socialforge/app/services/courses_service.rb

class CoursesService
  include ApplicationHelper
  include CoursesHelper
  #TODO:尚未整合权限系统
  #参数school_id为0或不传时返回所有课程，否则返回对应学校的课程
  #参数per_page_count分页功能，每页显示的课程数
  #参数page分页功能，当前页码
  def course_list params
    @school_id = params[:school_id]
    per_page_option = params[:per_page_count] || 10
    page_no = params[:page] || 1
    if @school_id == "0" || @school_id.nil?
      @courses_all = Course.active.visible.
        joins("LEFT JOIN #{CourseStatus.table_name} ON #{Course.table_name}.id = #{CourseStatus.table_name}.course_id")
    else
      @courses_all = Course.active.visible.
        joins("LEFT JOIN #{CourseStatus.table_name} ON #{Course.table_name}.id = #{CourseStatus.table_name}.course_id").
        where("#{Course.table_name}.school_id = ?", @school_id)
    end
    @course_count = @courses_all.count
    @course_pages = Redmine::Pagination::Paginator.new @course_count, per_page_option,page_no
    @courses = @courses_all.order("created_at desc")
    @courses = @courses.offset(@course_pages.offset).limit(@course_pages.per_page)
    course_list = []
    @courses.each do |course|
      course_list << {:course => course,:img_url => url_to_avatar(course)}
    end
    course_list
  end

  #搜索课程
  def search_course params
    courses_all = Course.all_course
    name = params[:name]
    if name.blank?
      raise 'sumbit empty'
    end
    @courses = courses_all.visible
    if params[:name].present?
      @courses_all = @courses.like(params[:name])
    else
      @courses_all =  @courses;
    end
    @courses_all
  end

  #获取头像
  def get_img obj
    url_to_avatar(obj)
  end

  #课程老师或课程学生列表
  def course_teacher_or_student_list params,course,current_user
    if course.is_a?(Course)
      c = course
    else
      c = Course.find(course)
    end
    if current_user.nil? || !(current_user.admin? || c.is_public == 1 || (c.is_public == 0 && current_user.member_of_course?(c)))
      raise '403'
    end
    @teachers= searchTeacherAndAssistant(c)
    #@canShowCode = isCourseTeacher(User.current.id,course) && params[:role] != '1'
    case params[:role]
      when '1'
        #@subPage_title = l :label_teacher_list
        @members = searchTeacherAndAssistant(c)
      when '2'
        #@subPage_title = l :label_student_list
        @members = searchStudent(c)
      else
        #@subPage_title = ''
        @members = c.member_principals.includes(:roles, :principal).all.sort
    end
    @members
  end

  #课程通知列表
  def course_news_list params
    if params[:course_id] && @course==nil
      @course = Course.find(params[:course_id])
    end
    scope = @course ? @course.news.course_visible : News.course_visible
  end

  #查看新闻权限验证
  def show_course_news_authorize(current_user,course)
    unless current_user.allowed_to?({:controller => 'news', :action => 'show'}, course)
      raise '403'
    end
  end

  #显示课程通知(包括评论) 需验证权限
  def show_course_news params,current_user
    @news = News.find(params[:id])
    @comments = @news.comments
    @comments.reverse! if current_user.wants_comments_in_reverse_order?
    [@news,@comments]
  end



  #显示课程
  def show_course(params,currnet_user)
    course = Course.find(params[:id])
    unless (course.is_public == 1 ||  currnet_user.member_of_course?(@course)|| currnet_user.admin?)
      raise '403'
    end
    course
  end

  #创建课程
  #current_user当前用户对象（不是id）
  # params[:course][:name]:课程名称
  #params[:course][:password]:密码
  #params[:course][:description]:描述
  #params[:course][:is_public]:是否公开1公开，0私有
  #params[:course][:open_student]:是否公开学生列表1公开，0不公开，不公开时非课程成员无法看到学生列表
  #params[:course][:course_type]:暂时默认给1值。
  #params[:term]：学期（秋季学期或春季学期）
  #params[:time]: 年份（例：2014）
  #params[:setup_time]：暂不传（貌似已经没用了）
  #params[:endup_time]: 暂不传（貌似已经没用了）
  #params[:class_period]:学时总数
  def create_course(params,current_user)
    if current_user.user_extensions.identity
      @course = Course.new
      @course.extra = 'course' + DateTime.parse(Time.now.to_s).strftime('%Y-%m-%d_%H-%M-%S').to_s
      @course.send(:safe_attributes=, params[:course], current_user)
      #@course.safe_attributes(current_user,params[:course])
      @course.tea_id = current_user.id
      @course.term = params[:term]
      @course.time = params[:time]
      #@course.school_id = params[:occupation]
      @course.school_id = current_user.user_extensions.school_id
      @course.setup_time = params[:setup_time]
      @course.endup_time = params[:endup_time]
      @course.class_period = params[:class_period]
    end

    @issue_custom_fields = IssueCustomField.sorted.all
    @trackers = Tracker.sorted.all

    if @course.save
      #unless User.current.admin?
      r = Role.givable.find_by_id(Setting.new_project_user_role_id.to_i) || Role.givable.first
      m = Member.new(:user => current_user, :roles => [r])
      m.project_id = -1
      course = CourseInfos.new(:user_id => current_user.id, :course_id => @course.id)
      #user_grades = UserGrade.create(:user_id => User.current.id, :course_id => @course.id)
      if params[:course][:is_public] == '1'
        course_status = CourseStatus.create(:course_id => @course.id, :watchers_count => 0, :changesets_count => 0, :grade => 0, :course_type => @course_tag)
      end
      @course.members << m
      @course.course_infos << course
    end
    @course
  end

  #验证编辑课程的权限
  #当前
  def edit_course_authorize(current_user,course)
    unless current_user.allowed_to?({:controller => 'courses', :action => 'update'}, course)
      raise '403'
    end
  end

  #编辑课程  需验证权限
  # params[:course][:name]:课程名称
  #params[:course][:password]:密码
  #params[:course][:description]:描述
  #params[:course][:is_public]:是否公开1公开，0私有
  #params[:course][:open_student]:是否公开学生列表1公开，0不公开，不公开时非课程成员无法看到学生列表
  #params[:course][:course_type]:暂时默认给1值。
  #params[:term]：学期（秋季学期或春季学期）
  #params[:time]: 年份（例：2014）
  #params[:class_period]:学时总数
  def edit_course(params,course,current_user)
    course.send(:safe_attributes=, params[:course], current_user)
    #course.safe_attributes = params[:course]
    course.time = params[:time]
    course.term = params[:term]
    course.class_period = params[:class_period]
    if course.save
      if params[:course][:is_public] == '0'
        course_status = CourseStatus.find_by_course_id(course.id)
        course_status.destroy if course_status
      elsif params[:course][:is_public] == '1'
        course_status = CourseStatus.find_by_course_id(course.id)
        course_status.destroy if course_status
        course_status = CourseStatus.create(:course_id => course.id,  :grade => 0)
      end
    end
    course
  end

  #退出课程
  #object_id: 课程id
  #user：当前用户
  def exit_course params,user
    @member = Member.where('course_id = ? and user_id = ?', params[:object_id], user.id)
    @member.first.destroy

    joined = StudentsForCourse.where('student_id = ? and course_id = ?', user.id, params[:object_id])
    joined.each do |join|
      join.delete
    end
  end

  #加入课程
  #object_id：课程id
  #course_password ：加入课程的密码
  #@state == 0 加入成功
  #@state == 1 密码错误
  #@state == 2 课程已过期 请联系课程管理员重启课程。(在配置课程处)
  #@state == 3 您已经加入了课程
  #@state == 4 您加入的课程不存在
  #@state == 5 您还未登录
  #@state 其他 未知错误，请稍后再试
  def join_course params
    course = Course.find_by_id params[:object_id]
    if course
      if course_endTime_timeout? course
        @state = 2
      else
        if User.current.member_of_course?(course)
          @state = 3
        else
          if params[:course_password] == course.password
            members = []
            members << Member.new(:role_ids => [10], :user_id => User.current.id)
            course.members << members
            StudentsForCourse.create(:student_id => User.current.id, :course_id => params[:object_id])
            @state = 0
          else
            @state = 1
          end
        end
      end
    else
      @state = 4
    end
    [@state,course]
  end

  #作业列表
  #已提交的作业数量获取 bid.homeworks.count
  #学生提问数量获取 bid.commit.nil? ? 0 : bid.commit
  def homework_list params,current_user
    if @course.is_public != 0 || current_user.member_of_course?(@course)
      @offset, @limit = api_offset_and_limit({:limit => 10})
      @bids = @course.homeworks.order('deadline DESC')
      @bids = @bids.like(params[:name]) if params[:name].present?
    else
      raise '403'
    end
  end

end