feat(locale): load every locale in locale.xml on request

Locale::LoadFromFile can keep the other locales' phrases too, and
GetPhrase(id, locale) answers in one of them, falling back to the default.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dCommon/Locale.cpp

@@ -3,12 +3,20 @@
 #include "Logger.h"
 
 namespace {
-	std::unordered_map<std::string, std::string> g_Phrases;
+	std::unordered_map<std::string, std::string> g_Phrases; // the default locale's
+	// The other locales' phrases (only loaded with allLocales), by locale
+	std::unordered_map<std::string, std::unordered_map<std::string, std::string>> g_Others;
+	std::vector<std::string> g_Locales;
 	bool g_Loaded = false;
 	const std::string g_Empty;
 }
 
-void Locale::LoadFromFile(const std::string& filepath, const std::string& locale) {
+void Locale::LoadFromFile(const std::string& filepath, const std::string& locale, bool allLocales) {
+	g_Phrases.clear();
+	g_Others.clear();
+	g_Locales.clear();
+	g_Loaded = false;
+
 	tinyxml2::XMLDocument doc;
 	if (doc.LoadFile(filepath.c_str()) != tinyxml2::XML_SUCCESS) {
 		LOG("Failed to load locale file: %s", filepath.c_str());
@@ -18,6 +26,18 @@ void Locale::LoadFromFile(const std::string& filepath, const std::string& locale
 	auto* root = doc.FirstChildElement("localization");
 	if (!root) return;
 
+	g_Locales.push_back(locale);
+	if (allLocales) {
+		if (auto* locales = root->FirstChildElement("locales")) {
+			for (auto* entry = locales->FirstChildElement("locale"); entry; entry = entry->NextSiblingElement("locale")) {
+				const char* name = entry->GetText();
+				if (!name || locale == name || g_Others.contains(name)) continue;
+				g_Locales.push_back(name);
+				g_Others[name];
+			}
+		}
+	}
+
 	auto* phrases = root->FirstChildElement("phrases");
 	if (!phrases) return;
 
@@ -27,18 +47,20 @@ void Locale::LoadFromFile(const std::string& filepath, const std::string& locale
 
 		for (auto* trans = phrase->FirstChildElement("translation"); trans; trans = trans->NextSiblingElement("translation")) {
 			const char* loc = trans->Attribute("locale");
-			if (loc && locale == loc) {
+			const char* text = trans->GetText();
-				const char* text = trans->GetText();
+			if (!loc || !text) continue;
-				if (text) {
+			if (locale == loc) {
-					g_Phrases[id] = text;
+				g_Phrases[id] = text;
-				}
+				if (!allLocales) break;
-				break;
+			} else if (allLocales) {
+				const auto other = g_Others.find(loc);
+				if (other != g_Others.end()) other->second[id] = text;
 			}
 		}
 	}
 
 	g_Loaded = true;
-	LOG("Loaded %zu locale phrases from %s (locale: %s)", g_Phrases.size(), filepath.c_str(), locale.c_str());
+	LOG("Loaded %zu locale phrases from %s (locale: %s, %zu other locale(s))", g_Phrases.size(), filepath.c_str(), locale.c_str(), g_Others.size());
 }
 
 const std::string& Locale::GetPhrase(const std::string& phraseId) {
@@ -47,6 +69,17 @@ const std::string& Locale::GetPhrase(const std::string& phraseId) {
 	return g_Empty;
 }
 
+const std::string& Locale::GetPhrase(const std::string& phraseId, const std::string& locale) {
+	if (const auto other = g_Others.find(locale); other != g_Others.end()) {
+		if (const auto it = other->second.find(phraseId); it != other->second.end()) return it->second;
+	}
+	return GetPhrase(phraseId);
+}
+
+const std::vector<std::string>& Locale::GetLocales() {
+	return g_Locales;
+}
+
 bool Locale::IsLoaded() {
 	return g_Loaded;
 }

dCommon/Locale.h

@@ -5,8 +5,17 @@
 #include <vector>
 
 namespace Locale {
-	void LoadFromFile(const std::string& filepath, const std::string& locale = "en_US");
+	/**
+	 * Load the client's locale.xml: the phrases of `locale` (the default, which GetPhrase(id) answers from) and, with
+	 * `allLocales`, those of every other locale the file lists too. Replaces what an earlier load read. Call before
+	 * other threads read phrases; lookups only read afterwards.
+	 */
+	void LoadFromFile(const std::string& filepath, const std::string& locale = "en_US", bool allLocales = false);
 	const std::string& GetPhrase(const std::string& phraseId);
+	// The phrase in `locale`, else in the default locale; empty when neither has it
+	const std::string& GetPhrase(const std::string& phraseId, const std::string& locale);
+	// The locales loaded ("en_US", "de_DE", ...), the default first; empty before a load
+	const std::vector<std::string>& GetLocales();
 	bool IsLoaded();
 	std::vector<std::string> GetPhraseIdsWithPrefix(const std::string& prefix);
 };