from rest_framework import serializers
from django.db import transaction
from .models import (
    Device, DeviceSerial, DeviceIP, MaintenanceRecord, DeviceAttachment
)
from loguru import logger


class DeviceSerialSerializer(serializers.ModelSerializer):
    class Meta:
        model = DeviceSerial
        fields = ['id', 'serial_number', 'serial_type', 'is_primary', 'remark']


class DeviceIPSerializer(serializers.ModelSerializer):
    class Meta:
        model = DeviceIP
        fields = ['id', 'ip_address', 'ip_type', 'is_primary', 'subnet_mask', 'gateway', 'vlan_id']


class MaintenanceRecordSerializer(serializers.ModelSerializer):
    class Meta:
        model = MaintenanceRecord
        fields = ['id', 'maintenance_date', 'fault_description', 'repair_content', 
                  'replaced_parts', 'maintenance_by', 'cost', 'remark']


class DeviceAttachmentSerializer(serializers.ModelSerializer):
    class Meta:
        model = DeviceAttachment
        fields = ['id', 'file', 'file_name', 'file_type', 'uploaded_at']
        read_only_fields = ['uploaded_at']


class DeviceSerializer(serializers.ModelSerializer):
    serials = DeviceSerialSerializer(many=True, required=False)
    ips = DeviceIPSerializer(many=True, required=False)
    maintenance_records = MaintenanceRecordSerializer(many=True, read_only=True)
    attachments = DeviceAttachmentSerializer(many=True, read_only=True)
    service_duration_days = serializers.IntegerField(read_only=True)
    is_warranty_expired = serializers.BooleanField(read_only=True)
    primary_serial = serializers.SerializerMethodField()
    primary_ip = serializers.SerializerMethodField()
    latest_maintenance = serializers.SerializerMethodField()

    class Meta:
        model = Device
        fields = ['id', 'location', 'building', 'floor', 'cabinet', 'device_name', 
                  'model', 'brand', 'mac_address', 'enable_date', 'last_inspection_date',
                  'thumbnail', 'status', 'responsible_person', 'warranty_expire',
                  'service_duration_days', 'is_warranty_expired', 'primary_serial', 
                  'primary_ip', 'latest_maintenance', 'serials', 'ips', 
                  'maintenance_records', 'attachments', 'created_at', 'updated_at']
        read_only_fields = ['created_at', 'updated_at']

    def get_primary_serial(self, obj):
        primary = obj.serials.filter(is_primary=True).first()
        if primary:
            return DeviceSerialSerializer(primary).data
        return None

    def get_primary_ip(self, obj):
        primary = obj.ips.filter(is_primary=True).first()
        if primary:
            return DeviceIPSerializer(primary).data
        return None

    def get_latest_maintenance(self, obj):
        latest = obj.maintenance_records.first()
        if latest:
            return MaintenanceRecordSerializer(latest).data
        return None

    @transaction.atomic
    def create(self, validated_data):
        serials_data = validated_data.pop('serials', [])
        ips_data = validated_data.pop('ips', [])
        
        device = Device.objects.create(**validated_data)
        
        for serial_data in serials_data:
            DeviceSerial.objects.create(device=device, **serial_data)
        
        for ip_data in ips_data:
            DeviceIP.objects.create(device=device, **ip_data)
        
        logger.info(f'Created device: {device.id} - {device.device_name}')
        return device

    @transaction.atomic
    def update(self, instance, validated_data):
        serials_data = validated_data.pop('serials', None)
        ips_data = validated_data.pop('ips', None)
        
        for attr, value in validated_data.items():
            setattr(instance, attr, value)
        instance.save()
        
        if serials_data is not None:
            instance.serials.all().delete()
            for serial_data in serials_data:
                DeviceSerial.objects.create(device=instance, **serial_data)
        
        if ips_data is not None:
            instance.ips.all().delete()
            for ip_data in ips_data:
                DeviceIP.objects.create(device=instance, **ip_data)
        
        logger.info(f'Updated device: {instance.id}')
        return instance


class DeviceListSerializer(serializers.ModelSerializer):
    primary_serial_number = serializers.SerializerMethodField()
    primary_ip_address = serializers.SerializerMethodField()
    latest_maintenance_summary = serializers.SerializerMethodField()
    service_duration_days = serializers.IntegerField(read_only=True)

    class Meta:
        model = Device
        fields = ['id', 'location', 'building', 'device_name', 'model', 'brand', 
                  'status', 'responsible_person', 'enable_date', 'thumbnail',
                  'primary_serial_number', 'primary_ip_address', 
                  'latest_maintenance_summary', 'service_duration_days']

    def get_primary_serial_number(self, obj):
        primary = obj.serials.filter(is_primary=True).first()
        return primary.serial_number if primary else None

    def get_primary_ip_address(self, obj):
        primary = obj.ips.filter(is_primary=True).first()
        return primary.ip_address if primary else None

    def get_latest_maintenance_summary(self, obj):
        latest = obj.maintenance_records.first()
        if latest:
            return f"{latest.maintenance_date}: {latest.fault_description[:50]}..." if latest.fault_description else str(latest.maintenance_date)
        return None