// ESP32 SHA accelerator (SHA-1 / SHA-256 / SHA-384 / SHA-512)
const K256 = new Int32Array([
  0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
  0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
  0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
  0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2]);
const H256 = [0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19];
const H1 = [0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0];
const rotr = (x, n) => (x >>> n) | (x << (32 - n));
const rotl = (x, n) => (x << n) | (x >>> (32 - n));

function sha256Block(st, w16) {
  const w = new Int32Array(64);
  for (let i = 0; i < 16; i++) w[i] = w16[i];
  for (let i = 16; i < 64; i++) {
    const s0 = rotr(w[i - 15], 7) ^ rotr(w[i - 15], 18) ^ (w[i - 15] >>> 3);
    const s1 = rotr(w[i - 2], 17) ^ rotr(w[i - 2], 19) ^ (w[i - 2] >>> 10);
    w[i] = (w[i - 16] + s0 + w[i - 7] + s1) | 0;
  }
  let a = st[0], b = st[1], c = st[2], d = st[3], e = st[4], f = st[5], g = st[6], h = st[7];
  for (let i = 0; i < 64; i++) {
    const S1 = rotr(e, 6) ^ rotr(e, 11) ^ rotr(e, 25);
    const ch = (e & f) ^ (~e & g);
    const t1 = (h + S1 + ch + K256[i] + w[i]) | 0;
    const S0 = rotr(a, 2) ^ rotr(a, 13) ^ rotr(a, 22);
    const maj = (a & b) ^ (a & c) ^ (b & c);
    const t2 = (S0 + maj) | 0;
    h = g; g = f; f = e; e = (d + t1) | 0; d = c; c = b; b = a; a = (t1 + t2) | 0;
  }
  st[0] = (st[0] + a) | 0; st[1] = (st[1] + b) | 0; st[2] = (st[2] + c) | 0; st[3] = (st[3] + d) | 0;
  st[4] = (st[4] + e) | 0; st[5] = (st[5] + f) | 0; st[6] = (st[6] + g) | 0; st[7] = (st[7] + h) | 0;
}
function sha1Block(st, w16) {
  const w = new Int32Array(80);
  for (let i = 0; i < 16; i++) w[i] = w16[i];
  for (let i = 16; i < 80; i++) w[i] = rotl(w[i - 3] ^ w[i - 8] ^ w[i - 14] ^ w[i - 16], 1);
  let a = st[0], b = st[1], c = st[2], d = st[3], e = st[4];
  for (let i = 0; i < 80; i++) {
    let f, k;
    if (i < 20) { f = (b & c) | (~b & d); k = 0x5A827999; }
    else if (i < 40) { f = b ^ c ^ d; k = 0x6ED9EBA1; }
    else if (i < 60) { f = (b & c) | (b & d) | (c & d); k = 0x8F1BBCDC; }
    else { f = b ^ c ^ d; k = 0xCA62C1D6; }
    const t = (rotl(a, 5) + f + e + k + w[i]) | 0;
    e = d; d = c; c = rotl(b, 30); b = a; a = t;
  }
  st[0] = (st[0] + a) | 0; st[1] = (st[1] + b) | 0; st[2] = (st[2] + c) | 0; st[3] = (st[3] + d) | 0; st[4] = (st[4] + e) | 0;
}
const K512 = [
  0x428a2f98d728ae22n, 0x7137449123ef65cdn, 0xb5c0fbcfec4d3b2fn, 0xe9b5dba58189dbbcn, 0x3956c25bf348b538n, 0x59f111f1b605d019n, 0x923f82a4af194f9bn, 0xab1c5ed5da6d8118n,
  0xd807aa98a3030242n, 0x12835b0145706fben, 0x243185be4ee4b28cn, 0x550c7dc3d5ffb4e2n, 0x72be5d74f27b896fn, 0x80deb1fe3b1696b1n, 0x9bdc06a725c71235n, 0xc19bf174cf692694n,
  0xe49b69c19ef14ad2n, 0xefbe4786384f25e3n, 0x0fc19dc68b8cd5b5n, 0x240ca1cc77ac9c65n, 0x2de92c6f592b0275n, 0x4a7484aa6ea6e483n, 0x5cb0a9dcbd41fbd4n, 0x76f988da831153b5n,
  0x983e5152ee66dfabn, 0xa831c66d2db43210n, 0xb00327c898fb213fn, 0xbf597fc7beef0ee4n, 0xc6e00bf33da88fc2n, 0xd5a79147930aa725n, 0x06ca6351e003826fn, 0x142929670a0e6e70n,
  0x27b70a8546d22ffcn, 0x2e1b21385c26c926n, 0x4d2c6dfc5ac42aedn, 0x53380d139d95b3dfn, 0x650a73548baf63den, 0x766a0abb3c77b2a8n, 0x81c2c92e47edaee6n, 0x92722c851482353bn,
  0xa2bfe8a14cf10364n, 0xa81a664bbc423001n, 0xc24b8b70d0f89791n, 0xc76c51a30654be30n, 0xd192e819d6ef5218n, 0xd69906245565a910n, 0xf40e35855771202an, 0x106aa07032bbd1b8n,
  0x19a4c116b8d2d0c8n, 0x1e376c085141ab53n, 0x2748774cdf8eeb99n, 0x34b0bcb5e19b48a8n, 0x391c0cb3c5c95a63n, 0x4ed8aa4ae3418acbn, 0x5b9cca4f7763e373n, 0x682e6ff3d6b2b8a3n,
  0x748f82ee5defb2fcn, 0x78a5636f43172f60n, 0x84c87814a1f0ab72n, 0x8cc702081a6439ecn, 0x90befffa23631e28n, 0xa4506cebde82bde9n, 0xbef9a3f7b2c67915n, 0xc67178f2e372532bn,
  0xca273eceea26619cn, 0xd186b8c721c0c207n, 0xeada7dd6cde0eb1en, 0xf57d4f7fee6ed178n, 0x06f067aa72176fban, 0x0a637dc5a2c898a6n, 0x113f9804bef90daen, 0x1b710b35131c471bn,
  0x28db77f523047d84n, 0x32caab7b40c72493n, 0x3c9ebe0a15c9bebcn, 0x431d67c49c100d4cn, 0x4cc5d4becb3e42b6n, 0x597f299cfc657e2an, 0x5fcb6fab3ad6faecn, 0x6c44198c4a475817n];
const H512 = [0x6a09e667f3bcc908n, 0xbb67ae8584caa73bn, 0x3c6ef372fe94f82bn, 0xa54ff53a5f1d36f1n, 0x510e527fade682d1n, 0x9b05688c2b3e6c1fn, 0x1f83d9abfb41bd6bn, 0x5be0cd19137e2179n];
const H384 = [0xcbbb9d5dc1059ed8n, 0x629a292a367cd507n, 0x9159015a3070dd17n, 0x152fecd8f70e5939n, 0x67332667ffc00b31n, 0x8eb44a8768581511n, 0xdb0c2e0d64f98fa7n, 0x47b5481dbefa4fa4n];
const M64 = (1n << 64n) - 1n;
const r64 = (x, n) => ((x >> BigInt(n)) | (x << BigInt(64 - n))) & M64;
function sha512Block(st, w32) {
  const w = new Array(80);
  for (let i = 0; i < 16; i++) w[i] = (BigInt(w32[2 * i] >>> 0) << 32n) | BigInt(w32[2 * i + 1] >>> 0);
  for (let i = 16; i < 80; i++) {
    const s0 = r64(w[i - 15], 1) ^ r64(w[i - 15], 8) ^ (w[i - 15] >> 7n);
    const s1 = r64(w[i - 2], 19) ^ r64(w[i - 2], 61) ^ (w[i - 2] >> 6n);
    w[i] = (w[i - 16] + s0 + w[i - 7] + s1) & M64;
  }
  let [a, b, c, d, e, f, g, h] = st;
  for (let i = 0; i < 80; i++) {
    const S1 = r64(e, 14) ^ r64(e, 18) ^ r64(e, 41);
    const ch = (e & f) ^ (~e & M64 & g);
    const t1 = (h + S1 + ch + K512[i] + w[i]) & M64;
    const S0 = r64(a, 28) ^ r64(a, 34) ^ r64(a, 39);
    const maj = (a & b) ^ (a & c) ^ (b & c);
    const t2 = (S0 + maj) & M64;
    h = g; g = f; f = e; e = (d + t1) & M64; d = c; c = b; b = a; a = (t1 + t2) & M64;
  }
  const n = [a, b, c, d, e, f, g, h];
  for (let i = 0; i < 8; i++) st[i] = (st[i] + n[i]) & M64;
}

export class ShaEngine {
  constructor(soc) { this.soc = soc; this.text = new Int32Array(32); this.s1 = H1.slice(); this.s256 = new Int32Array(H256); this.s512 = H512.slice(); }
  read(off) { if (off < 0x80) return this.text[off >> 2]; return 0; }
  write(off, v) {
    const t = this.text;
    if (off < 0x80) { t[off >> 2] = v; return; }
    switch (off) {
      case 0x80: this.s1 = H1.slice(); sha1Block(this.s1, t); break;
      case 0x84: sha1Block(this.s1, t); break;
      case 0x88: for (let i = 0; i < 5; i++) t[i] = this.s1[i]; break;
      case 0x90: this.s256 = new Int32Array(H256); sha256Block(this.s256, t); break;
      case 0x94: sha256Block(this.s256, t); break;
      case 0x98: for (let i = 0; i < 8; i++) t[i] = this.s256[i]; break;
      case 0xA0: this.s512 = H384.slice(); sha512Block(this.s512, t); break;
      case 0xB0: this.s512 = H512.slice(); sha512Block(this.s512, t); break;
      case 0xA4: case 0xB4: sha512Block(this.s512, t); break;
      case 0xA8: case 0xB8: for (let i = 0; i < 8; i++) { t[2 * i] = Number((this.s512[i] >> 32n) & 0xFFFFFFFFn) | 0; t[2 * i + 1] = Number(this.s512[i] & 0xFFFFFFFFn) | 0; } break;
    }
  }
}