## This helper be included in applicationHelper
module CoursesHelper
	# 返回学生数量，即roles表中定义的Reporter， 返回结果 -1 为查询失败
	def studentCount project
		searchCountByRoles project, 5
	end

	# 返回教师数量，即roles表中定义的Manager， 返回结果 -1 为查询失败
	def teacherCount project
		searchCountByRoles project, 3
	end

	# 返回TA数量，即roles表中定义的TA， 返回结果 -1 为查询失败
	def teacherAssistantCount project
		searchCountByRoles project, 7
	end

	# 根据角色查询
	def searchCountByRoles project, roles_id
		people = searchPeopleByRoles project, roles_id
		people.count
	end

	# 根据角色查人
	def searchPeopleByRoles project, roles_id
		people = []
		begin
			people = project.members.joins(:member_roles).where("member_roles.role_id = :role_id", {:role_id => roles_id })
		rescue Exception => e
			logger.error "[CoursesHelper] ===> #{e}"
		end
		people
	end
end