/// 결재(Approval) 엔티티
///
/// - 결재 기본 정보와 현재 단계, 라인(단계/이력) 데이터를 포함한다.
/// - presentation/data 레이어 구현에 의존하지 않는다.
class Approval {
  Approval({
    this.id,
    required this.approvalNo,
    required this.transactionNo,
    required this.status,
    this.currentStep,
    required this.requester,
    required this.requestedAt,
    this.decidedAt,
    this.note,
    this.isActive = true,
    this.isDeleted = false,
    this.steps = const [],
    this.histories = const [],
    this.createdAt,
    this.updatedAt,
  });

  final int? id;
  final String approvalNo;
  final String transactionNo;
  final ApprovalStatus status;
  final ApprovalStep? currentStep;
  final ApprovalRequester requester;
  final DateTime requestedAt;
  final DateTime? decidedAt;
  final String? note;
  final bool isActive;
  final bool isDeleted;
  final List<ApprovalStep> steps;
  final List<ApprovalHistory> histories;
  final DateTime? createdAt;
  final DateTime? updatedAt;

  Approval copyWith({
    int? id,
    String? approvalNo,
    String? transactionNo,
    ApprovalStatus? status,
    ApprovalStep? currentStep,
    ApprovalRequester? requester,
    DateTime? requestedAt,
    DateTime? decidedAt,
    String? note,
    bool? isActive,
    bool? isDeleted,
    List<ApprovalStep>? steps,
    List<ApprovalHistory>? histories,
    DateTime? createdAt,
    DateTime? updatedAt,
  }) {
    return Approval(
      id: id ?? this.id,
      approvalNo: approvalNo ?? this.approvalNo,
      transactionNo: transactionNo ?? this.transactionNo,
      status: status ?? this.status,
      currentStep: currentStep ?? this.currentStep,
      requester: requester ?? this.requester,
      requestedAt: requestedAt ?? this.requestedAt,
      decidedAt: decidedAt ?? this.decidedAt,
      note: note ?? this.note,
      isActive: isActive ?? this.isActive,
      isDeleted: isDeleted ?? this.isDeleted,
      steps: steps ?? this.steps,
      histories: histories ?? this.histories,
      createdAt: createdAt ?? this.createdAt,
      updatedAt: updatedAt ?? this.updatedAt,
    );
  }
}

class ApprovalStatus {
  ApprovalStatus({required this.id, required this.name, this.color});

  final int id;
  final String name;
  final String? color;
}

class ApprovalRequester {
  ApprovalRequester({
    required this.id,
    required this.employeeNo,
    required this.name,
  });

  final int id;
  final String employeeNo;
  final String name;
}

class ApprovalStep {
  ApprovalStep({
    this.id,
    required this.stepOrder,
    required this.approver,
    required this.status,
    required this.assignedAt,
    this.decidedAt,
    this.note,
  });

  final int? id;
  final int stepOrder;
  final ApprovalApprover approver;
  final ApprovalStatus status;
  final DateTime assignedAt;
  final DateTime? decidedAt;
  final String? note;
}

class ApprovalApprover {
  ApprovalApprover({
    required this.id,
    required this.employeeNo,
    required this.name,
  });

  final int id;
  final String employeeNo;
  final String name;
}

class ApprovalHistory {
  ApprovalHistory({
    this.id,
    required this.action,
    this.fromStatus,
    required this.toStatus,
    required this.approver,
    required this.actionAt,
    this.note,
  });

  final int? id;
  final ApprovalAction action;
  final ApprovalStatus? fromStatus;
  final ApprovalStatus toStatus;
  final ApprovalApprover approver;
  final DateTime actionAt;
  final String? note;
}

class ApprovalAction {
  ApprovalAction({required this.id, required this.name});

  final int id;
  final String name;
}

/// 결재 단계에서 수행 가능한 행위 타입
///
/// - API `approval_actions` 테이블의 대표 코드와 매핑된다.
/// - UI에서는 이 타입을 기반으로 표시 라벨과 권한을 제어한다.
enum ApprovalStepActionType { approve, reject, comment }

extension ApprovalStepActionTypeX on ApprovalStepActionType {
  /// API 호출 시 사용되는 행위 코드
  String get code {
    switch (this) {
      case ApprovalStepActionType.approve:
        return 'approve';
      case ApprovalStepActionType.reject:
        return 'reject';
      case ApprovalStepActionType.comment:
        return 'comment';
    }
  }
}

/// 결재 생성 입력 모델
class ApprovalInput {
  ApprovalInput({required this.transactionId, this.note});

  final int transactionId;
  final String? note;

  Map<String, dynamic> toPayload() {
    return {'transaction_id': transactionId, 'note': note};
  }
}

/// 결재 단계 행위 입력 모델
///
/// - `POST /approval-steps/{id}/actions` 요청 바디를 구성한다.
/// - `note`는 비고가 있을 때만 포함한다.
class ApprovalStepActionInput {
  ApprovalStepActionInput({
    required this.stepId,
    required this.actionId,
    this.note,
  });

  final int stepId;
  final int actionId;
  final String? note;

  Map<String, dynamic> toPayload() {
    return {
      'id': stepId,
      'approval_action_id': actionId,
      if (note != null && note!.trim().isNotEmpty) 'note': note,
    };
  }
}

/// 결재 단계를 일괄 등록/재배치하기 위한 입력 모델
class ApprovalStepAssignmentInput {
  ApprovalStepAssignmentInput({required this.approvalId, required this.steps});

  final int approvalId;
  final List<ApprovalStepAssignmentItem> steps;

  Map<String, dynamic> toPayload() {
    return {'id': approvalId, 'steps': steps.map((e) => e.toJson()).toList()};
  }
}

class ApprovalStepAssignmentItem {
  ApprovalStepAssignmentItem({
    required this.stepOrder,
    required this.approverId,
    this.note,
  });

  final int stepOrder;
  final int approverId;
  final String? note;

  Map<String, dynamic> toJson() {
    return {
      'step_order': stepOrder,
      'approver_id': approverId,
      if (note != null && note!.trim().isNotEmpty) 'note': note,
    };
  }
}