improve translation key guessing

We still don't recover many/most of the keys, but we at least get some in
most projects that I've tested this with, which will enable people
to search through the project and add the rest

utility/import_exporter.cpp

@@ -433,6 +433,42 @@ Error ImportExporter::recreate_plugin_configs(const String &output_dir) {
 	return OK;
 }
 
+#define TEST_TR_KEY(key)                          \
+	test = default_translation->get_message(key); \
+	if (test == s) {                              \
+		return key;                               \
+	}                                             \
+	key = key.to_upper();                         \
+	test = default_translation->get_message(key); \
+	if (test == s) {                              \
+		return key;                               \
+	}                                             \
+	key = key.to_lower();                         \
+	test = default_translation->get_message(key); \
+	if (test == s) {                              \
+		return key;                               \
+	}
+
+String guess_key_from_tr(String s, Ref<Translation> default_translation) {
+	static const Vector<String> prefixes = { "$$", "##", "TR_", "KEY_TEXT_" };
+	String key = s;
+	String test;
+	TEST_TR_KEY(key);
+	String str = s;
+	//remove punctuation
+	str = str.replace("\n", "").replace(".", "").replace("…", "").replace("!", "").replace("?", "");
+	str = str.strip_escapes().strip_edges().replace(" ", "_");
+	key = str;
+	TEST_TR_KEY(key);
+	// Try adding prefixes
+	for (String prefix : prefixes) {
+		key = prefix + str;
+		TEST_TR_KEY(key);
+	}
+	// failed
+	return "";
+}
+
 Error ImportExporter::export_translation(const String &output_dir, Ref<ImportInfo> &iinfo) {
 	Error err;
 	ResourceFormatLoaderCompat rlc;
@@ -490,42 +526,16 @@ Error ImportExporter::export_translation(const String &output_dir, Ref<ImportInf
 		translations.push_back(tr);
 	}
 	// We can't recover the keys from Optimized translations, we have to guess
-	Vector<String> prefixes = { "$$", "##", "TR_" };
 	int missing_keys = 0;
 	if (keys.size() == 0) {
 		for (const StringName &s : default_messages) {
-			String key = s;
-			String test = default_translation->get_message(key);
-			if (test == s) {
-				keys.push_back(key);
-				continue;
-			}
-			// Try adding "$$", "##", or "TR_"
-			for (String prefix : prefixes) {
-				key = prefix + s;
-				test = default_translation->get_message(key);
-				if (test == s) {
-					break;
-				}
-			}
-			if (test == s) {
-				keys.push_back(key);
-				continue;
-			}
-			// this is another common format for popular translation exporters
-			String str = s;
-			//remove punctuation
-			str = str.replace("\n", "").replace(".", "").replace("…", "").replace("!", "").replace("?", "").replace("-", "");
-			str = str.strip_escapes().strip_edges().replace(" ", "_");
-			key = "KEY_TEXT_" + str.to_upper();
-			test = default_translation->get_message(key);
-			if (test == s) {
+			String key = guess_key_from_tr(s, default_translation);
+			if (key.is_empty()) {
+				missing_keys++;
+				keys.push_back("<MISSING KEY " + s + ">");
+			} else {
 				keys.push_back(key);
-				continue;
 			}
-			// if we've hit here, we didn't find the key
-			missing_keys++;
-			keys.push_back("<MISSING KEY " + s + ">");
 		}
 	}
 	header += "\n";