/// <summary>
/// 发表一篇Blog
/// </summary>
/// <param name="personId">PersonID</param>
/// <param name="content">Blog的内容</param>
/// <param name="attachContents">Blog的附件</param>
/// <param name="accessInfo">Blog的访问控制</param>
/// <param name="groupId">当Blog的访问控制为群可见则需要指定GroupID</param>
/// <param name="forwardBlogId">转发的BlogID</param>
/// <returns></returns>
public async Task<Blog> CreateBlogAsync(long personId, string content, BlogInfoAccessInfo accessInfo, long? groupId = null, List<long> attachContentIds = null, long? forwardBlogId = null)
{
using(var dbTransaction = _dbContext.Database.BeginTransaction())
{
try
{
BlogAccessControlHandler bacHandler = new BlogAccessControlHandler(_dbContext);
//1. 创建Blog对象并保存。
Blog blog = new Blog()
{
PersonID = personId,
Content = content,
IsDeleted = false
};
this.Add(blog);
await SaveChangesAsync();
//2. 判断是否有附件，有则建立与Blog的关联。
if (attachContentIds != null && attachContentIds.Count > 0)
{
ContentHandler contentHandler = new ContentHandler(_dbContext);
BlogXContentHandler bxcHandler = new BlogXContentHandler(_dbContext);
#region 检查attachContent集合。
List<Content> attachContents = await contentHandler.Fetch(x => attachContentIds.Contains(x.ID)).ToListAsync();
bool isDifferentType = attachContents.Select(x => x.Type).Distinct().Count() > 1;
if(isDifferentType)
{
throw new DisplayableException("不能发不同类型内容的Blog");
}
int photoCount = attachContents.Count(x => x.Type == ContentType.Photo);
int musicCount = attachContents.Count(x => x.Type == ContentType.Music);
int videoCount = attachContents.Count(x => x.Type == ContentType.Video);
if(photoCount > 6)
{
throw new DisplayableException("发表图片不能超过6张");
}
if (musicCount > 1)
{
throw new DisplayableException("发表音乐不能超过1首");
}
if (videoCount > 1)
{
throw new DisplayableException("发表视频不能超过1个");
}
#endregion
foreach (var attachContentId in attachContentIds)
{
BlogXContent bxc = new BlogXContent()
{
BlogID = blog.ID,
ContentID = attachContentId
};
bxcHandler.Add(bxc);
}
await SaveChangesAsync();
}
//3. 判断当前是否转发Blog，是则建立转发Blog与新Blog的关联。
if(forwardBlogId.HasValue)
{
//3.1 判断ForwardBlog是否存在。
Blog forwardBlog = await GetByIdAsync(forwardBlogId);
if(forwardBlog == null || forwardBlog.IsDeleted)
{
throw new DisplayableException("该Blog不存在或者已经被删除");
}
//3.2 判断ForwardBlog是否转发了Blog，如果是则关联2条Blog，否则只关联当前要转发的Blog。
BlogXBlogHandler bxbHandler = new BlogXBlogHandler(_dbContext);
BlogXBlog blogXblog = new BlogXBlog();
blogXblog.NewBlogID = blog.ID;
blogXblog.BaseBlogID = forwardBlog.ID;
blogXblog.IsBase = false;
//3.3 判断ForwardBlog是否有转发Blog。
Blog baseBlog = await bxbHandler.GetBaseBlogByBlogIdAsync(forwardBlog.ID);
if(baseBlog == null)
{
blogXblog.IsBase = true;
}
else
{
BlogXBlog baseBlogXblog = new BlogXBlog();
baseBlogXblog.NewBlogID = blog.ID;
baseBlogXblog.BaseBlogID = baseBlog.ID;
baseBlogXblog.IsBase = true;
bxbHandler.Add(baseBlogXblog);
}
bxbHandler.Add(blogXblog);
await SaveChangesAsync();
}
//4. 建立AccessControl访问控制。
BlogAccessControl blogAccessControl = new BlogAccessControl()
{
BlogID = blog.ID,
AccessLevel = accessInfo
};
bacHandler.Add(blogAccessControl);
await SaveChangesAsync();
//5. 判断如果访问控制为GroupOnly，则建立AccessControlXGroup关系。
if(accessInfo == BlogInfoAccessInfo.GroupOnly)
{
if(groupId == null)
{
throw new DisplayableException("未指定组");
}
BlogAccessControlXGroupHandler bacxgHandler = new BlogAccessControlXGroupHandler(_dbContext);
BlogAccessControlXGroup bacxg = new BlogAccessControlXGroup()
{
BlogAccessControlID = blogAccessControl.ID,
GroupID = (long)groupId
};
bacxgHandler.Add(bacxg);
await SaveChangesAsync();
}
dbTransaction.Commit();
return blog;
}
catch (Exception)
{
dbTransaction.Rollback();
throw;
}
}
}