/**
 * Copyright (c) 2017, Emil Bay github@tixz.dk
 *
 * Permission to use, copy, modify, and/or distribute this software for any purpose with or without
 * fee is hereby granted, provided that the above copyright notice and this permission notice appear
 * in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
 * SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 *
 * @see LICENSE: {@link https://github.com/emilbayes/blake2b/blob/master/LICENSE}
 */

/**
 * Since the implementation is only one short file, this file is directly copied here instead of
 * adding it as a dependency in the package.json file. That way we not only avoid adding another
 * dependency but we can easily tweak the code to our needs: We removed the WebAssembly (WASM)
 * implementation which takes some time to load and which we do not need for now, and added
 * TypeScript types. The modifications from the original source are kept to a minimum:
 *
 *   - This file is excluded from formatting in `.prettierignore` and from linting.
 *   - Code that is not necessary is commented out with four slashes (i.e. '////') instead of
 *     removed.
 *   - CommonJS exports have been converted to ESModules.
 *   - Instead of the original `nanoassert` library, we use our internal implementation of `assert`.
 *
 * @see {@link https://www.npmjs.com/package/blake2b}
 * @see {@link https://prettier.io/docs/en/ignore.html}
 * @see SOURCE: {@link https://raw.githubusercontent.com/emilbayes/blake2b/1f63e02/index.js}
 */

/* eslint-disable */

import {assert} from '../../utils/assert';
//// var b2wasm = require('blake2b-wasm')

// 64-bit unsigned addition
// Sets v[a,a+1] += v[b,b+1]
// v should be a Uint32Array
function ADD64AA (v, a, b) {
  var o0 = v[a] + v[b]
  var o1 = v[a + 1] + v[b + 1]
  if (o0 >= 0x100000000) {
    o1++
  }
  v[a] = o0
  v[a + 1] = o1
}

// 64-bit unsigned addition
// Sets v[a,a+1] += b
// b0 is the low 32 bits of b, b1 represents the high 32 bits
function ADD64AC (v, a, b0, b1) {
  var o0 = v[a] + b0
  if (b0 < 0) {
    o0 += 0x100000000
  }
  var o1 = v[a + 1] + b1
  if (o0 >= 0x100000000) {
    o1++
  }
  v[a] = o0
  v[a + 1] = o1
}

// Little-endian byte access
function B2B_GET32 (arr, i) {
  return (arr[i] ^
  (arr[i + 1] << 8) ^
  (arr[i + 2] << 16) ^
  (arr[i + 3] << 24))
}

// G Mixing function
// The ROTRs are inlined for speed
function B2B_G (a, b, c, d, ix, iy) {
  var x0 = m[ix]
  var x1 = m[ix + 1]
  var y0 = m[iy]
  var y1 = m[iy + 1]

  ADD64AA(v, a, b) // v[a,a+1] += v[b,b+1] ... in JS we must store a uint64 as two uint32s
  ADD64AC(v, a, x0, x1) // v[a, a+1] += x ... x0 is the low 32 bits of x, x1 is the high 32 bits

  // v[d,d+1] = (v[d,d+1] xor v[a,a+1]) rotated to the right by 32 bits
  var xor0 = v[d] ^ v[a]
  var xor1 = v[d + 1] ^ v[a + 1]
  v[d] = xor1
  v[d + 1] = xor0

  ADD64AA(v, c, d)

  // v[b,b+1] = (v[b,b+1] xor v[c,c+1]) rotated right by 24 bits
  xor0 = v[b] ^ v[c]
  xor1 = v[b + 1] ^ v[c + 1]
  v[b] = (xor0 >>> 24) ^ (xor1 << 8)
  v[b + 1] = (xor1 >>> 24) ^ (xor0 << 8)

  ADD64AA(v, a, b)
  ADD64AC(v, a, y0, y1)

  // v[d,d+1] = (v[d,d+1] xor v[a,a+1]) rotated right by 16 bits
  xor0 = v[d] ^ v[a]
  xor1 = v[d + 1] ^ v[a + 1]
  v[d] = (xor0 >>> 16) ^ (xor1 << 16)
  v[d + 1] = (xor1 >>> 16) ^ (xor0 << 16)

  ADD64AA(v, c, d)

  // v[b,b+1] = (v[b,b+1] xor v[c,c+1]) rotated right by 63 bits
  xor0 = v[b] ^ v[c]
  xor1 = v[b + 1] ^ v[c + 1]
  v[b] = (xor1 >>> 31) ^ (xor0 << 1)
  v[b + 1] = (xor0 >>> 31) ^ (xor1 << 1)
}

// Initialization Vector
var BLAKE2B_IV32 = new Uint32Array([
  0xF3BCC908, 0x6A09E667, 0x84CAA73B, 0xBB67AE85,
  0xFE94F82B, 0x3C6EF372, 0x5F1D36F1, 0xA54FF53A,
  0xADE682D1, 0x510E527F, 0x2B3E6C1F, 0x9B05688C,
  0xFB41BD6B, 0x1F83D9AB, 0x137E2179, 0x5BE0CD19
])

var SIGMA8 = [
  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
  14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3,
  11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4,
  7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8,
  9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13,
  2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9,
  12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11,
  13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10,
  6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5,
  10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0,
  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
  14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3
]

// These are offsets into a uint64 buffer.
// Multiply them all by 2 to make them offsets into a uint32 buffer,
// because this is Javascript and we don't have uint64s
var SIGMA82 = new Uint8Array(SIGMA8.map(function (x) { return x * 2 }))

// Compression function. 'last' flag indicates last block.
// Note we're representing 16 uint64s as 32 uint32s
var v = new Uint32Array(32)
var m = new Uint32Array(32)
function blake2bCompress (ctx, last) {
  var i = 0

  // init work variables
  for (i = 0; i < 16; i++) {
    v[i] = ctx.h[i]
    v[i + 16] = BLAKE2B_IV32[i]
  }

  // low 64 bits of offset
  v[24] = v[24] ^ ctx.t
  v[25] = v[25] ^ (ctx.t / 0x100000000)
  // high 64 bits not supported, offset may not be higher than 2**53-1

  // last block flag set ?
  if (last) {
    v[28] = ~v[28]
    v[29] = ~v[29]
  }

  // get little-endian words
  for (i = 0; i < 32; i++) {
    m[i] = B2B_GET32(ctx.b, 4 * i)
  }

  // twelve rounds of mixing
  for (i = 0; i < 12; i++) {
    B2B_G(0, 8, 16, 24, SIGMA82[i * 16 + 0], SIGMA82[i * 16 + 1])
    B2B_G(2, 10, 18, 26, SIGMA82[i * 16 + 2], SIGMA82[i * 16 + 3])
    B2B_G(4, 12, 20, 28, SIGMA82[i * 16 + 4], SIGMA82[i * 16 + 5])
    B2B_G(6, 14, 22, 30, SIGMA82[i * 16 + 6], SIGMA82[i * 16 + 7])
    B2B_G(0, 10, 20, 30, SIGMA82[i * 16 + 8], SIGMA82[i * 16 + 9])
    B2B_G(2, 12, 22, 24, SIGMA82[i * 16 + 10], SIGMA82[i * 16 + 11])
    B2B_G(4, 14, 16, 26, SIGMA82[i * 16 + 12], SIGMA82[i * 16 + 13])
    B2B_G(6, 8, 18, 28, SIGMA82[i * 16 + 14], SIGMA82[i * 16 + 15])
  }

  for (i = 0; i < 16; i++) {
    ctx.h[i] = ctx.h[i] ^ v[i] ^ v[i + 16]
  }
}

// reusable parameter_block
var parameter_block = new Uint8Array([
  0, 0, 0, 0,      //  0: outlen, keylen, fanout, depth
  0, 0, 0, 0,      //  4: leaf length, sequential mode
  0, 0, 0, 0,      //  8: node offset
  0, 0, 0, 0,      // 12: node offset
  0, 0, 0, 0,      // 16: node depth, inner length, rfu
  0, 0, 0, 0,      // 20: rfu
  0, 0, 0, 0,      // 24: rfu
  0, 0, 0, 0,      // 28: rfu
  0, 0, 0, 0,      // 32: salt
  0, 0, 0, 0,      // 36: salt
  0, 0, 0, 0,      // 40: salt
  0, 0, 0, 0,      // 44: salt
  0, 0, 0, 0,      // 48: personal
  0, 0, 0, 0,      // 52: personal
  0, 0, 0, 0,      // 56: personal
  0, 0, 0, 0       // 60: personal
])

// Creates a BLAKE2b hashing context
// Requires an output length between 1 and 64 bytes
// Takes an optional Uint8Array key
function Blake2b (outlen, key, salt, personal) {
  // zero out parameter_block before usage
  parameter_block.fill(0)
  // state, 'param block'

  this.b = new Uint8Array(128)
  this.h = new Uint32Array(16)
  this.t = 0 // input count
  this.c = 0 // pointer within buffer
  this.outlen = outlen // output length in bytes

  parameter_block[0] = outlen
  if (key) parameter_block[1] = key.length
  parameter_block[2] = 1 // fanout
  parameter_block[3] = 1 // depth

  if (salt) parameter_block.set(salt, 32)
  if (personal) parameter_block.set(personal, 48)

  // initialize hash state
  for (var i = 0; i < 16; i++) {
    this.h[i] = BLAKE2B_IV32[i] ^ B2B_GET32(parameter_block, i * 4)
  }

  // key the hash, if applicable
  if (key) {
    blake2bUpdate(this, key)
    // at the end
    this.c = 128
  }
}

Blake2b.prototype.update = function (input) {
  assert(input instanceof Uint8Array, 'input must be Uint8Array or Buffer')
  blake2bUpdate(this, input)
  return this
}

Blake2b.prototype.digest = function (out) {
  var buf = (!out || out === 'binary' || out === 'hex') ? new Uint8Array(this.outlen) : out
  assert(buf instanceof Uint8Array, 'out must be "binary", "hex", Uint8Array, or Buffer')
  assert(buf.length >= this.outlen, 'out must have at least outlen bytes of space')
  blake2bFinal(this, buf)
  if (out === 'hex') return hexSlice(buf)
  return buf
}

Blake2b.prototype.final = Blake2b.prototype.digest

Blake2b.ready = function (cb) {
  b2wasm.ready(function () {
    cb() // ignore the error
  })
}

// Updates a BLAKE2b streaming hash
// Requires hash context and Uint8Array (byte array)
function blake2bUpdate (ctx, input) {
  for (var i = 0; i < input.length; i++) {
    if (ctx.c === 128) { // buffer full ?
      ctx.t += ctx.c // add counters
      blake2bCompress(ctx, false) // compress (not last)
      ctx.c = 0 // counter to zero
    }
    ctx.b[ctx.c++] = input[i]
  }
}

// Completes a BLAKE2b streaming hash
// Returns a Uint8Array containing the message digest
function blake2bFinal (ctx, out) {
  ctx.t += ctx.c // mark last block offset

  while (ctx.c < 128) { // fill up with zeros
    ctx.b[ctx.c++] = 0
  }
  blake2bCompress(ctx, true) // final block flag = 1

  for (var i = 0; i < ctx.outlen; i++) {
    out[i] = ctx.h[i >> 2] >> (8 * (i & 3))
  }
  return out
}

function hexSlice (buf) {
  var str = ''
  for (var i = 0; i < buf.length; i++) str += toHex(buf[i])
  return str
}

function toHex (n) {
  if (n < 16) return '0' + n.toString(16)
  return n.toString(16)
}

var Proto = Blake2b

export function createHash(outlen, key, salt, personal, noAssert) {
  if (noAssert !== true) {
    assert(outlen >= BYTES_MIN, 'outlen must be at least ' + BYTES_MIN + ', was given ' + outlen)
    assert(outlen <= BYTES_MAX, 'outlen must be at most ' + BYTES_MAX + ', was given ' + outlen)
    if (key != null) {
      assert(key instanceof Uint8Array, 'key must be Uint8Array or Buffer')
      assert(key.length >= KEYBYTES_MIN, 'key must be at least ' + KEYBYTES_MIN + ', was given ' + key.length)
      assert(key.length <= KEYBYTES_MAX, 'key must be at most ' + KEYBYTES_MAX + ', was given ' + key.length)
    }
    if (salt != null) {
      assert(salt instanceof Uint8Array, 'salt must be Uint8Array or Buffer')
      assert(salt.length === SALTBYTES, 'salt must be exactly ' + SALTBYTES + ', was given ' + salt.length)
    }
    if (personal != null) {
      assert(personal instanceof Uint8Array, 'personal must be Uint8Array or Buffer')
      assert(personal.length === PERSONALBYTES, 'personal must be exactly ' + PERSONALBYTES + ', was given ' + personal.length)
    }
  }

  return new Proto(outlen, key, salt, personal)
}

//// module.exports.ready = function (cb) {
////   b2wasm.ready(function () { // ignore errors
////     cb()
////   })
//// }

//// module.exports.WASM_SUPPORTED = b2wasm.SUPPORTED
//// module.exports.WASM_LOADED = false

export var BYTES_MIN = 16;
export var BYTES_MAX = 64;
export var BYTES = 32;
export var KEYBYTES_MIN = 16;
export var KEYBYTES_MAX = 64;
export var KEYBYTES = 32;
export var SALTBYTES = 16;
export var PERSONALBYTES = 16;

//// b2wasm.ready(function (err) {
////   if (!err) {
////     module.exports.WASM_LOADED = true
////     module.exports = b2wasm
////   }
//// })
