/**
 * SHA1
 * Implementation of SHA1 algorithm as described in RFC 3174
 * @see https://www.ietf.org/rfc/rfc3174.txt
 *
 * @param {string} string input to be hashed
 * @param {boolean} [raw=false] If the optional binary is set to true, then the sha1 digest is instead returned in raw binary format with a length of 20, otherwise the returned value is a 40-character hexadecimal number.
 * @return {string|false} Calculated the sha1 hash of a string, returning false if fail
 */
const sha1 = (string, raw = false) => {
    string = typeof string === 'number' ? string.toString() : (
        typeof string === 'boolean' ? (string ? '1' : '0') : string + ''
    );

    const strLen = string.length;
    const len = strLen * 8;
    const binLen = strLen >> 2;
    if (binLen <= 0) {
        return false;
    }

    const rotate_left = (n, s) => (n << s) | (n >>> (32 - s));
    const safe_add_16b = (x, y) =>  ((x >> 16) + (y >> 16) + (((x & 0xFFFF) + (y & 0xFFFF)) >> 16) << 16) | (((x & 0xFFFF) + (y & 0xFFFF)) & 0xFFFF);
    /**
     * Perform the appropriate triplet combination function for the current iteration
     * @param {number} t
     * @param {number} b
     * @param {number} c
     * @param {number} d
     * @return {number}
     */
    const sha1_ft = (t, b, c, d) => {
        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
     * @param {number} t
     * @return {number}
     */
    const sha1_kt = (t)  => {
        if (t < 20) {
            return 1518500249;
        }
        if (t < 40) {
            return 1859775393;
        }
        if (t < 60) {
            return -1894007588;
        }
        return -899497514;
    }
    let i, t;
    let binArray = new Array(binLen);
    for (i = 0; i < len; i += 8) {
        binArray[i >> 5] |= (string.charCodeAt(i / 8) & 0xFF) << (24 - i % 32);
    }
    /* append padding */
    binArray[len >> 5] |= 0x80 << (24 - len % 32);
    binArray[((len + 64 >> 9) << 4) + 15] = len;
    let wordArray = Array(80),
        a = 1732584193,
        b = -271733879,
        c = -1732584194,
        d = 271733878,
        e = -1009589776;

    for (i = 0; i < binArray.length; i += 16) {
        let oldA = a,
            oldB = b,
            oldC = c,
            oldD = d,
            oldE = e;

        for (let j = 0; j < 80; j++) {
            wordArray[j] = j < 16 ? binArray[i + j] : rotate_left(wordArray[j - 3] ^ wordArray[j - 8] ^ wordArray[j - 14] ^ wordArray[j - 16], 1);
            t = safe_add_16b(
                safe_add_16b(
                    rotate_left(a, 5),
                    sha1_ft(j, b, c, d)
                ),
                safe_add_16b(
                    safe_add_16b(e, wordArray[j]),
                    sha1_kt(j)
                )
            );
            e = d;
            d = c;
            c = rotate_left(b, 30);
            b = a;
            a = t;
        }
        a = safe_add_16b(a, oldA);
        b = safe_add_16b(b, oldB);
        c = safe_add_16b(c, oldC);
        d = safe_add_16b(d, oldD);
        e = safe_add_16b(e, oldE);
    }
    binArray = [a, b, c, d, e]; // reuse binArray variable
    let hash  =  '';
     // convert big-endian
    if (raw) {
        for (let i = 0; i < 160; i += 8) {
            hash += String.fromCharCode((binArray[i >> 5] >>> (32 - 8 - i % 32)) & 0xFF);
        }
    } else {
        const HEX = '0123456789abcdef';
        for (let i = 0; i < 20; i++) {
            hash += HEX.charAt((binArray[i >> 2] >> ((3 - i % 4) * 8 + 4)) & 0xF);
            hash += HEX.charAt((binArray[i >> 2] >> ((3 - i % 4) * 8)) & 0xF);
        }
    }
    return hash;
}

/**
 * HMAC-SHA1
 * Implementation of HMAC-SHA1 algorithm as described in RFC 2104
 * @see https://www.ietf.org/rfc/rfc2104.txt
 *
 * @param {string} string input to be hashed
 * @param {string} key secret key
 * @param {boolean} [raw=false] If the optional binary is set to true, then the sha1 digest is instead returned in raw binary format with a length of 20, otherwise the returned value is a 40-character hexadecimal number.
 * @return {string|false} returning hashed data, otherwise false if fail
 */
const hmac_sha1 = (string, key, raw = false) => {
    key = typeof key === 'number' ? key.toString() : (
        // boolean is 1 or 0
        typeof key === 'boolean' ? (key ? '1' : '0') : key + ''
    );
    string = typeof string === 'number' ? string.toString() : (
        typeof string === 'boolean' ? (string ? '1' : '0') : string + ''
    );
    if (key.length > 64) {
        // keys longer than block-size are shortened
        key = sha1(key, true);
        if (key === false) {
            return false;
        }
    }
    const bytes = new Array(64);
    let len = key.length;
    while (len--) {
        bytes[len] = key.charCodeAt(len) & 0xFF;
    }
    let oPadding = '',
        iPadding = '';
    while (bytes.length > 0) {
        const byte = bytes.shift();
        oPadding += String.fromCharCode(byte ^ 0x5C);
        iPadding += String.fromCharCode(byte ^ 0x36);
    }
    const iPadRes = sha1(iPadding + string, true);
    return iPadRes ? sha1(oPadding + iPadRes, raw) : false;
}