1 files changed, 62 insertions, 0 deletions
diff --git a/serialize/json-helper.hpp b/serialize/json-helper.hpp
new file mode 100644
index 00000000..af6fd211
--- /dev/null
+++ b/serialize/json-helper.hpp
@@ -0,0 +1,62 @@
+#pragma once
+#include <tuple>
+#include <fstream>
+#include <exception>
+#include <filesystem>
+#include <nlohmann/json.hpp>
+#include <Corrade/Utility/DebugStl.h>
+
+template<typename t>
+struct json_helper final {
+    [[nodiscard]] static std::tuple<t, bool> from_json(const std::filesystem::path& pathname) noexcept;
+    [[nodiscard]] static bool to_json(const t& self, const std::filesystem::path& pathname) noexcept;
+};
+
+template<typename t>
+std::tuple<t, bool> json_helper<t>::from_json(const std::filesystem::path& pathname) noexcept {
+    using namespace nlohmann;
+    using Corrade::Utility::Error;
+    std::ifstream s;
+    s.exceptions(s.exceptions() | std::ios::failbit | std::ios::badbit);
+    try {
+        s.open(pathname, std::ios_base::in);
+    } catch (const std::ios::failure& e) {
+        Error{Error::Flag::NoSpace} << "failed to open '" << pathname << "': " << e.what();
+        return { {}, false };
+    }
+    t ret;
+    try {
+        json j;
+        s >> j;
+        using nlohmann::from_json;
+        from_json(j, ret);
+    } catch (const std::exception& e) {
+        Error{Error::Flag::NoSpace} << "failed to parse '" << pathname << "': " << e.what();
+        return { {}, false };
+    }
+    return { std::move(ret), true };
+}
+
+template<typename t>
+bool json_helper<t>::to_json(const t& self, const std::filesystem::path& pathname) noexcept {
+    using Corrade::Utility::Error;
+    try {
+        nlohmann::json j(self);
+
+        std::ofstream s;
+        s.exceptions(s.exceptions() | std::ios::failbit | std::ios::badbit);
+        try {
+            s.open(pathname, std::ios_base::out | std::ios_base::trunc);
+        } catch (const std::ios::failure& e) {
+            Error{Error::Flag::NoSpace} << "failed to open '" << pathname << "' for writing: " << e.what();
+            return false;
+        }
+        s << j.dump(4);
+        s.flush();
+    } catch (const std::exception& e) {
+        Error{Error::Flag::NoSpace} << "failed writing to '" << pathname << "': " << e.what();
+        return false;
+    }
+
+    return true;
+}