/// <summary>
/// 发送消息，验证发送体，不验证登陆用户（Controller验证）
/// </summary>
/// <param name="response"></param>
/// <param name="request"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
public async Task SendMessageAsync([Required] ResponseMessage response, [Required] SendMsgRequest request, CancellationToken cancellationToken)
{
// 参数验证：发送体不为null，发送人id和接收人id存在，消息内容不能为 string.IsNullOrWhiteSpace，消息不能重复发送（客户端监控）
// 判断请求体是否存在错误
if (request.Send == null)
{
response.Wrap(ResponseDefine.BadRequset, "发送体不能为空");
return;
}
if (request.Send.Msg == null)
{
response.Wrap(ResponseDefine.BadRequset, "消息体不能为空");
return;
}
if (request.Send.FromUserId == null || request.Send.ToUserId == null)
{
response.Wrap(ResponseDefine.BadRequset, "发送或接收人的ID不能为0");
return;
}
if (string.IsNullOrWhiteSpace(request.Send.Msg.Detail))
{
response.Wrap(ResponseDefine.BadRequset, "消息内容不能为空");
return;
}
// 判断发信人与收信人存在
User fromUser = _UserStore.ReadAsync(a => a.Where(b => b.Id == request.Send.FromUserId), CancellationToken.None).Result;
if (fromUser == null)
{
Def.Response.UserNotFound(response, request.Send.FromUserId);
}
User toUser = _UserStore.ReadAsync(a => a.Where(b => b.Id == request.Send.ToUserId), CancellationToken.None).Result;
if (toUser == null)
{
Def.Response.UserNotFound(response, request.Send.ToUserId);
}
// 消息不可重复：在数据库中比较与上一条消息的发送时间是否一致，TODO: 另外可以比较当前时间与上一条的内容一致但是时间间隔过短
// 改造，生成LastMessage(long )方法
var lastSend = await Store.ReadAsync(a => a.Where(b => b.FromUserId == fromUser.Id && b.ToUserId == toUser.Id && b.FromTime == a.Max(c => c.FromTime)), CancellationToken.None);
if (lastSend != null && request.Send.FromTime == lastSend.FromTime)
{
response.Wrap(ResponseDefine.PostRepeat, "消息不可以重复发送");
}
else
{
// 使用事务刷新数据，保持数据一致性
using (var trans = await _transaction.BeginTransaction())
{
try
{
// 先保存Msg获取MsgId
var msg = await _MessageStore.CreateAsync(new Message
{
Detail = request.Send.Msg.Detail
});
// 再保存Send获取保存后的Send
if (msg.Id == null)
{
throw new Exception("WS------ 再数据库中创建Message时返回保存的Message不完整：\r\n" + msg);
}
else
{
//Thread.Sleep(5);
var send = await Store.CreateAsync(new Send
{
Type = request.Send.Type ?? "Private",
FromUserId = request.Send.FromUserId,
FromTime = request.Send.FromTime ?? DateTime.Now,
ToUserId = request.Send.ToUserId,
MsgId = msg.Id,
_CreateUserId = "1"
}, cancellationToken);
}
trans.Commit();
}
catch (Exception e)
{
trans.Rollback();
throw new Exception("使用事务保存数据时出现异常：\r\n", e);
}
}
}
}
