From 34854d87f4f18fb1d4e6874104f2e3f834df0cc8 Mon Sep 17 00:00:00 2001
From: Tuan Nghia Nguyen <nghia.nguyen@anscenter.com>
Date: Wed, 8 Apr 2026 15:22:48 +1000
Subject: [PATCH] Fix Uncode server API

---
 modules/ANSUtilities/ANSUtilities.cpp | 43 ++++++++++++++++++++++-----
 1 file changed, 36 insertions(+), 7 deletions(-)

diff --git a/modules/ANSUtilities/ANSUtilities.cpp b/modules/ANSUtilities/ANSUtilities.cpp
index 74f4c57..9529969 100644
--- a/modules/ANSUtilities/ANSUtilities.cpp
+++ b/modules/ANSUtilities/ANSUtilities.cpp
@@ -18,6 +18,15 @@ std::timed_mutex timeImageMutex;
 
 namespace ANSCENTER
 {
+    // Helper: detect if a std::string is actually UTF-16LE (e.g. from LabVIEW).
+    // Heuristic: length >= 4, even, and first printable ASCII char is followed by 0x00.
+    static bool IsLikelyUTF16LE(const std::string& str) {
+        if (str.size() < 4 || (str.size() % 2 != 0)) return false;
+        unsigned char b0 = static_cast<unsigned char>(str[0]);
+        unsigned char b1 = static_cast<unsigned char>(str[1]);
+        return (b0 >= 0x20 && b0 <= 0x7E && b1 == 0x00);
+    }
+
     static void VerifyGlobalANSUltilityLicense(const std::string& licenseKey) {
         try {
             static const std::vector<std::pair<int, std::string>> licenseChecks = {
@@ -1148,9 +1157,9 @@ namespace ANSCENTER
         for (int i = offset; i + 1 < endPos; i += 2) {
             uint16_t codepoint = static_cast<unsigned char>(utf16leBytes[i])
                                | (static_cast<unsigned char>(utf16leBytes[i + 1]) << 8);
-            // Pass through printable ASCII including space (0x20-0x7E)
-            // Escape control characters and non-ASCII as \uXXXX
-            if (codepoint >= 0x20 && codepoint <= 0x7E) {
+            // Pass through printable ASCII (0x20-0x7E) and common whitespace (tab, LF, CR)
+            // Escape other control characters and non-ASCII as \uXXXX
+            if ((codepoint >= 0x20 && codepoint <= 0x7E) || codepoint == 0x09 || codepoint == 0x0A || codepoint == 0x0D) {
                 result += static_cast<char>(codepoint);
             } else {
                 char buf[7];
@@ -1163,17 +1172,22 @@ namespace ANSCENTER
 
     std::string ANSUtilities::ConvertUTF8ToUnicodeEscapes(const std::string& utf8Str) {
         if (utf8Str.empty()) return "";
+        // Auto-detect UTF-16LE input (LabVIEW may pass UTF-16LE strings)
+        if (IsLikelyUTF16LE(utf8Str)) {
+            std::string asUtf8 = ConvertUTF16LEToUTF8(utf8Str.data(), static_cast<int>(utf8Str.size()));
+            return ConvertUTF8ToUnicodeEscapes(asUtf8);
+        }
         std::string result;
         result.reserve(utf8Str.size() * 2);
         size_t i = 0;
         while (i < utf8Str.size()) {
             unsigned char c = static_cast<unsigned char>(utf8Str[i]);
-            if (c >= 0x20 && c <= 0x7E) {
-                // Printable ASCII including space (0x20-0x7E) — pass through as-is
+            if ((c >= 0x20 && c <= 0x7E) || c == '\t' || c == '\n' || c == '\r') {
+                // Printable ASCII (0x20-0x7E) and common whitespace (tab, LF, CR) — pass through
                 result += utf8Str[i];
                 i++;
             } else if (c <= 0x7F) {
-                // Control chars (0x00-0x1F), DEL (0x7F) — escape as \uXXXX
+                // Other control chars (0x00-0x08, 0x0B, 0x0C, 0x0E-0x1F), DEL (0x7F) — escape as \uXXXX
                 char buf[7];
                 snprintf(buf, sizeof(buf), "\\u%04x", c);
                 result += buf;
@@ -1239,6 +1253,11 @@ namespace ANSCENTER
 
     std::string ANSUtilities::DoubleEscapeUnicode(const std::string& str) {
         if (str.empty()) return "";
+        // Auto-detect UTF-16LE input (LabVIEW may pass UTF-16LE strings)
+        if (IsLikelyUTF16LE(str)) {
+            std::string asUtf8 = ConvertUTF16LEToUTF8(str.data(), static_cast<int>(str.size()));
+            return DoubleEscapeUnicode(asUtf8);
+        }
         std::string result;
         result.reserve(str.size() + str.size() / 4);
         for (size_t i = 0; i < str.size(); i++) {
@@ -1253,11 +1272,21 @@ namespace ANSCENTER
     }
 
     std::string ANSUtilities::ConvertUTF8ToDoubleEscapedUnicode(const std::string& utf8Str) {
-        return DoubleEscapeUnicode(ConvertUTF8ToUnicodeEscapes(utf8Str));
+        if (utf8Str.empty()) return "";
+        // Auto-detect UTF-16LE input (LabVIEW may pass UTF-16LE strings)
+        std::string inputStr = IsLikelyUTF16LE(utf8Str)
+            ? ConvertUTF16LEToUTF8(utf8Str.data(), static_cast<int>(utf8Str.size()))
+            : utf8Str;
+        return DoubleEscapeUnicode(ConvertUTF8ToUnicodeEscapes(inputStr));
     }
 
     std::string ANSUtilities::UnescapeDoubleEscapedUnicode(const std::string& str) {
         if (str.empty()) return "";
+        // Auto-detect UTF-16LE input (LabVIEW may pass UTF-16LE strings)
+        if (IsLikelyUTF16LE(str)) {
+            std::string asUtf8 = ConvertUTF16LEToUTF8(str.data(), static_cast<int>(str.size()));
+            return UnescapeDoubleEscapedUnicode(asUtf8);
+        }
         // Quick scan: if no \\u pattern exists, return original string unchanged
         bool found = false;
         for (size_t i = 0; i + 2 < str.size(); i++) {