redmine-workflow-engine/app/controllers/issue_workflows_controller.rb

class IssueWorkflowsController < ApplicationController
  before_action :find_issue
  before_action :find_or_create_workflow_state

  def show
    @steps = @workflow_state.custom_workflow.workflow_steps.ordered
    @current_step = @workflow_state.current_step
  end

  def next_step
    if @workflow_state.can_proceed?(User.current)
      selected_assignee_id = params[:assignee_id]
      if @workflow_state.proceed!(User.current, selected_assignee_id)
        flash[:notice] = '다음 단계로 이동했습니다.'
      else
        flash[:error] = '다음 단계로 이동할 수 없습니다.'
      end
    else
      flash[:error] = '이 단계를 완료할 권한이 없습니다.'
    end
    redirect_to issue_path(@issue)
  end

  def prev_step
    if @workflow_state.can_go_back?(User.current)
      if @workflow_state.go_back!(User.current)
        flash[:notice] = '이전 단계로 되돌렸습니다.'
      else
        flash[:error] = '이전 단계로 이동할 수 없습니다.'
      end
    else
      flash[:error] = '이전 단계로 되돌릴 권한이 없습니다.'
    end
    redirect_to issue_path(@issue)
  end

  def complete
    current_step = @workflow_state.current_step
    if current_step&.is_end && (User.current.admin? || current_step.assignee?(User.current))
      @issue.init_journal(User.current, "워크플로우 완료 처리")
      @issue.status_id = 5  # 완료 상태
      if @issue.save(validate: false)
        @workflow_state.update(completed_at: Time.current, completed_by: User.current)
        flash[:notice] = '이슈가 완료 처리되었습니다.'
      else
        flash[:error] = '완료 처리에 실패했습니다.'
      end
    else
      flash[:error] = '완료 처리 권한이 없습니다.'
    end
    redirect_to issue_path(@issue)
  end

  def reject
    current_step = @workflow_state.current_step
    reason = params[:reason].to_s.strip

    unless current_step && !current_step.is_start && (User.current.admin? || current_step.assignee?(User.current))
      flash[:error] = '반려 권한이 없습니다.'
      redirect_to issue_path(@issue)
      return
    end

    if reason.blank?
      flash[:error] = '반려 사유를 입력해주세요.'
      redirect_to issue_path(@issue)
      return
    end

    # 항상 최초 단계로 반려
    first_step = @workflow_state.custom_workflow.workflow_steps.ordered.first

    if first_step
      # 이력 남기기
      @issue.init_journal(User.current, "[반려] #{current_step.name} → #{first_step.name}\n사유: #{reason}")

      # 상태 변경 (최초 단계의 상태로)
      if first_step.issue_status_id.present?
        @issue.status_id = first_step.issue_status_id
      end

      # 담당자 변경 - 개인 사용자일 때만, 그룹/부서는 미지정
      user_assignees = first_step.workflow_step_assignees.where(assignee_type: 'user')
      if user_assignees.any?
        @issue.assigned_to_id = user_assignees.first.assignee_id
      elsif first_step.workflow_step_assignees.any?
        @issue.assigned_to_id = nil
      end

      @issue.save(validate: false)
      @workflow_state.update(current_step: first_step, completed_at: nil, completed_by: nil)

      flash[:notice] = "#{first_step.name} 단계로 반려되었습니다."
    else
      flash[:error] = '반려 대상 단계를 찾을 수 없습니다.'
    end

    redirect_to issue_path(@issue)
  end

  def skip_step
    # 관리자만 단계 건너뛰기 가능
    unless User.current.admin?
      flash[:error] = '관리자만 단계를 건너뛸 수 있습니다.'
      redirect_to issue_path(@issue)
      return
    end

    current_step = @workflow_state.current_step
    target_step_id = params[:target_step_id]
    reason = params[:reason].to_s.strip

    if target_step_id.blank?
      flash[:error] = '이동할 단계를 선택해주세요.'
      redirect_to issue_path(@issue)
      return
    end

    target_step = WorkflowStep.find_by(id: target_step_id)

    if target_step && target_step.custom_workflow_id == @workflow_state.custom_workflow_id
      # 이력 남기기
      note = "[단계 건너뛰기] #{current_step&.name || '(시작)'} → #{target_step.name}"
      note += "\n사유: #{reason}" if reason.present?
      @issue.init_journal(User.current, note)

      # 상태 변경
      if target_step.issue_status_id.present?
        @issue.status_id = target_step.issue_status_id
      end

      # 담당자 변경 - 개인 사용자일 때만, 그룹/부서는 미지정
      user_assignees = target_step.workflow_step_assignees.where(assignee_type: 'user')
      if user_assignees.any?
        @issue.assigned_to_id = user_assignees.first.assignee_id
      elsif target_step.workflow_step_assignees.any?
        @issue.assigned_to_id = nil
      end

      @issue.save(validate: false)
      @workflow_state.update(current_step: target_step, completed_at: nil, completed_by: nil)

      flash[:notice] = "#{target_step.name} 단계로 이동했습니다."
    else
      flash[:error] = '이동할 단계를 찾을 수 없습니다.'
    end

    redirect_to issue_path(@issue)
  end

  private

  def find_issue
    @issue = Issue.find(params[:issue_id])
  rescue ActiveRecord::RecordNotFound
    render_404
  end

  def find_or_create_workflow_state
    @workflow_state = IssueWorkflowState.find_by(issue_id: @issue.id)

    unless @workflow_state
      workflow = CustomWorkflow.find_for_issue(@issue)
      if workflow
        @workflow_state = IssueWorkflowState.create!(
          issue: @issue,
          custom_workflow: workflow,
          current_step: workflow.start_step,
          started_at: Time.current
        )
      else
        flash[:warning] = '이 이슈에 적용할 워크플로우가 없습니다.'
        redirect_to issue_path(@issue)
      end
    end
  end
end