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import { HashAlgorithm } from "./hash.ts";
/* * Calculate the SHA-1 of an array of big-endian words, and a bit length */function binb_sha1(x: number[], len: number): number[] {  /* append padding */  x[len >> 5] |= 0x80 << (24 - (len % 32));  x[(((len + 64) >> 9) << 4) + 15] = len;
  const w: number[] = [];  let a = 1732584193;  let b = -271733879;  let c = -1732584194;  let d = 271733878;  let e = -1009589776;
  for (let i = 0; i < x.length; i += 16) {    const olda = a;    const oldb = b;    const oldc = c;    const oldd = d;    const olde = e;
    for (let j = 0; j < 80; j++) {      if (j < 16) w[j] = x[i + j];      else w[j] = bit_rol(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1);      var t = safe_add(        safe_add(bit_rol(a, 5), sha1_ft(j, b, c, d)),        safe_add(safe_add(e, w[j]), sha1_kt(j)),      );      e = d;      d = c;      c = bit_rol(b, 30);      b = a;      a = t;    }
    a = safe_add(a, olda);    b = safe_add(b, oldb);    c = safe_add(c, oldc);    d = safe_add(d, oldd);    e = safe_add(e, olde);  }  return [a, b, c, d, e];}
/* * Perform the appropriate triplet combination function for the current * iteration */function sha1_ft(t: number, b: number, c: number, d: number): number {  if (t < 20) return (b & c) | (~b & d);  if (t < 40) return b ^ c ^ d;  if (t < 60) return (b & c) | (b & d) | (c & d);  return b ^ c ^ d;}
/* * Determine the appropriate additive constant for the current iteration */function sha1_kt(t: number): number {  return t < 20    ? 1518500249    : t < 40    ? 1859775393    : t < 60    ? -1894007588    : -899497514;}
/* * Add integers, wrapping at 2^32. This uses 16-bit operations internally * to work around bugs in some JS interpreters. */function safe_add(x: number, y: number): number {  const lsw = (x & 0xffff) + (y & 0xffff);  const msw = (x >> 16) + (y >> 16) + (lsw >> 16);  return (msw << 16) | (lsw & 0xffff);}
/* * Bitwise rotate a 32-bit number to the left. */function bit_rol(num: number, cnt: number): number {  return (num << cnt) | (num >>> (32 - cnt));}
export class Sha1Hash implements HashAlgorithm {  digest(bytes: Uint8Array): Uint8Array {    let data: number[] = [];    for (var i = 0; i < bytes.length * 8; i += 8) {      data[i >> 5] |= (bytes[i / 8] & 0xff) << (24 - (i % 32));    }    data = binb_sha1(data, bytes.length * 8);    return this.toStrBytes(data);  }
  /*   * Convert an array of big-endian words to a string   */  private toStrBytes(input: number[]): Uint8Array {    let pos = 0;    const data = new Uint8Array(input.length * 4);    for (let i = 0; i < input.length * 32; i += 8) {      data[pos++] = (input[i >> 5] >> (24 - (i % 32))) & 0xff;    }    return data;  }}