'use strict'
var Buffer = require('buffer').Buffer
var inherits = require('inherits')
var HashBase = require('hash-base')

var ARRAY16 = new Array(16)

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

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

var sl = [
  11, 14, 15, 12, 5, 8, 7, 9, 11, 13, 14, 15, 6, 7, 9, 8,
  7, 6, 8, 13, 11, 9, 7, 15, 7, 12, 15, 9, 11, 7, 13, 12,
  11, 13, 6, 7, 14, 9, 13, 15, 14, 8, 13, 6, 5, 12, 7, 5,
  11, 12, 14, 15, 14, 15, 9, 8, 9, 14, 5, 6, 8, 6, 5, 12,
  9, 15, 5, 11, 6, 8, 13, 12, 5, 12, 13, 14, 11, 8, 5, 6
]

var sr = [
  8, 9, 9, 11, 13, 15, 15, 5, 7, 7, 8, 11, 14, 14, 12, 6,
  9, 13, 15, 7, 12, 8, 9, 11, 7, 7, 12, 7, 6, 15, 13, 11,
  9, 7, 15, 11, 8, 6, 6, 14, 12, 13, 5, 14, 13, 13, 7, 5,
  15, 5, 8, 11, 14, 14, 6, 14, 6, 9, 12, 9, 12, 5, 15, 8,
  8, 5, 12, 9, 12, 5, 14, 6, 8, 13, 6, 5, 15, 13, 11, 11
]

var hl = [0x00000000, 0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xa953fd4e]
var hr = [0x50a28be6, 0x5c4dd124, 0x6d703ef3, 0x7a6d76e9, 0x00000000]

function RIPEMD160 () {
  HashBase.call(this, 64)

  // state
  this._a = 0x67452301
  this._b = 0xefcdab89
  this._c = 0x98badcfe
  this._d = 0x10325476
  this._e = 0xc3d2e1f0
}

inherits(RIPEMD160, HashBase)

RIPEMD160.prototype._update = function () {
  var words = ARRAY16
  for (var j = 0; j < 16; ++j) words[j] = this._block.readInt32LE(j * 4)

  var al = this._a | 0
  var bl = this._b | 0
  var cl = this._c | 0
  var dl = this._d | 0
  var el = this._e | 0

  var ar = this._a | 0
  var br = this._b | 0
  var cr = this._c | 0
  var dr = this._d | 0
  var er = this._e | 0

  // computation
  for (var i = 0; i < 80; i += 1) {
    var tl
    var tr
    if (i < 16) {
      tl = fn1(al, bl, cl, dl, el, words[zl[i]], hl[0], sl[i])
      tr = fn5(ar, br, cr, dr, er, words[zr[i]], hr[0], sr[i])
    } else if (i < 32) {
      tl = fn2(al, bl, cl, dl, el, words[zl[i]], hl[1], sl[i])
      tr = fn4(ar, br, cr, dr, er, words[zr[i]], hr[1], sr[i])
    } else if (i < 48) {
      tl = fn3(al, bl, cl, dl, el, words[zl[i]], hl[2], sl[i])
      tr = fn3(ar, br, cr, dr, er, words[zr[i]], hr[2], sr[i])
    } else if (i < 64) {
      tl = fn4(al, bl, cl, dl, el, words[zl[i]], hl[3], sl[i])
      tr = fn2(ar, br, cr, dr, er, words[zr[i]], hr[3], sr[i])
    } else { // if (i<80) {
      tl = fn5(al, bl, cl, dl, el, words[zl[i]], hl[4], sl[i])
      tr = fn1(ar, br, cr, dr, er, words[zr[i]], hr[4], sr[i])
    }

    al = el
    el = dl
    dl = rotl(cl, 10)
    cl = bl
    bl = tl

    ar = er
    er = dr
    dr = rotl(cr, 10)
    cr = br
    br = tr
  }

  // update state
  var t = (this._b + cl + dr) | 0
  this._b = (this._c + dl + er) | 0
  this._c = (this._d + el + ar) | 0
  this._d = (this._e + al + br) | 0
  this._e = (this._a + bl + cr) | 0
  this._a = t
}

RIPEMD160.prototype._digest = function () {
  // create padding and handle blocks
  this._block[this._blockOffset++] = 0x80
  if (this._blockOffset > 56) {
    this._block.fill(0, this._blockOffset, 64)
    this._update()
    this._blockOffset = 0
  }

  this._block.fill(0, this._blockOffset, 56)
  this._block.writeUInt32LE(this._length[0], 56)
  this._block.writeUInt32LE(this._length[1], 60)
  this._update()

  // produce result
  var buffer = Buffer.alloc ? Buffer.alloc(20) : new Buffer(20)
  buffer.writeInt32LE(this._a, 0)
  buffer.writeInt32LE(this._b, 4)
  buffer.writeInt32LE(this._c, 8)
  buffer.writeInt32LE(this._d, 12)
  buffer.writeInt32LE(this._e, 16)
  return buffer
}

function rotl (x, n) {
  return (x << n) | (x >>> (32 - n))
}

function fn1 (a, b, c, d, e, m, k, s) {
  return (rotl((a + (b ^ c ^ d) + m + k) | 0, s) + e) | 0
}

function fn2 (a, b, c, d, e, m, k, s) {
  return (rotl((a + ((b & c) | ((~b) & d)) + m + k) | 0, s) + e) | 0
}

function fn3 (a, b, c, d, e, m, k, s) {
  return (rotl((a + ((b | (~c)) ^ d) + m + k) | 0, s) + e) | 0
}

function fn4 (a, b, c, d, e, m, k, s) {
  return (rotl((a + ((b & d) | (c & (~d))) + m + k) | 0, s) + e) | 0
}

function fn5 (a, b, c, d, e, m, k, s) {
  return (rotl((a + (b ^ (c | (~d))) + m + k) | 0, s) + e) | 0
}

module.exports = RIPEMD160