// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
/*
 * [js-sha1]{@link https://github.com/emn178/js-sha1}
 *
 * @version 0.6.0
 * @author Chen, Yi-Cyuan [emn178@gmail.com]
 * @copyright Chen, Yi-Cyuan 2014-2017
 * @license MIT
 */

export type Message = string | number[] | ArrayBuffer;

const HEX_CHARS = "0123456789abcdef".split("");
const EXTRA = [-2147483648, 8388608, 32768, 128] as const;
const SHIFT = [24, 16, 8, 0] as const;

const blocks: number[] = [];

export class Sha1 {
  #blocks!: number[];
  #block!: number;
  #start!: number;
  #bytes!: number;
  #hBytes!: number;
  #finalized!: boolean;
  #hashed!: boolean;

  #h0 = 0x67452301;
  #h1 = 0xefcdab89;
  #h2 = 0x98badcfe;
  #h3 = 0x10325476;
  #h4 = 0xc3d2e1f0;
  #lastByteIndex = 0;

  constructor(sharedMemory = false) {
    if (sharedMemory) {
      // deno-fmt-ignore
      blocks[0] = blocks[16] = blocks[1] = blocks[2] = blocks[3] = blocks[4] = blocks[5] = blocks[6] = blocks[7] = blocks[8] = blocks[9] = blocks[10] = blocks[11] = blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0;
      this.#blocks = blocks;
    } else {
      this.#blocks = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
    }

    this.#h0 = 0x67452301;
    this.#h1 = 0xefcdab89;
    this.#h2 = 0x98badcfe;
    this.#h3 = 0x10325476;
    this.#h4 = 0xc3d2e1f0;

    this.#block = this.#start = this.#bytes = this.#hBytes = 0;
    this.#finalized = this.#hashed = false;
  }

  update(message: Message): this {
    if (this.#finalized) {
      return this;
    }

    let msg: string | number[] | Uint8Array | undefined;
    if (message instanceof ArrayBuffer) {
      msg = new Uint8Array(message);
    } else {
      msg = message;
    }

    let index = 0;
    const length = msg.length;
    const blocks = this.#blocks;

    while (index < length) {
      let i: number;
      if (this.#hashed) {
        this.#hashed = false;
        blocks[0] = this.#block;
        // deno-fmt-ignore
        blocks[16] = blocks[1] = blocks[2] = blocks[3] = blocks[4] = blocks[5] = blocks[6] = blocks[7] = blocks[8] = blocks[9] = blocks[10] = blocks[11] = blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0;
      }

      if (typeof msg !== "string") {
        for (i = this.#start; index < length && i < 64; ++index) {
          blocks[i >> 2] |= msg[index] << SHIFT[i++ & 3];
        }
      } else {
        for (i = this.#start; index < length && i < 64; ++index) {
          let code = msg.charCodeAt(index);
          if (code < 0x80) {
            blocks[i >> 2] |= code << SHIFT[i++ & 3];
          } else if (code < 0x800) {
            blocks[i >> 2] |= (0xc0 | (code >> 6)) << SHIFT[i++ & 3];
            blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3];
          } else if (code < 0xd800 || code >= 0xe000) {
            blocks[i >> 2] |= (0xe0 | (code >> 12)) << SHIFT[i++ & 3];
            blocks[i >> 2] |= (0x80 | ((code >> 6) & 0x3f)) << SHIFT[i++ & 3];
            blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3];
          } else {
            code = 0x10000 +
              (((code & 0x3ff) << 10) | (msg.charCodeAt(++index) & 0x3ff));
            blocks[i >> 2] |= (0xf0 | (code >> 18)) << SHIFT[i++ & 3];
            blocks[i >> 2] |= (0x80 | ((code >> 12) & 0x3f)) << SHIFT[i++ & 3];
            blocks[i >> 2] |= (0x80 | ((code >> 6) & 0x3f)) << SHIFT[i++ & 3];
            blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3];
          }
        }
      }

      this.#lastByteIndex = i;
      this.#bytes += i - this.#start;
      if (i >= 64) {
        this.#block = blocks[16];
        this.#start = i - 64;
        this.hash();
        this.#hashed = true;
      } else {
        this.#start = i;
      }
    }
    if (this.#bytes > 4294967295) {
      this.#hBytes += (this.#bytes / 4294967296) >>> 0;
      this.#bytes = this.#bytes >>> 0;
    }
    return this;
  }

  private finalize(): void {
    if (this.#finalized) {
      return;
    }
    this.#finalized = true;
    const blocks = this.#blocks;
    const i = this.#lastByteIndex;
    blocks[16] = this.#block;
    blocks[i >> 2] |= EXTRA[i & 3];
    this.#block = blocks[16];
    if (i >= 56) {
      if (!this.#hashed) {
        this.hash();
      }
      blocks[0] = this.#block;
      // deno-fmt-ignore
      blocks[16] = blocks[1] = blocks[2] = blocks[3] = blocks[4] = blocks[5] = blocks[6] = blocks[7] = blocks[8] = blocks[9] = blocks[10] = blocks[11] = blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0;
    }
    blocks[14] = (this.#hBytes << 3) | (this.#bytes >>> 29);
    blocks[15] = this.#bytes << 3;
    this.hash();
  }

  private hash(): void {
    let a = this.#h0;
    let b = this.#h1;
    let c = this.#h2;
    let d = this.#h3;
    let e = this.#h4;
    let f: number;
    let j: number;
    let t: number;
    const blocks = this.#blocks;

    for (j = 16; j < 80; ++j) {
      t = blocks[j - 3] ^ blocks[j - 8] ^ blocks[j - 14] ^ blocks[j - 16];
      blocks[j] = (t << 1) | (t >>> 31);
    }

    for (j = 0; j < 20; j += 5) {
      f = (b & c) | (~b & d);
      t = (a << 5) | (a >>> 27);
      e = (t + f + e + 1518500249 + blocks[j]) >>> 0;
      b = (b << 30) | (b >>> 2);

      f = (a & b) | (~a & c);
      t = (e << 5) | (e >>> 27);
      d = (t + f + d + 1518500249 + blocks[j + 1]) >>> 0;
      a = (a << 30) | (a >>> 2);

      f = (e & a) | (~e & b);
      t = (d << 5) | (d >>> 27);
      c = (t + f + c + 1518500249 + blocks[j + 2]) >>> 0;
      e = (e << 30) | (e >>> 2);

      f = (d & e) | (~d & a);
      t = (c << 5) | (c >>> 27);
      b = (t + f + b + 1518500249 + blocks[j + 3]) >>> 0;
      d = (d << 30) | (d >>> 2);

      f = (c & d) | (~c & e);
      t = (b << 5) | (b >>> 27);
      a = (t + f + a + 1518500249 + blocks[j + 4]) >>> 0;
      c = (c << 30) | (c >>> 2);
    }

    for (; j < 40; j += 5) {
      f = b ^ c ^ d;
      t = (a << 5) | (a >>> 27);
      e = (t + f + e + 1859775393 + blocks[j]) >>> 0;
      b = (b << 30) | (b >>> 2);

      f = a ^ b ^ c;
      t = (e << 5) | (e >>> 27);
      d = (t + f + d + 1859775393 + blocks[j + 1]) >>> 0;
      a = (a << 30) | (a >>> 2);

      f = e ^ a ^ b;
      t = (d << 5) | (d >>> 27);
      c = (t + f + c + 1859775393 + blocks[j + 2]) >>> 0;
      e = (e << 30) | (e >>> 2);

      f = d ^ e ^ a;
      t = (c << 5) | (c >>> 27);
      b = (t + f + b + 1859775393 + blocks[j + 3]) >>> 0;
      d = (d << 30) | (d >>> 2);

      f = c ^ d ^ e;
      t = (b << 5) | (b >>> 27);
      a = (t + f + a + 1859775393 + blocks[j + 4]) >>> 0;
      c = (c << 30) | (c >>> 2);
    }

    for (; j < 60; j += 5) {
      f = (b & c) | (b & d) | (c & d);
      t = (a << 5) | (a >>> 27);
      e = (t + f + e - 1894007588 + blocks[j]) >>> 0;
      b = (b << 30) | (b >>> 2);

      f = (a & b) | (a & c) | (b & c);
      t = (e << 5) | (e >>> 27);
      d = (t + f + d - 1894007588 + blocks[j + 1]) >>> 0;
      a = (a << 30) | (a >>> 2);

      f = (e & a) | (e & b) | (a & b);
      t = (d << 5) | (d >>> 27);
      c = (t + f + c - 1894007588 + blocks[j + 2]) >>> 0;
      e = (e << 30) | (e >>> 2);

      f = (d & e) | (d & a) | (e & a);
      t = (c << 5) | (c >>> 27);
      b = (t + f + b - 1894007588 + blocks[j + 3]) >>> 0;
      d = (d << 30) | (d >>> 2);

      f = (c & d) | (c & e) | (d & e);
      t = (b << 5) | (b >>> 27);
      a = (t + f + a - 1894007588 + blocks[j + 4]) >>> 0;
      c = (c << 30) | (c >>> 2);
    }

    for (; j < 80; j += 5) {
      f = b ^ c ^ d;
      t = (a << 5) | (a >>> 27);
      e = (t + f + e - 899497514 + blocks[j]) >>> 0;
      b = (b << 30) | (b >>> 2);

      f = a ^ b ^ c;
      t = (e << 5) | (e >>> 27);
      d = (t + f + d - 899497514 + blocks[j + 1]) >>> 0;
      a = (a << 30) | (a >>> 2);

      f = e ^ a ^ b;
      t = (d << 5) | (d >>> 27);
      c = (t + f + c - 899497514 + blocks[j + 2]) >>> 0;
      e = (e << 30) | (e >>> 2);

      f = d ^ e ^ a;
      t = (c << 5) | (c >>> 27);
      b = (t + f + b - 899497514 + blocks[j + 3]) >>> 0;
      d = (d << 30) | (d >>> 2);

      f = c ^ d ^ e;
      t = (b << 5) | (b >>> 27);
      a = (t + f + a - 899497514 + blocks[j + 4]) >>> 0;
      c = (c << 30) | (c >>> 2);
    }

    this.#h0 = (this.#h0 + a) >>> 0;
    this.#h1 = (this.#h1 + b) >>> 0;
    this.#h2 = (this.#h2 + c) >>> 0;
    this.#h3 = (this.#h3 + d) >>> 0;
    this.#h4 = (this.#h4 + e) >>> 0;
  }

  hex(): string {
    this.finalize();

    const h0 = this.#h0;
    const h1 = this.#h1;
    const h2 = this.#h2;
    const h3 = this.#h3;
    const h4 = this.#h4;

    return (
      HEX_CHARS[(h0 >> 28) & 0x0f] +
      HEX_CHARS[(h0 >> 24) & 0x0f] +
      HEX_CHARS[(h0 >> 20) & 0x0f] +
      HEX_CHARS[(h0 >> 16) & 0x0f] +
      HEX_CHARS[(h0 >> 12) & 0x0f] +
      HEX_CHARS[(h0 >> 8) & 0x0f] +
      HEX_CHARS[(h0 >> 4) & 0x0f] +
      HEX_CHARS[h0 & 0x0f] +
      HEX_CHARS[(h1 >> 28) & 0x0f] +
      HEX_CHARS[(h1 >> 24) & 0x0f] +
      HEX_CHARS[(h1 >> 20) & 0x0f] +
      HEX_CHARS[(h1 >> 16) & 0x0f] +
      HEX_CHARS[(h1 >> 12) & 0x0f] +
      HEX_CHARS[(h1 >> 8) & 0x0f] +
      HEX_CHARS[(h1 >> 4) & 0x0f] +
      HEX_CHARS[h1 & 0x0f] +
      HEX_CHARS[(h2 >> 28) & 0x0f] +
      HEX_CHARS[(h2 >> 24) & 0x0f] +
      HEX_CHARS[(h2 >> 20) & 0x0f] +
      HEX_CHARS[(h2 >> 16) & 0x0f] +
      HEX_CHARS[(h2 >> 12) & 0x0f] +
      HEX_CHARS[(h2 >> 8) & 0x0f] +
      HEX_CHARS[(h2 >> 4) & 0x0f] +
      HEX_CHARS[h2 & 0x0f] +
      HEX_CHARS[(h3 >> 28) & 0x0f] +
      HEX_CHARS[(h3 >> 24) & 0x0f] +
      HEX_CHARS[(h3 >> 20) & 0x0f] +
      HEX_CHARS[(h3 >> 16) & 0x0f] +
      HEX_CHARS[(h3 >> 12) & 0x0f] +
      HEX_CHARS[(h3 >> 8) & 0x0f] +
      HEX_CHARS[(h3 >> 4) & 0x0f] +
      HEX_CHARS[h3 & 0x0f] +
      HEX_CHARS[(h4 >> 28) & 0x0f] +
      HEX_CHARS[(h4 >> 24) & 0x0f] +
      HEX_CHARS[(h4 >> 20) & 0x0f] +
      HEX_CHARS[(h4 >> 16) & 0x0f] +
      HEX_CHARS[(h4 >> 12) & 0x0f] +
      HEX_CHARS[(h4 >> 8) & 0x0f] +
      HEX_CHARS[(h4 >> 4) & 0x0f] +
      HEX_CHARS[h4 & 0x0f]
    );
  }

  toString(): string {
    return this.hex();
  }

  digest(): number[] {
    this.finalize();

    const h0 = this.#h0;
    const h1 = this.#h1;
    const h2 = this.#h2;
    const h3 = this.#h3;
    const h4 = this.#h4;

    return [
      (h0 >> 24) & 0xff,
      (h0 >> 16) & 0xff,
      (h0 >> 8) & 0xff,
      h0 & 0xff,
      (h1 >> 24) & 0xff,
      (h1 >> 16) & 0xff,
      (h1 >> 8) & 0xff,
      h1 & 0xff,
      (h2 >> 24) & 0xff,
      (h2 >> 16) & 0xff,
      (h2 >> 8) & 0xff,
      h2 & 0xff,
      (h3 >> 24) & 0xff,
      (h3 >> 16) & 0xff,
      (h3 >> 8) & 0xff,
      h3 & 0xff,
      (h4 >> 24) & 0xff,
      (h4 >> 16) & 0xff,
      (h4 >> 8) & 0xff,
      h4 & 0xff,
    ];
  }

  array(): number[] {
    return this.digest();
  }

  arrayBuffer(): ArrayBuffer {
    this.finalize();

    const buffer = new ArrayBuffer(20);
    const dataView = new DataView(buffer);
    dataView.setUint32(0, this.#h0);
    dataView.setUint32(4, this.#h1);
    dataView.setUint32(8, this.#h2);
    dataView.setUint32(12, this.#h3);
    dataView.setUint32(16, this.#h4);

    return buffer;
  }
}