// NOTE: Requires testharness.js
// http://www.w3.org/2008/webapps/wiki/Harness

function testEncodeDecode(encoding, min, max) {
  function cpname(n) {
    return 'U+' + ((n <= 0xFFFF) ?
                   ('0000' + n.toString(16).toUpperCase()).slice(-4) :
                   n.toString(16).toUpperCase());
  }

  test(
    function() {
      var string, i, j, BATCH_SIZE = 0x1000;
      for (i = min; i < max; i += BATCH_SIZE) {
        string = '';
        for (j = i; j < i + BATCH_SIZE && j < max; j += 1) {
          if (0xd800 <= j && j <= 0xdfff) {
            // surrogate half
            continue;
          } else if (j > 0xffff) {
            // outside BMP - encode as surrogate pair
            string += String.fromCharCode(
              0xd800 + ((j >> 10) & 0x3ff),
              0xdc00 + (j & 0x3ff));
          } else {
            string += String.fromCharCode(i);
          }
        }
        var encoded = TextEncoder(encoding).encode(string);
        var decoded = TextDecoder(encoding).decode(encoded);
        assert_equals(string, decoded, 'Round trip ' + cpname(i) + " - " + cpname(j));
      }
    },
    encoding + " - Encode/Decode Range " + cpname(min) + " - " + cpname(max)
  );
}

testEncodeDecode('UTF-8', 0, 0x10FFFF);
testEncodeDecode('UTF-16LE', 0, 0x10FFFF);
testEncodeDecode('UTF-16BE', 0, 0x10FFFF);

// Inspired by:
// http://ecmanaut.blogspot.com/2006/07/encoding-decoding-utf8-in-javascript.html
function encode_utf8(string) {
  var utf8 = unescape(encodeURIComponent(string));
  var octets = [], i;
  for (i = 0; i < utf8.length; i += 1) {
    octets.push(utf8.charCodeAt(i));
  }
  return octets;
}

function decode_utf8(octets) {
  var utf8 = String.fromCharCode.apply(null, octets);
  return decodeURIComponent(escape(utf8));
}

test(
  function() {
    var actual, expected, str, i, j, BATCH_SIZE = 0x1000;

    for (i = 0; i < 0x10FFFF; i += BATCH_SIZE) {
      str = '';
      for (j = i; j < i + BATCH_SIZE; j += 1) {
        if (0xd800 <= j && j <= 0xdfff) {
          // surrogate half
          continue;
        } else if (j > 0xffff) {
          // outside BMP - encode as surrogate pair
          str += String.fromCharCode(
            0xd800 + ((j >> 10) & 0x3ff),
            0xdc00 + (j & 0x3ff));
        } else {
          str += String.fromCharCode(i);
        }
      }
      expected = encode_utf8(str);

      actual = TextEncoder('UTF-8').encode(str);
      assert_array_equals(actual, expected, 'expected equal encodings');
    }
  },
  "UTF-8 encoding (compare against unescape/encodeURIComponent)"
);

test(
  function() {
    var encoded, actual, expected, str, i, j, BATCH_SIZE = 0x1000;

    for (i = 0; i < 0x10FFFF; i += BATCH_SIZE) {
      str = '';
      for (j = i; j < i + BATCH_SIZE; j += 1) {
        if (0xd800 <= j && j <= 0xdfff) {
          // surrogate half
          continue;
        } else if (j > 0xffff) {
          // outside BMP - encode as surrogate pair
          str += String.fromCharCode(
            0xd800 + ((j >> 10) & 0x3ff),
            0xdc00 + (j & 0x3ff));
        } else {
          str += String.fromCharCode(i);
        }
      }

      encoded = encode_utf8(str);

      expected = decode_utf8(encoded);
      actual = TextDecoder('UTF-8').decode(new Uint8Array(encoded));

      assert_equals(actual, expected, 'expected equal decodings');
    }
  },
  "UTF-8 decoding (compare against decodeURIComponent/escape)"
);

function testEncodeDecodeSample(encoding, string, expected) {
  test(
    function() {
      var encoded = TextEncoder(encoding).encode(string);
      assert_array_equals(encoded, expected, 'expected equal encodings ' + encoding);

      var decoded = TextDecoder(encoding).decode(new Uint8Array(expected));
      assert_equals(decoded, string, 'expected equal decodings ' + encoding);
    },
    encoding + " - Encode/Decode - reference sample"
  );
}

testEncodeDecodeSample(
  "utf-8",
  "z\xA2\u6C34\uD834\uDD1E\uDBFF\uDFFD", // z, cent, CJK water, G-Clef, Private-use character
  [0x7A, 0xC2, 0xA2, 0xE6, 0xB0, 0xB4, 0xF0, 0x9D, 0x84, 0x9E, 0xF4, 0x8F, 0xBF, 0xBD]
);
testEncodeDecodeSample(
  "utf-16le",
  "z\xA2\u6C34\uD834\uDD1E\uDBFF\uDFFD", // z, cent, CJK water, G-Clef, Private-use character
  [0x7A, 0x00, 0xA2, 0x00, 0x34, 0x6C, 0x34, 0xD8, 0x1E, 0xDD, 0xFF, 0xDB, 0xFD, 0xDF]
);
testEncodeDecodeSample(
  "utf-16be",
  "z\xA2\u6C34\uD834\uDD1E\uDBFF\uDFFD", // z, cent, CJK water, G-Clef, Private-use character
  [0x00, 0x7A, 0x00, 0xA2, 0x6C, 0x34, 0xD8, 0x34, 0xDD, 0x1E, 0xDB, 0xFF, 0xDF, 0xFD]
);
testEncodeDecodeSample(
  "utf-16",
  "z\xA2\u6C34\uD834\uDD1E\uDBFF\uDFFD", // z, cent, CJK water, G-Clef, Private-use character
  [0x7A, 0x00, 0xA2, 0x00, 0x34, 0x6C, 0x34, 0xD8, 0x1E, 0xDD, 0xFF, 0xDB, 0xFD, 0xDF]
);

test(
  function() {
    var badStrings = [
      { input: '\ud800', expected: '\ufffd' }, // Surrogate half
      { input: '\udc00', expected: '\ufffd' }, // Surrogate half
      { input: 'abc\ud800def', expected: 'abc\ufffddef' }, // Surrogate half
      { input: 'abc\udc00def', expected: 'abc\ufffddef' }, // Surrogate half
      { input: '\udc00\ud800', expected: '\ufffd\ufffd' } // Wrong order
    ];

    badStrings.forEach(
      function(t) {
        var encoded = TextEncoder('utf-8').encode(t.input);
        var decoded = TextDecoder('utf-8').decode(encoded);
        assert_equals(t.expected, decoded);
      });
  },
  "bad data"
);

test(
  function() {
    var bad = [
      { encoding: 'utf-8', input: [0xC0] }, // ends early
      { encoding: 'utf-8', input: [0xC0, 0x00] }, // invalid trail
      { encoding: 'utf-8', input: [0xC0, 0xC0] }, // invalid trail
      { encoding: 'utf-8', input: [0xE0] }, // ends early
      { encoding: 'utf-8', input: [0xE0, 0x00] }, // invalid trail
      { encoding: 'utf-8', input: [0xE0, 0xC0] }, // invalid trail
      { encoding: 'utf-8', input: [0xE0, 0x80, 0x00] }, // invalid trail
      { encoding: 'utf-8', input: [0xE0, 0x80, 0xC0] }, // invalid trail
      { encoding: 'utf-8', input: [0xFC, 0x80, 0x80, 0x80, 0x80, 0x80] }, // > 0x10FFFF
      { encoding: 'utf-16', input: [0x00] }, // truncated code unit
      { encoding: 'utf-16', input: [0x00, 0xd8] }, // surrogate half
      { encoding: 'utf-16', input: [0x00, 0xd8, 0x00, 0x00] }, // surrogate half
      { encoding: 'utf-16', input: [0x00, 0xdc, 0x00, 0x00] }, // trail surrogate
      { encoding: 'utf-16', input: [0x00, 0xdc, 0x00, 0xd8] }  // swapped surrogates
      // TODO: Single byte encoding cases
    ];

    bad.forEach(
      function(t) {
        assert_throws({name: 'EncodingError'}, function () {
          TextDecoder(t.encoding, {fatal: true}).decode(new Uint8Array(t.input));
        });
      });
  },
  "fatal flag"
);

test(
  function() {
    var encodings = [
      { label: 'utf-8', encoding: 'utf-8' },
      { label: 'utf-16', encoding: 'utf-16le' },
      { label: 'utf-16le', encoding: 'utf-16le' },
      { label: 'utf-16be', encoding: 'utf-16be' },
      { label: 'ascii', encoding: 'windows-1252' },
      { label: 'iso-8859-1', encoding: 'windows-1252' }
    ];

    encodings.forEach(
      function(test) {
        assert_equals(TextDecoder(test.label.toLowerCase()).encoding, test.encoding);
        assert_equals(TextDecoder(test.label.toUpperCase()).encoding, test.encoding);
      });
  },
  "Encoding names are case insensitive"
);

test(
  function() {
    var utf8_bom = [0xEF, 0xBB, 0xBF];
    var utf8 = [0x7A, 0xC2, 0xA2, 0xE6, 0xB0, 0xB4, 0xF0, 0x9D, 0x84, 0x9E, 0xF4, 0x8F, 0xBF, 0xBD];

    var utf16le_bom = [0xff, 0xfe];
    var utf16le = [0x7A, 0x00, 0xA2, 0x00, 0x34, 0x6C, 0x34, 0xD8, 0x1E, 0xDD, 0xFF, 0xDB, 0xFD, 0xDF];

    var utf16be_bom = [0xfe, 0xff];
    var utf16be = [0x00, 0x7A, 0x00, 0xA2, 0x6C, 0x34, 0xD8, 0x34, 0xDD, 0x1E, 0xDB, 0xFF, 0xDF, 0xFD];

    var string = "z\xA2\u6C34\uD834\uDD1E\uDBFF\uDFFD"; // z, cent, CJK water, G-Clef, Private-use character

    // missing BOMs
    assert_equals(TextDecoder('utf-8').decode(new Uint8Array(utf8)), string);
    assert_equals(TextDecoder('utf-16le').decode(new Uint8Array(utf16le)), string);
    assert_equals(TextDecoder('utf-16be').decode(new Uint8Array(utf16be)), string);

    // matching BOMs
    assert_equals(TextDecoder('utf-8').decode(new Uint8Array(utf8_bom.concat(utf8))), string);
    assert_equals(TextDecoder('utf-16le').decode(new Uint8Array(utf16le_bom.concat(utf16le))), string);
    assert_equals(TextDecoder('utf-16be').decode(new Uint8Array(utf16be_bom.concat(utf16be))), string);

    // mismatching BOMs
    assert_not_equals(TextDecoder('utf-8').decode(new Uint8Array(utf16le_bom.concat(utf8))), string);
    assert_not_equals(TextDecoder('utf-8').decode(new Uint8Array(utf16be_bom.concat(utf8))), string);
    assert_not_equals(TextDecoder('utf-16le').decode(new Uint8Array(utf8_bom.concat(utf16le))), string);
    assert_not_equals(TextDecoder('utf-16le').decode(new Uint8Array(utf16be_bom.concat(utf16le))), string);
    assert_not_equals(TextDecoder('utf-16be').decode(new Uint8Array(utf8_bom.concat(utf16be))), string);
    assert_not_equals(TextDecoder('utf-16be').decode(new Uint8Array(utf16le_bom.concat(utf16be))), string);
  },
  "Byte-order marks"
);

test(
  function () {
    assert_equals(TextDecoder("utf-8").encoding, "utf-8"); // canonical case
    assert_equals(TextDecoder("UTF-16").encoding, "utf-16le"); // canonical case and name
    assert_equals(TextDecoder("UTF-16BE").encoding, "utf-16be"); // canonical case and name
    assert_equals(TextDecoder("iso8859-1").encoding, "windows-1252"); // canonical case and name
    assert_equals(TextDecoder("iso-8859-1").encoding, "windows-1252"); // canonical case and name
  },
  "Encoding names"
);

test(
  function () {
    ["utf-8", "utf-16le", "utf-16be"].forEach(function (encoding) {
      var string = "\x00123ABCabc\x80\xFF\u0100\u1000\uFFFD\uD800\uDC00\uDBFF\uDFFF";
      var encoded = TextEncoder(encoding).encode(string);

      for (var len = 1; len <= 5; ++len) {
        var out = "", decoder = TextDecoder(encoding);
        for (var i = 0; i < encoded.length; i += len) {
          var sub = [];
          for (var j = i; j < encoded.length && j < i + len; ++j) {
            sub.push(encoded[j]);
          }
          out += decoder.decode(new Uint8Array(sub), {stream: true});
        }
        out += decoder.decode();
        assert_equals(out, string, "streaming decode " + encoding);
      }
    });
  },
  "Streaming Decode"
);

test(
  function () {
    var jis = [0x82, 0xC9, 0x82, 0xD9, 0x82, 0xF1];
    var expected = "\u306B\u307B\u3093"; // Nihon
    assert_equals(TextDecoder("shift_jis").decode(new Uint8Array(jis)), expected);
  },
  "Shift_JIS Decode"
);

test(
  function () {
    var encodings = ["utf-8", "ibm866", "iso-8859-2", "iso-8859-3", "iso-8859-4", "iso-8859-5", "iso-8859-6", "iso-8859-7", "iso-8859-8", "iso-8859-8-i", "iso-8859-10", "iso-8859-13", "iso-8859-14", "iso-8859-15", "iso-8859-16", "koi8-r", "koi8-u", "macintosh", "windows-874", "windows-1250", "windows-1251", "windows-1252", "windows-1253", "windows-1254", "windows-1255", "windows-1256", "windows-1257", "windows-1258", "x-mac-cyrillic", "gbk", "gb18030", "hz-gb-2312", "big5", "euc-jp", "iso-2022-jp", "shift_jis", "euc-kr", "iso-2022-kr", "x-user-defined"];

    encodings.forEach(function (encoding) {
      var string = '', bytes = [];
      for (var i = 0; i < 128; ++i) {

        // Encodings that have escape codes in 0x00-0x7F
        if (encoding === "hz-gb-2312" && i === 0x7E)
          continue;
        if (encoding === "iso-2022-jp" && i === 0x1B)
          continue;
        if (encoding === "iso-2022-kr" && (i === 0x0E || i === 0x0F || i === 0x1B))
          continue;

        string += String.fromCharCode(i);
        bytes.push(i);
      }
      var ascii_encoded = TextEncoder('utf-8').encode(string);
      assert_equals(TextDecoder(encoding).decode(ascii_encoded), string, encoding);
      //assert_array_equals(TextEncoder(encoding).encode(string), bytes, encoding);
    });
  },
  "Supersets of ASCII decode ASCII correctly"
);

test(
  function () {
    assert_throws({name: 'EncodingError'}, function() { TextDecoder("utf-8", {fatal: true}).decode(new Uint8Array([0xff])); });
    // This should not hang:
    TextDecoder("utf-8").decode(new Uint8Array([0xff]));

    assert_throws({name: 'EncodingError'}, function() { TextDecoder("utf-16", {fatal: true}).decode(new Uint8Array([0x00])); });
    // This should not hang:
    TextDecoder("utf-16").decode(new Uint8Array([0x00]));

    assert_throws({name: 'EncodingError'}, function() { TextDecoder("utf-16be", {fatal: true}).decode(new Uint8Array([0x00])); });
    // This should not hang:
    TextDecoder("utf-16be").decode(new Uint8Array([0x00]));
  },
  "Non-fatal errors at EOF"
);

test(
  function () {

    var utf_encodings = ["utf-8", "utf-16le", "utf-16be"];

    var legacy_encodings = ["ibm866", "iso-8859-2", "iso-8859-3", "iso-8859-4", "iso-8859-5", "iso-8859-6", "iso-8859-7", "iso-8859-8", "iso-8859-8-i", "iso-8859-10", "iso-8859-13", "iso-8859-14", "iso-8859-15", "iso-8859-16", "koi8-r", "koi8-u", "macintosh", "windows-874", "windows-1250", "windows-1251", "windows-1252", "windows-1253", "windows-1254", "windows-1255", "windows-1256", "windows-1257", "windows-1258", "x-mac-cyrillic", "gbk", "gb18030", "hz-gb-2312", "big5", "euc-jp", "iso-2022-jp", "shift_jis", "euc-kr", "iso-2022-kr", "x-user-defined"];

    utf_encodings.forEach(function(encoding) {
      assert_equals(TextDecoder(encoding).encoding, encoding);
      assert_equals(TextEncoder(encoding).encoding, encoding);
    });

    legacy_encodings.forEach(function(encoding) {
      assert_equals(TextDecoder(encoding).encoding, encoding);
      assert_throws({name: 'TypeError'}, function() { TextEncoder(encoding); });
    });
  },
  "Non-UTF encodings supported only for decode, not encode"
);