/**
 * 零依赖 MD5 实现
 * 直接从 ai_uniapp_v2/utils/md5.js 复用，用于生成请求 nonce
 * 用法：import md5 from '@/utils/md5.js' → md5('abc')
 */
function safeAdd(x, y) {
  const lsw = (x & 0xffff) + (y & 0xffff)
  const msw = (x >> 16) + (y >> 16) + (lsw >> 16)
  return (msw << 16) | (lsw & 0xffff)
}

function rotl(num, cnt) {
  return (num << cnt) | (num >>> (32 - cnt))
}

function cmn(q, a, b, x, s, t) {
  return safeAdd(rotl(safeAdd(safeAdd(a, q), safeAdd(x, t)), s), b)
}
function ff(a, b, c, d, x, s, t) { return cmn((b & c) | (~b & d), a, b, x, s, t) }
function gg(a, b, c, d, x, s, t) { return cmn((b & d) | (c & ~d), a, b, x, s, t) }
function hh(a, b, c, d, x, s, t) { return cmn(b ^ c ^ d, a, b, x, s, t) }
function ii(a, b, c, d, x, s, t) { return cmn(c ^ (b | ~d), a, b, x, s, t) }

function coreMd5(x, len) {
  x[len >> 5] |= 0x80 << len % 32
  x[(((len + 64) >>> 9) << 4) + 14] = len
  let a = 1732584193, b = -271733879, c = -1732584194, d = 271733878
  for (let i = 0; i < x.length; i += 16) {
    const oa = a, ob = b, oc = c, od = d
    a = ff(a,b,c,d, x[i],   7, -680876936)
    d = ff(d,a,b,c, x[i+1], 12, -389564586)
    c = ff(c,d,a,b, x[i+2], 17,  606105819)
    b = ff(b,c,d,a, x[i+3], 22, -1044525330)
    a = ff(a,b,c,d, x[i+4],  7, -176418897)
    d = ff(d,a,b,c, x[i+5], 12,  1200080426)
    c = ff(c,d,a,b, x[i+6], 17, -1473231341)
    b = ff(b,c,d,a, x[i+7], 22, -45705983)
    a = ff(a,b,c,d, x[i+8],  7,  1770035416)
    d = ff(d,a,b,c, x[i+9], 12, -1958414417)
    c = ff(c,d,a,b, x[i+10],17, -42063)
    b = ff(b,c,d,a, x[i+11],22, -1990404162)
    a = ff(a,b,c,d, x[i+12], 7,  1804603682)
    d = ff(d,a,b,c, x[i+13],12, -40341101)
    c = ff(c,d,a,b, x[i+14],17, -1502002290)
    b = ff(b,c,d,a, x[i+15],22,  1236535329)
    a = gg(a,b,c,d, x[i+1],  5, -165796510)
    d = gg(d,a,b,c, x[i+6],  9, -1069501632)
    c = gg(c,d,a,b, x[i+11],14,  643717713)
    b = gg(b,c,d,a, x[i],   20, -373897302)
    a = gg(a,b,c,d, x[i+5],  5, -701558691)
    d = gg(d,a,b,c, x[i+10], 9,  38016083)
    c = gg(c,d,a,b, x[i+15],14, -660478335)
    b = gg(b,c,d,a, x[i+4], 20, -405537848)
    a = gg(a,b,c,d, x[i+9],  5,  568446438)
    d = gg(d,a,b,c, x[i+14], 9, -1019803690)
    c = gg(c,d,a,b, x[i+3], 14, -187363961)
    b = gg(b,c,d,a, x[i+8], 20,  1163531501)
    a = gg(a,b,c,d, x[i+13], 5, -1444681467)
    d = gg(d,a,b,c, x[i+2],  9, -51403784)
    c = gg(c,d,a,b, x[i+7], 14,  1735328473)
    b = gg(b,c,d,a, x[i+12],20, -1926607734)
    a = hh(a,b,c,d, x[i+5],  4, -378558)
    d = hh(d,a,b,c, x[i+8], 11, -2022574463)
    c = hh(c,d,a,b, x[i+11],16,  1839030562)
    b = hh(b,c,d,a, x[i+14],23, -35309556)
    a = hh(a,b,c,d, x[i+1],  4, -1530992060)
    d = hh(d,a,b,c, x[i+4], 11,  1272893353)
    c = hh(c,d,a,b, x[i+7], 16, -155497632)
    b = hh(b,c,d,a, x[i+10],23, -1094730640)
    a = hh(a,b,c,d, x[i+13], 4,  681279174)
    d = hh(d,a,b,c, x[i],   11, -358537222)
    c = hh(c,d,a,b, x[i+3], 16, -722521979)
    b = hh(b,c,d,a, x[i+6], 23,  76029189)
    a = hh(a,b,c,d, x[i+9],  4, -640364487)
    d = hh(d,a,b,c, x[i+12],11, -421815835)
    c = hh(c,d,a,b, x[i+15],16,  530742520)
    b = hh(b,c,d,a, x[i+2], 23, -995338651)
    a = ii(a,b,c,d, x[i],    6, -198630844)
    d = ii(d,a,b,c, x[i+7], 10,  1126891415)
    c = ii(c,d,a,b, x[i+14],15, -1416354905)
    b = ii(b,c,d,a, x[i+5], 21, -57434055)
    a = ii(a,b,c,d, x[i+12], 6,  1700485571)
    d = ii(d,a,b,c, x[i+3], 10, -1894986606)
    c = ii(c,d,a,b, x[i+10],15, -1051523)
    b = ii(b,c,d,a, x[i+1], 21, -2054922799)
    a = ii(a,b,c,d, x[i+8],  6,  1873313359)
    d = ii(d,a,b,c, x[i+15],10, -30611744)
    c = ii(c,d,a,b, x[i+6], 15, -1560198380)
    b = ii(b,c,d,a, x[i+13],21,  1309151649)
    a = ii(a,b,c,d, x[i+4],  6, -145523070)
    d = ii(d,a,b,c, x[i+11],10, -1120210379)
    c = ii(c,d,a,b, x[i+2], 15,  718787259)
    b = ii(b,c,d,a, x[i+9], 21, -343485551)
    a = safeAdd(a, oa); b = safeAdd(b, ob); c = safeAdd(c, oc); d = safeAdd(d, od)
  }
  return [a, b, c, d]
}

function binlToRstr(i) { let o = ''; for (let j = 0; j < i.length * 32; j += 8) o += String.fromCharCode((i[j >> 5] >>> j % 32) & 0xff); return o }
function rstrToBinl(i) { const o = []; for (let j = 0; j < i.length * 8; j += 8) o[j >> 5] |= (i.charCodeAt(j / 8) & 0xff) << j % 32; return o }
function rstrMd5(s) { return binlToRstr(coreMd5(rstrToBinl(s), s.length * 8)) }
function rstrToHex(i) { const h = '0123456789abcdef'; let o = ''; for (let j = 0; j < i.length; j++) { const x = i.charCodeAt(j); o += h.charAt((x >>> 4) & 0x0f) + h.charAt(x & 0x0f) } return o }
function strToUtf8(i) { return unescape(encodeURIComponent(i)) }

export default function md5(str) {
  return rstrToHex(rstrMd5(strToUtf8(String(str))))
}