Convert runtime-loaded l10n to string literals chosen at compile time

4 files changed, 12 insertions, 393 deletions

diff --git a/core/src/Utils/I18n.cpp b/core/src/Utils/I18n.cpp
deleted file mode 100644
index e5131cc..0000000
--- a/core/src/Utils/I18n.cpp
+++ /dev/null
@@ -1,300 +0,0 @@
-#include "I18n.hpp"
-
-#include <json/reader.h>
-#include <json/value.h>
-#include <tsl/array_map.h>
-#include <filesystem>
-#include <fstream>
-#include <stdexcept>
-#include <string_view>
-#include <utility>
-
-namespace fs = std::filesystem;
-using namespace std::literals::string_view_literals;
-
-namespace {
-
-struct LanguageInfo
-{
-	std::string CodeName;
-	std::string LocaleName;
-	fs::path File;
-};
-
-class I18nState
-{
-public:
-	static I18nState& Get()
-	{
-		static I18nState instance;
-		return instance;
-	}
-
-public:
-	tsl::array_map<char, LanguageInfo> LocaleInfos;
-	tsl::array_map<char, std::string> CurrentEntries;
-	LanguageInfo* CurrentLanguage = nullptr;
-	bool Unloaded = false;
-
-	void Unload()
-	{
-		Unloaded = true;
-		CurrentEntries = {};
-	}
-
-	void EnsureLoaded()
-	{
-		if (Unloaded) {
-			Unloaded = false;
-			Reload();
-		}
-	}
-
-	void Reload()
-	{
-		if (!CurrentLanguage) return;
-
-		std::ifstream ifs(CurrentLanguage->File);
-		Json::Value root;
-		ifs >> root;
-
-		for (auto name : root.getMemberNames()) {
-			if (name == "$localized_name") {
-				continue;
-			}
-
-			auto& value = root[name];
-			if (value.isString()) {
-				CurrentEntries.insert(name, value.asCString());
-			}
-		}
-	}
-};
-
-std::string FindLocalizedName(const fs::path& localeFile)
-{
-	std::ifstream ifs(localeFile);
-	if (!ifs) {
-		throw std::runtime_error("Failed to open locale file.");
-	}
-
-	Json::Value root;
-	ifs >> root;
-	if (auto& name = root["$localized_name"]; name.isString()) {
-		return std::string(name.asCString());
-	} else {
-		throw std::runtime_error("Failed to find $localized_name in language file.");
-	}
-}
-
-} // namespace
-
-void I18n::Init()
-{
-	auto& state = I18nState::Get();
-
-	auto dir = fs::current_path() / "locale";
-	if (!fs::exists(dir)) {
-		throw std::runtime_error("Failed to find locale directory.");
-	}
-
-	for (auto& elm : fs::directory_iterator{ dir }) {
-		if (!elm.is_regular_file()) continue;
-
-		auto& path = elm.path();
-		auto codeName = path.stem().string();
-
-		state.LocaleInfos.emplace(
-			codeName,
-			LanguageInfo{
-				.CodeName = codeName,
-				.LocaleName = FindLocalizedName(path),
-				.File = path,
-			});
-	}
-}
-
-void I18n::Shutdown()
-{
-	auto& state = I18nState::Get();
-	state.LocaleInfos.clear();
-	state.CurrentEntries.clear();
-	state.CurrentLanguage = nullptr;
-	state.Unloaded = false;
-}
-
-void I18n::Unload()
-{
-	auto& state = I18nState::Get();
-	state.Unload();
-	OnUnload();
-}
-
-std::string_view I18n::GetLanguage()
-{
-	auto& state = I18nState::Get();
-	return state.CurrentLanguage->CodeName;
-}
-
-bool I18n::SetLanguage(std::string_view lang)
-{
-	auto& state = I18nState::Get();
-	if (state.CurrentLanguage &&
-		state.CurrentLanguage->CodeName == lang)
-	{
-		return false;
-	}
-
-	if (auto iter = state.LocaleInfos.find(lang); iter != state.LocaleInfos.end()) {
-		state.CurrentLanguage = &iter.value();
-		state.Reload();
-	}
-
-	OnLanguageChange();
-	return true;
-}
-
-std::optional<std::string_view> I18n::Lookup(std::string_view key)
-{
-	auto& state = I18nState::Get();
-	state.EnsureLoaded();
-
-	auto iter = state.CurrentEntries.find(key);
-	if (iter != state.CurrentEntries.end()) {
-		return iter.value();
-	} else {
-		return std::nullopt;
-	}
-}
-
-std::string_view I18n::LookupUnwrap(std::string_view key)
-{
-	auto o = Lookup(key);
-	if (!o) {
-		std::string msg;
-		msg.append("Unable to find locale for '");
-		msg.append(key);
-		msg.append("'.");
-		throw std::runtime_error(std::move(msg));
-	};
-	return o.value();
-}
-
-std::string_view I18n::LookupLanguage(std::string_view lang)
-{
-	auto& state = I18nState::Get();
-	auto iter = state.LocaleInfos.find(lang);
-	if (iter != state.LocaleInfos.end()) {
-		return iter.value().LocaleName;
-	} else {
-		return ""sv;
-	}
-}
-
-BasicTranslation::BasicTranslation(std::string_view key)
-	: mContent{ I18n::LookupUnwrap(key) }
-{
-}
-
-const std::string& BasicTranslation::GetString() const
-{
-	return mContent;
-}
-
-const char* BasicTranslation::Get() const
-{
-	return mContent.c_str();
-}
-
-FormattedTranslation::FormattedTranslation(std::string_view key)
-{
-	auto src = I18n::LookupUnwrap(key);
-
-	mMinimumResultLen = 0;
-
-	bool escape = false;
-	bool matchingCloseBrace = false;
-	std::string buf;
-	for (char c : src) {
-		switch (c) {
-			case '\\': {
-				// Disallow double (or more) escaping
-				if (escape) {
-					buf += '\\';
-					escape = false;
-					break;
-				}
-
-				escape = true;
-			} break;
-
-			case '{': {
-				// Escaping an opening brace cause the whole "argument" (if any) gets parsed as a part of the previous literal
-				if (escape) {
-					buf += '{';
-					escape = false;
-					break;
-				}
-
-				// Generate literal
-				mMinimumResultLen += buf.size();
-				mParsedElements.push_back(Element{ std::move(buf) }); // Should also clear buf
-
-				matchingCloseBrace = true;
-			} break;
-			case '}': {
-				if (escape) {
-					throw std::runtime_error("Cannot escape '}', put \\ before the '{' if intended to escape braces.");
-				}
-
-				// If there is no pairing '{', simply treat this as a normal character
-				// (escaping for closing braces)
-				if (!matchingCloseBrace) {
-					buf += '}';
-					break;
-				}
-
-				// Generate argument
-				if (buf.empty()) {
-					// No index given, default to use current argument's index
-					auto currArgIdx = (int)mNumArguments;
-					mParsedElements.push_back(Element{ currArgIdx });
-				} else {
-					// Use provided index
-					int argIdx = std::stoi(buf);
-					mParsedElements.push_back(Element{ argIdx });
-					buf.clear();
-				}
-			} break;
-
-			default: {
-				if (escape) {
-					throw std::runtime_error("Cannot escape normal character '" + std::to_string(c) + "'.");
-				}
-
-				buf += c;
-			} break;
-		}
-	}
-}
-
-std::string FormattedTranslation::Format(std::span<Argument> args)
-{
-	if (args.size() != mNumArguments) {
-		throw std::runtime_error("Invalid number of arguments for FormattedTranslation::Format, expected " + std::to_string(mNumArguments) + " but found " + std::to_string(args.size()) + ".");
-	}
-
-	std::string result;
-	result.reserve(mMinimumResultLen);
-
-	for (auto& elm : mParsedElements) {
-		if (auto literal = std::get_if<std::string>(&elm)) {
-			result.append(*literal);
-		}
-		if (auto idx = std::get_if<int>(&elm)) {
-			result.append(args[*idx]);
-		}
-	}
-
-	return result;
-}
diff --git a/core/src/Utils/I18n.hpp b/core/src/Utils/I18n.hpp
index 6285d60..e9eaac9 100644
--- a/core/src/Utils/I18n.hpp
+++ b/core/src/Utils/I18n.hpp
@@ -1,87 +1,10 @@
 #pragma once
 
-#include "Utils/Sigslot.hpp"
-#include "Utils/fwd.hpp"
+#include "Utils/Macros.hpp"
 
-#include <cstddef>
-#include <optional>
-#include <span>
-#include <string>
-#include <string_view>
-#include <variant>
-#include <vector>
-
-class I18n
-{
-public:
-	static inline Signal<> OnLanguageChange{};
-	static inline Signal<> OnUnload{};
-
-	static void Init();
-	static void Shutdown();
-
-	/// Discard in-memory mapping from key to locale entries.
-	/// When any of the entry accessors are invoked, unloaded entries will be reloaded.
-	static void Unload();
-
-	static std::string_view GetLanguage();
-	static bool SetLanguage(std::string_view lang);
-
-	/* Entry accessors */
-	/// Find the localized entry with the given key, return \c std::nullopt if does not exist. Reloads locale entries if they are currently unloaded.
-	static std::optional<std::string_view> Lookup(std::string_view key);
-	/// Find the localized entry with the given key, throw an exception if does not exist. EnsureLoaded locale entries if they are currently unloaded.
-	static std::string_view LookupUnwrap(std::string_view key);
-
-	/// Query the localized name of a locale, e.g. "en_US" -> "English - United States".
-	/// If the queried locale does not exist, an empty string will be returned (existing locales can never have an empty localized name).
-	static std::string_view LookupLanguage(std::string_view lang);
-};
-
-struct StringArgument
-{
-	std::string Value;
-};
-
-struct IntArgument
-{
-	int Value;
-};
-
-struct FloatArgument
-{
-	double Value;
-};
-
-class BasicTranslation
-{
-private:
-	std::string mContent;
-
-public:
-	BasicTranslation(std::string_view key);
-	const std::string& GetString() const;
-	const char* Get() const;
-};
-
-class FormattedTranslation
-{
-public:
-	using Element = std::variant<std::string, int>;
-	using Argument = std::string;
-
-private:
-	std::vector<Element> mParsedElements;
-	size_t mNumArguments;
-	size_t mMinimumResultLen;
-
-public:
-	FormattedTranslation(std::string_view key);
-	std::string Format(std::span<Argument> args);
-};
-
-class NumericTranslation
-{
-public:
-	// TODO
-};
+#if !defined(TARGET_LOCALE)
+#	define I18N_TEXT(defaultText, name) defaultText
+#else
+#	include TARGET_LOCALE_FILE
+#	define I18N_TEXT(defaultText, name) name
+#endif
diff --git a/core/src/Utils/Macros.hpp b/core/src/Utils/Macros.hpp
index 68b93fb..6958ed1 100644
--- a/core/src/Utils/Macros.hpp
+++ b/core/src/Utils/Macros.hpp
@@ -1,7 +1,12 @@
 #pragma once
 
+#define STRINGIFY_IMPL(text) #text
+#define STRINGIFY(text) STRINGIFY_IMPL(text)
+
 #define CONCAT_IMPL(a, b) a##b
 #define CONCAT(a, b) CONCAT_IMPL(a, b)
+#define CONCAT_3(a, b, c) CONCAT(a, CONCAT(b, c))
+#define CONCAT_4(a, b, c, d) CONCAT(CONCAT(a, b), CONCAT(c, d))
 
 #define UNIQUE_NAME(prefix) CONCAT(prefix, __COUNTER__)
 #define UNIQUE_NAME_LINE(prefix) CONCAT(prefix, __LINE__)
diff --git a/core/src/Utils/fwd.hpp b/core/src/Utils/fwd.hpp
index 74e642d..5d1fe45 100644
--- a/core/src/Utils/fwd.hpp
+++ b/core/src/Utils/fwd.hpp
@@ -4,15 +4,6 @@
 class RgbaColor;
 class HsvColor;
 
-// I18n.hpp
-class I18n;
-struct StringArgument;
-struct IntArgument;
-struct FloatArgument;
-class BasicTranslation;
-class FormattedTranslation;
-class NumericTranslation;
-
 // Sigslot.hpp
 class SignalStub;
 template <class... TArgs>