add get nssai

src/impl/SliceSelectionSubscriptionDataRetrievalApiImpl.cpp

@@ -31,7 +31,43 @@ void SliceSelectionSubscriptionDataRetrievalApiImpl::get_nssai(
     const Pistache::Optional<Pistache::Http::Header::Raw> &ifNoneMatch,
     const Pistache::Optional<Pistache::Http::Header::Raw> &ifModifiedSince,
     Pistache::Http::ResponseWriter &response) {
-  response.send(Pistache::Http::Code::Ok, "Do some magic\n");
+   // 1. populate remote uri for udp request
+    std::string udr_ip = std::string(inet_ntoa(*((struct in_addr *)&udm_cfg.nudr.addr4)));
+    std::string udr_port = std::to_string(udm_cfg.nudr.port);
+    //std::string remote_uri = udr_ip + ":" + udr_port + "/nudr-dr/v2/subscription-data/"+supi+plmnId+"/provisioned-data/am-data";
+    std::string remote_uri = udr_ip + ":" + udr_port + "/nudr-dr/v2/subscription-data/"+supi+"/456789/provisioned-data/sm-data";
+
+    std::string method("GET");
+    std::string body("");
+    std::string response_get;
+    Logger::udm_sdm().debug("UDR: GET Request: "+ remote_uri);
+    // 2. invoke curl to get response from udr
+    long http_code = Curl::curl_http_client(remote_uri, method, body, response_get);
+    // 3. process response
+    nlohmann::json response_data_json = {};
+    nlohmann::json return_response_data_json = {};
+    try {
+            Logger::udm_sdm().debug("subscription-data: GET Response: "+response_get);
+            
+            response_data_json = nlohmann::json::parse(response_get.c_str());
+            // TODO: 1. shall check if "singleNassai" is existing or not, if not, raise exception
+            // TODO: 2. return_response_data_json: need to check if here is required to allocate memory first. Or check json code to confirm, otherwise codedump might happen
+            return_response_data_json["singleNssai"] = response_data_json["singleNssai"]
+        } catch (nlohmann::json::exception &e) {
+                 Logger::udm_sdm().info("Could not get json content from UDR response");
+                 ProblemDetails problem_details;
+                 nlohmann::json json_problem_details;
+                 problem_details.setCause("USER_NOT_FOUND");
+                 problem_details.setStatus(404);
+                 problem_details.setDetail("User " + supi + " not found in Database");                 
+                 to_json(json_problem_details, problem_details);
+                 Logger::udm_sdm().error("User " + supi + " not found in Database");
+                 Logger::udm_sdm().info("Send 404 Not_Found response to client");
+                 response.send(Pistache::Http::Code::Not_Found, json_problem_details.dump());
+                 return;
+          }
+    Logger::udm_sdm().debug("http reponse code %d.\n",http_code);
+    response.send(static_cast<Pistache::Http::Code>(http_code), return_response_data_json.dump());
 }
 
 } // namespace api