trustieforge/app/controllers/exercise_controller.rb

class ExerciseController < ApplicationController
  layout "base_courses"

  before_filter :find_exercise_and_course, :only => [:create_exercise_question, :edit, :update, :show, :destroy,
                                                        :commit_exercise, :commit_answer,:publish_exercise,:republish_exercise,
                                                        :show_student_result,:student_exercise_list, :update_question_num,
                                                        :send_to_course, :get_student_uncomplete_question, :edit_question_score]
  before_filter :find_course, :only => [:index,:new,:create]
  include ExerciseHelper

  def index
=begin
    publish_exercises = Exercise.where("publish_time is not null and exercise_status = 1 and publish_time <=?",Time.now)
    publish_exercises.each do |exercise|
      exercise.update_column('exercise_status', 2)
      course = exercise.course
      course.members.each do |m|
        if m.user_id != exercise.user_id
          exercise.course_messages << CourseMessage.new(:user_id => m.user_id, :course_id => course.id, :viewed => false, :status => 2)
        end
      end
    end
=end

    if @course.is_public == 0 && !(User.current.member_of_course?(@course)||User.current.admin?)
      render_403
      return
    end
    remove_invalid_exercise(@course)
    @is_teacher = User.current.allowed_to?(:as_teacher,@course)
    if @is_teacher
      exercises = @course.exercises.order("created_at asc")
    else
      exercises = @course.exercises.where("exercise_status <> 1").order("created_at asc")
    end
    @exercises = paginateHelper exercises,20 #分页
    @left_nav_type = 8
    respond_to do |format|
      format.html
    end
  end

  def show
=begin
    publish_exercises = Exercise.where("publish_time is not null and exercise_status = 1 and publish_time <=?",Time.now)
    publish_exercises.each do |exercise|
      exercise.update_column('exercise_status', 2)
      course = exercise.course
      course.members.each do |m|
        if m.user_id != exercise.user_id
          exercise.course_messages << CourseMessage.new(:user_id => m.user_id, :course_id => course.id, :viewed => false, :status => 2)
        end
      end
    end
=end

    unless User.current.member_of_course?(@course) || User.current.admin?
      render_403
      return
    end
    @exercise = Exercise.find params[:id]
    @exercise.course_messages.where(:user_id => User.current.id, :viewed => 0).update_all(:viewed => true)

    @is_teacher = User.current.allowed_to?(:as_teacher,@course)
    exercise_end = @exercise.end_time.nil? ? false : @exercise.end_time > Time.now
    if @exercise.time == -1
      @can_edit_excercise = exercise_end
    else
      @can_edit_excercise = exercise_end && !has_commit_exercise?(@exercise.id,User.current.id)
    end
    unless @is_teacher
      @exercise_user = ExerciseUser.where("user_id=? and exercise_id=?", User.current.id, @exercise.id).first
      if @exercise_user.nil?
        @exercise_user = ExerciseUser.create(:user_id => User.current.id, :exercise_id => @exercise.id, :start_at => Time.now, :status => false)
      end
      #score = calculate_student_score(@exercise, User.current)
      #@exercise_user.update_attributes(:objective_score => score, :score => (score + (@exercise_user.subjective_score > 0 ? @exercise_user.subjective_score : 0)))
    end
    # @percent = get_percent(@exercise,User.current)
    @exercise_questions = @exercise.exercise_questions
    @left_nav_type = 8
    respond_to do |format|
      format.html {render :layout => 'base_courses'}
    end
    #end
  end

  def new
    option = {
        :exercise_name => "",
        :course_id => @course.id,
        :exercise_status => 1,
        :user_id => User.current.id,
        :time => "",
        :end_time => "",
        :publish_time => "",
        :exercise_description => "",
        :show_result => 1
    }
    @exercise = Exercise.create option
    if @exercise
      redirect_to edit_exercise_url @exercise.id
    end
  end

  def create
    if params[:exercise]
      exercise = Exercise.find(params[:exercise_id]) if params[:exercise_id]
      exercise ||= Exercise.new
      exercise.exercise_name = params[:exercise][:exercise_name]
      exercise.exercise_description = params[:exercise][:exercise_description]
      exercise.end_time = Time.at(params[:exercise][:end_time].to_time.to_i + 16*60*60 -1)
      exercise.publish_time = params[:exercise][:publish_time]
      exercise.user_id = User.current.id
      exercise.time = params[:exercise][:time]
      exercise.course_id = params[:course_id]
      exercise.exercise_status = 1
      if exercise.save
        @exercise = exercise
        respond_to do |format|
          format.js
        end
      end
    end
  end

  def edit
    @left_nav_type = 8
    respond_to do |format|
      format.html{render :layout => 'base_courses'}
  end
  end

  def update
    @exercise.exercise_name = params[:exercise][:exercise_name]
    @exercise.exercise_description = params[:exercise][:exercise_description]
    @exercise.time =  params[:exercise][:time].blank? ? -1 : params[:exercise][:time]
    @exercise.end_time = Time.at(params[:exercise][:end_time].to_time.to_i + 16*60*60 -1)
    @exercise.publish_time = params[:exercise][:publish_time]
    @exercise.show_result = params[:show_result] ? 1 : 0
    @exercise.question_random = params[:question_random] ? 0 : 1
    @exercise.choice_random = params[:choice_random] ? 0 : 1
    if @exercise.save
      respond_to do |format|
        format.js
      end
    else
      render_404
      end
  end

  def destroy
    @is_teacher = User.current.allowed_to?(:as_teacher,@course) || User.current.admin?
    if @exercise && @exercise.destroy
      if @is_teacher
        exercises = Exercise.where("course_id =?", @course.id)
      else
        exercises = Exercise.where("course_id =? and exercise_status =?", @course.id, 2)
      end
      @exercises = paginateHelper exercises,20 #分页
      respond_to do |format|
        format.js
      end
    end
  end

  # 统计结果
  def statistics_result
    @exercise = Exercise.find(params[:id])
    exercise_questions = @exercise.exercise_questions
    @exercise_questions = paginateHelper exercise_questions, 5
    @left_nav_type = 8
    respond_to do |format|
      format.html{render :layout => 'base_courses'}
    end
  end

  # 添加题目
  # question_type 1：单选 2：多选 3：填空题
  def create_exercise_question
    question_title = params[:question_title].nil? || params[:question_title].empty? ? l(:label_enter_single_title) : params[:question_title]
    option = {
        :question_title => question_title,
        :question_type => params[:question_type] || 1,
        :question_number => params[:question_type] == "1"? @exercise.exercise_questions.where("question_type = 1").count + 1 :
                              (params[:question_type] == "2" ? (@exercise.exercise_questions.where("question_type = 2").count + 1) :
                              (params[:question_type] == "3" ? (@exercise.exercise_questions.where("question_type = 3").count + 1) :
                              @exercise.exercise_questions.where("question_type = 4").count + 1)),
        :question_score => params[:question_score]
    }
    @exercise_questions = @exercise.exercise_questions.new option
    # params[:question_answer] 题目选项
    if params[:question_answer]
      for i in 1..params[:question_answer].count
        answer = (params[:question_answer].values[i-1].nil? || params[:question_answer].values[i-1].empty?) ? l(:label_new_answer) : params[:question_answer].values[i-1]
        question_option = {
            :choice_position => i,
            :choice_text => answer
        }
        @exercise_questions.exercise_choices.new question_option
      end
    end
    # 如果是插入的话，那么从插入的这个id以后的question_num都将要+1
    if params[:quest_id]
      @is_insert = true
      if @exercise_questions.question_type == 1
        ExerciseQuestion.where("question_number>? and question_type=?",params[:quest_num].to_i, 1).update_all(" question_number = question_number + 1")
        #@exercise.exercise_questions.where("question_number > #{params[:quest_num].to_i} and question_type == 1").update_all(" question_number = question_number + 1")
      elsif @exercise_questions.question_type == 2
        ExerciseQuestion.where("question_number>? and question_type=?",params[:quest_num].to_i, 2).update_all(" question_number = question_number + 1")
      elsif @exercise_questions.question_type == 3
        ExerciseQuestion.where("question_number>? and question_type=?",params[:quest_num].to_i, 3).update_all(" question_number = question_number + 1")
      else
        ExerciseQuestion.where("question_number>? and question_type=?",params[:quest_num].to_i, 4).update_all(" question_number = question_number + 1")
      end
      # @exercise_question_num = params[:quest_num].to_i
      @exercise_questions.question_number = params[:quest_num].to_i + 1
    end
    if @exercise_questions.save
      # params[:exercise_choice] 标准答案参数
      # 问答题标准答案有三个，单独处理
      if @exercise_questions.question_type == 3
        for i in 1..params[:exercise_choice].count
          standart_answer = ExerciseStandardAnswer.new
          standart_answer.exercise_question_id =  @exercise_questions.id
          standart_answer.answer_text = params[:exercise_choice].values[i-1]
          standart_answer.save
        end
      elsif @exercise_questions.question_type == 4
        unless params[:exercise_choice] == ""
          standart_answer = ExerciseStandardAnswer.new
          standart_answer.exercise_question_id =  @exercise_questions.id
          standart_answer.answer_text = params[:exercise_choice]
          standart_answer.save
        end
      else
        standart_answer = ExerciseStandardAnswer.new
        standart_answer.exercise_question_id =  @exercise_questions.id
        if  @exercise_questions.question_type == 1
          standart_answer.exercise_choice_id = sigle_selection_standard_answer(params[:exercise_choice])
        elsif @exercise_questions.question_type == 2
          standart_answer.exercise_choice_id = multiselect_standard_answer(params[:exercise_choice])
        end
        standart_answer.save
      end
      respond_to do |format|
        format.js
      end
    end

  end

  # 修改题目
  # params[:exercise_question]  The id of exercise_question
  # params[:question_answer]  eg:A、B、C选项
  def update_exercise_question
    @exercise_question = ExerciseQuestion.find params[:exercise_question]
    @exercise_question.question_title = params[:question_title].nil? || params[:question_title].empty? ? l(:label_enter_single_title) : params[:question_title]
    @exercise_question.question_score = params[:question_score]
    # 处理选项:如果选了某个选项，那么则要删除之前的选项
    if params[:question_answer]
      @exercise_question.exercise_choices.each do |answer|
        answer.destroy unless params[:question_answer].keys.include? answer.id.to_s
      end
      for i in 1..params[:question_answer].count
        question = @exercise_question.exercise_choices.find_by_id params[:question_answer].keys[i-1]
        answer = (params[:question_answer].values[i-1].nil? || params[:question_answer].values[i-1].empty?) ? l(:label_new_answer) : params[:question_answer].values[i-1]
        if question
          question.choice_position = i
          question.choice_text = answer
          question.save
        else
          question_option = {
              :choice_position => i,
              :choice_text => answer
          }
          @exercise_question.exercise_choices.new question_option
        end
      end
    end
    # 更新标准答案
    if params[:exercise_choice]
      if @exercise_question.question_type == 3
        # 删除不合理的选项
        @exercise_question.exercise_standard_answers.each do |answer|
          answer.destroy unless params[:exercise_choice].keys.include? answer.id.to_s
        end
        for i in 1..params[:exercise_choice].count
          # 找到对应的标准答案
          question_standart = @exercise_question.exercise_standard_answers.find_by_id params[:exercise_choice].keys[i-1]
          # 标准答案值
          answer_standart = (params[:exercise_choice].values[i-1].nil? || params[:exercise_choice].values[i-1].empty?) ? l(:label_new_answer) : params[:exercise_choice].values[i-1]
          if question_standart
            question_standart.answer_text = answer_standart
            question_standart.save
          else
            standart_answer_option = {
                :answer_text => answer_standart
            }
            @exercise_question.exercise_standard_answers.new standart_answer_option
          end
        end
      elsif @exercise_question.question_type == 4
        answer_standart = @exercise_question.exercise_standard_answers.empty? ? nil : @exercise_question.exercise_standard_answers.first
        if params[:exercise_choice] == "" && !answer_standart.nil?
          answer_standart.destroy
        elsif params[:exercise_choice] != "" && !answer_standart.nil?
          answer_standart.answer_text = params[:exercise_choice]
          answer_standart.save
        elsif params[:exercise_choice] != "" && answer_standart.nil?
          standart_answer_option = {
              :answer_text => params[:exercise_choice]
          }
          @exercise_question.exercise_standard_answers.new standart_answer_option
        end
      else
        answer_standart = @exercise_question.exercise_standard_answers.first ? @exercise_question.exercise_standard_answers.first : ExerciseStandardAnswer.new(:exercise_question_id => @exercise_question.id)
        answer_standart.exercise_choice_id = @exercise_question.question_type == 1 ? sigle_selection_standard_answer(params[:exercise_choice]) : multiselect_standard_answer(params[:exercise_choice])
        answer_standart.save
      end
      @exercise_question.save
      @exercise = @exercise_question.exercise
      respond_to do |format|
        format.js
      end
    end
  end

  # 删除题目
  def delete_exercise_question
    @exercise_question = ExerciseQuestion.find params[:exercise_question]
    @exercise = @exercise_question.exercise

    if @exercise_question.question_type == 1
      ExerciseQuestion.where("question_number>? and question_type=?",params[:quest_num].to_i, 1).update_all(" question_number = question_number - 1")
      #@exercise.exercise_questions.where("question_number > #{params[:quest_num].to_i} and question_type == 1").update_all(" question_number = question_number + 1")
    elsif @exercise_question.question_type == 2
      ExerciseQuestion.where("question_number>? and question_type=?",params[:quest_num].to_i, 2).update_all(" question_number = question_number - 1")
    elsif @exercise_question.question_type == 3
      ExerciseQuestion.where("question_number>? and question_type=?",params[:quest_num].to_i, 3).update_all(" question_number = question_number - 1")
    else
      ExerciseQuestion.where("question_number>? and question_type=?",params[:quest_num].to_i, 4).update_all(" question_number = question_number - 1")
    end
    # @exercise_question_num = params[:quest_num].to_i
    # @exercise_questions.question_number = params[:quest_num].to_i - 1
    #
    # exercise_questions = @exercise.exercise_questions.where("question_number > #{@exercise_question.question_number}")
    # exercise_questions.each do |question|
    #   question.question_number -= 1
    #   question.save
    # end
    if @exercise_question && @exercise_question.destroy
      respond_to do |format|
        format.js
      end
    end
  end

  #题目上移/下移
  def update_question_num
    @exercise_question = ExerciseQuestion.find params[:ques_id]
    exercise_questions = @exercise.exercise_questions
    if @exercise_question
      if params[:opr] == 'up' && @exercise_question.question_number > 1
        @before_que = exercise_questions.where("question_type = #{@exercise_question.question_type} and question_number = #{@exercise_question.question_number - 1}").first
        if @before_que && @exercise_question.update_attribute('question_number', @exercise_question.question_number - 1)
          @before_que.update_attribute('question_number', @before_que.question_number + 1)
        end
      elsif params[:opr] == 'down' && @exercise_question.question_number < exercise_questions.count
        @after_que = exercise_questions.where("question_type = #{@exercise_question.question_type} and question_number = #{@exercise_question.question_number + 1}").first
        if @after_que && @exercise_question.update_attribute('question_number', @exercise_question.question_number + 1)
          @after_que.update_attribute('question_number', @after_que.question_number - 1)
        end
      end
      respond_to do |format|
        format.js
      end
    end
  end

  # 发送试卷
  def send_to_course
    params[:course_ids].each do |course|
      option = {
          :exercise_name => @exercise.exercise_name,
          :exercise_status => 1,
          :user_id => User.current.id,
          :show_result => 1,
          :course_id => course.to_i,
          :time => @exercise.time,
          :exercise_description => @exercise.exercise_description,
          :question_random => @exercise.question_random,
          :choice_random => @exercise.choice_random
      }
      exercise = Exercise.create option

      @exercise.exercise_questions.each do |q|
        option = {
            :question_title => q[:question_title],
            :question_type => q[:question_type] || 1,
            :question_number => q[:question_number],
            :question_score => q[:question_score]
        }
        exercise_question = exercise.exercise_questions.new option

        for i in 1..q.exercise_choices.count
          choice_option = {
              :choice_position => i,
              :choice_text => q.exercise_choices[i-1][:choice_text]
          }
          exercise_question.exercise_choices.new choice_option
        end

        for i in 1..q.exercise_standard_answers.count
          standard_answer_option = {
              :exercise_choice_id => q.exercise_standard_answers[i-1][:exercise_choice_id],
              :answer_text => q.exercise_standard_answers[i-1][:answer_text]
          }
          exercise_question.exercise_standard_answers.new standard_answer_option
        end
      end
      exercise.save
    end
    respond_to do |format|
      format.js
    end
  end

  # 搜索当前用户任教的班级（不包含该试卷所在的班级）
  def search_courses
    @user = User.current
    if !params[:name].nil?
      search = "%#{params[:name].to_s.strip.downcase}%"
      @courses = @user.courses.not_deleted.where("courses.id != #{params[:course].to_i} and (#{Course.table_name}.id = #{params[:search].to_i } or #{Course.table_name}.name like :p)",:p=>search).reorder("created_at desc").select {|course| @user.allowed_to?(:as_teacher,course)}
    else
      @courses = @user.courses.not_deleted.where("courses.id != #{params[:course].to_i}").reorder("created_at desc").select {|course| @user.allowed_to?(:as_teacher,course)}
    end
    respond_to do |format|
      format.js
    end
  end

  # 发布试卷
  def publish_exercise
    @is_teacher = User.current.allowed_to?(:as_teacher,@course)
    @index = params[:index]
    @exercise.exercise_status = 2
    @exercise.publish_time = Time.now
    if @exercise.save
      #redirect_to exercise_index_url(:course_id=> @course.id)
      respond_to do |format|
        format.js
      end
    end
  end

  # 重新发布试卷
  # 重新发布的时候会删除所有的答题
  def republish_exercise
    @is_teacher = User.current.allowed_to?(:as_teacher,@course)
    @index = params[:index]
    @exercise.exercise_questions.each do |exercise_question|
      exercise_question.exercise_answers.destroy_all
    end
    @exercise.course_messages.destroy_all
    @exercise.exercise_users.destroy_all
    @exercise.exercise_status = 1
    @exercise.publish_time = nil
    @exercise.save
    respond_to do |format|
      format.js
    end
  end

  def student_exercise_list
=begin
    if @exercise.end_time <= Time.now
      @course.student.each do |student|
        if ExerciseUser.where("user_id = ? && exercise_id = ?",student.student_id,@exercise.id).empty?
          ExerciseUser.create(:user_id => student.student_id, :exercise_id => @exercise.id, :start_at => @exercise.end_time, :status => true,:score=>0)
        end

        s_score = calculate_student_score(@exercise, student.student)
        exercise_user = ExerciseUser.where("user_id =? and exercise_id=?", student.student_id, @exercise.id).first
        exercise_user.update_attributes(:score => s_score)
      end
    end
=end
    @name,@select_group = params[:name].to_s.strip || "",params[:group]
    @is_teacher = User.current.allowed_to?(:as_teacher,@course) || User.current.admin?
    if @is_teacher
      @all_exercises = @course.exercises.order("created_at desc")
    else
      @all_exercises = @course.exercises.where("exercise_status > 1").order("created_at desc")
    end
    student_id = @course.student.blank? ? "(-1)" : "(" + @course.student.map{|student| student.student_id}.join(",") + ")"
    if @select_group
      if @select_group == "0"
        none_group_students = @course.members.select{ |member| member.course_group_id == 0 }
        if none_group_students.empty?
          student_in_group = '(0)'
        else
          student_in_group = '(' + none_group_students.map{ |member| member.user_id }.join(',')  + ')'
        end
      elsif @select_group == "-1"
        all_group_students = @course.members.select{ |member| member.course_group_id }
        if all_group_students.empty?
          student_in_group = '(0)'
        else
          student_in_group = '(' + all_group_students.map{ |member| member.user_id }.join(',')  + ')'
        end
      else
        course_group = CourseGroup.find_by_id(@select_group)
        group_students = course_group.users
        if group_students.empty?
          student_in_group = '(0)'
        else
          student_in_group = '(' + group_students.map{ |user| user.id }.join(',')  + ')'
        end
      end
      if @is_teacher || (!@exercise.exercise_users.where("user_id = #{User.current.id}").empty? && @exercise.end_time <= Time.now)
        @exercise_users_list = search_exercise_member @exercise.exercise_users.where("user_id in #{student_id} and user_id in #{student_in_group}"), @name
        @show_all = true;
      elsif !@exercise.exercise_users.where("user_id = #{User.current.id}").empty? && @exercise.end_time > Time.now
        @exercise_users_list = search_exercise_member @exercise.exercise_users.where("user_id = ? and user_id in #{student_id} and user_id in #{student_in_group}",User.current.id), @name
      else
        @exercise_users_list = []
      end

    else
      if @is_teacher || (!@exercise.exercise_users.where("user_id = #{User.current.id}").empty? && @exercise.end_time <= Time.now)
        @exercise_users_list = search_exercise_member @exercise.exercise_users.where("user_id in #{student_id}"), @name
        @show_all = true;
      elsif !@exercise.exercise_users.where("user_id = #{User.current.id}").empty? && @exercise.end_time > Time.now
        @exercise_users_list = search_exercise_member @exercise.exercise_users.where("user_id = ? and user_id in #{student_id}",User.current.id), @name
      else
        @exercise_users_list = []
      end
    end
    @exercise_count = @exercise.exercise_users.where("commit_status = 1 and user_id in #{student_id}").count
    @left_nav_type = 8
    respond_to do |format|
      format.js
      format.html
      format.xls {
        filename = "#{@course.teacher.lastname.to_s + @course.teacher.firstname}_#{@course.name}_#{@course.time.to_s + @course.term}_#{@exercise.exercise_name}#{l(:excel_exercise_list)}.xls"
        send_data(exercise_to_xls(@exercise_users_list), :type => "text/excel;charset=utf-8; header=present",
                  :filename => filename_for_content_disposition(filename))
      }
    end
  end

  # 学生提交答卷，选中答案的过程中提交
  def commit_answer
    eq = ExerciseQuestion.find(params[:exercise_question_id])
    # 已提交过的且是限时的则不允许答题
    if (has_commit_exercise?(@exercise.id,User.current.id) && (!User.current.admin?) && @exercise.time != -1) || @exercise.end_time < Time.now
      render :json => {:text => "failure"}
      return
    end
    if eq.question_type == 1
      # 单选题
      ea = ExerciseAnswer.find_by_exercise_question_id_and_user_id(params[:exercise_question_id],User.current.id)
      if ea.nil?
        # 尚未答该题，添加答案
        ea = ExerciseAnswer.new
        ea.user_id = User.current.id
        ea.exercise_question_id = params[:exercise_question_id]
      end
      #修改该题对应答案
      ea.exercise_choice_id = params[:exercise_choice_id]
      if ea.save
        # 保存成功返回成功信息及当前以答题百分比
        uncomplete_question = get_uncomplete_question(@exercise, User.current)
        if uncomplete_question.count < 1
          complete = 1;
        else
          complete = 0;
        end
        @percent = get_percent(@exercise,User.current)
        render :json => {:text => "ok" ,:complete => complete,:percent => format("%.2f" ,@percent)}
      else
        #返回失败信息
        render :json => {:text => "failure"}
      end
    elsif eq.question_type == 2
      #多选题
      ea = ExerciseAnswer.find_by_exercise_choice_id_and_user_id(params[:exercise_choice_id],User.current.id)
      if ea.nil?
        #尚未答该题，添加答案
        ea = ExerciseAnswer.new
        ea.user_id = User.current.id
        ea.exercise_question_id = params[:exercise_question_id]
        ea.exercise_choice_id = params[:exercise_choice_id]
        if ea.save
          uncomplete_question = get_uncomplete_question(@exercise, User.current)
          if uncomplete_question.count < 1
            complete = 1;
          else
            complete = 0;
          end
          is_answer = User.current.exercise_answer.where(:exercise_question_id => params[:exercise_question_id].to_i).count > 0
          @percent = get_percent(@exercise,User.current)
          render :json => {:text => "ok",:complete => complete,:percent => format("%.2f" ,@percent),:is_answer => is_answer}
        else
          render :json => {:text => "failure"}
        end
      else
        #pv不为空，则当前选项之前已被选择，再次点击则是不再选择该项，故删除该答案
        if ea.delete
          is_answer = User.current.exercise_answer.where(:exercise_question_id => params[:exercise_question_id].to_i).count > 0
          @percent = get_percent(@exercise, User.current)
          render :json => {:text => "false" ,:percent => format("%.2f" , @percent),:is_answer => is_answer}
        else
          render :json => {:text => "failure"}
        end
      end
    elsif eq.question_type == 3 || eq.question_type == 4
      #单行文本，多行文本题
      ea = ExerciseAnswer.find_by_exercise_question_id_and_user_id(params[:exercise_question_id], User.current.id)
      if ea.nil?
        # ea为空之前尚未答题，添加答案
        if params[:answer_text].nil? || params[:answer_text].blank?
          #用户提交空答案，视作不作答
          @percent = get_percent(@exercise,User.current)
          render :json => {:text => "",:percent => format("%.2f", @percent)}
        else
          #添加答案
          ea = ExerciseAnswer.new
          ea.user_id = User.current.id
          ea.exercise_question_id = params[:exercise_question_id]
          ea.answer_text = params[:answer_text]
          if ea.save
            uncomplete_question = get_uncomplete_question(@exercise, User.current)
            if uncomplete_question.count < 1
              complete = 1;
            else
              complete = 0;
            end
            @percent = get_percent(@exercise,User.current)
            render :json => {:text => ea.answer_text,:complete => complete,:percent => format("%.2f",@percent)}
          else
            render :json => {:text => "failure"}
          end
        end

      else
        # ea不为空说明用户之前已作答
        if params[:answer_text].nil? || params[:answer_text].blank?
          # 用户提交空答案，视为删除答案
          if ea.delete
            @percent = get_percent(@exercise,User.current)
            render :json => {:text => "",:percent => format("%.2f", @percent)}
          else
            render :json => {:text => "failure"}
          end
        else
          #用户修改答案
          ea.answer_text = params[:answer_text]
          if ea.save
            @percent = get_percent(@exercise,User.current)
            render :json => {:text => ea.answer_text,:percent => format("%.2f", @percent)}
          else
            render :json => {:text => "failure"}
          end
        end
      end

    else
      render :json => {:text => "failure"}
    end
  end

  # 提交问卷
  def commit_exercise
    # 老师不需要提交
    if User.current.allowed_to?(:as_teacher,@course)
      # if @exercise.publish_time.nil? || @exercise.publish_time <= Time.now
      #   @exercise.update_attributes(:exercise_status => 2)
      #   @exercise.update_attributes(:publish_time => Time.now)
      #   course = @exercise.course
      #   course.members.each do |m|
      #     @exercise.course_messages << CourseMessage.new(:user_id => m.user_id, :course_id => course.id, :viewed => false, :status => 2)
      #   end
      #   redirect_to exercise_url(@exercise)
      #   return
      # elsif @exercise.publish_time > Time.now
      #   redirect_to exercise_url(@exercise)
      #   return
      # end
      # redirect_to exercise_url(@exercise)
      # REDO: 提示提交成功
    else
      # 更新提交状态
      cur_exercise_user = ExerciseUser.where("user_id =? and exercise_id=?", User.current, @exercise.id).first
      cur_exercise_user.update_attributes(:status => 1, :commit_status => 1)
      if @exercise.time && @exercise.time != -1
        score = calculate_student_score(@exercise, User.current)
        cur_exercise_user.update_attributes(:score => score)
      end
      # 答题过程中需要统计完成量
      #@uncomplete_question = get_uncomplete_question(@exercise, User.current)
      # 获取改学生的考试得分
      #@score = calculate_student_score(@exercise, User.current)
      # @score = 100
      # if @uncomplete_question.count < 1
      #   # 查看是否有已提交记录
      #   cur_exercise_user.score = @score
      #   if cur_exercise_user.save
      #   #redirect_to poll_index_path(:polls_group_id => @course.id,:polls_type => 'Course')
      #     @status = 0 #提交成功
      #   else
      #     @status = 2 #未知错误
      #   end
      # else
      #   @status = 1 #有未做得必答题
      # end
      # @save = params[:save].to_i if params[:save]
      respond_to do |format|
        format.js
      end
    end
  end

  # 获取学生未答情况
  def get_student_uncomplete_question
    time_limit = @exercise.time == -1 || @exercise.time.nil?
    uncomplete_count = get_uncomplete_question(@exercise, User.current).count
    render :json => {:time_limit => time_limit, :uncomplete_count => uncomplete_count}
  end

  # 主观题打分
  def edit_question_score
    exercise_user = @exercise.exercise_users.where(:user_id => params[:user_id].to_i).first
    exercise_answer = ExerciseAnswer.where(:user_id => params[:user_id].to_i, :exercise_question_id => params[:exercise_question_id].to_i).first
    exercise_question = ExerciseQuestion.where(:id => params[:exercise_question_id].to_i).first
    if exercise_user && exercise_answer && exercise_question
      score = params[:score].to_i
      unless score > exercise_question.question_score || score < 0
        exercise_answer.update_attributes(:score => score)
        exercise_user.update_attributes(:subjective_score => calculate_subjective_score(@exercise, exercise_user.user))
        exercise_user.update_attributes(:score => ((exercise_user.objective_score > 0 ? exercise_user.objective_score : 0) + (exercise_user.subjective_score > 0 ? exercise_user.subjective_score : 0)))
        render :json => {:status => 1, :score => score, :total_score => exercise_user.score}
      else
        render :json => {:status => 2}
      end
    else
      render :json => {:status => 0}
    end
  end

  #查看学生的答卷情况
  def show_student_result
    @user = User.find params[:user_id]
    @can_edit_excercise = false
    @exercise_questions = @exercise.exercise_questions
    #score = calculate_student_score(@exercise, @user)
    #eu = get_exercise_user(@exercise.id, @user.id)
    #eu.update_attributes(:score => score)
    @exercise_user = ExerciseUser.where("user_id =? and exercise_id=?", @user.id, @exercise.id).first
    @left_nav_type = 8
    respond_to do |format|
      format.html {render :layout => 'base_courses'}
    end
  end

  # 计算学生得分
  def calculate_student_score(exercise, user)
    score = 0
    score1 = 0
    score2 = 0
    score3 = 0
    exercise_qustions = exercise.exercise_questions
    exercise_qustions.each do |question|
      answer = get_user_answer(question, user)
      standard_answer = get_user_standard_answer(question, user)
      unless answer.empty?
        # 问答题有多个答案
        if question.question_type == 3 && !standard_answer.empty?
          if standard_answer.include?(answer.first.answer_text)
            score1 = score1+ question.question_score unless question.question_score.nil?
          end
        elsif question.question_type == 1 && !standard_answer.nil?
          if answer.first.exercise_choice.choice_position == standard_answer.exercise_choice_id
            score2 = score2 + question.question_score unless question.question_score.nil?
          end
        elsif question.question_type == 2 && !standard_answer.nil?
          arr = get_mulscore(question, user)
          if arr.to_i == standard_answer.exercise_choice_id
            score3 = score3 + question.question_score unless question.question_score.nil?
          end
          # ecs = ExerciseAnswer.where("user_id =? and exercise_question_id =?", user.id, question.id)
          # arr = []
          # ecs.each do |ec|
          #   arr << ec.exercise_choice.choice_position
          # end
          # arr.sort
          # arr = arr.join("")
          # if arr.to_i == standard_answer.exercise_choice_id
          #   score3 = score + question.question_score unless question.question_score.nil?
          # end
        end
      end
    end
    score = score1 + score2 + score3
  end

  # 计算主观题总分
  def calculate_subjective_score exercise, user
    score = 0
    exercise_questions = exercise.exercise_questions.where(:question_type => 4)
    exercise_answers = user.exercise_answer.where(:exercise_question_id => exercise_questions.map(&:id))
    exercise_answers.each do |ea|
      if ea.score != -1
        score += ea.score
      end
    end
    score
  end

  #导入试卷的弹框
  def other_exercise
    # 查作者是我，或者作者是当前课程的老师，且不在当前课程内的试卷 进行导入
    @order,@b_sort = params[:order] || "created_at",params[:sort] || "desc"
    @r_sort = @b_sort == "desc" ? "asc" : "desc"
    courses = User.current.courses.not_deleted.select { |course| User.current.allowed_to?(:as_teacher,course)}
    course_ids = courses.empty? ? "(-1)" : "(" + courses.map { |course| course.id}.join(',') + ")"
    #none_courses = User.current.courses.where("is_delete = 1 or #{Course.table_name}.id = #{params[:course_id].to_i}")
    #none_course_ids = none_courses.empty? ? "(-1)" : "(" + none_courses.map { |course| course.id}.join(',') + ")"
    @exercises = Exercise.where("(user_id = #{User.current.id} or course_id in #{course_ids}) and course_id != #{params[:course_id].to_i}").order("#{@order} #{@b_sort}")
    @course_id = params[:course_id]
    @is_remote = true
    @ex_count = @exercises.count
    @ex_pages = Paginator.new @ex_count, 10, params['page'] || 1
    @offset ||= @ex_pages.offset
    @exercises = paginateHelper @exercises,10
    respond_to do |format|
      format.js
    end
  end

  #搜索导入页面的试卷
  def search_exercises
    @order,@b_sort = params[:order] || "created_at",params[:sort] || "desc"
    @r_sort = @b_sort == "desc" ? "asc" : "desc"
    search = params[:name].to_s.strip.downcase
    courses = User.current.courses.not_deleted.select { |course| User.current.allowed_to?(:as_teacher,course)}
    course_ids = courses.empty? ? "(-1)" : "(" + courses.map { |course| course.id}.join(',') + ")"
    @exercises = Exercise.where("(user_id = #{User.current.id} or course_id in #{course_ids}) and course_id != #{params[:course_id].to_i} and exercise_name like '%#{search}%'").order("#{@order} #{@b_sort}")
    @is_remote = true
    @ex_count = @exercises.count
    @ex_pages = Paginator.new @ex_count, 10, params['page'] || 1
    @offset ||= @ex_pages.offset
    @exercises = paginateHelper @exercises,10
    @course_id = params[:course_id]
    respond_to do |format|
      format.js
    end
  end

  #将选择的试卷导入到班级
  def import_other_exercise
    course_id = params[:course_id]
    @course = Course.find(course_id)
    params[:exercise_id].each_with_index do |ex,i|
      exercise = Exercise.find(ex)
      option = {
          :exercise_name => exercise.exercise_name,
          :exercise_status => 1,
          :user_id => User.current.id,
          :show_result => 1,
          :course_id => @course.id,
          :time => exercise.time,
          :exercise_description => exercise.exercise_description
      }
      @exercise = Exercise.create option

      exercise.exercise_questions.each do |q|
        option = {
            :question_title => q[:question_title],
            :question_type => q[:question_type] || 1,
            :question_number => q[:question_number],
            :question_score => q[:question_score]
        }
        @exercise_question = @exercise.exercise_questions.new option

        for i in 1..q.exercise_choices.count
          choice_option = {
              :choice_position => i,
              :choice_text => q.exercise_choices[i-1][:choice_text]
          }
          @exercise_question.exercise_choices.new choice_option
        end

        for i in 1..q.exercise_standard_answers.count
          standard_answer_option = {
              :exercise_choice_id => q.exercise_standard_answers[i-1][:exercise_choice_id],
              :answer_text => q.exercise_standard_answers[i-1][:answer_text]
          }
          @exercise_question.exercise_standard_answers.new standard_answer_option
        end
      end
      @exercise.save
    end
    respond_to do |format|
      format.js
    end
  end

  private
  #测验列表转换为excel
  def exercise_to_xls items
    xls_report = StringIO.new
    book = Spreadsheet::Workbook.new
    sheet1 = book.create_worksheet :name => "exercise"
    blue = Spreadsheet::Format.new :color => :blue, :weight => :bold, :size => 10
    sheet1.row(0).default_format = blue
    sheet1.row(0).concat([l(:excel_user_id),l(:excel_user_name),l(:excel_nickname),l(:excel_student_id),l(:excel_mail),l(:excel_objective_score),l(:excel_subjective_score),l(:excel_f_score),l(:excel_answer_time)])
    count_row = 1
    items.each do |exercise|
      sheet1[count_row,0]=exercise.user.id
      sheet1[count_row,1] = exercise.user.lastname.to_s + exercise.user.firstname.to_s
      sheet1[count_row,2] = exercise.user.login
      sheet1[count_row,3] = exercise.user.user_extensions.student_id
      sheet1[count_row,4] = exercise.user.mail
      sheet1[count_row,5] = exercise.objective_score == -1 ? "0.0" : format("%.1f",exercise.objective_score)
      sheet1[count_row,6] = exercise.subjective_score == -1 ? "0.0" : format("%.1f",exercise.subjective_score)
      sheet1[count_row,7] = exercise.score
      sheet1[count_row,8] = exercise.commit_status == 0 ? l(:excel_no_answer) : format_time(exercise.created_at)
      count_row += 1
    end
    book.write xls_report
    xls_report.string
  end

  #根据条件过滤作业结果
  def search_exercise_member exercises,name
    if name == ""
      select_exercises = exercises
    else
      name = name.downcase
      select_exercises = exercises.select{ |exercise|
        exercise.user[:login].to_s.downcase.include?(name) || exercise.user.user_extensions[:student_id].to_s.downcase.include?(name) || (exercise.user[:lastname].to_s.downcase + exercise.user[:firstname].to_s.downcase).include?(name)
      }
    end
    select_exercises
  end

  # ExerciseUser记录用户是否已提交问卷有对应的记录则已提交，没有则新建一个
  def get_exercise_user exercise_id,user_id
    eu = ExerciseUser.find_by_exercise_id_and_user_id(exercise_id,user_id)
    if eu.nil?
      eu = ExerciseUser.new
    end
    eu
  end

  # 获取当前学生回答问题的答案
  def get_user_answer(question,user)
    # user_answer = ExerciseAnswer.where("user_id=? and exercise_question_id=?", user.id, question.id).first
    user_answer = question.exercise_answers.where("#{ExerciseAnswer.table_name}.user_id = #{user.id}")
    user_answer
  end

  # 获取问题的标准答案
  def get_user_standard_answer(question,user)
    if question.question_type == 3
      standard_answer =[]
      question.exercise_standard_answers.each do |answer|
        standard_answer << answer.answer_text
      end
    else
      standard_answer = question.exercise_standard_answers.first
    end
    standard_answer
  end
  # 是否完成了答题
  def get_complete_question(exercise,user)
    questions = exercise.exercise_questions.includes(:exercise_answers)
    complete_question = []
    questions.each do |question|
      answers = question.exercise_answers.select{|e| e.user_id == user.id}
      if !(answers.nil? || answers.count < 1)
        complete_question << question
      end
    end
    complete_question
  end

  # 获取答题百分比
  def get_percent exercise,user
    complete_count = get_complete_question(exercise,user).count
    if exercise.exercise_questions.count == 0
      return 0
    else
      return (complete_count.to_f / exercise.exercise_questions.count.to_f)*100
    end
  end

  def remove_invalid_exercise(course)
    exercises = course.exercises.where("exercise_name=?","")
    unless exercises.empty?
      exercises.each do |exercise|
        if exercise.exercise_questions.empty?
          exercise.destroy
        end
      end
    end
  end

  def find_exercise_and_course
    @exercise = Exercise.find params[:id]
    @course = Course.find @exercise.course_id
  rescue Exception => e
    render_404
  end

  def find_course
    @course = Course.find params[:course_id]
  rescue Exception => e
    render_404
  end
end