feat(api): add auth HTTP controller with tests

backend/src/controllers/auth_controller.cc

@@ -0,0 +1,75 @@
+#include "csp/controllers/auth_controller.h"
+
+#include "csp/app_state.h"
+#include "csp/services/auth_service.h"
+
+#include <drogon/HttpResponse.h>
+
+namespace csp::controllers {
+
+namespace {
+
+drogon::HttpResponsePtr JsonError(drogon::HttpStatusCode code,
+                                 const std::string& msg) {
+  Json::Value j;
+  j["ok"] = false;
+  j["error"] = msg;
+  auto resp = drogon::HttpResponse::newHttpJsonResponse(j);
+  resp->setStatusCode(code);
+  return resp;
+}
+
+drogon::HttpResponsePtr JsonOk(const services::AuthResult& r) {
+  Json::Value j;
+  j["ok"] = true;
+  j["user_id"] = r.user_id;
+  j["token"] = r.token;
+  j["expires_at"] = Json::Int64(r.expires_at);
+  auto resp = drogon::HttpResponse::newHttpJsonResponse(j);
+  resp->setStatusCode(drogon::k200OK);
+  return resp;
+}
+
+std::pair<std::string, std::string> ParseUsernamePassword(
+    const drogon::HttpRequestPtr& req) {
+  const auto json = req->getJsonObject();
+  if (!json) throw std::runtime_error("body must be json");
+
+  const auto username = (*json).get("username", "").asString();
+  const auto password = (*json).get("password", "").asString();
+
+  if (username.empty() || password.empty()) {
+    throw std::runtime_error("username/password required");
+  }
+  return {username, password};
+}
+
+}  // namespace
+
+void AuthController::registerUser(
+    const drogon::HttpRequestPtr& req,
+    std::function<void(const drogon::HttpResponsePtr&)>&& cb) {
+  try {
+    const auto [username, password] = ParseUsernamePassword(req);
+    services::AuthService auth(AppState::Instance().db());
+    const auto r = auth.Register(username, password);
+    cb(JsonOk(r));
+  } catch (const std::exception& e) {
+    cb(JsonError(drogon::k400BadRequest, e.what()));
+  }
+}
+
+void AuthController::login(
+    const drogon::HttpRequestPtr& req,
+    std::function<void(const drogon::HttpResponsePtr&)>&& cb) {
+  try {
+    const auto [username, password] = ParseUsernamePassword(req);
+    services::AuthService auth(AppState::Instance().db());
+    const auto r = auth.Login(username, password);
+    cb(JsonOk(r));
+  } catch (const std::exception& e) {
+    cb(JsonError(drogon::k400BadRequest, e.what()));
+  }
+}
+
+}  // namespace csp::controllers