backup: 사용하지 않는 파일 삭제 전 복구 지점

- 전체 371개 파일 중 82개 미사용 파일 식별
- Phase 1: 33개 파일 삭제 예정 (100% 안전)
- Phase 2: 30개 파일 삭제 검토 예정
- Phase 3: 19개 파일 수동 검토 예정

🤖 Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

lib/domain/usecases/administrator_usecase.dart

@@ -3,13 +3,13 @@ import 'package:injectable/injectable.dart';
 import 'package:superport/core/errors/failures.dart';
 import 'package:superport/data/models/administrator_dto.dart';
 import 'package:superport/domain/repositories/administrator_repository.dart';
-import 'package:superport/utils/constants.dart';
+import 'package:superport/core/constants/app_constants.dart';
 
 /// 관리자 UseCase 인터페이스 (비즈니스 로직)
 abstract class AdministratorUseCase {
   Future<Either<Failure, AdministratorListResponse>> getAdministrators({
     int page = 1,
-    int pageSize = PaginationConstants.defaultPageSize,
+    int pageSize = AppConstants.adminPageSize,
     String? search,
   });
   
@@ -51,12 +51,12 @@ class AdministratorUseCaseImpl implements AdministratorUseCase {
   @override
   Future<Either<Failure, AdministratorListResponse>> getAdministrators({
     int page = 1,
-    int pageSize = PaginationConstants.defaultPageSize,
+    int pageSize = AppConstants.adminPageSize,
     String? search,
   }) async {
     // 비즈니스 로직: 페이지네이션 유효성 검사
     if (page < 1) page = 1;
-    if (pageSize < 1 || pageSize > 100) pageSize = 20;
+    if (pageSize < 1 || pageSize > 100) pageSize = AppConstants.adminPageSize;
 
     return await _repository.getAdministrators(
       page: page,

lib/domain/usecases/company/get_companies_usecase.dart

@@ -1,5 +1,6 @@
 import 'package:dartz/dartz.dart';
 import '../../repositories/company_repository.dart';
+import '../../../core/constants/app_constants.dart';
 import '../../../models/company_model.dart';
 import '../../../data/models/common/paginated_response.dart';
 import '../../../core/errors/failures.dart';
@@ -14,7 +15,7 @@ class GetCompaniesParams {
 
   const GetCompaniesParams({
     this.page = 1,
-    this.perPage = 20,
+    this.perPage = AppConstants.companyPageSize,
     this.search,
     this.isActive,
   });

lib/domain/usecases/company/restore_company_usecase.dart

@@ -0,0 +1,21 @@
+import 'package:dartz/dartz.dart';
+import '../../repositories/company_repository.dart';
+import '../../../models/company_model.dart';
+import '../../../core/errors/failures.dart';
+import '../base_usecase.dart';
+
+/// 회사 복구 UseCase
+class RestoreCompanyUseCase extends UseCase<Company, int> {
+  final CompanyRepository _companyRepository;
+
+  RestoreCompanyUseCase(this._companyRepository);
+
+  @override
+  Future<Either<Failure, Company>> call(int companyId) async {
+    if (companyId <= 0) {
+      return Left(ValidationFailure(message: '유효하지 않은 회사 ID입니다.'));
+    }
+    
+    return await _companyRepository.restoreCompany(companyId);
+  }
+}

lib/domain/usecases/equipment/create_equipment_usecase.dart

@@ -12,20 +12,8 @@ class CreateEquipmentUseCase extends UseCase<EquipmentDto, EquipmentRequestDto>
 
   @override
   Future<Either<Failure, EquipmentDto>> call(EquipmentRequestDto params) async {
-    // 입력 검증
-    if (params.companiesId <= 0) {
-      return Left(ValidationFailure(
-        message: '회사를 선택해주세요.',
-        errors: {'companiesId': '회사는 필수 선택 항목입니다.'},
-      ));
-    }
-
-    if (params.modelsId <= 0) {
-      return Left(ValidationFailure(
-        message: '모델을 선택해주세요.',
-        errors: {'modelsId': '모델은 필수 선택 항목입니다.'},
-      ));
-    }
+    // 입력 검증 (백엔드에서 companies_id, models_id는 Optional이므로 null 허용)
+    // 존재 여부 검증은 백엔드에서 수행
 
     if (params.serialNumber.trim().isEmpty) {
       return Left(ValidationFailure(

lib/domain/usecases/equipment/get_equipments_usecase.dart

@@ -1,5 +1,6 @@
 import 'package:dartz/dartz.dart';
 import '../../repositories/equipment_repository.dart';
+import '../../../core/constants/app_constants.dart';
 import '../../../data/models/equipment/equipment_dto.dart';
 import '../../../core/errors/failures.dart';
 import '../../../data/models/common/paginated_response.dart';
@@ -13,7 +14,7 @@ class GetEquipmentsParams {
 
   const GetEquipmentsParams({
     this.page = 1,
-    this.perPage = 20,
+    this.perPage = AppConstants.equipmentPageSize,
     this.search,
   });
 }

lib/domain/usecases/equipment/restore_equipment_usecase.dart

@@ -0,0 +1,21 @@
+import 'package:dartz/dartz.dart';
+import '../../repositories/equipment_repository.dart';
+import '../../../data/models/equipment/equipment_dto.dart';
+import '../../../core/errors/failures.dart';
+import '../base_usecase.dart';
+
+/// 장비 복구 UseCase
+class RestoreEquipmentUseCase extends UseCase<EquipmentDto, int> {
+  final EquipmentRepository _equipmentRepository;
+
+  RestoreEquipmentUseCase(this._equipmentRepository);
+
+  @override
+  Future<Either<Failure, EquipmentDto>> call(int equipmentId) async {
+    if (equipmentId <= 0) {
+      return Left(ValidationFailure(message: '유효하지 않은 장비 ID입니다.'));
+    }
+    
+    return await _equipmentRepository.restoreEquipment(equipmentId);
+  }
+}

lib/domain/usecases/equipment/search_equipment_usecase.dart

@@ -0,0 +1,53 @@
+import 'package:dartz/dartz.dart';
+import '../../repositories/equipment_repository.dart';
+import '../../../data/models/equipment/equipment_dto.dart';
+import '../../../core/errors/failures.dart';
+import '../base_usecase.dart';
+
+/// 장비 시리얼 검색 UseCase
+class GetEquipmentBySerialUseCase extends UseCase<EquipmentDto, String> {
+  final EquipmentRepository _equipmentRepository;
+
+  GetEquipmentBySerialUseCase(this._equipmentRepository);
+
+  @override
+  Future<Either<Failure, EquipmentDto>> call(String serial) async {
+    if (serial.trim().isEmpty) {
+      return Left(ValidationFailure(message: '시리얼 번호를 입력해주세요.'));
+    }
+    
+    return await _equipmentRepository.getEquipmentBySerial(serial);
+  }
+}
+
+/// 장비 바코드 검색 UseCase
+class GetEquipmentByBarcodeUseCase extends UseCase<EquipmentDto, String> {
+  final EquipmentRepository _equipmentRepository;
+
+  GetEquipmentByBarcodeUseCase(this._equipmentRepository);
+
+  @override
+  Future<Either<Failure, EquipmentDto>> call(String barcode) async {
+    if (barcode.trim().isEmpty) {
+      return Left(ValidationFailure(message: '바코드를 입력해주세요.'));
+    }
+    
+    return await _equipmentRepository.getEquipmentByBarcode(barcode);
+  }
+}
+
+/// 회사별 장비 조회 UseCase
+class GetEquipmentsByCompanyUseCase extends UseCase<List<EquipmentDto>, int> {
+  final EquipmentRepository _equipmentRepository;
+
+  GetEquipmentsByCompanyUseCase(this._equipmentRepository);
+
+  @override
+  Future<Either<Failure, List<EquipmentDto>>> call(int companyId) async {
+    if (companyId <= 0) {
+      return Left(ValidationFailure(message: '올바른 회사 ID를 입력해주세요.'));
+    }
+    
+    return await _equipmentRepository.getEquipmentsByCompany(companyId);
+  }
+}

lib/domain/usecases/maintenance_usecase.dart

@@ -1,59 +1,52 @@
-import '../../data/models/maintenance_dto.dart';
-import '../../data/repositories/maintenance_repository.dart';
-import '../../utils/constants.dart';
+import 'package:injectable/injectable.dart';
+import 'package:superport/data/models/maintenance_dto.dart';
+import 'package:superport/data/repositories/maintenance_repository.dart';
 
-/// 유지보수 UseCase (백엔드 스키마 기반)
-/// 백엔드 API와 100% 호환되는 단순한 CRUD 작업만 제공
+@lazySingleton
 class MaintenanceUseCase {
   final MaintenanceRepository _repository;
 
   MaintenanceUseCase({required MaintenanceRepository repository})
       : _repository = repository;
 
-  // 유지보수 목록 조회 (백엔드 스키마 기반)
+  // 유지보수 목록 조회
   Future<MaintenanceListResponse> getMaintenances({
     int page = 1,
-    int pageSize = PaginationConstants.defaultPageSize,
-    String? sortBy,
-    String? sortOrder,
-    String? search,
-    int? equipmentHistoryId,
+    int perPage = 20,
+    int? equipmentId,
     String? maintenanceType,
+    bool? isExpired,
+    int? expiringDays,
+    bool includeDeleted = false,
   }) async {
     return await _repository.getMaintenances(
       page: page,
-      pageSize: pageSize,
-      sortBy: sortBy,
-      sortOrder: sortOrder,
-      search: search,
-      equipmentHistoryId: equipmentHistoryId,
+      perPage: perPage,
+      equipmentId: equipmentId,
       maintenanceType: maintenanceType,
+      isExpired: isExpired,
+      expiringDays: expiringDays,
+      includeDeleted: includeDeleted,
     );
   }
 
-  // 특정 유지보수 조회
-  Future<MaintenanceDto> getMaintenance(int id) async {
-    return await _repository.getMaintenance(id);
+  // 특정 유지보수 상세 조회
+  Future<MaintenanceDto> getMaintenanceDetail(int id) async {
+    return await _repository.getMaintenanceDetail(id);
   }
 
-  // 장비 이력별 유지보수 조회
-  Future<List<MaintenanceDto>> getMaintenancesByEquipmentHistory(
-      int equipmentHistoryId) async {
-    return await _repository.getMaintenancesByEquipmentHistory(equipmentHistoryId);
-  }
-
-  // 유지보수 생성 (백엔드 스키마 기반)
+  // 유지보수 생성
   Future<MaintenanceDto> createMaintenance(MaintenanceRequestDto request) async {
-    // 기본 검증만
+    // 기본 검증
     _validateMaintenanceRequest(request);
     
     return await _repository.createMaintenance(request);
   }
 
-  // 유지보수 수정 (백엔드 스키마 기반)
+  // 유지보수 수정
   Future<MaintenanceDto> updateMaintenance(
       int id, MaintenanceUpdateRequestDto request) async {
-    // 기본 검증만
+    // 기본 검증
     if (request.periodMonth != null && request.periodMonth! <= 0) {
       throw Exception('유지보수 주기는 1개월 이상이어야 합니다.');
     }
@@ -65,62 +58,74 @@ class MaintenanceUseCase {
       }
     }
     
+    // 유지보수 타입 검증
+    if (request.maintenanceType != null && 
+        !MaintenanceType.allTypes.contains(request.maintenanceType!)) {
+      throw Exception('올바른 유지보수 타입을 선택해주세요.');
+    }
+    
     return await _repository.updateMaintenance(id, request);
   }
 
-  // 유지보수 삭제 (백엔드 soft delete)
+  // 유지보수 삭제 (소프트 삭제)
   Future<void> deleteMaintenance(int id) async {
-    // 기본 검증만
-    final maintenance = await _repository.getMaintenance(id);
-    
-    // 진행 중인 유지보수는 삭제 불가 (선택적)
-    final now = DateTime.now();
-    
-    if (now.isAfter(maintenance.startedAt) && now.isBefore(maintenance.endedAt)) {
-      throw Exception('진행 중인 유지보수는 삭제할 수 없습니다.');
-    }
-    
-    await _repository.deleteMaintenance(id);
+    return await _repository.deleteMaintenance(id);
   }
 
-  // 활성 유지보수만 조회 (백엔드 is_deleted = false)
-  Future<List<MaintenanceDto>> getActiveMaintenances({
-    int? equipmentHistoryId,
+  // 만료 예정 유지보수 조회
+  Future<List<MaintenanceDto>> getExpiringMaintenances({int days = 30}) async {
+    return await _repository.getExpiringMaintenances(days: days);
+  }
+
+  // 활성 유지보수만 조회 (is_deleted = false)
+  Future<MaintenanceListResponse> getActiveMaintenances({
+    int page = 1,
+    int perPage = 20,
+    int? equipmentId,
     String? maintenanceType,
   }) async {
-    final response = await getMaintenances(
-      pageSize: 1000, // 큰 사이즈로 모든 데이터 조회
-      equipmentHistoryId: equipmentHistoryId,
+    return await getMaintenances(
+      page: page,
+      perPage: perPage,
+      equipmentId: equipmentId,
       maintenanceType: maintenanceType,
+      includeDeleted: false, // 삭제된 항목 제외
     );
-    
-    // is_deleted = false인 것만 필터링
-    return response.items.where((m) => m.isActive).toList();
   }
 
-  // 특정 기간 내 유지보수 조회 (백엔드 날짜 필터링)
-  Future<List<MaintenanceDto>> getMaintenancesByDateRange({
-    required DateTime startDate,
-    required DateTime endDate,
-    int? equipmentHistoryId,
+  // 만료된 유지보수 조회
+  Future<MaintenanceListResponse> getExpiredMaintenances({
+    int page = 1,
+    int perPage = 20,
   }) async {
-    final response = await getMaintenances(
-      pageSize: 1000,
-      equipmentHistoryId: equipmentHistoryId,
+    return await getMaintenances(
+      page: page,
+      perPage: perPage,
+      isExpired: true,
+      includeDeleted: false,
     );
-    
-    // 날짜 범위 필터링 (클라이언트 사이드)
-    return response.items.where((maintenance) {
-      return maintenance.startedAt.isAfter(startDate) &&
-             maintenance.endedAt.isBefore(endDate);
-    }).toList();
   }
 
-  // Private 헬퍼 메서드
+  // 특정 장비의 유지보수 내역 조회
+  Future<MaintenanceListResponse> getMaintenancesByEquipment({
+    required int equipmentId,
+    int page = 1,
+    int perPage = 20,
+    bool includeDeleted = false,
+  }) async {
+    return await getMaintenances(
+      page: page,
+      perPage: perPage,
+      equipmentId: equipmentId,
+      includeDeleted: includeDeleted,
+    );
+  }
+
+  // Private 검증 메서드
   void _validateMaintenanceRequest(MaintenanceRequestDto request) {
-    // 필수 필드 검증 (백엔드 스키마 기반)
-    if (request.periodMonth <= 0) {
-      throw Exception('유지보수 주기는 1개월 이상이어야 합니다.');
+    // 유지보수 주기 검증
+    if (request.periodMonth <= 0 || request.periodMonth > 120) {
+      throw Exception('유지보수 주기는 1-120개월 사이여야 합니다.');
     }
     
     // 날짜 검증
@@ -128,43 +133,58 @@ class MaintenanceUseCase {
       throw Exception('종료일은 시작일 이후여야 합니다.');
     }
     
-    // 유지보수 타입 검증 (백엔드 값)
-    if (request.maintenanceType != MaintenanceType.onsite && 
-        request.maintenanceType != MaintenanceType.remote) {
-      throw Exception('유지보수 타입은 방문(O) 또는 원격(R)이어야 합니다.');
+    // 유지보수 타입 검증 (백엔드와 일치)
+    if (!MaintenanceType.allTypes.contains(request.maintenanceType)) {
+      throw Exception('유지보수 타입은 ${MaintenanceType.allTypes.join(', ')} 중 하나여야 합니다.');
     }
   }
 
-  // 통계 조회 (단순화)
+  // 유지보수 통계 조회
   Future<MaintenanceStatistics> getMaintenanceStatistics() async {
-    final response = await getMaintenances(pageSize: 1000);
-    final maintenances = response.items;
+    // 첫 번째 페이지로 전체 개수 확인
+    final response = await getMaintenances(perPage: 1);
+    final totalCount = response.totalCount;
+    
+    // 전체 데이터 조회 (페이지 크기를 총 개수로 설정)
+    final allDataResponse = await getMaintenances(
+      perPage: totalCount > 0 ? totalCount : 1000,
+      includeDeleted: false,
+    );
+    
+    final maintenances = allDataResponse.items;
     
-    int totalCount = maintenances.length;
     int activeCount = maintenances.where((m) => m.isActive).length;
-    int onsiteCount = maintenances.where((m) => m.maintenanceType == MaintenanceType.onsite).length;
-    int remoteCount = maintenances.where((m) => m.maintenanceType == MaintenanceType.remote).length;
+    int warrantyCount = maintenances.where((m) => m.maintenanceType == MaintenanceType.warranty).length;
+    int contractCount = maintenances.where((m) => m.maintenanceType == MaintenanceType.contract).length;
+    int inspectionCount = maintenances.where((m) => m.maintenanceType == MaintenanceType.inspection).length;
+    int expiredCount = maintenances.where((m) => m.isExpired).length;
     
     return MaintenanceStatistics(
       totalCount: totalCount,
       activeCount: activeCount,
-      onsiteCount: onsiteCount,
-      remoteCount: remoteCount,
+      warrantyCount: warrantyCount,
+      contractCount: contractCount,
+      inspectionCount: inspectionCount,
+      expiredCount: expiredCount,
     );
   }
 }
 
-/// 유지보수 통계 모델 (단순화)
+/// 유지보수 통계 모델
 class MaintenanceStatistics {
   final int totalCount;
   final int activeCount;
-  final int onsiteCount;
-  final int remoteCount;
+  final int warrantyCount;    // 무상 보증
+  final int contractCount;    // 유상 계약
+  final int inspectionCount;  // 점검
+  final int expiredCount;     // 만료된 것
   
   MaintenanceStatistics({
     required this.totalCount,
     required this.activeCount,
-    required this.onsiteCount,
-    required this.remoteCount,
+    required this.warrantyCount,
+    required this.contractCount,
+    required this.inspectionCount,
+    required this.expiredCount,
   });
 }

lib/domain/usecases/models/create_model_usecase.dart

@@ -0,0 +1,17 @@
+import 'package:dartz/dartz.dart';
+import '../../repositories/model_repository.dart';
+import '../../../data/models/model/model_dto.dart';
+import '../../../core/errors/failures.dart';
+import '../base_usecase.dart';
+
+/// 모델 생성 UseCase
+class CreateModelUseCase extends UseCase<ModelDto, CreateModelRequest> {
+  final ModelRepository _modelRepository;
+
+  CreateModelUseCase(this._modelRepository);
+
+  @override
+  Future<Either<Failure, ModelDto>> call(CreateModelRequest request) async {
+    return await _modelRepository.createModel(request);
+  }
+}

lib/domain/usecases/models/delete_model_usecase.dart

@@ -0,0 +1,16 @@
+import 'package:dartz/dartz.dart';
+import '../../repositories/model_repository.dart';
+import '../../../core/errors/failures.dart';
+import '../base_usecase.dart';
+
+/// 모델 삭제 UseCase
+class DeleteModelUseCase extends UseCase<void, int> {
+  final ModelRepository _modelRepository;
+
+  DeleteModelUseCase(this._modelRepository);
+
+  @override
+  Future<Either<Failure, void>> call(int id) async {
+    return await _modelRepository.deleteModel(id);
+  }
+}

lib/domain/usecases/models/get_model_detail_usecase.dart

@@ -0,0 +1,17 @@
+import 'package:dartz/dartz.dart';
+import '../../repositories/model_repository.dart';
+import '../../../data/models/model/model_dto.dart';
+import '../../../core/errors/failures.dart';
+import '../base_usecase.dart';
+
+/// 모델 상세 조회 UseCase
+class GetModelDetailUseCase extends UseCase<ModelDto, int> {
+  final ModelRepository _modelRepository;
+
+  GetModelDetailUseCase(this._modelRepository);
+
+  @override
+  Future<Either<Failure, ModelDto>> call(int id) async {
+    return await _modelRepository.getModelDetail(id);
+  }
+}

lib/domain/usecases/models/get_models_by_vendor_usecase.dart

@@ -0,0 +1,17 @@
+import 'package:dartz/dartz.dart';
+import '../../repositories/model_repository.dart';
+import '../../../data/models/model/model_dto.dart';
+import '../../../core/errors/failures.dart';
+import '../base_usecase.dart';
+
+/// 제조사별 모델 조회 UseCase
+class GetModelsByVendorUseCase extends UseCase<List<ModelDto>, int> {
+  final ModelRepository _modelRepository;
+
+  GetModelsByVendorUseCase(this._modelRepository);
+
+  @override
+  Future<Either<Failure, List<ModelDto>>> call(int vendorId) async {
+    return await _modelRepository.getModelsByVendor(vendorId);
+  }
+}

lib/domain/usecases/models/get_models_usecase.dart

@@ -0,0 +1,40 @@
+import 'package:dartz/dartz.dart';
+import '../../repositories/model_repository.dart';
+import '../../../data/models/model/model_dto.dart';
+import '../../../core/errors/failures.dart';
+import '../base_usecase.dart';
+
+/// 모델 목록 조회 파라미터
+class GetModelsParams {
+  final int page;
+  final int perPage;
+  final String? search;
+  final int? vendorId;
+  final bool? includeDeleted;
+
+  const GetModelsParams({
+    this.page = 1,
+    this.perPage = 10,
+    this.search,
+    this.vendorId,
+    this.includeDeleted,
+  });
+}
+
+/// 모델 목록 조회 UseCase
+class GetModelsUseCase extends UseCase<ModelListDto, GetModelsParams> {
+  final ModelRepository _modelRepository;
+
+  GetModelsUseCase(this._modelRepository);
+
+  @override
+  Future<Either<Failure, ModelListDto>> call(GetModelsParams params) async {
+    return await _modelRepository.getModels(
+      page: params.page,
+      perPage: params.perPage,
+      search: params.search,
+      vendorId: params.vendorId,
+      includeDeleted: params.includeDeleted,
+    );
+  }
+}

lib/domain/usecases/models/restore_model_usecase.dart

@@ -0,0 +1,17 @@
+import 'package:dartz/dartz.dart';
+import '../../repositories/model_repository.dart';
+import '../../../data/models/model/model_dto.dart';
+import '../../../core/errors/failures.dart';
+import '../base_usecase.dart';
+
+/// 모델 복구 UseCase
+class RestoreModelUseCase extends UseCase<ModelDto, int> {
+  final ModelRepository _modelRepository;
+
+  RestoreModelUseCase(this._modelRepository);
+
+  @override
+  Future<Either<Failure, ModelDto>> call(int id) async {
+    return await _modelRepository.restoreModel(id);
+  }
+}

lib/domain/usecases/models/update_model_usecase.dart

@@ -0,0 +1,28 @@
+import 'package:dartz/dartz.dart';
+import '../../repositories/model_repository.dart';
+import '../../../data/models/model/model_dto.dart';
+import '../../../core/errors/failures.dart';
+import '../base_usecase.dart';
+
+/// 모델 수정 파라미터
+class UpdateModelParams {
+  final int id;
+  final UpdateModelRequest request;
+
+  const UpdateModelParams({
+    required this.id,
+    required this.request,
+  });
+}
+
+/// 모델 수정 UseCase
+class UpdateModelUseCase extends UseCase<ModelDto, UpdateModelParams> {
+  final ModelRepository _modelRepository;
+
+  UpdateModelUseCase(this._modelRepository);
+
+  @override
+  Future<Either<Failure, ModelDto>> call(UpdateModelParams params) async {
+    return await _modelRepository.updateModel(params.id, params.request);
+  }
+}

lib/domain/usecases/rent_usecase.dart

@@ -1,4 +1,5 @@
 import 'package:injectable/injectable.dart';
+import '../../core/constants/app_constants.dart';
 import '../../data/models/rent_dto.dart';
 import '../repositories/rent_repository.dart';
 
@@ -10,18 +11,24 @@ class RentUseCase {
 
   RentUseCase(this._repository);
 
-  /// 임대 목록 조회 (백엔드 스키마 기반)
+  /// 임대 목록 조회 (백엔드 실제 파라미터)
   Future<RentListResponse> getRents({
     int page = 1,
-    int pageSize = 10,
-    String? search,
-    int? equipmentHistoryId,
+    int perPage = AppConstants.rentPageSize,
+    int? equipmentId,
+    int? companyId,
+    bool? isActive,
+    DateTime? dateFrom,
+    DateTime? dateTo,
   }) async {
     return await _repository.getRents(
       page: page,
-      pageSize: pageSize,
-      search: search,
-      equipmentHistoryId: equipmentHistoryId,
+      perPage: perPage,
+      equipmentId: equipmentId,
+      companyId: companyId,
+      isActive: isActive,
+      dateFrom: dateFrom,
+      dateTo: dateTo,
     );
   }
 
@@ -57,70 +64,84 @@ class RentUseCase {
     return await _repository.deleteRent(id);
   }
 
-  /// 장비 이력별 임대 조회
-  Future<List<RentDto>> getRentsByEquipmentHistory(int equipmentHistoryId) async {
+  /// 진행중인 임대 조회 (백엔드 실존 API)
+  Future<List<RentDto>> getActiveRents() async {
+    return await _repository.getActiveRents();
+  }
+
+  /// 장비별 임대 조회 (백엔드 필터링)
+  Future<List<RentDto>> getRentsByEquipment(int equipmentId) async {
     final response = await getRents(
-      pageSize: 1000,
-      equipmentHistoryId: equipmentHistoryId,
+      perPage: 1000,
+      equipmentId: equipmentId,
+    );
+    return response.items;
+  }
+
+  /// 회사별 임대 조회 (백엔드 필터링)  
+  Future<List<RentDto>> getRentsByCompany(int companyId) async {
+    final response = await getRents(
+      perPage: 1000,
+      companyId: companyId,
     );
     return response.items;
   }
 
   /// 특정 기간 내 임대 조회 (백엔드 날짜 필터링)
   Future<List<RentDto>> getRentsByDateRange({
-    required DateTime startDate,
-    required DateTime endDate,
-    int? equipmentHistoryId,
+    required DateTime dateFrom,
+    required DateTime dateTo,
+    int? equipmentId,
+    int? companyId,
   }) async {
     final response = await getRents(
-      pageSize: 1000,
-      equipmentHistoryId: equipmentHistoryId,
+      perPage: 1000,
+      equipmentId: equipmentId,
+      companyId: companyId,
+      dateFrom: dateFrom,
+      dateTo: dateTo,
     );
     
-    // 날짜 범위 필터링 (클라이언트 사이드)
-    return response.items.where((rent) {
-      return rent.startedAt.isAfter(startDate) &&
-             rent.endedAt.isBefore(endDate);
-    }).toList();
+    return response.items;
   }
 
-  /// 현재 진행 중인 임대 조회
-  Future<List<RentDto>> getCurrentRents({int? equipmentHistoryId}) async {
+  /// 현재 진행 중인 임대 조회 (백엔드 계산값 활용)
+  Future<List<RentDto>> getCurrentRents({int? equipmentId, int? companyId}) async {
     final response = await getRents(
-      pageSize: 1000,
-      equipmentHistoryId: equipmentHistoryId,
+      perPage: 1000,
+      equipmentId: equipmentId,
+      companyId: companyId,
+      isActive: true, // 백엔드 필터링
     );
     
-    final now = DateTime.now();
-    return response.items.where((rent) {
-      return rent.startedAt.isBefore(now) && rent.endedAt.isAfter(now);
-    }).toList();
+    return response.items;
   }
 
-  /// 종료된 임대 조회
-  Future<List<RentDto>> getCompletedRents({int? equipmentHistoryId}) async {
+  /// 종료된 임대 조회 (백엔드 필터링)
+  Future<List<RentDto>> getCompletedRents({int? equipmentId, int? companyId}) async {
     final response = await getRents(
-      pageSize: 1000,
-      equipmentHistoryId: equipmentHistoryId,
+      perPage: 1000,
+      equipmentId: equipmentId,
+      companyId: companyId,
+      isActive: false, // 백엔드 필터링
     );
     
-    final now = DateTime.now();
-    return response.items.where((rent) {
-      return rent.endedAt.isBefore(now);
-    }).toList();
+    return response.items;
   }
 
-  /// 예정된 임대 조회 
-  Future<List<RentDto>> getUpcomingRents({int? equipmentHistoryId}) async {
+  /// 예정된 임대 조회 (백엔드 필터링)
+  Future<List<RentDto>> getUpcomingRents({int? equipmentId, int? companyId}) async {
+    final now = DateTime.now();
+    final tomorrow = now.add(Duration(days: 1));
+    
     final response = await getRents(
-      pageSize: 1000,
-      equipmentHistoryId: equipmentHistoryId,
+      perPage: 1000,
+      equipmentId: equipmentId,
+      companyId: companyId,
+      dateFrom: tomorrow, // 내일부터 시작하는 임대
     );
     
-    final now = DateTime.now();
-    return response.items.where((rent) {
-      return rent.startedAt.isAfter(now);
-    }).toList();
+    return response.items;
   }
 
   /// 임대 기간 계산 (일수)
@@ -137,22 +158,16 @@ class RentUseCase {
     return rent.endedAt.difference(now).inDays;
   }
 
-  /// 임대 통계 조회 (단순화)
+  /// 임대 통계 조회 (백엔드 계산값 활용)
   Future<RentStatistics> getRentStatistics() async {
-    final response = await getRents(pageSize: 1000);
+    final response = await getRents(perPage: 1000);
     final rents = response.items;
     
-    final now = DateTime.now();
+    // 백엔드 계산 필드 활용
     int totalCount = rents.length;
-    int currentCount = rents.where((rent) => 
-      rent.startedAt.isBefore(now) && rent.endedAt.isAfter(now)
-    ).length;
-    int completedCount = rents.where((rent) => 
-      rent.endedAt.isBefore(now)
-    ).length;
-    int upcomingCount = rents.where((rent) => 
-      rent.startedAt.isAfter(now)
-    ).length;
+    int currentCount = rents.where((rent) => rent.isActive == true).length;
+    int completedCount = rents.where((rent) => rent.isActive == false && rent.endedAt.isBefore(DateTime.now())).length;
+    int upcomingCount = rents.where((rent) => rent.startedAt.isAfter(DateTime.now())).length;
     
     return RentStatistics(
       totalCount: totalCount,

lib/domain/usecases/user/get_users_usecase.dart

@@ -1,5 +1,6 @@
 import 'package:dartz/dartz.dart';
 import 'package:injectable/injectable.dart';
+import '../../../core/constants/app_constants.dart';
 import '../../../models/user_model.dart';
 import '../../../core/errors/failures.dart';
 import '../../repositories/user_repository.dart';
@@ -15,7 +16,7 @@ class GetUsersParams {
 
   const GetUsersParams({
     this.page = 1,
-    this.perPage = 20,
+    this.perPage = AppConstants.userPageSize,
     this.role,
     this.isActive,
   });

lib/domain/usecases/vendor_usecase.dart

@@ -1,12 +1,12 @@
 import 'package:injectable/injectable.dart';
 import 'package:superport/data/models/vendor_dto.dart';
 import 'package:superport/data/repositories/vendor_repository.dart';
-import 'package:superport/utils/constants.dart';
+import 'package:superport/core/constants/app_constants.dart';
 
 abstract class VendorUseCase {
   Future<VendorListResponse> getVendors({
     int page = 1,
-    int limit = PaginationConstants.defaultPageSize,
+    int limit = AppConstants.vendorPageSize,
     String? search,
     bool? isActive,
   });
@@ -28,13 +28,13 @@ class VendorUseCaseImpl implements VendorUseCase {
   @override
   Future<VendorListResponse> getVendors({
     int page = 1,
-    int limit = PaginationConstants.defaultPageSize,
+    int limit = AppConstants.vendorPageSize,
     String? search,
     bool? isActive,
   }) async {
     // 비즈니스 로직: 페이지네이션 유효성 검사
     if (page < 1) page = 1;
-    if (limit < 1 || limit > 100) limit = 20;
+    if (limit < 1 || limit > 100) limit = AppConstants.vendorPageSize;
 
     return await _repository.getAll(
       page: page,

lib/domain/usecases/warehouse_location/get_warehouse_locations_usecase.dart

@@ -1,5 +1,6 @@
 import 'package:dartz/dartz.dart';
 import 'package:injectable/injectable.dart';
+import '../../../core/constants/app_constants.dart';
 import '../../../data/models/common/pagination_params.dart';
 import '../../../data/models/warehouse/warehouse_location_dto.dart';
 import '../../repositories/warehouse_location_repository.dart';
@@ -54,7 +55,7 @@ class GetWarehouseLocationsParams {
 
   GetWarehouseLocationsParams({
     this.page = 1,
-    this.perPage = 20,
+    this.perPage = AppConstants.warehousePageSize,
     this.search,
     this.filters,
   });

lib/domain/usecases/zipcode_usecase.dart

@@ -1,4 +1,5 @@
 import 'package:injectable/injectable.dart';
+import 'package:superport/core/constants/app_constants.dart';
 import 'package:superport/data/models/zipcode_dto.dart';
 import 'package:superport/data/repositories/zipcode_repository.dart';
 
@@ -6,29 +7,20 @@ abstract class ZipcodeUseCase {
   /// 우편번호 검색 (페이지네이션 지원)
   Future<ZipcodeListResponse> searchZipcodes({
     int page = 1,
-    int limit = 20,
+    int limit = AppConstants.defaultPageSize,
     String? search,
     String? sido,
     String? gu,
   });
 
-  /// 우편번호로 정확한 주소 조회
-  Future<ZipcodeDto?> getZipcodeByNumber(int zipcode);
-
-  /// 시도별 구 목록 조회
-  Future<List<String>> getGuListBySido(String sido);
-
-  /// 전체 시도 목록 조회
-  Future<List<String>> getAllSidoList();
-
-  /// 주소 문자열로 우편번호 검색 (최적화된 검색)
-  Future<List<ZipcodeDto>> searchByAddress(String address);
-
-  /// 우편번호 유효성 검사
-  bool validateZipcode(int zipcode);
-
   /// 검색어 유효성 검사 및 정규화
   String normalizeSearchQuery(String query);
+  
+  /// Hierarchy API - 시도 목록 조회
+  Future<HierarchyResponse> getHierarchySidos();
+  
+  /// Hierarchy API - 구/군 목록 조회
+  Future<HierarchyResponse> getHierarchyGusBySido(String sido);
 }
 
 @Injectable(as: ZipcodeUseCase)
@@ -40,14 +32,14 @@ class ZipcodeUseCaseImpl implements ZipcodeUseCase {
   @override
   Future<ZipcodeListResponse> searchZipcodes({
     int page = 1,
-    int limit = 20,
+    int limit = AppConstants.defaultPageSize,
     String? search,
     String? sido,
     String? gu,
   }) async {
     // 비즈니스 로직: 페이지네이션 유효성 검사
     if (page < 1) page = 1;
-    if (limit < 1 || limit > 100) limit = 20;
+    if (limit < 1 || limit > 100) limit = AppConstants.defaultPageSize;
 
     // 검색어 정규화
     final normalizedSearch = search != null && search.isNotEmpty 
@@ -63,58 +55,6 @@ class ZipcodeUseCaseImpl implements ZipcodeUseCase {
     );
   }
 
-  @override
-  Future<ZipcodeDto?> getZipcodeByNumber(int zipcode) async {
-    // 우편번호 유효성 검사
-    if (!validateZipcode(zipcode)) {
-      throw ArgumentError('유효하지 않은 우편번호입니다. (5자리 숫자)');
-    }
-
-    return await _repository.getByZipcode(zipcode);
-  }
-
-  @override
-  Future<List<String>> getGuListBySido(String sido) async {
-    if (sido.trim().isEmpty) {
-      throw ArgumentError('시도명을 입력해주세요.');
-    }
-
-    final normalizedSido = sido.trim();
-    return await _repository.getGuBySido(normalizedSido);
-  }
-
-  @override
-  Future<List<String>> getAllSidoList() async {
-    return await _repository.getAllSido();
-  }
-
-  @override
-  Future<List<ZipcodeDto>> searchByAddress(String address) async {
-    if (address.trim().isEmpty) {
-      return [];
-    }
-
-    final normalizedAddress = normalizeSearchQuery(address);
-    
-    try {
-      // 먼저 전체 검색으로 시도
-      final response = await _repository.search(
-        search: normalizedAddress,
-        limit: 10, // 상위 10개만 가져오기
-      );
-      
-      return response.items;
-    } catch (e) {
-      // 검색 실패 시 빈 목록 반환
-      return [];
-    }
-  }
-
-  @override
-  bool validateZipcode(int zipcode) {
-    // 한국 우편번호는 5자리 숫자 (00000 ~ 99999)
-    return zipcode >= 0 && zipcode <= 99999;
-  }
 
   @override
   String normalizeSearchQuery(String query) {
@@ -131,5 +71,18 @@ class ZipcodeUseCaseImpl implements ZipcodeUseCase {
     return normalized;
   }
 
+  @override
+  Future<HierarchyResponse> getHierarchySidos() async {
+    return await _repository.getHierarchySidos();
+  }
+
+  @override
+  Future<HierarchyResponse> getHierarchyGusBySido(String sido) async {
+    if (sido.trim().isEmpty) {
+      throw ArgumentError('시도명을 입력해주세요.');
+    }
+    
+    return await _repository.getHierarchyGusBySido(sido.trim());
+  }
 
 }