from rest_framework import viewsets
from rest_framework.exceptions import PermissionDenied
from rest_framework.pagination import LimitOffsetPagination
from rest_framework.permissions import IsAuthenticated, DjangoModelPermissions
from django.contrib.auth.models import Permission
from . import serializers


class BaseViewSet(viewsets.ModelViewSet):
    pagination_class = LimitOffsetPagination

    def get_queryset(self):
        qs = super().get_queryset()
        # 如果是超级用户，返回所有数据
        # TODO: 测试结束后要取注释
        # if self.request.user.is_superuser:
        #     return qs
        return qs.filter(merchant=self.request.user.employee.merchant)

    def perform_create(self, serializer):
        try:
            merchant = self.request.user.employee.merchant
            serializer.save(merchant_id=merchant.id)
        except AttributeError:
            raise PermissionDenied("无权限创建该对象")


class QuickInputViewSet(viewsets.ModelViewSet):
    queryset = serializers.basic_models.QuickInput.objects
    serializer_class = serializers.QuickInputSerializer

    def filter_queryset(self, queryset):
        qs = super().filter_queryset(queryset)
        group = self.request.query_params.get('group')
        if group:
            qs = qs.filter(group=group)
        return qs


class ProductViewSet(BaseViewSet):
    queryset = serializers.basic_models.Product.objects
    serializer_class = serializers.ProductSerializer


class WareHouseViewSet(BaseViewSet):
    queryset = serializers.basic_models.WareHouse.objects
    serializer_class = serializers.WareHouseSerializer


class ProductCategoryViewSet(BaseViewSet):
    queryset = serializers.basic_models.ProductCategory.objects
    serializer_class = serializers.ProductCategorySerializer


class SupplierViewSet(BaseViewSet):
    queryset = serializers.basic_models.Supplier.objects
    serializer_class = serializers.SupplierSerializer


class EmployeeViewSet(BaseViewSet):
    queryset = serializers.basic_models.Employee.objects
    serializer_class = serializers.EmployeeSerializer


class EmployeeTypeViewSet(BaseViewSet):
    queryset = serializers.basic_models.EmployeeType.objects
    serializer_class = serializers.EmployeeTypeSerializer


class CustomerViewSet(BaseViewSet):
    queryset = serializers.basic_models.Customer.objects
    serializer_class = serializers.CustomerSerializer
    permission_classes = [IsAuthenticated, DjangoModelPermissions]

    def perform_create(self, serializer):
        merchant = self.request.user.employee.merchant
        employee = self.request.user.employee
        serializer.save(merchant=merchant, created_by=employee)

    def can_view_all(self) -> bool:
        return self.request.user.is_superuser or self.request.user.has_perm('basic_info.view_all_customers')

    def get_queryset(self):
        qs = super().get_queryset()
        # 应用可见性过滤
        from basic_info.services import CustomerVisibilityService
        if self.can_view_all():
            return qs.filter(merchant=self.request.user.employee.merchant)
        return CustomerVisibilityService.filter_customers_for_employee(qs, self.request.user)
    
    def has_permission(self, request, view):
        if request.user.is_superuser or request.user.has_perm('basic_info.view_all_customer'):
            return True
        return super().has_permission(request, view)


class VehicleTypeViewSet(BaseViewSet):
    queryset = serializers.basic_models.VehicleType.objects
    serializer_class = serializers.VehicleTypeSerializer


class BankAccountViewSet(BaseViewSet):
    queryset = serializers.basic_models.BankAccount.objects
    serializer_class = serializers.BankAccountSerializer


class DeviceInfoViewSet(BaseViewSet):
    queryset = serializers.basic_models.DeviceInfo.objects
    serializer_class = serializers.DeviceInfoSerializer


class VehicleTransportRecordViewSet(BaseViewSet):
    queryset = serializers.basic_models.VehicleTransportRecord.objects
    serializer_class = serializers.VehicleTransportRecordSerializer


class UserProfileViewSet(BaseViewSet):
    queryset = serializers.basic_models.UserProfile.objects
    serializer_class = serializers.UserProfileSerializer

    def filter_queryset(self, queryset):
        try:
            merchant = self.request.user.employee.merchant
            return super().filter_queryset(queryset).filter(merchant=merchant)
        except AttributeError:
            raise PermissionDenied("无权限访问该对象")