From 26fe1711e3ab829b9f94a05d79dad54a7feda004 Mon Sep 17 00:00:00 2001
From: Kamil Leszczuk <kamituel@gmail.com>
Date: Mon, 26 May 2014 21:28:33 +0200
Subject: [PATCH] Bug 1003723: Support for UTF-16 encoded RTD_TEXT NDEF records

---
 apps/system/js/nfc_manager.js             | 14 ++++-----
 apps/system/test/unit/nfc_manager_test.js |  6 ++--
 apps/system/test/unit/nfc_utils_test.js   | 18 +++++++++++
 shared/js/nfc_utils.js                    | 37 ++++++++++++++++++++++-
 4 files changed, 64 insertions(+), 11 deletions(-)

diff --git a/apps/system/js/nfc_manager.js b/apps/system/js/nfc_manager.js
index 8f01840b9239..cacba1e695c9 100644
--- a/apps/system/js/nfc_manager.js
+++ b/apps/system/js/nfc_manager.js
@@ -454,17 +454,17 @@ var NfcManager = {
 
   formatTextRecord: function nm_formatTextRecord(record) {
     var status = record.payload[0];
-    var languageLength = status & NDEF.RTD_TEXT_IANA_LENGTH;
+    var langLen = status & NDEF.RTD_TEXT_IANA_LENGTH;
     var language = NfcUtils.toUTF8(
-                     record.payload.subarray(1, languageLength + 1));
-    var encoding = status & NDEF.RTD_TEXT_ENCODING;
+                     record.payload.subarray(1, langLen + 1));
+    var encoding = (status & NDEF.RTD_TEXT_ENCODING) !== 0 ? 1 : 0;
     var text;
     var encodingString;
-    if (encoding == NDEF.RTD_TEXT_UTF8) {
-      text = NfcUtils.toUTF8(record.payload.subarray(languageLength + 1));
+    if (encoding === NDEF.RTD_TEXT_UTF8) {
+      text = NfcUtils.toUTF8(record.payload.subarray(langLen + 1));
       encodingString = 'UTF-8';
-    } else if (encoding == NDEF.RTD_TEXT_UTF16) {
-      text = NfcUtils.toUTF16(record.payload.subarray(languageLength + 2));
+    } else if (encoding === NDEF.RTD_TEXT_UTF16) {
+      text = NfcUtils.UTF16BytesToString(record.payload.subarray(langLen + 1));
       encodingString = 'UTF-16';
     }
 
diff --git a/apps/system/test/unit/nfc_manager_test.js b/apps/system/test/unit/nfc_manager_test.js
index d50e0043db3e..da296e02c47c 100644
--- a/apps/system/test/unit/nfc_manager_test.js
+++ b/apps/system/test/unit/nfc_manager_test.js
@@ -192,7 +192,6 @@ suite('Nfc Manager Functions', function() {
       assert.equal(activityOptions.data.encoding, 'UTF-8');
     });
 
-    /* should be uncommented once Bug 1003723 will be fixed 
     test('TNF well known rtd text utf 16', function() {
       var payload = Uint8Array([0x82, 0x65, 0x6E, 0xFF,
                                 0xFE, 0x48, 0x00, 0x6F,
@@ -207,12 +206,13 @@ suite('Nfc Manager Functions', function() {
                                             new Uint8Array(),
                                             payload)];
 
-      var activityOptions = execCommonTest(dummyNdefMsg);
+      var activityOptions = execCommonTest(dummyNdefMsg, 'text');
+
       assert.equal(activityOptions.data.text, 'Ho! UTF-16 en');
       assert.equal(activityOptions.data.rtd, NDEF.RTD_TEXT);
       assert.equal(activityOptions.data.language, 'en');
       assert.equal(activityOptions.data.encoding, 'UTF-16');
-    });*/
+    });
 
     test('TNF well known rtd uri', function() {
       var payload = new Uint8Array([0x04, 0x77, 0x69, 0x6B,
diff --git a/apps/system/test/unit/nfc_utils_test.js b/apps/system/test/unit/nfc_utils_test.js
index 2e424a234e49..5b4978465092 100644
--- a/apps/system/test/unit/nfc_utils_test.js
+++ b/apps/system/test/unit/nfc_utils_test.js
@@ -63,6 +63,24 @@ suite('NFC Utils', function() {
     assert.equal(nullStr, null);
   });
 
+  suite('String <> byte conversions', function() {
+    test('UTF16BytesToString', function() {
+      assert.equal('©', NfcUtils.UTF16BytesToString([0xFE, 0xFF, 0x00, 0xA9]));
+      assert.equal('©', NfcUtils.UTF16BytesToString([0xFF, 0xFE, 0xA9, 0x00]));
+      assert.equal('ą', NfcUtils.UTF16BytesToString([0x01, 0x05]));
+
+      var foxArr = [0x00, 0x42, 0x00, 0x69, 0x00, 0x67, 0x00, 0x20, 0x00, 0x62,
+                    0x00, 0x72, 0x00, 0x6F, 0x00, 0x77, 0x00, 0x6E, 0x00, 0x20,
+                    0x00, 0x66, 0x00, 0x6F, 0x00, 0x78, 0x00, 0x21, 0x00, 0x20,
+                    0x00, 0x44, 0x00, 0x75, 0x01, 0x7C, 0x00, 0x79, 0x00, 0x20,
+                    0x00, 0x62, 0x00, 0x72, 0x01, 0x05, 0x00, 0x7A, 0x00, 0x6F,
+                    0x00, 0x77, 0x00, 0x79, 0x00, 0x20, 0x00, 0x6C, 0x00, 0x69,
+                    0x00, 0x73, 0x00, 0x3F];
+      var foxTxt = 'Big brown fox! Duży brązowy lis?';
+      assert.equal(foxTxt, NfcUtils.UTF16BytesToString(foxArr));
+    });
+  });
+
   suite('NDEF Conversions', function() {
     var urlNDEF; // MozNDEFRecord
     var urlU8a; // Uint8Array
diff --git a/shared/js/nfc_utils.js b/shared/js/nfc_utils.js
index 4f36e25aaad5..19b89e59691b 100644
--- a/shared/js/nfc_utils.js
+++ b/shared/js/nfc_utils.js
@@ -100,7 +100,7 @@ const NDEF = {
   },
 
   RTD_TEXT_IANA_LENGTH: 0x3F,
-  RTD_TEXT_ENCODING: 0x40,
+  RTD_TEXT_ENCODING: 0x80,
   RTD_TEXT_UTF8: 0,
   RTD_TEXT_UTF16: 1
 };
@@ -232,6 +232,41 @@ NfcUtils = {
     return str;
   },
 
+  /**
+   * Decodes UTF-16 bytes array into a String
+   *
+   * @param {Array} array containing UTF-16 encoded bytes
+   * @return {String}
+   */
+  UTF16BytesToString: function UTF16BytesToString(array) {
+      // if BOM not present Big-endian should be used
+      // NFCForum-TS-RTD_Text_1.0
+      var offset1 = 0, offset2 = 1, i = 0;
+
+      if (array[0] === 0xFE && array[1] === 0xFF) {
+        i = 2;
+      } else if (array[0] === 0xFF && array[1] === 0xFE) {
+        i = 2;
+        offset1 = 1;
+        offset2 = 0;
+      }
+
+      var str = '';
+      for (var len = array.length; i < len; i += 2) {
+          var b1 = array[i + offset1];
+          if (b1 < 0xD8 || b1 >= 0xE0) {
+            var b2 = array[i + offset2];
+            var word = (b1 << 8) + b2;
+            str += String.fromCharCode(word);
+          } else {
+            i += 2;
+            // as for now we handle only BMP characters
+          }
+      }
+
+      return str;
+  },
+
   /*****************************************************************************
    * createBuffer: returns a NfcBuffer helper object that makes it easier to
    * read from a Uint8Array.