working data store

include/data.hpp

@@ -0,0 +1,14 @@
+#pragma once
+#include <experimental/filesystem>
+#include <json.hpp>
+
+namespace fs = std::experimental::filesystem;
+
+class data : public json {
+  fs::path &get_data_path();
+  void create_data_directory();
+  fs::path get_store_path();
+
+public:
+  data();
+};

include/store.hpp

@@ -1,9 +1,11 @@
 #pragma once
+#include <data.hpp>
 #include <json.hpp>
 #include <web_server.hpp>
 
 class Application {
   HttpServer http_server;
+  data dat;
 
   static void web_server_started(std::size_t port);
   static void secure_web_server_started(std::size_t port);

src/data.cpp

@@ -0,0 +1,43 @@
+#include <data.hpp>
+#include <fstream>
+#include <iostream>
+#include <unistd.h>
+
+fs::path &data::get_data_path() {
+  static fs::path p("");
+  if (p.native().length() != 0) {
+    return p;
+  }
+  const int uid = getuid();
+  if (uid == 0) {
+    p = fs::path("/") / "var" / "lib" / "store";
+  } else if (const auto ptr = std::getenv("HOME")) {
+    p = fs::path(ptr) / ".local" / "lib" / "store";
+  }
+  return p;
+}
+
+data::data() : json(json::object()) {
+  if (!fs::exists(get_data_path())) {
+    create_data_directory();
+  }
+  const auto data_file = get_store_path();
+  if (!fs::exists(data_file)) {
+    try {
+      std::ofstream f(data_file);
+      f << json::object();
+    } catch (const std::exception &e) {
+      std::cerr << "Could not create config file:\n" << e.what() << std::endl;
+    }
+  }
+}
+
+void data::create_data_directory() {
+  std::error_code ec;
+  fs::create_directories(get_data_path(), ec);
+  if (ec) {
+    std::cerr << "Unable to create configuration directory:\n" << ec.message();
+  }
+}
+
+fs::path data::get_store_path() { return get_data_path() / "store.json"; }