/* Test case for bug 317216
 *
 * Uses nsIConverterInputStream to decode UTF-16 text with valid surrogate
 * pairs and lone surrogate characters
 *
 * Sample text is: "A" in Mathematical Bold Capitals (U+1D400)
 *
 * The test uses buffers of 4 different lengths to test end of buffer in mid-
 * UTF16 character and mid-surrogate pair
 */

const { NetUtil } = ChromeUtils.importESModule(
  "resource://gre/modules/NetUtil.sys.mjs"
);

const test = [
  // 0: Valid surrogate pair
  [
    "%D8%35%DC%20%00%2D%00%2D",
    //    expected: surrogate pair
    "\uD835\uDC20--",
  ],
  // 1: Lone high surrogate
  [
    "%D8%35%00%2D%00%2D",
    //    expected: one replacement char
    "\uFFFD--",
  ],
  // 2: Lone low surrogate
  [
    "%DC%20%00%2D%00%2D",
    //    expected: one replacement char
    "\uFFFD--",
  ],
  // 3: Two high surrogates
  [
    "%D8%35%D8%35%00%2D%00%2D",
    //    expected: two replacement chars
    "\uFFFD\uFFFD--",
  ],
  // 4: Two low surrogates
  [
    "%DC%20%DC%20%00%2D%00%2D",
    //    expected: two replacement chars
    "\uFFFD\uFFFD--",
  ],
  // 5: Low surrogate followed by high surrogate
  [
    "%DC%20%D8%35%00%2D%00%2D",
    //    expected: two replacement chars
    "\uFFFD\uFFFD--",
  ],
  // 6: Lone high surrogate followed by valid surrogate pair
  [
    "%D8%35%D8%35%DC%20%00%2D%00%2D",
    //    expected: replacement char followed by surrogate pair
    "\uFFFD\uD835\uDC20--",
  ],
  // 7: Lone low surrogate followed by valid surrogate pair
  [
    "%DC%20%D8%35%DC%20%00%2D%00%2D",
    //    expected: replacement char followed by surrogate pair
    "\uFFFD\uD835\uDC20--",
  ],
  // 8: Valid surrogate pair followed by lone high surrogate
  [
    "%D8%35%DC%20%D8%35%00%2D%00%2D",
    //    expected: surrogate pair followed by replacement char
    "\uD835\uDC20\uFFFD--",
  ],
  // 9: Valid surrogate pair followed by lone low surrogate
  [
    "%D8%35%DC%20%DC%20%00%2D%00%2D",
    //    expected: surrogate pair followed by replacement char
    "\uD835\uDC20\uFFFD--",
  ],
  // 10: Lone high surrogate at the end of the input
  [
    "%D8%35%",
    //    expected: one replacement char
    "\uFFFD",
  ],
  // 11: Half code unit at the end of the input
  [
    "%D8",
    //    expected: one replacement char
    "\uFFFD",
  ],
];

const ConverterInputStream = Components.Constructor(
  "@mozilla.org/intl/converter-input-stream;1",
  "nsIConverterInputStream",
  "init"
);

function testCase(testText, expectedText, bufferLength, charset) {
  var dataURI = "data:text/plain;charset=" + charset + "," + testText;
  var channel = NetUtil.newChannel({
    uri: dataURI,
    loadUsingSystemPrincipal: true,
  });
  var testInputStream = channel.open();
  var testConverter = new ConverterInputStream(
    testInputStream,
    charset,
    bufferLength,
    0xfffd
  );

  if (!(testConverter instanceof Ci.nsIUnicharLineInputStream)) {
    throw new Error("not line input stream");
  }

  var outStr = "";
  var more;
  do {
    // read the line and check for eof
    var line = {};
    more = testConverter.readLine(line);
    outStr += line.value;
  } while (more);

  // escape the strings before comparing for better readability
  Assert.equal(escape(outStr), escape(expectedText));
}

// Add 32 dummy characters to the test text to work around the minimum buffer
// size of an ns*Buffer
const MINIMUM_BUFFER_SIZE = 32;
function padBytes(str) {
  var padding = "";
  for (var i = 0; i < MINIMUM_BUFFER_SIZE; ++i) {
    padding += "%00%2D";
  }
  return padding + str;
}

function padUnichars(str) {
  var padding = "";
  for (var i = 0; i < MINIMUM_BUFFER_SIZE; ++i) {
    padding += "-";
  }
  return padding + str;
}

// Byte-swap %-encoded utf-16
function flip(str) {
  return str.replace(/(%..)(%..)/g, "$2$1");
}

function run_test() {
  for (var i = 0; i < 12; ++i) {
    for (
      var bufferLength = MINIMUM_BUFFER_SIZE;
      bufferLength < MINIMUM_BUFFER_SIZE + 4;
      ++bufferLength
    ) {
      var testText = padBytes(test[i][0]);
      var expectedText = padUnichars(test[i][1]);
      testCase(testText, expectedText, bufferLength, "UTF-16BE");
      testCase(flip(testText), expectedText, bufferLength, "UTF-16LE");
    }
  }
}