// handle exception based on the enum type status, and interpolate the exception message.
static RDJTPResponse HandleException(RDJTPStatus state, string msg = "")
{
var response = new RDJTPResponse();
switch (state)
{
case RDJTPStatus.Not_Found:
response.Status = "5 Not Found";
break;
case RDJTPStatus.Bad_Request:
if (msg != "")
{
response.Status = $"4 Bad Request {msg}";
}
else
{
response.Status = "4 Bad Request";
}
break;
case RDJTPStatus.Error:
response.Status = "6 Error";
break;
default:
response.Status = "6 Error";
break;
}
return(response);
}
static void Respond(NetworkStream strm, RDJTPResponse resp)
{
var jsonresponse = JsonConvert.SerializeObject(resp);
var payload = Encoding.UTF8.GetBytes(jsonresponse);
strm.Write(payload, 0, payload.Length);
}
// no need for checks. just return body.
static RDJTPResponse HandleEcho(RDJTPRequest req)
{
var response = new RDJTPResponse()
{
Status = "1 OK", Body = req.Body
};
return(response);
}
static RDJTPResponse HandleRead(RDJTPRequest req, List <Category> categories)
{
var response = new RDJTPResponse();
var path = req.Path.Split("/");
// if only 3 elements exists in path, we have /api/categories
// if over, we have /api/categories/<id>
if (path.Length < 4)
{
response.Status = "1 Ok";
response.Body = JsonConvert.SerializeObject(categories);
return(response);
}
else
{
response.Status = "1 Ok";
int cid;
// path[3] is id - try to parse
if (!int.TryParse(path[3], out cid))
{
return(HandleException(RDJTPStatus.Bad_Request));
}
var element = categories.Find(x => x.cid == cid);
if (element == null)
{
return(HandleException(RDJTPStatus.Not_Found));
}
response.Body = JsonConvert.SerializeObject(element);
return(response);
}
}
static void Main(string[] args)
{
var port = 5000;
var ip = IPAddress.Parse("127.0.0.1");
var server = new TcpListener(ip, port);
server.Start();
Console.WriteLine("server started...");
// init - state
var cat1 = new Category()
{
cid = 1, name = "Beverages"
};
var cat2 = new Category()
{
cid = 2, name = "Condiments"
};
var cat3 = new Category()
{
cid = 3, name = "Confections"
};
var categories = new List <Category>()
{
cat1, cat2, cat3
};
var typesOfMethods = new List <string>()
{
"create", "update", "delete", "read", "echo"
};
while (true)
{
var client = server.AcceptTcpClient();
// create new task for each client
Task.Run(() =>
{
var expmsg = "";
Console.WriteLine("client connected!");
var strm = client.GetStream();
var buffer = new byte[client.ReceiveBufferSize];
var reqContent = strm.Read(buffer, 0, buffer.Length);
var request = Encoding.UTF8.GetString(buffer, 0, reqContent);
expmsg = CheckMissing(request);
// if expmsg is not null or empty, an exception occured.
if (!string.IsNullOrEmpty(expmsg))
{
Respond(strm, HandleException(RDJTPStatus.Bad_Request, expmsg));
strm.Close();
return;
}
// parsing request
var rdjtpReq = ParseRequest(request);
expmsg = CheckDate(rdjtpReq);
// if expmsg is not null or empty, an exception occured.
if (!string.IsNullOrEmpty(expmsg))
{
Respond(strm, HandleException(RDJTPStatus.Bad_Request, expmsg));
strm.Close();
return;
}
if (!CheckRequest(rdjtpReq))
{
var msg = CheckResource(rdjtpReq);
Respond(strm, HandleException(RDJTPStatus.Bad_Request, $"missing resource {msg}"));
strm.Close();
return;
}
if (!typesOfMethods.Contains(rdjtpReq.Method))
{
Respond(strm, HandleException(RDJTPStatus.Bad_Request, "illegal method"));
strm.Close();
return;
}
if (!CheckRoute(rdjtpReq))
{
var expresponse = HandleException(RDJTPStatus.Not_Found);
var path = rdjtpReq.Path.Split("/");
if (path.Length < 3)
{
expresponse = HandleException(RDJTPStatus.Bad_Request);
Respond(strm, expresponse);
strm.Close();
return;
}
if (path[1] != "api" || path[2] != "categories")
{
expresponse = HandleException(RDJTPStatus.Bad_Request);
Respond(strm, expresponse);
strm.Close();
return;
}
if (rdjtpReq.Body == null)
{
expresponse.Status += " missing body";
}
Respond(strm, expresponse);
strm.Close();
return;
}
// success up until now
var response = new RDJTPResponse();
switch (rdjtpReq.Method)
{
case "create":
response = HandleCreate(rdjtpReq, categories);
break;
case "update":
response = HandleUpdate(rdjtpReq, categories);
break;
case "delete":
response = HandleDelete(rdjtpReq, categories);
break;
case "echo":
response = HandleEcho(rdjtpReq);
break;
case "read":
response = HandleRead(rdjtpReq, categories);
break;
default:
response = HandleException(RDJTPStatus.Error);
break;
}
Respond(strm, response);
strm.Close();
});
}
}
