).delete()
        for slot in slots:
            if slot < 0 or slot > 47:
                raise ParseError("时段索引超出范围")
            try:
                MroomSlot.objects.create(booking=booking, slot=slot, mdate=mdate, mroom=mroom)
            except Exception as e:
                raise ParseError(f"时段已预订,请刷新重选-{e}")
        return booking

    @transaction.atomic
    def update(self, instance, validated_data):
        mroom = validated_data.pop('mroom')
        slots = validated_data.pop('slots')
        mdate = validated_data.pop('mdate')
        booking = super().update(instance, validated_data)
        MroomSlot.objects.filter(booking=instance).delete()
        for slot in slots:
            if slot < 0 or slot > 47:
                raise ParseError("时段索引超出范围")
            try:
                MroomSlot.objects.create(booking=booking, slot=slot, mdate=mdate, mroom=mroom)
            except Exception as e:
                raise ParseError(f"时段已预订,请刷新重选-{e}")
        return booking
        


class MroomSlotSerializer(CustomModelSerializer):
    booking_title = serializers.CharField(source='booking.title', read_only=True)
    class Meta:
        model = MroomSlot
        fields = '__all__'