결재 단계 편집 다이얼로그 구현

lib/features/approvals/step/domain/entities/approval_step_input.dart

@@ -0,0 +1,61 @@
+/// 결재 단계 생성/수정 입력 모델
+///
+/// - 단계 순서, 승인자, 비고 등의 값을 API 페이로드로 직렬화한다.
+/// - `approvalId`는 생성 시에만 필요하며 수정 시에는 null로 둘 수 있다.
+class ApprovalStepInput {
+  ApprovalStepInput({
+    this.approvalId,
+    required this.stepOrder,
+    required this.approverId,
+    this.statusId,
+    this.assignedAt,
+    this.decidedAt,
+    this.note,
+  }) : assert(stepOrder > 0, '단계 순서는 1 이상의 정수여야 합니다.'),
+       assert(approverId > 0, '승인자 ID는 양수여야 합니다.');
+
+  final int? approvalId;
+  final int stepOrder;
+  final int approverId;
+  final int? statusId;
+  final DateTime? assignedAt;
+  final DateTime? decidedAt;
+  final String? note;
+
+  /// API 요청 페이로드를 구성한다.
+  Map<String, dynamic> toPayload() {
+    final payload = <String, dynamic>{
+      'step_order': stepOrder,
+      'approver_id': approverId,
+      if (statusId != null) 'status_id': statusId,
+      if (assignedAt != null)
+        'assigned_at': assignedAt!.toUtc().toIso8601String(),
+      if (decidedAt != null) 'decided_at': decidedAt!.toUtc().toIso8601String(),
+      if (note != null && note!.trim().isNotEmpty) 'note': note,
+    };
+    if (approvalId != null) {
+      payload['approval_id'] = approvalId;
+    }
+    return payload;
+  }
+
+  ApprovalStepInput copyWith({
+    int? approvalId,
+    int? stepOrder,
+    int? approverId,
+    int? statusId,
+    DateTime? assignedAt,
+    DateTime? decidedAt,
+    String? note,
+  }) {
+    return ApprovalStepInput(
+      approvalId: approvalId ?? this.approvalId,
+      stepOrder: stepOrder ?? this.stepOrder,
+      approverId: approverId ?? this.approverId,
+      statusId: statusId ?? this.statusId,
+      assignedAt: assignedAt ?? this.assignedAt,
+      decidedAt: decidedAt ?? this.decidedAt,
+      note: note ?? this.note,
+    );
+  }
+}