from rest_framework import serializers
from sitemanagement.models import Sensor, Alert

class NotificationSerializer(serializers.ModelSerializer):
    type = serializers.SerializerMethodField()
    priority = serializers.SerializerMethodField()
    timestamp = serializers.DateTimeField(source='created_at')
    acknowledged = serializers.BooleanField(source='resolved', default=False)
    
    class Meta:
        model = Alert
        fields = ('id', 'type', 'timestamp', 'acknowledged', 'priority')
        
    def get_type(self, obj):
        return 'critical' if obj.severity == 'critical' else 'warning'
        
    def get_priority(self, obj):
        return 'high' if obj.severity == 'critical' else 'medium'

class DetectorSerializer(serializers.ModelSerializer):
    detector_id = serializers.SerializerMethodField()
    type = serializers.SerializerMethodField()
    name = serializers.SerializerMethodField()
    object = serializers.SerializerMethodField()
    status = serializers.SerializerMethodField()
    zone = serializers.SerializerMethodField()
    floor = serializers.SerializerMethodField()
    notifications = NotificationSerializer(source='alerts', many=True)

    class Meta:
        model = Sensor
        fields = ('detector_id', 'type', 'name', 'object', 'status', 'zone', 'floor', 'notifications')

    def get_detector_id(self, obj):
        return obj.name or f"{obj.sensor_type.code}-{obj.id}"

    def get_type(self, obj):
        # маппинг типов сенсоров на нужные значения
        sensor_type_mapping = {
            'GA': 'fire_detector',
            'PE': 'pressure_sensor',
            'GLE': 'gas_detector'
        }
        return sensor_type_mapping.get(obj.sensor_type.code, 'unknown')

    def get_name(self, obj):
        return f"{obj.sensor_type.name} {obj.serial_number}"

    def get_object(self, obj):
        # получаем первую зону датчика и её объект
        zone = obj.zones.first()
        if zone:
            return zone.object.title
        return None

    def get_status(self, obj):
        # проверяем наличие активных алертов
        latest_alert = obj.alerts.filter(resolved=False).first()
        if latest_alert:
            return latest_alert.severity  # вернет 'warning' или 'critical'
        return 'normal'

    def get_zone(self, obj):
        zone = obj.zones.first()
        if zone:
            return zone.name
        return None

    def get_floor(self, obj):
        # получаем этаж из зоны
        zone = obj.zones.first()
        if zone:
            return zone.floor
        return None  # если датчик не привязали к зоне

class DetectorsResponseSerializer(serializers.Serializer):
    detectors = serializers.SerializerMethodField()

    def get_detectors(self, sensors):
        detector_serializer = DetectorSerializer(sensors, many=True)
        return {
            sensor['detector_id']: sensor 
            for sensor in detector_serializer.data
        }