/*
* author：邓帅
* QQ：540043604
*/
/// <summary>
/// 按courseId删除Seminar.
/// 先根据CourseId获得所有的seminar的信息，然后根据seminar信息删除相关topic的记录，然后再根据SeminarId删除SeminarGroup表记录,最后再将seminar的信息删除
/// </summary>
/// <param name="courseId">课程Id</param>
/// <seealso cref="M:Xmu.Crms.Shared.Service.ISeminarService.ListSeminarByCourseId(System.Int64)"/>
/// <seealso cref="M:Xmu.Crms.Shared.Service.ITopicService.DeleteTopicBySeminarId(System.Int64)"/>
/// <seealso cref="M:Xmu.Crms.Shared.Service.ISeminarGroupService.DeleteSeminarGroupBySeminarId(System.Int64)"/>
/// <exception cref="T:System.ArgumentException">格式错误时抛出</exception>
/// <exception cref="T:Xmu.Crms.Shared.Exceptions.CourseNotFoundException">该课程不存在时抛出</exception>
public void DeleteSeminarByCourseId(long courseId)
{
if (courseId < 0)
{
throw new ArgumentException();
}
if (_db.Course.Find(courseId) == null)
{
throw new CourseNotFoundException();
}
var course = _db.Course.Find(courseId);
List <Seminar> seminars;
seminars = ListSeminarByCourseId(courseId).ToList();
foreach (Seminar seminar in seminars)
{
_seminarGroupService.DeleteSeminarGroupBySeminarId(seminar.Id);
_topicService.DeleteTopicBySeminarId(seminar.Id);
}
_db.Seminar.RemoveRange(seminars);
_db.SaveChanges();
}