Add Visione backend foundation

common/Http.cc

@@ -0,0 +1,35 @@
+#include "common/Http.h"
+
+namespace visione::http
+{
+drogon::HttpResponsePtr json(Json::Value body, drogon::HttpStatusCode status)
+{
+    auto response = drogon::HttpResponse::newHttpJsonResponse(std::move(body));
+    response->setStatusCode(status);
+    return response;
+}
+
+drogon::HttpResponsePtr error(const std::string &code,
+                              drogon::HttpStatusCode status,
+                              const std::string &message)
+{
+    Json::Value body;
+    body["error"] = code;
+    if (!message.empty())
+    {
+        body["message"] = message;
+    }
+    return json(std::move(body), status);
+}
+
+Json::Value requireJson(const drogon::HttpRequestPtr &request)
+{
+    const auto &body = request->getJsonObject();
+    if (!body)
+    {
+        return Json::Value(Json::nullValue);
+    }
+    return *body;
+}
+}  // namespace visione::http
+