'use strict';

exports.readUInt32BE = function readUInt32BE(bytes, off) {
  var res =  (bytes[0 + off] << 24) |
             (bytes[1 + off] << 16) |
             (bytes[2 + off] << 8) |
             bytes[3 + off];
  return res >>> 0;
};

exports.writeUInt32BE = function writeUInt32BE(bytes, value, off) {
  bytes[0 + off] = value >>> 24;
  bytes[1 + off] = (value >>> 16) & 0xff;
  bytes[2 + off] = (value >>> 8) & 0xff;
  bytes[3 + off] = value & 0xff;
};

exports.ip = function ip(inL, inR, out, off) {
  var outL = 0;
  var outR = 0;

  for (var i = 6; i >= 0; i -= 2) {
    for (var j = 0; j <= 24; j += 8) {
      outL <<= 1;
      outL |= (inR >>> (j + i)) & 1;
    }
    for (var j = 0; j <= 24; j += 8) {
      outL <<= 1;
      outL |= (inL >>> (j + i)) & 1;
    }
  }

  for (var i = 6; i >= 0; i -= 2) {
    for (var j = 1; j <= 25; j += 8) {
      outR <<= 1;
      outR |= (inR >>> (j + i)) & 1;
    }
    for (var j = 1; j <= 25; j += 8) {
      outR <<= 1;
      outR |= (inL >>> (j + i)) & 1;
    }
  }

  out[off + 0] = outL >>> 0;
  out[off + 1] = outR >>> 0;
};

exports.rip = function rip(inL, inR, out, off) {
  var outL = 0;
  var outR = 0;

  for (var i = 0; i < 4; i++) {
    for (var j = 24; j >= 0; j -= 8) {
      outL <<= 1;
      outL |= (inR >>> (j + i)) & 1;
      outL <<= 1;
      outL |= (inL >>> (j + i)) & 1;
    }
  }
  for (var i = 4; i < 8; i++) {
    for (var j = 24; j >= 0; j -= 8) {
      outR <<= 1;
      outR |= (inR >>> (j + i)) & 1;
      outR <<= 1;
      outR |= (inL >>> (j + i)) & 1;
    }
  }

  out[off + 0] = outL >>> 0;
  out[off + 1] = outR >>> 0;
};

exports.pc1 = function pc1(inL, inR, out, off) {
  var outL = 0;
  var outR = 0;

  // 7, 15, 23, 31, 39, 47, 55, 63
  // 6, 14, 22, 30, 39, 47, 55, 63
  // 5, 13, 21, 29, 39, 47, 55, 63
  // 4, 12, 20, 28
  for (var i = 7; i >= 5; i--) {
    for (var j = 0; j <= 24; j += 8) {
      outL <<= 1;
      outL |= (inR >> (j + i)) & 1;
    }
    for (var j = 0; j <= 24; j += 8) {
      outL <<= 1;
      outL |= (inL >> (j + i)) & 1;
    }
  }
  for (var j = 0; j <= 24; j += 8) {
    outL <<= 1;
    outL |= (inR >> (j + i)) & 1;
  }

  // 1, 9, 17, 25, 33, 41, 49, 57
  // 2, 10, 18, 26, 34, 42, 50, 58
  // 3, 11, 19, 27, 35, 43, 51, 59
  // 36, 44, 52, 60
  for (var i = 1; i <= 3; i++) {
    for (var j = 0; j <= 24; j += 8) {
      outR <<= 1;
      outR |= (inR >> (j + i)) & 1;
    }
    for (var j = 0; j <= 24; j += 8) {
      outR <<= 1;
      outR |= (inL >> (j + i)) & 1;
    }
  }
  for (var j = 0; j <= 24; j += 8) {
    outR <<= 1;
    outR |= (inL >> (j + i)) & 1;
  }

  out[off + 0] = outL >>> 0;
  out[off + 1] = outR >>> 0;
};

exports.r28shl = function r28shl(num, shift) {
  return ((num << shift) & 0xfffffff) | (num >>> (28 - shift));
};

var pc2table = [
  // inL => outL
  14, 11, 17, 4, 27, 23, 25, 0,
  13, 22, 7, 18, 5, 9, 16, 24,
  2, 20, 12, 21, 1, 8, 15, 26,

  // inR => outR
  15, 4, 25, 19, 9, 1, 26, 16,
  5, 11, 23, 8, 12, 7, 17, 0,
  22, 3, 10, 14, 6, 20, 27, 24
];

exports.pc2 = function pc2(inL, inR, out, off) {
  var outL = 0;
  var outR = 0;

  var len = pc2table.length >>> 1;
  for (var i = 0; i < len; i++) {
    outL <<= 1;
    outL |= (inL >>> pc2table[i]) & 0x1;
  }
  for (var i = len; i < pc2table.length; i++) {
    outR <<= 1;
    outR |= (inR >>> pc2table[i]) & 0x1;
  }

  out[off + 0] = outL >>> 0;
  out[off + 1] = outR >>> 0;
};

exports.expand = function expand(r, out, off) {
  var outL = 0;
  var outR = 0;

  outL = ((r & 1) << 5) | (r >>> 27);
  for (var i = 23; i >= 15; i -= 4) {
    outL <<= 6;
    outL |= (r >>> i) & 0x3f;
  }
  for (var i = 11; i >= 3; i -= 4) {
    outR |= (r >>> i) & 0x3f;
    outR <<= 6;
  }
  outR |= ((r & 0x1f) << 1) | (r >>> 31);

  out[off + 0] = outL >>> 0;
  out[off + 1] = outR >>> 0;
};

var sTable = [
  14, 0, 4, 15, 13, 7, 1, 4, 2, 14, 15, 2, 11, 13, 8, 1,
  3, 10, 10, 6, 6, 12, 12, 11, 5, 9, 9, 5, 0, 3, 7, 8,
  4, 15, 1, 12, 14, 8, 8, 2, 13, 4, 6, 9, 2, 1, 11, 7,
  15, 5, 12, 11, 9, 3, 7, 14, 3, 10, 10, 0, 5, 6, 0, 13,

  15, 3, 1, 13, 8, 4, 14, 7, 6, 15, 11, 2, 3, 8, 4, 14,
  9, 12, 7, 0, 2, 1, 13, 10, 12, 6, 0, 9, 5, 11, 10, 5,
  0, 13, 14, 8, 7, 10, 11, 1, 10, 3, 4, 15, 13, 4, 1, 2,
  5, 11, 8, 6, 12, 7, 6, 12, 9, 0, 3, 5, 2, 14, 15, 9,

  10, 13, 0, 7, 9, 0, 14, 9, 6, 3, 3, 4, 15, 6, 5, 10,
  1, 2, 13, 8, 12, 5, 7, 14, 11, 12, 4, 11, 2, 15, 8, 1,
  13, 1, 6, 10, 4, 13, 9, 0, 8, 6, 15, 9, 3, 8, 0, 7,
  11, 4, 1, 15, 2, 14, 12, 3, 5, 11, 10, 5, 14, 2, 7, 12,

  7, 13, 13, 8, 14, 11, 3, 5, 0, 6, 6, 15, 9, 0, 10, 3,
  1, 4, 2, 7, 8, 2, 5, 12, 11, 1, 12, 10, 4, 14, 15, 9,
  10, 3, 6, 15, 9, 0, 0, 6, 12, 10, 11, 1, 7, 13, 13, 8,
  15, 9, 1, 4, 3, 5, 14, 11, 5, 12, 2, 7, 8, 2, 4, 14,

  2, 14, 12, 11, 4, 2, 1, 12, 7, 4, 10, 7, 11, 13, 6, 1,
  8, 5, 5, 0, 3, 15, 15, 10, 13, 3, 0, 9, 14, 8, 9, 6,
  4, 11, 2, 8, 1, 12, 11, 7, 10, 1, 13, 14, 7, 2, 8, 13,
  15, 6, 9, 15, 12, 0, 5, 9, 6, 10, 3, 4, 0, 5, 14, 3,

  12, 10, 1, 15, 10, 4, 15, 2, 9, 7, 2, 12, 6, 9, 8, 5,
  0, 6, 13, 1, 3, 13, 4, 14, 14, 0, 7, 11, 5, 3, 11, 8,
  9, 4, 14, 3, 15, 2, 5, 12, 2, 9, 8, 5, 12, 15, 3, 10,
  7, 11, 0, 14, 4, 1, 10, 7, 1, 6, 13, 0, 11, 8, 6, 13,

  4, 13, 11, 0, 2, 11, 14, 7, 15, 4, 0, 9, 8, 1, 13, 10,
  3, 14, 12, 3, 9, 5, 7, 12, 5, 2, 10, 15, 6, 8, 1, 6,
  1, 6, 4, 11, 11, 13, 13, 8, 12, 1, 3, 4, 7, 10, 14, 7,
  10, 9, 15, 5, 6, 0, 8, 15, 0, 14, 5, 2, 9, 3, 2, 12,

  13, 1, 2, 15, 8, 13, 4, 8, 6, 10, 15, 3, 11, 7, 1, 4,
  10, 12, 9, 5, 3, 6, 14, 11, 5, 0, 0, 14, 12, 9, 7, 2,
  7, 2, 11, 1, 4, 14, 1, 7, 9, 4, 12, 10, 14, 8, 2, 13,
  0, 15, 6, 12, 10, 9, 13, 0, 15, 3, 3, 5, 5, 6, 8, 11
];

exports.substitute = function substitute(inL, inR) {
  var out = 0;
  for (var i = 0; i < 4; i++) {
    var b = (inL >>> (18 - i * 6)) & 0x3f;
    var sb = sTable[i * 0x40 + b];

    out <<= 4;
    out |= sb;
  }
  for (var i = 0; i < 4; i++) {
    var b = (inR >>> (18 - i * 6)) & 0x3f;
    var sb = sTable[4 * 0x40 + i * 0x40 + b];

    out <<= 4;
    out |= sb;
  }
  return out >>> 0;
};

var permuteTable = [
  16, 25, 12, 11, 3, 20, 4, 15, 31, 17, 9, 6, 27, 14, 1, 22,
  30, 24, 8, 18, 0, 5, 29, 23, 13, 19, 2, 26, 10, 21, 28, 7
];

exports.permute = function permute(num) {
  var out = 0;
  for (var i = 0; i < permuteTable.length; i++) {
    out <<= 1;
    out |= (num >>> permuteTable[i]) & 0x1;
  }
  return out >>> 0;
};

exports.padSplit = function padSplit(num, size, group) {
  var str = num.toString(2);
  while (str.length < size)
    str = '0' + str;

  var out = [];
  for (var i = 0; i < size; i += group)
    out.push(str.slice(i, i + group));
  return out.join(' ');
};