add src/ikarus subdir and make names unique for objects per scope

Signed-off-by: Folling <mail@folling.io>

src/ikarus/values/value.hpp

@@ -0,0 +1,76 @@
+#pragma once
+
+#include <boost/json.hpp>
+#include <boost/variant2.hpp>
+
+#include <cppbase/result.hpp>
+
+#include <ikarus/errors.hpp>
+#include <ikarus/persistence/project.hpp>
+
+struct IkarusValue {
+public:
+    using Data = boost::variant2::variant<struct IkarusToggleValue *, struct IkarusNumberValue *, struct IkarusTextValue *>;
+    constexpr static auto SMALL_VEC_VALUE_SIZE = 8;
+
+public:
+    explicit IkarusValue(Data data);
+
+    IkarusValue(IkarusValue const &) = default;
+    IkarusValue(IkarusValue &&) noexcept = default;
+
+    IkarusValue & operator=(IkarusValue const &) = default;
+    IkarusValue & operator=(IkarusValue &&) noexcept = default;
+
+    virtual ~IkarusValue() = default;
+
+public:
+    struct FromJsonError {};
+
+    [[nodiscard]] static cppbase::Result<IkarusValue *, FromJsonError> from_json(boost::json::value json);
+    [[nodiscard]] boost::json::value to_json() const;
+
+public:
+    Data data;
+};
+
+template<>
+struct fmt::formatter<IkarusValue::FromJsonError> {
+    template<typename FormatParseContext>
+    constexpr static auto parse(FormatParseContext & ctx) {
+        return ctx.end();
+    }
+
+    constexpr static auto format([[maybe_unused]] IkarusValue::FromJsonError const & error, fmt::format_context & ctx) {
+        return fmt::format_to(ctx.out(), "unable to parse ikarus value JSON");
+    }
+};
+
+template<typename... Args>
+IkarusValue * fetch_value_from_db(IkarusProject * project, IkarusErrorData * error_out, std::string_view query, Args &&... args) {
+    IKARUS_VTRYRV_OR_FAIL(
+        auto const value_str,
+        nullptr,
+        "unable to fetch entity property value from database: {}",
+        IkarusErrorInfo_Database_QueryFailed,
+        project->db->query_one<std::string>(query, std::forward<Args>(args)...)
+    );
+
+    boost::json::error_code ec{};
+    boost::json::value json_value = boost::json::parse(value_str, ec);
+
+    if (ec) {
+        IKARUS_SET_ERROR(fmt::format("invalid json is stored in database: {}", ec.message()), IkarusErrorInfo_Database_InvalidState);
+        return nullptr;
+    }
+
+    IKARUS_VTRYRV_OR_FAIL(
+        auto const ret,
+        nullptr,
+        "unable to fetch entity property value: {}",
+        IkarusErrorInfo_LibIkarus_CannotPerformOperation,
+        IkarusValue::from_json(std::move(json_value))
+    );
+
+    return ret;
+}