/**
 * qrcode
 * @param typeNumber 1 to 40
 * @param errorCorrectLevel 'L','M','Q','H'
 */
var qrcode = function(typeNumber, errorCorrectLevel) {

  var PAD0 = 0xEC
  var PAD1 = 0x11

  var _typeNumber = typeNumber
  var _errorCorrectLevel = QRErrorCorrectLevel[errorCorrectLevel]
  var _modules = null
  var _moduleCount = 0
  var _dataCache = null
  var _dataList = new Array()

  var _this = {}

  var makeImpl = function(test, maskPattern) {

    _moduleCount = _typeNumber * 4 + 17
    _modules = function(moduleCount) {
	    var modules = new Array(moduleCount)
	    for (var row = 0; row < moduleCount; row += 1) {
        modules[row] = new Array(moduleCount)
        for (var col = 0; col < moduleCount; col += 1) {
		    modules[row][col] = null
        }
	    }
	    return modules
    }(_moduleCount)

    setupPositionProbePattern(0, 0)
    setupPositionProbePattern(_moduleCount - 7, 0)
    setupPositionProbePattern(0, _moduleCount - 7)
    setupPositionAdjustPattern()
    setupTimingPattern()
    setupTypeInfo(test, maskPattern)

    if (_typeNumber >= 7) {
	    setupTypeNumber(test)
    }

    if (_dataCache == null) {
	    _dataCache = createData(_typeNumber, _errorCorrectLevel, _dataList)
    }

    mapData(_dataCache, maskPattern)
  }

  var setupPositionProbePattern = function(row, col) {

    for (var r = -1; r <= 7; r += 1) {

	    if (row + r <= -1 || _moduleCount <= row + r) continue

	    for (var c = -1; c <= 7; c += 1) {

        if (col + c <= -1 || _moduleCount <= col + c) continue

        if ( (0 <= r && r <= 6 && (c == 0 || c == 6) )
		     || (0 <= c && c <= 6 && (r == 0 || r == 6) )
		     || (2 <= r && r <= 4 && 2 <= c && c <= 4) ) {
		    _modules[row + r][col + c] = true
        } else {
		    _modules[row + r][col + c] = false
        }
	    }
    }
  }

  var getBestMaskPattern = function() {

    var minLostPoint = 0
    var pattern = 0

    for (var i = 0; i < 8; i += 1) {

	    makeImpl(true, i)

	    var lostPoint = QRUtil.getLostPoint(_this)

	    if (i == 0 || minLostPoint > lostPoint) {
        minLostPoint = lostPoint
        pattern = i
	    }
    }

    return pattern
  }

  var setupTimingPattern = function() {

    for (var r = 8; r < _moduleCount - 8; r += 1) {
	    if (_modules[r][6] != null) {
        continue
	    }
	    _modules[r][6] = (r % 2 == 0)
    }

    for (var c = 8; c < _moduleCount - 8; c += 1) {
	    if (_modules[6][c] != null) {
        continue
	    }
	    _modules[6][c] = (c % 2 == 0)
    }
  }

  var setupPositionAdjustPattern = function() {

    var pos = QRUtil.getPatternPosition(_typeNumber)

    for (var i = 0; i < pos.length; i += 1) {

	    for (var j = 0; j < pos.length; j += 1) {

        var row = pos[i]
        var col = pos[j]

        if (_modules[row][col] != null) {
		    continue
        }

        for (var r = -2; r <= 2; r += 1) {

		    for (var c = -2; c <= 2; c += 1) {

            if (r == -2 || r == 2 || c == -2 || c == 2
			    || (r == 0 && c == 0) ) {
			    _modules[row + r][col + c] = true
            } else {
			    _modules[row + r][col + c] = false
            }
		    }
        }
	    }
    }
  }

  var setupTypeNumber = function(test) {

    var bits = QRUtil.getBCHTypeNumber(_typeNumber)

    for (var i = 0; i < 18; i += 1) {
	    var mod = (!test && ( (bits >> i) & 1) == 1)
	    _modules[Math.floor(i / 3)][i % 3 + _moduleCount - 8 - 3] = mod
    }

    for (var i = 0; i < 18; i += 1) {
	    var mod = (!test && ( (bits >> i) & 1) == 1)
	    _modules[i % 3 + _moduleCount - 8 - 3][Math.floor(i / 3)] = mod
    }
  }

  var setupTypeInfo = function(test, maskPattern) {

    var data = (_errorCorrectLevel << 3) | maskPattern
    var bits = QRUtil.getBCHTypeInfo(data)

    // vertical
    for (var i = 0; i < 15; i += 1) {

	    var mod = (!test && ( (bits >> i) & 1) == 1)

	    if (i < 6) {
        _modules[i][8] = mod
	    } else if (i < 8) {
        _modules[i + 1][8] = mod
	    } else {
        _modules[_moduleCount - 15 + i][8] = mod
	    }
    }

    // horizontal
    for (var i = 0; i < 15; i += 1) {

	    var mod = (!test && ( (bits >> i) & 1) == 1)

	    if (i < 8) {
        _modules[8][_moduleCount - i - 1] = mod
	    } else if (i < 9) {
        _modules[8][15 - i - 1 + 1] = mod
	    } else {
        _modules[8][15 - i - 1] = mod
	    }
    }

    // fixed module
    _modules[_moduleCount - 8][8] = (!test)
  }

  var mapData = function(data, maskPattern) {

    var inc = -1
    var row = _moduleCount - 1
    var bitIndex = 7
    var byteIndex = 0
    var maskFunc = QRUtil.getMaskFunction(maskPattern)

    for (var col = _moduleCount - 1; col > 0; col -= 2) {

	    if (col == 6) col -= 1

	    while (true) {

        for (var c = 0; c < 2; c += 1) {

		    if (_modules[row][col - c] == null) {

            var dark = false

            if (byteIndex < data.length) {
			    dark = ( ( (data[byteIndex] >>> bitIndex) & 1) == 1)
            }

            var mask = maskFunc(row, col - c)

            if (mask) {
			    dark = !dark
            }

            _modules[row][col - c] = dark
            bitIndex -= 1

            if (bitIndex == -1) {
			    byteIndex += 1
			    bitIndex = 7
            }
		    }
        }

        row += inc

        if (row < 0 || _moduleCount <= row) {
		    row -= inc
		    inc = -inc
		    break
        }
	    }
    }
  }

  var createBytes = function(buffer, rsBlocks) {

    var offset = 0

    var maxDcCount = 0
    var maxEcCount = 0

    var dcdata = new Array(rsBlocks.length)
    var ecdata = new Array(rsBlocks.length)

    for (var r = 0; r < rsBlocks.length; r += 1) {

	    var dcCount = rsBlocks[r].dataCount
	    var ecCount = rsBlocks[r].totalCount - dcCount

	    maxDcCount = Math.max(maxDcCount, dcCount)
	    maxEcCount = Math.max(maxEcCount, ecCount)

	    dcdata[r] = new Array(dcCount)

	    for (var i = 0; i < dcdata[r].length; i += 1) {
        dcdata[r][i] = 0xff & buffer.getBuffer()[i + offset]
	    }
	    offset += dcCount

	    var rsPoly = QRUtil.getErrorCorrectPolynomial(ecCount)
	    var rawPoly = qrPolynomial(dcdata[r], rsPoly.getLength() - 1)

	    var modPoly = rawPoly.mod(rsPoly)
	    ecdata[r] = new Array(rsPoly.getLength() - 1)
	    for (var i = 0; i < ecdata[r].length; i += 1) {
        var modIndex = i + modPoly.getLength() - ecdata[r].length
        ecdata[r][i] = (modIndex >= 0)? modPoly.getAt(modIndex) : 0
	    }
    }

    var totalCodeCount = 0
    for (var i = 0; i < rsBlocks.length; i += 1) {
	    totalCodeCount += rsBlocks[i].totalCount
    }

    var data = new Array(totalCodeCount)
    var index = 0

    for (var i = 0; i < maxDcCount; i += 1) {
	    for (var r = 0; r < rsBlocks.length; r += 1) {
        if (i < dcdata[r].length) {
		    data[index] = dcdata[r][i]
		    index += 1
        }
	    }
    }

    for (var i = 0; i < maxEcCount; i += 1) {
	    for (var r = 0; r < rsBlocks.length; r += 1) {
        if (i < ecdata[r].length) {
		    data[index] = ecdata[r][i]
		    index += 1
        }
	    }
    }

    return data
  }

  var createData = function(typeNumber, errorCorrectLevel, dataList) {

    var rsBlocks = QRRSBlock.getRSBlocks(typeNumber, errorCorrectLevel)

    var buffer = qrBitBuffer()

    for (var i = 0; i < dataList.length; i += 1) {
	    var data = dataList[i]
	    buffer.put(data.getMode(), 4)
	    buffer.put(data.getLength(), QRUtil.getLengthInBits(data.getMode(), typeNumber) )
	    data.write(buffer)
    }

    // calc num max data.
    var totalDataCount = 0
    for (var i = 0; i < rsBlocks.length; i += 1) {
	    totalDataCount += rsBlocks[i].dataCount
    }

    if (buffer.getLengthInBits() > totalDataCount * 8) {
	    throw new Error('code length overflow. ('
			    + buffer.getLengthInBits()
			    + '>'
			    + totalDataCount * 8
			    + ')')
    }

    // end code
    if (buffer.getLengthInBits() + 4 <= totalDataCount * 8) {
	    buffer.put(0, 4)
    }

    // padding
    while (buffer.getLengthInBits() % 8 != 0) {
	    buffer.putBit(false)
    }

    // padding
    while (true) {

	    if (buffer.getLengthInBits() >= totalDataCount * 8) {
        break
	    }
	    buffer.put(PAD0, 8)

	    if (buffer.getLengthInBits() >= totalDataCount * 8) {
        break
	    }
	    buffer.put(PAD1, 8)
    }

    return createBytes(buffer, rsBlocks)
  }

  _this.addData = function(data) {
    var newData = qr8BitByte(data)
    _dataList.push(newData)
    _dataCache = null
  }

  _this.isDark = function(row, col) {
    if (row < 0 || _moduleCount <= row || col < 0 || _moduleCount <= col) {
	    throw new Error(row + ',' + col)
    }
    return _modules[row][col]
  }

  _this.getModuleCount = function() {
    return _moduleCount
  }

  _this.make = function() {
    makeImpl(false, getBestMaskPattern() )
  }

  _this.createTableTag = function(cellSize, margin) {

    cellSize = cellSize || 2
    margin = (typeof margin == 'undefined')? cellSize * 4 : margin

    var qrHtml = ''

    qrHtml += '<table style="'
    qrHtml += ' border-width: 0px; border-style: none;'
    qrHtml += ' border-collapse: collapse;'
    qrHtml += ' padding: 0px; margin: ' + margin + 'px;'
    qrHtml += '">'
    qrHtml += '<tbody>'

    for (var r = 0; r < _this.getModuleCount(); r += 1) {

	    qrHtml += '<tr>'

	    for (var c = 0; c < _this.getModuleCount(); c += 1) {
        qrHtml += '<td style="'
        qrHtml += ' border-width: 0px; border-style: none;'
        qrHtml += ' border-collapse: collapse;'
        qrHtml += ' padding: 0px; margin: 0px;'
        qrHtml += ' width: ' + cellSize + 'px;'
        qrHtml += ' height: ' + cellSize + 'px;'
        qrHtml += ' background-color: '
        qrHtml += _this.isDark(r, c)? '#000000' : '#ffffff'
        qrHtml += ';'
        qrHtml += '"/>'
	    }

	    qrHtml += '</tr>'
    }

    qrHtml += '</tbody>'
    qrHtml += '</table>'

    return qrHtml
  }

  _this.createImgTag = function(cellSize, margin, size) {

    cellSize = cellSize || 2
    margin = (typeof margin == 'undefined')? cellSize * 4 : margin

    var min = margin
    var max = _this.getModuleCount() * cellSize + margin

    return createImgTag(size, size, function(x, y) {
	    if (min <= x && x < max && min <= y && y < max) {
        var c = Math.floor( (x - min) / cellSize)
        var r = Math.floor( (y - min) / cellSize)
        return _this.isDark(r, c)? 0 : 1
	    } else {
        return 1
	    }
    } )
  }

  return _this
}

//---------------------------------------------------------------------
// qrcode.stringToBytes
//---------------------------------------------------------------------

qrcode.stringToBytes = function(s) {
  var bytes = new Array()
  for (var i = 0; i < s.length; i += 1) {
    var c = s.charCodeAt(i)
    bytes.push(c & 0xff)
  }
  return bytes
}

//---------------------------------------------------------------------
// qrcode.createStringToBytes
//---------------------------------------------------------------------

/**
 * @param unicodeData base64 string of byte array.
 * [16bit Unicode],[16bit Bytes], ...
 * @param numChars
 */
qrcode.createStringToBytes = function(unicodeData, numChars) {

  // create conversion map.

  var unicodeMap = function() {

    var bin = base64DecodeInputStream(unicodeData)
    var read = function() {
	    var b = bin.read()
	    if (b == -1) throw new Error()
	    return b
    }

    var count = 0
    var unicodeMap = {}
    while (true) {
	    var b0 = bin.read()
	    if (b0 == -1) break
	    var b1 = read()
	    var b2 = read()
	    var b3 = read()
	    var k = String.fromCharCode( (b0 << 8) | b1)
	    var v = (b2 << 8) | b3
	    unicodeMap[k] = v
	    count += 1
    }
    if (count != numChars) {
	    throw new Error(count + ' != ' + numChars)
    }

    return unicodeMap
  }()

  var unknownChar = '?'.charCodeAt(0)

  return function(s) {
    var bytes = new Array()
    for (var i = 0; i < s.length; i += 1) {
	    var c = s.charCodeAt(i)
	    if (c < 128) {
        bytes.push(c)
	    } else {
        var b = unicodeMap[s.charAt(i)]
        if (typeof b == 'number') {
		    if ( (b & 0xff) == b) {
            // 1byte
            bytes.push(b)
		    } else {
            // 2bytes
            bytes.push(b >>> 8)
            bytes.push(b & 0xff)
		    }
        } else {
		    bytes.push(unknownChar)
        }
	    }
    }
    return bytes
  }
}

//---------------------------------------------------------------------
// QRMode
//---------------------------------------------------------------------

var QRMode = {
  MODE_NUMBER :		1 << 0,
  MODE_ALPHA_NUM : 	1 << 1,
  MODE_8BIT_BYTE : 	1 << 2,
  MODE_KANJI :		1 << 3
}

//---------------------------------------------------------------------
// QRErrorCorrectLevel
//---------------------------------------------------------------------

var QRErrorCorrectLevel = {
  L : 1,
  M : 0,
  Q : 3,
  H : 2
}

//---------------------------------------------------------------------
// QRMaskPattern
//---------------------------------------------------------------------

var QRMaskPattern = {
  PATTERN000 : 0,
  PATTERN001 : 1,
  PATTERN010 : 2,
  PATTERN011 : 3,
  PATTERN100 : 4,
  PATTERN101 : 5,
  PATTERN110 : 6,
  PATTERN111 : 7
}

//---------------------------------------------------------------------
// QRUtil
//---------------------------------------------------------------------

var QRUtil = function() {

  var PATTERN_POSITION_TABLE = [
    [],
    [6, 18],
    [6, 22],
    [6, 26],
    [6, 30],
    [6, 34],
    [6, 22, 38],
    [6, 24, 42],
    [6, 26, 46],
    [6, 28, 50],
    [6, 30, 54],
    [6, 32, 58],
    [6, 34, 62],
    [6, 26, 46, 66],
    [6, 26, 48, 70],
    [6, 26, 50, 74],
    [6, 30, 54, 78],
    [6, 30, 56, 82],
    [6, 30, 58, 86],
    [6, 34, 62, 90],
    [6, 28, 50, 72, 94],
    [6, 26, 50, 74, 98],
    [6, 30, 54, 78, 102],
    [6, 28, 54, 80, 106],
    [6, 32, 58, 84, 110],
    [6, 30, 58, 86, 114],
    [6, 34, 62, 90, 118],
    [6, 26, 50, 74, 98, 122],
    [6, 30, 54, 78, 102, 126],
    [6, 26, 52, 78, 104, 130],
    [6, 30, 56, 82, 108, 134],
    [6, 34, 60, 86, 112, 138],
    [6, 30, 58, 86, 114, 142],
    [6, 34, 62, 90, 118, 146],
    [6, 30, 54, 78, 102, 126, 150],
    [6, 24, 50, 76, 102, 128, 154],
    [6, 28, 54, 80, 106, 132, 158],
    [6, 32, 58, 84, 110, 136, 162],
    [6, 26, 54, 82, 110, 138, 166],
    [6, 30, 58, 86, 114, 142, 170]
  ]
  var G15 = (1 << 10) | (1 << 8) | (1 << 5) | (1 << 4) | (1 << 2) | (1 << 1) | (1 << 0)
  var G18 = (1 << 12) | (1 << 11) | (1 << 10) | (1 << 9) | (1 << 8) | (1 << 5) | (1 << 2) | (1 << 0)
  var G15_MASK = (1 << 14) | (1 << 12) | (1 << 10) | (1 << 4) | (1 << 1)

  var _this = {}

  var getBCHDigit = function(data) {
    var digit = 0
    while (data != 0) {
	    digit += 1
	    data >>>= 1
    }
    return digit
  }

  _this.getBCHTypeInfo = function(data) {
    var d = data << 10
    while (getBCHDigit(d) - getBCHDigit(G15) >= 0) {
	    d ^= (G15 << (getBCHDigit(d) - getBCHDigit(G15) ) )
    }
    return ( (data << 10) | d) ^ G15_MASK
  }

  _this.getBCHTypeNumber = function(data) {
    var d = data << 12
    while (getBCHDigit(d) - getBCHDigit(G18) >= 0) {
	    d ^= (G18 << (getBCHDigit(d) - getBCHDigit(G18) ) )
    }
    return (data << 12) | d
  }

  _this.getPatternPosition = function(typeNumber) {
    return PATTERN_POSITION_TABLE[typeNumber - 1]
  }

  _this.getMaskFunction = function(maskPattern) {

    switch (maskPattern) {

	    case QRMaskPattern.PATTERN000 :
      return function(i, j) { return (i + j) % 2 == 0 }
	    case QRMaskPattern.PATTERN001 :
      return function(i, j) { return i % 2 == 0 }
	    case QRMaskPattern.PATTERN010 :
      return function(i, j) { return j % 3 == 0 }
	    case QRMaskPattern.PATTERN011 :
      return function(i, j) { return (i + j) % 3 == 0 }
	    case QRMaskPattern.PATTERN100 :
      return function(i, j) { return (Math.floor(i / 2) + Math.floor(j / 3) ) % 2 == 0 }
	    case QRMaskPattern.PATTERN101 :
      return function(i, j) { return (i * j) % 2 + (i * j) % 3 == 0 }
	    case QRMaskPattern.PATTERN110 :
      return function(i, j) { return ( (i * j) % 2 + (i * j) % 3) % 2 == 0 }
	    case QRMaskPattern.PATTERN111 :
      return function(i, j) { return ( (i * j) % 3 + (i + j) % 2) % 2 == 0 }

    default :
      throw new Error('bad maskPattern:' + maskPattern)
    }
  }

  _this.getErrorCorrectPolynomial = function(errorCorrectLength) {
    var a = qrPolynomial([1], 0)
    for (var i = 0; i < errorCorrectLength; i += 1) {
	    a = a.multiply(qrPolynomial([1, QRMath.gexp(i)], 0) )
    }
    return a
  }

  _this.getLengthInBits = function(mode, type) {

    if (1 <= type && type < 10) {

	    // 1 - 9

	    switch(mode) {
      case QRMode.MODE_NUMBER 	: return 10
      case QRMode.MODE_ALPHA_NUM 	: return 9
      case QRMode.MODE_8BIT_BYTE	: return 8
      case QRMode.MODE_KANJI		: return 8
		    default :
		    throw new Error('mode:' + mode)
	    }

    } else if (type < 27) {

	    // 10 - 26

	    switch(mode) {
      case QRMode.MODE_NUMBER 	: return 12
      case QRMode.MODE_ALPHA_NUM 	: return 11
      case QRMode.MODE_8BIT_BYTE	: return 16
      case QRMode.MODE_KANJI		: return 10
		    default :
		    throw new Error('mode:' + mode)
	    }

    } else if (type < 41) {

	    // 27 - 40

	    switch(mode) {
      case QRMode.MODE_NUMBER 	: return 14
      case QRMode.MODE_ALPHA_NUM	: return 13
      case QRMode.MODE_8BIT_BYTE	: return 16
      case QRMode.MODE_KANJI		: return 12
		    default :
		    throw new Error('mode:' + mode)
	    }

    } else {
	    throw new Error('type:' + type)
    }
  }

  _this.getLostPoint = function(qrcode) {

    var moduleCount = qrcode.getModuleCount()

    var lostPoint = 0

    // LEVEL1

    for (var row = 0; row < moduleCount; row += 1) {
	    for (var col = 0; col < moduleCount; col += 1) {

        var sameCount = 0
        var dark = qrcode.isDark(row, col)

        for (var r = -1; r <= 1; r += 1) {

		    if (row + r < 0 || moduleCount <= row + r) {
            continue
		    }

		    for (var c = -1; c <= 1; c += 1) {

            if (col + c < 0 || moduleCount <= col + c) {
			    continue
            }

            if (r == 0 && c == 0) {
			    continue
            }

            if (dark == qrcode.isDark(row + r, col + c) ) {
			    sameCount += 1
            }
		    }
        }

        if (sameCount > 5) {
		    lostPoint += (3 + sameCount - 5)
        }
	    }
    };

    // LEVEL2

    for (var row = 0; row < moduleCount - 1; row += 1) {
	    for (var col = 0; col < moduleCount - 1; col += 1) {
        var count = 0
        if (qrcode.isDark(row, col) ) count += 1
        if (qrcode.isDark(row + 1, col) ) count += 1
        if (qrcode.isDark(row, col + 1) ) count += 1
        if (qrcode.isDark(row + 1, col + 1) ) count += 1
        if (count == 0 || count == 4) {
		    lostPoint += 3
        }
	    }
    }

    // LEVEL3

    for (var row = 0; row < moduleCount; row += 1) {
	    for (var col = 0; col < moduleCount - 6; col += 1) {
        if (qrcode.isDark(row, col)
		    && !qrcode.isDark(row, col + 1)
		    && qrcode.isDark(row, col + 2)
		    && qrcode.isDark(row, col + 3)
		    && qrcode.isDark(row, col + 4)
		    && !qrcode.isDark(row, col + 5)
		    && qrcode.isDark(row, col + 6) ) {
		    lostPoint += 40
        }
	    }
    }

    for (var col = 0; col < moduleCount; col += 1) {
	    for (var row = 0; row < moduleCount - 6; row += 1) {
        if (qrcode.isDark(row, col)
		    && !qrcode.isDark(row + 1, col)
		    && qrcode.isDark(row + 2, col)
		    && qrcode.isDark(row + 3, col)
		    && qrcode.isDark(row + 4, col)
		    && !qrcode.isDark(row + 5, col)
		    && qrcode.isDark(row + 6, col) ) {
		    lostPoint += 40
        }
	    }
    }

    // LEVEL4

    var darkCount = 0

    for (var col = 0; col < moduleCount; col += 1) {
	    for (var row = 0; row < moduleCount; row += 1) {
        if (qrcode.isDark(row, col) ) {
		    darkCount += 1
        }
	    }
    }

    var ratio = Math.abs(100 * darkCount / moduleCount / moduleCount - 50) / 5
    lostPoint += ratio * 10

    return lostPoint
  }

  return _this
}()

//---------------------------------------------------------------------
// QRMath
//---------------------------------------------------------------------

var QRMath = function() {

  var EXP_TABLE = new Array(256)
  var LOG_TABLE = new Array(256)

  // initialize tables
  for (var i = 0; i < 8; i += 1) {
    EXP_TABLE[i] = 1 << i
  }
  for (var i = 8; i < 256; i += 1) {
    EXP_TABLE[i] = EXP_TABLE[i - 4]
	    ^ EXP_TABLE[i - 5]
	    ^ EXP_TABLE[i - 6]
	    ^ EXP_TABLE[i - 8]
  }
  for (var i = 0; i < 255; i += 1) {
    LOG_TABLE[EXP_TABLE[i] ] = i
  }

  var _this = {}

  _this.glog = function(n) {

    if (n < 1) {
	    throw new Error('glog(' + n + ')')
    }

    return LOG_TABLE[n]
  }

  _this.gexp = function(n) {

    while (n < 0) {
	    n += 255
    }

    while (n >= 256) {
	    n -= 255
    }

    return EXP_TABLE[n]
  }

  return _this
}()

//---------------------------------------------------------------------
// qrPolynomial
//---------------------------------------------------------------------

function qrPolynomial(num, shift) {

  if (typeof num.length == 'undefined') {
    throw new Error(num.length + '/' + shift)
  }

  var _num = function() {
    var offset = 0
    while (offset < num.length && num[offset] == 0) {
	    offset += 1
    }
    var _num = new Array(num.length - offset + shift)
    for (var i = 0; i < num.length - offset; i += 1) {
	    _num[i] = num[i + offset]
    }
    return _num
  }()

  var _this = {}

  _this.getAt = function(index) {
    return _num[index]
  }

  _this.getLength = function() {
    return _num.length
  }

  _this.multiply = function(e) {

    var num = new Array(_this.getLength() + e.getLength() - 1)

    for (var i = 0; i < _this.getLength(); i += 1) {
	    for (var j = 0; j < e.getLength(); j += 1) {
        num[i + j] ^= QRMath.gexp(QRMath.glog(_this.getAt(i) ) + QRMath.glog(e.getAt(j) ) )
	    }
    }

    return qrPolynomial(num, 0)
  }

  _this.mod = function(e) {

    if (_this.getLength() - e.getLength() < 0) {
	    return _this
    }

    var ratio = QRMath.glog(_this.getAt(0) ) - QRMath.glog(e.getAt(0) )

    var num = new Array(_this.getLength() )
    for (var i = 0; i < _this.getLength(); i += 1) {
	    num[i] = _this.getAt(i)
    }

    for (var i = 0; i < e.getLength(); i += 1) {
	    num[i] ^= QRMath.gexp(QRMath.glog(e.getAt(i) ) + ratio)
    }

    // recursive call
    return qrPolynomial(num, 0).mod(e)
  }

  return _this
};

//---------------------------------------------------------------------
// QRRSBlock
//---------------------------------------------------------------------

var QRRSBlock = function() {


  // [1: [L, M, Q, H], ..]
  var RS_BLOCK_TABLE=[[1,26,19],[1,26,16],[1,26,13],[1,26,9],[1,44,34],[1,44,28],[1,44,22],[1,44,16],[1,70,55],[1,70,44],[2,35,17],[2,35,13],[1,100,80],[2,50,32],[2,50,24],[4,25,9],[1,134,108],[2,67,43],[2,33,15,2,34,16],[2,33,11,2,34,12],[2,86,68],[4,43,27],[4,43,19],[4,43,15],[2,98,78],[4,49,31],[2,32,14,4,33,15],[4,39,13,1,40,14],[2,121,97],[2,60,38,2,61,39],[4,40,18,2,41,19],[4,40,14,2,41,15],[2,146,116],[3,58,36,2,59,37],[4,36,16,4,37,17],[4,36,12,4,37,13],[2,86,68,2,87,69],[4,69,43,1,70,44],[6,43,19,2,44,20],[6,43,15,2,44,16],[4,101,81],[1,80,50,4,81,51],[4,50,22,4,51,23],[3,36,12,8,37,13],[2,116,92,2,117,93],[6,58,36,2,59,37],[4,46,20,6,47,21],[7,42,14,4,43,15],[4,133,107],[8,59,37,1,60,38],[8,44,20,4,45,21],[12,33,11,4,34,12],[3,145,115,1,146,116],[4,64,40,5,65,41],[11,36,16,5,37,17],[11,36,12,5,37,13],[5,109,87,1,110,88],[5,65,41,5,66,42],[5,54,24,7,55,25],[11,36,12],[5,122,98,1,123,99],[7,73,45,3,74,46],[15,43,19,2,44,20],[3,45,15,13,46,16],[1,135,107,5,136,108],[10,74,46,1,75,47],[1,50,22,15,51,23],[2,42,14,17,43,15],[5,150,120,1,151,121],[9,69,43,4,70,44],[17,50,22,1,51,23],[2,42,14,19,43,15],[3,141,113,4,142,114],[3,70,44,11,71,45],[17,47,21,4,48,22],[9,39,13,16,40,14],[3,135,107,5,136,108],[3,67,41,13,68,42],[15,54,24,5,55,25],[15,43,15,10,44,16],[4,144,116,4,145,117],[17,68,42],[17,50,22,6,51,23],[19,46,16,6,47,17],[2,139,111,7,140,112],[17,74,46],[7,54,24,16,55,25],[34,37,13],[4,151,121,5,152,122],[4,75,47,14,76,48],[11,54,24,14,55,25],[16,45,15,14,46,16],[6,147,117,4,148,118],[6,73,45,14,74,46],[11,54,24,16,55,25],[30,46,16,2,47,17],[8,132,106,4,133,107],[8,75,47,13,76,48],[7,54,24,22,55,25],[22,45,15,13,46,16],[10,142,114,2,143,115],[19,74,46,4,75,47],[28,50,22,6,51,23],[33,46,16,4,47,17],[8,152,122,4,153,123],[22,73,45,3,74,46],[8,53,23,26,54,24],[12,45,15,28,46,16],[3,147,117,10,148,118],[3,73,45,23,74,46],[4,54,24,31,55,25],[11,45,15,31,46,16],[7,146,116,7,147,117],[21,73,45,7,74,46],[1,53,23,37,54,24],[19,45,15,26,46,16],[5,145,115,10,146,116],[19,75,47,10,76,48],[15,54,24,25,55,25],[23,45,15,25,46,16],[13,145,115,3,146,116],[2,74,46,29,75,47],[42,54,24,1,55,25],[23,45,15,28,46,16],[17,145,115],[10,74,46,23,75,47],[10,54,24,35,55,25],[19,45,15,35,46,16],[17,145,115,1,146,116],[14,74,46,21,75,47],[29,54,24,19,55,25],[11,45,15,46,46,16],[13,145,115,6,146,116],[14,74,46,23,75,47],[44,54,24,7,55,25],[59,46,16,1,47,17],[12,151,121,7,152,122],[12,75,47,26,76,48],[39,54,24,14,55,25],[22,45,15,41,46,16],[6,151,121,14,152,122],[6,75,47,34,76,48],[46,54,24,10,55,25],[2,45,15,64,46,16],[17,152,122,4,153,123],[29,74,46,14,75,47],[49,54,24,10,55,25],[24,45,15,46,46,16],[4,152,122,18,153,123],[13,74,46,32,75,47],[48,54,24,14,55,25],[42,45,15,32,46,16],[20,147,117,4,148,118],[40,75,47,7,76,48],[43,54,24,22,55,25],[10,45,15,67,46,16],[19,148,118,6,149,119],[18,75,47,31,76,48],[34,54,24,34,55,25],[20,45,15,61,46,16]]

  var qrRSBlock = function(totalCount, dataCount) {
    var _this = {}
    _this.totalCount = totalCount
    _this.dataCount = dataCount
    return _this
  }

  var _this = {}

  var getRsBlockTable = function(typeNumber, errorCorrectLevel) {

    switch(errorCorrectLevel) {
	    case QRErrorCorrectLevel.L :
      return RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 0]
	    case QRErrorCorrectLevel.M :
      return RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 1]
	    case QRErrorCorrectLevel.Q :
      return RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 2]
	    case QRErrorCorrectLevel.H :
      return RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 3]
    default :
      return undefined
    }
  }

  _this.getRSBlocks = function(typeNumber, errorCorrectLevel) {

    var rsBlock = getRsBlockTable(typeNumber, errorCorrectLevel)

    if (typeof rsBlock == 'undefined') {
	    throw new Error('bad rs block @ typeNumber:' + typeNumber +
			    '/errorCorrectLevel:' + errorCorrectLevel)
    }

    var length = rsBlock.length / 3

    var list = new Array()

    for (var i = 0; i < length; i += 1) {

	    var count = rsBlock[i * 3 + 0]
	    var totalCount = rsBlock[i * 3 + 1]
	    var dataCount = rsBlock[i * 3 + 2]

	    for (var j = 0; j < count; j += 1) {
        list.push(qrRSBlock(totalCount, dataCount) )
	    }
    }

    return list
  }

  return _this
}()

//---------------------------------------------------------------------
// qrBitBuffer
//---------------------------------------------------------------------

var qrBitBuffer = function() {

  var _buffer = new Array()
  var _length = 0

  var _this = {}

  _this.getBuffer = function() {
    return _buffer
  }

  _this.getAt = function(index) {
    var bufIndex = Math.floor(index / 8)
    return ( (_buffer[bufIndex] >>> (7 - index % 8) ) & 1) == 1
  }

  _this.put = function(num, length) {
    for (var i = 0; i < length; i += 1) {
	    _this.putBit( ( (num >>> (length - i - 1) ) & 1) == 1)
    }
  }

  _this.getLengthInBits = function() {
    return _length
  }

  _this.putBit = function(bit) {

    var bufIndex = Math.floor(_length / 8)
    if (_buffer.length <= bufIndex) {
	    _buffer.push(0)
    }

    if (bit) {
	    _buffer[bufIndex] |= (0x80 >>> (_length % 8) )
    }

    _length += 1
  }

  return _this
}

//---------------------------------------------------------------------
// qr8BitByte
//---------------------------------------------------------------------

var qr8BitByte = function(data) {

  var _mode = QRMode.MODE_8BIT_BYTE
  var _data = data
  var _parsedData = []

  var _this = {}


  // Added to support UTF-8 Characters
  for (var i = 0, l = _data.length; i < l; i++) {
    var byteArray = []
    var code = _data.charCodeAt(i)

    if (code > 0x10000) {
	    byteArray[0] = 0xF0 | ((code & 0x1C0000) >>> 18)
	    byteArray[1] = 0x80 | ((code & 0x3F000) >>> 12)
	    byteArray[2] = 0x80 | ((code & 0xFC0) >>> 6)
	    byteArray[3] = 0x80 | (code & 0x3F)
    } else if (code > 0x800) {
	    byteArray[0] = 0xE0 | ((code & 0xF000) >>> 12)
	    byteArray[1] = 0x80 | ((code & 0xFC0) >>> 6)
	    byteArray[2] = 0x80 | (code & 0x3F)
    } else if (code > 0x80) {
	    byteArray[0] = 0xC0 | ((code & 0x7C0) >>> 6)
	    byteArray[1] = 0x80 | (code & 0x3F)
    } else {
	    byteArray[0] = code
    }

    // Fix Unicode corruption bug
    _parsedData.push(byteArray)
  }

  _parsedData = Array.prototype.concat.apply([], _parsedData)

  if (_parsedData.length != _data.length) {
    _parsedData.unshift(191)
    _parsedData.unshift(187)
    _parsedData.unshift(239)
  }

  var _bytes = _parsedData

  _this.getMode = function() {
    return _mode
  }

  _this.getLength = function(buffer) {
    return _bytes.length
  }

  _this.write = function(buffer) {
    for (var i = 0; i < _bytes.length; i += 1) {
	    buffer.put(_bytes[i], 8)
    }
  }

  return _this
}

//=====================================================================
// GIF Support etc.
//

//---------------------------------------------------------------------
// byteArrayOutputStream
//---------------------------------------------------------------------

var byteArrayOutputStream = function() {

  var _bytes = new Array()

  var _this = {}

  _this.writeByte = function(b) {
    _bytes.push(b & 0xff)
  }

  _this.writeShort = function(i) {
    _this.writeByte(i)
    _this.writeByte(i >>> 8)
  }

  _this.writeBytes = function(b, off, len) {
    off = off || 0
    len = len || b.length
    for (var i = 0; i < len; i += 1) {
	    _this.writeByte(b[i + off])
    }
  }

  _this.writeString = function(s) {
    for (var i = 0; i < s.length; i += 1) {
	    _this.writeByte(s.charCodeAt(i) )
    }
  }

  _this.toByteArray = function() {
    return _bytes
  }

  _this.toString = function() {
    var s = ''
    s += '['
    for (var i = 0; i < _bytes.length; i += 1) {
	    if (i > 0) {
        s += ','
	    }
	    s += _bytes[i]
    }
    s += ']'
    return s
  }

  return _this
}

//---------------------------------------------------------------------
// base64EncodeOutputStream
//---------------------------------------------------------------------

var base64EncodeOutputStream = function() {

  var _buffer = 0
  var _buflen = 0
  var _length = 0
  var _base64 = ''

  var _this = {}

  var writeEncoded = function(b) {
    _base64 += String.fromCharCode(encode(b & 0x3f) )
  }

  var encode = function(n) {
    if (n < 0) {
	    // error.
    } else if (n < 26) {
	    return 0x41 + n
    } else if (n < 52) {
	    return 0x61 + (n - 26)
    } else if (n < 62) {
	    return 0x30 + (n - 52)
    } else if (n == 62) {
	    return 0x2b
    } else if (n == 63) {
	    return 0x2f
    }
    throw new Error('n:' + n)
  }

  _this.writeByte = function(n) {

    _buffer = (_buffer << 8) | (n & 0xff)
    _buflen += 8
    _length += 1

    while (_buflen >= 6) {
	    writeEncoded(_buffer >>> (_buflen - 6) )
	    _buflen -= 6
    }
  }

  _this.flush = function() {

    if (_buflen > 0) {
	    writeEncoded(_buffer << (6 - _buflen) )
	    _buffer = 0
	    _buflen = 0
    }

    if (_length % 3 != 0) {
	    // padding
	    var padlen = 3 - _length % 3
	    for (var i = 0; i < padlen; i += 1) {
        _base64 += '='
	    }
    }
  }

  _this.toString = function() {
    return _base64
  }

  return _this
}

//---------------------------------------------------------------------
// base64DecodeInputStream
//---------------------------------------------------------------------

var base64DecodeInputStream = function(str) {

  var _str = str
  var _pos = 0
  var _buffer = 0
  var _buflen = 0

  var _this = {}

  _this.read = function() {

    while (_buflen < 8) {

	    if (_pos >= _str.length) {
        if (_buflen == 0) {
		    return -1
        }
        throw new Error('unexpected end of file./' + _buflen)
	    }

	    var c = _str.charAt(_pos)
	    _pos += 1

	    if (c == '=') {
        _buflen = 0
        return -1
	    } else if (c.match(/^\s$/) ) {
        // ignore if whitespace.
        continue
	    }

	    _buffer = (_buffer << 6) | decode(c.charCodeAt(0) )
	    _buflen += 6
    }

    var n = (_buffer >>> (_buflen - 8) ) & 0xff
    _buflen -= 8
    return n
  }

  var decode = function(c) {
    if (0x41 <= c && c <= 0x5a) {
	    return c - 0x41
    } else if (0x61 <= c && c <= 0x7a) {
	    return c - 0x61 + 26
    } else if (0x30 <= c && c <= 0x39) {
	    return c - 0x30 + 52
    } else if (c == 0x2b) {
	    return 62
    } else if (c == 0x2f) {
	    return 63
    } else {
	    throw new Error('c:' + c)
    }
  }

  return _this
}

//---------------------------------------------------------------------
// gifImage (B/W)
//---------------------------------------------------------------------

var gifImage = function(width, height) {

  var _width = width
  var _height = height
  var _data = new Array(width * height)

  var _this = {}

  _this.setPixel = function(x, y, pixel) {
    _data[y * _width + x] = pixel
  }

  _this.write = function(out) {

    //---------------------------------
    // GIF Signature

    out.writeString('GIF87a')

    //---------------------------------
    // Screen Descriptor

    out.writeShort(_width)
    out.writeShort(_height)

    out.writeByte(0x80) // 2bit
    out.writeByte(0)
    out.writeByte(0)

    //---------------------------------
    // Global Color Map

    // black
    out.writeByte(0x00)
    out.writeByte(0x00)
    out.writeByte(0x00)

    // white
    out.writeByte(0xff)
    out.writeByte(0xff)
    out.writeByte(0xff)

    //---------------------------------
    // Image Descriptor

    out.writeString(',')
    out.writeShort(0)
    out.writeShort(0)
    out.writeShort(_width)
    out.writeShort(_height)
    out.writeByte(0)

    //---------------------------------
    // Local Color Map

    //---------------------------------
    // Raster Data

    var lzwMinCodeSize = 2
    var raster = getLZWRaster(lzwMinCodeSize)

    out.writeByte(lzwMinCodeSize)

    var offset = 0

    while (raster.length - offset > 255) {
	    out.writeByte(255)
	    out.writeBytes(raster, offset, 255)
	    offset += 255
    }

    out.writeByte(raster.length - offset)
    out.writeBytes(raster, offset, raster.length - offset)
    out.writeByte(0x00)

    //---------------------------------
    // GIF Terminator
    out.writeString(';')
  }

  var bitOutputStream = function(out) {

    var _out = out
    var _bitLength = 0
    var _bitBuffer = 0

    var _this = {}

    _this.write = function(data, length) {

	    if ( (data >>> length) != 0) {
        throw new Error('length over')
	    }

	    while (_bitLength + length >= 8) {
        _out.writeByte(0xff & ( (data << _bitLength) | _bitBuffer) )
        length -= (8 - _bitLength)
        data >>>= (8 - _bitLength)
        _bitBuffer = 0
        _bitLength = 0
	    }

	    _bitBuffer = (data << _bitLength) | _bitBuffer
	    _bitLength = _bitLength + length
    }

    _this.flush = function() {
	    if (_bitLength > 0) {
        _out.writeByte(_bitBuffer)
	    }
    }

    return _this
  }

  var getLZWRaster = function(lzwMinCodeSize) {

    var clearCode = 1 << lzwMinCodeSize
    var endCode = (1 << lzwMinCodeSize) + 1
    var bitLength = lzwMinCodeSize + 1

    // Setup LZWTable
    var table = lzwTable()

    for (var i = 0; i < clearCode; i += 1) {
	    table.add(String.fromCharCode(i) )
    }
    table.add(String.fromCharCode(clearCode) )
    table.add(String.fromCharCode(endCode) )

    var byteOut = byteArrayOutputStream()
    var bitOut = bitOutputStream(byteOut)

    // clear code
    bitOut.write(clearCode, bitLength)

    var dataIndex = 0

    var s = String.fromCharCode(_data[dataIndex])
    dataIndex += 1

    while (dataIndex < _data.length) {

	    var c = String.fromCharCode(_data[dataIndex])
	    dataIndex += 1

	    if (table.contains(s + c) ) {

        s = s + c

	    } else {

        bitOut.write(table.indexOf(s), bitLength)

        if (table.size() < 0xfff) {

		    if (table.size() == (1 << bitLength) ) {
            bitLength += 1
		    }

		    table.add(s + c)
        }

        s = c
	    }
    }

    bitOut.write(table.indexOf(s), bitLength)

    // end code
    bitOut.write(endCode, bitLength)

    bitOut.flush()

    return byteOut.toByteArray()
  }

  var lzwTable = function() {

    var _map = {}
    var _size = 0

    var _this = {}

    _this.add = function(key) {
	    if (_this.contains(key) ) {
        throw new Error('dup key:' + key)
	    }
	    _map[key] = _size
	    _size += 1
    }

    _this.size = function() {
	    return _size
    }

    _this.indexOf = function(key) {
	    return _map[key]
    }

    _this.contains = function(key) {
	    return typeof _map[key] != 'undefined'
    }

    return _this
  }

  return _this
}

var createImgTag = function(width, height, getPixel, alt) {

  var gif = gifImage(width, height)
  for (var y = 0; y < height; y += 1) {
    for (var x = 0; x < width; x += 1) {
	    gif.setPixel(x, y, getPixel(x, y) )
    }
  }

  var b = byteArrayOutputStream()
  gif.write(b)

  var base64 = base64EncodeOutputStream()
  var bytes = b.toByteArray()
  for (var i = 0; i < bytes.length; i += 1) {
    base64.writeByte(bytes[i])
  }
  base64.flush()

  var img = ''
  img += 'data:image/gif;base64,'
  img += base64

  return img
}

//---------------------------------------------------------------------
// returns qrcode function.

var drawImg = function(text, options) {
  options = options || {}
  var typeNumber = options.typeNumber || 4
  var errorCorrectLevel = options.errorCorrectLevel || 'M'
  var size = options.size || 500

  var qr

  try {
    qr = qrcode(typeNumber, errorCorrectLevel || 'M')
    qr.addData(text)
    qr.make()
  } catch (e) {
    if(typeNumber >= 40) {
      throw new Error('Text too long to encode')
    } else {
      return drawImg(text, {
        size: size,
        errorCorrectLevel: errorCorrectLevel,
        typeNumber: typeNumber + 1
      })
    }
  }

  // calc cellsize and margin
  var cellsize = parseInt(size / qr.getModuleCount())
  var margin = parseInt((size - qr.getModuleCount() * cellsize) / 2)

  return qr.createImgTag(cellsize, margin, size)
}
module.exports = {
  drawImg: drawImg
}