RESTful API Server

 // Copyright (C) 2022 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

 #include "apibehavior.h"
 #include "types.h"
 #include "utils.h"
 #include <QtCore/QCoreApplication>
 #include <QtHttpServer/QHttpServer>

 #define SCHEME "http"
 #define HOST "127.0.0.1"
 #define PORT 49425

 template<typename T>
 void addCrudRoutes(QHttpServer &httpServer, const QString &apiPath, CrudApi<T> &api,
                    const SessionApi &sessionApi)
 {
     httpServer.route(
             QString("%1").arg(apiPath), QHttpServerRequest::Method::Get,
             [&api](const QHttpServerRequest &request) { return api.getPaginatedList(request); });

     httpServer.route(QString("%1/<arg>").arg(apiPath), QHttpServerRequest::Method::Get,
                      [&api](qint64 itemId) { return api.getItem(itemId); });

     httpServer.route(QString("%1").arg(apiPath), QHttpServerRequest::Method::Post,
                      [&api, &sessionApi](const QHttpServerRequest &request) {
                          if (!sessionApi.authorize(request)) {
                              return QHttpServerResponse(
                                      QHttpServerResponder::StatusCode::Unauthorized);
                          }
                          return api.postItem(request);
                      });

     httpServer.route(QString("%1/<arg>").arg(apiPath), QHttpServerRequest::Method::Put,
                      [&api, &sessionApi](qint64 itemId, const QHttpServerRequest &request) {
                          if (!sessionApi.authorize(request)) {
                              return QHttpServerResponse(
                                      QHttpServerResponder::StatusCode::Unauthorized);
                          }
                          return api.updateItem(itemId, request);
                      });

     httpServer.route(QString("%1/<arg>").arg(apiPath), QHttpServerRequest::Method::Patch,
                      [&api, &sessionApi](qint64 itemId, const QHttpServerRequest &request) {
                          if (!sessionApi.authorize(request)) {
                              return QHttpServerResponse(
                                      QHttpServerResponder::StatusCode::Unauthorized);
                          }
                          return api.updateItemFields(itemId, request);
                      });

     httpServer.route(QString("%1/<arg>").arg(apiPath), QHttpServerRequest::Method::Delete,
                      [&api, &sessionApi](qint64 itemId, const QHttpServerRequest &request) {
                          if (!sessionApi.authorize(request)) {
                              return QHttpServerResponse(
                                      QHttpServerResponder::StatusCode::Unauthorized);
                          }
                          return api.deleteItem(itemId);
                      });
 }

 int main(int argc, char *argv[])
 {
     QCoreApplication app(argc, argv);

     QCommandLineParser parser;
     parser.addOptions({
             { "port", QCoreApplication::translate("main", "The port the server listens on."),
               "port" },
     });
     parser.addHelpOption();
     parser.process(app);

     quint16 portArg = PORT;
     if (!parser.value("port").isEmpty())
         portArg = parser.value("port").toUShort();

     auto colorFactory = std::make_unique<ColorFactory>();
     auto colors = tryLoadFromFile<Color>(*colorFactory, ":/assets/colors.json");
     CrudApi<Color> colorsApi(std::move(colors), std::move(colorFactory));

     auto userFactory = std::make_unique<UserFactory>(SCHEME, HOST, portArg);
     auto users = tryLoadFromFile<User>(*userFactory, ":/assets/users.json");
     CrudApi<User> usersApi(std::move(users), std::move(userFactory));

     auto sessionEntryFactory = std::make_unique<SessionEntryFactory>();
     auto sessions = tryLoadFromFile<SessionEntry>(*sessionEntryFactory, ":/assets/sessions.json");
     SessionApi sessionApi(std::move(sessions), std::move(sessionEntryFactory));

     // Setup QHttpServer
     QHttpServer httpServer;
     httpServer.route("/", []() {
         return "Qt Colorpalette example server. Please see documentation for API description";
     });

     addCrudRoutes(httpServer, "/api/unknown", colorsApi, sessionApi);
     addCrudRoutes(httpServer, "/api/users", usersApi, sessionApi);

     // Login resource
     httpServer.route(
             "/api/login", QHttpServerRequest::Method::Post,
             [&sessionApi](const QHttpServerRequest &request) { return sessionApi.login(request); });

     httpServer.route("/api/register", QHttpServerRequest::Method::Post,
                      [&sessionApi](const QHttpServerRequest &request) {
                          return sessionApi.registerSession(request);
                      });

     httpServer.route("/api/logout", QHttpServerRequest::Method::Post,
                      [&sessionApi](const QHttpServerRequest &request) {
                          return sessionApi.logout(request);
                      });

     // Images resource
     httpServer.route("/img/faces/<arg>-image.jpg", QHttpServerRequest::Method::Get,
                      [](qint64 imageId, const QHttpServerRequest &) {
                          return QHttpServerResponse::fromFile(
                                  QString(":/assets/img/%1-image.jpg").arg(imageId));
                      });

     const auto port = httpServer.listen(QHostAddress::Any, portArg);
     if (!port) {
         qDebug() << QCoreApplication::translate("QHttpServerExample",
                                                 "Server failed to listen on a port.");
         return 0;
     }

     qDebug() << QCoreApplication::translate(
                         "QHttpServerExample",
                         "Running on http://127.0.0.1:%1/ (Press CTRL+C to quit)")
                         .arg(port);

     return app.exec();
 }