/// <summary>
/// 添加一条评论
/// </summary>
/// <param name="personId">评论者ID</param>
/// <param name="blogId">评论的BlogID</param>
/// <param name="content">评论内容</param>
/// <param name="photoContentIds">评论的附件ID(仅限图片)</param>
/// <param name="baseCommentId">被评论的CommentID</param>
/// <returns></returns>
public async Task<Comment> AddCommentAsync(long personId, long blogId, string content, List<long> photoContentIds = null, long? baseCommentId = null)
{
BlogHandler blogHandler = new BlogHandler(_dbContext);
GroupHandler groupHandler = new GroupHandler(_dbContext);
PersonHandler perHandler = new PersonHandler(_dbContext);
//1. 检查要评论的Blog是否存在。
Blog beCommentBlog = await blogHandler.GetByIdAsync(blogId);
//2. 如果为空或者被逻辑删除，则Exception。
if (beCommentBlog == null || beCommentBlog.IsDeleted)
{
throw new DisplayableException("要评论的Blog不存在或者已经被删除");
}
//2.1 自己评论自己的Blog永远可以，所以只需要判断不同的PersonID。
if(beCommentBlog.PersonID != personId)
{
//3. 检查当前用户是否被该评论Blog的用户加入了黑名单，如果是则不能进行评论。
Group beCommentBlogPersonBlackList = await groupHandler.Include(x => x.GroupMembers).SingleOrDefaultAsync(x => x.PersonID == beCommentBlog.PersonID && x.Type == GroupType.BlackList);
if (beCommentBlogPersonBlackList != null && beCommentBlogPersonBlackList.GroupMembers.Count > 0)
{
bool isBlocked = beCommentBlogPersonBlackList.GroupMembers.Select(x => x.PersonID).Contains(personId);
if (isBlocked)
{
throw new DisplayableException("由于用户设置，你无法回复评论。");
}
}
//4. 检查评论Blog的用户消息设置，是否允许评论。
Person beCommentBlogPerson = await perHandler.GetByIdAsync(beCommentBlog.PersonID);
if (beCommentBlogPerson != null)
{
//4.1 如果评论只允许关注的人评论，则判断Blog的用户的是否关注了当前用户。
if (beCommentBlogPerson.AllowablePersonForComment == AllowablePersonForComment.FollowerOnly)
{
//4.2 判断关注的人集合是否已经加载。
if (!_dbContext.Entry(beCommentBlogPerson).Collection(x => x.MyFollowingPersons).IsLoaded)
{
_dbContext.Entry(beCommentBlogPerson).Collection(x => x.MyFollowingPersons).Load();
}
bool isFollow = beCommentBlogPerson.MyFollowingPersons.Select(x => x.FollowingID).Contains(personId);
if (!isFollow)
{
throw new DisplayableException("由于用户设置，你无法回复评论。");
}
}
//4.3 如果评论只允许粉丝评论，则判断当前用户是否关注了该Blog用户。
else if (beCommentBlogPerson.AllowablePersonForComment == AllowablePersonForComment.FansOnly)
{
//4.4 判断粉丝集合是否已经加载。
if (!_dbContext.Entry(beCommentBlogPerson).Collection(x => x.MyFans).IsLoaded)
{
_dbContext.Entry(beCommentBlogPerson).Collection(x => x.MyFans).Load();
}
bool isFans = beCommentBlogPerson.MyFans.Select(x => x.FollowerID).Contains(personId);
if (!isFans)
{
throw new DisplayableException("由于用户设置，你无法回复评论。");
}
}
}
//5. 检查评论Blog的用户消息设置，是否允许评论附带图片。
if(photoContentIds != null && photoContentIds.Count > 0)
{
if(!beCommentBlogPerson.AllowCommentAttachContent)
{
throw new DisplayableException("由于用户设置，你回复评论无法添加图片。");
}
}
}
using(var dbTransaction = _dbContext.Database.BeginTransaction())
{
try
{
//6. 建立Comment对象并保存。
Comment comment = new Comment()
{
PersonID = personId,
BlogID = blogId,
Content = content
};
this.Add(comment);
await SaveChangesAsync();
//7. 判断是否有图片，有则建立与Comment的关联。
if (photoContentIds != null && photoContentIds.Count > 0)
{
if(photoContentIds.Count > 6)
{
throw new DisplayableException("评论最多附件6张图片");
}
ContentHandler contentHandler = new ContentHandler(_dbContext);
//7.1 判断附件是否为图片。
List<Content> photoContents = await contentHandler.Fetch(x => photoContentIds.Contains(x.ID)).ToListAsync();
if(!photoContents.Any(x => x.Type == ContentType.Photo))
{
throw new DisplayableException("评论只能附件图片");
}
//7.2 建立Comment与Content的关联。
CommentXContentHandler cxcHandler = new CommentXContentHandler(_dbContext);
foreach (var photoContentId in photoContentIds)
{
CommentXContent cxc = new CommentXContent()
{
CommentID = comment.ID,
ContentID = photoContentId
};
cxcHandler.Add(cxc);
}
await SaveChangesAsync();
}
//8. 判断当前评论是否评论Blog里的其他评论，如果是则建立关联。
if(baseCommentId != null)
{
//8.1 判断被评论ID是否存在。
Comment baseComment = await GetByIdAsync(baseCommentId);
if(baseComment == null)
{
throw new DisplayableException("此评论不存在或者已经被删除");
}
//8.2 判断被评论的BlogID是否与当前评论的BlogID一致。
if(baseComment.BlogID != blogId)
{
throw new DisplayableException("此评论的BlogID与被评论的BlogID不一致");
}
//8.3 建立关联。
CommentXCommentHandler cxcHandler = new CommentXCommentHandler(_dbContext);
CommentXComment cxc = new CommentXComment()
{
BaseCommentID = (long)baseCommentId,
NewCommentID = comment.ID
};
cxcHandler.Add(cxc);
await SaveChangesAsync();
}
dbTransaction.Commit();
return comment;
}
catch (Exception)
{
dbTransaction.Rollback();
throw;
}
}
}
