diff --git a/app/controllers/submissions_controller.rb b/app/controllers/submissions_controller.rb
new file mode 100644
--- /dev/null
+++ b/app/controllers/submissions_controller.rb
@@ -0,0 +1,108 @@
+class SubmissionsController < ApplicationController
+  before_action :authenticate
+  before_action :submission_authorization, only: [:show, :direct_edit_submission, :download, :edit]
+  before_action :admin_authorization, only: [:rejudge]
+
+  # GET /submissions
+  # GET /submissions.json
+  # Show problem selection and user's submission of that problem
+  def index
+    @user = @current_user
+    @problems = @user.available_problems
+
+    if params[:problem_id]==nil
+      @problem = nil
+      @submissions = nil
+    else
+      @problem = Problem.find_by_id(params[:problem_id])
+      if (@problem == nil) or (not @problem.available)
+        redirect_to main_list_path
+        flash[:notice] = 'Error: submissions for that problem are not viewable.'
+        return
+      end
+      @submissions = Submission.find_all_by_user_problem(@user.id, @problem.id).order(id: :desc)
+    end
+  end
+
+  # GET /submissions/1
+  # GET /submissions/1.json
+  def show
+    @submission = Submission.find(params[:id])
+
+    #log the viewing
+    user = User.find(session[:user_id])
+    SubmissionViewLog.create(user_id: session[:user_id],submission_id: @submission.id) unless user.admin?
+
+    @task = @submission.task
+  end
+
+  def download
+    @submission = Submission.find(params[:id])
+    send_data(@submission.source, {:filename => @submission.download_filename, :type => 'text/plain'})
+  end
+
+  def compiler_msg
+    @submission = Submission.find(params[:id])
+    respond_to do |format|
+      format.js
+    end
+  end
+
+  #on-site new submission on specific problem
+  def direct_edit_problem
+    @problem = Problem.find(params[:problem_id])
+    @source = ''
+    render 'edit'
+  end
+
+  # GET /submissions/1/edit
+  def edit
+    @submission = Submission.find(params[:id])
+    @source = @submission.source.to_s
+    @problem = @submission.problem
+    @lang_id = @submission.language.id
+  end
+
+
+  def get_latest_submission_status
+    @problem = Problem.find(params[:pid])
+    @submission = Submission.find_last_by_user_and_problem(params[:uid],params[:pid])
+    puts User.find(params[:uid]).login
+    puts Problem.find(params[:pid]).name
+    puts 'nil' unless @submission
+    respond_to do |format|
+      format.js
+    end
+  end
+
+  # GET /submissions/:id/rejudge
+  def rejudge
+    @submission = Submission.find(params[:id])
+    @task = @submission.task
+    @task.status_inqueue! if @task
+    respond_to do |format|
+      format.js
+    end
+  end
+
+protected
+
+  def submission_authorization
+    #admin always has privileged
+    if @current_user.admin?
+      return true
+    end
+
+    sub = Submission.find(params[:id])
+    if sub.problem.available?
+      puts "sub = #{sub.user.id}, current = #{@current_user.id}"
+      return true if GraderConfiguration["right.user_view_submission"] or sub.user == @current_user
+    end
+
+    #default to NO
+    unauthorized_redirect
+    return false
+  end
+
+    
+end