private void HandleResponse(HttpListenerContext context)
{
// There are bunch of exceptions that can happen here.
// 1. Client closes connection. This will cause our response's stream to close.
// We may see errors such as "The specified network name is no longer available"
// or "The I/O operation has been aborted because of either a thread exit or an application request".
// NEITHER or these should cause the program to crash. Simply grab the next connection and move on.
// 2. ObjectDisposeExceptions can happen if the above happens as well. We'll handle those when needed.
try
{
HttpListenerRequest request = context.Request;
HttpListenerResponse response = context.Response;
HttpResponseInfo info = null;
// ---- Determine Response and Action to take ----
try
{
NameValueCollection queryString;
using (StreamReader reader = new StreamReader(request.InputStream))
{
queryString = HttpUtility.ParseQueryString(reader.ReadToEnd());
}
info = this.responseHandler.HandleResposne(request.RawUrl, request.HttpMethod, queryString);
}
catch (Exception e)
{
StringBuilder builder = new StringBuilder();
builder.AppendLine("Unexpected Exception while determining HTTP Response:");
builder.AppendLine(e.ToString());
this.OnError?.Invoke(builder.ToString());
info = new HttpResponseInfo
{
ContentType = ContentType.Xml,
Error = ErrorMessage.Unknown,
Message = e.Message,
ResponseStatus = HttpResponseStatus.ServerError
};
}
finally
{
// ---- Write Response (error or okay) to the client. ----
try
{
response.StatusCode = Convert.ToInt32(info.HttpStatusCode);
byte[] buffer = Encoding.UTF8.GetBytes(info.ToString());
response.ContentLength64 = buffer.LongLength;
response.OutputStream.Write(buffer, 0, buffer.Length);
}
catch (Exception e)
{
StringBuilder builder = new StringBuilder();
builder.AppendLine("Error when writing HTTP Response");
builder.AppendLine(e.ToString());
this.OnError?.Invoke(builder.ToString());
}
finally
{
response.Close(); // <- REMEMBER TO CLOSE THIS!
}
}
}
catch (Exception e)
{
StringBuilder builder = new StringBuilder();
builder.AppendLine("Caught Exception when handling HTTP Response: ");
builder.AppendLine(e.Message);
builder.AppendLine("This can happen for several expected reasons, we're probably okay!");
builder.AppendLine(e.StackTrace);
this.OnError?.Invoke(builder.ToString());
}
}
// ---------------- Functions ----------------
public HttpResponseInfo HandleResposne(string url, string method, NameValueCollection queryString)
{
ContentType contentType = ContentType.Xml;
try
{
if (queryString.AllKeys.Contains("format"))
{
if (Enum.TryParse(queryString["format"], out ContentType parsedType) == false)
{
return(new HttpResponseInfo
{
ContentType = contentType,
Error = ErrorMessage.InvalidFormat,
Message = "Invalid format: " + queryString["format"],
ResponseStatus = HttpResponseStatus.ClientError
});
}
else
{
contentType = parsedType;
}
}
if (method.EqualsIgnoreCase("POST") == false)
{
return(new HttpResponseInfo
{
ContentType = contentType,
Error = ErrorMessage.InvalidMethod,
Message = "Request must be a POST request, nothing else is currently supported. Got: " + method,
ResponseStatus = HttpResponseStatus.ClientError
});
}
if (this.IsIrcConnected == false)
{
// If after all of this, we are not connected, tell the client
// that the bot is not connected.
return(new HttpResponseInfo
{
ContentType = contentType,
Error = ErrorMessage.NotConnectedToIrc,
Message = "IRC Bot not connected, can not send command.",
ResponseStatus = HttpResponseStatus.ServerError
});
}
HttpResponseInfo info = DoRequestAction(url, queryString, contentType);
return(info);
}
catch (Exception err)
{
return(new HttpResponseInfo
{
ContentType = contentType,
Error = ErrorMessage.Unknown,
Message = err.Message,
ResponseStatus = HttpResponseStatus.ServerError
});
}
}