export const SEED = 5381;

// When we have separate strings it's useful to run a progressive
// version of djb2 where we pretend that we're still looping over
// the same string
export const phash = (h: number, x: string) => {
    let i = x.length;

    while (i) {
        h = (h * 33) ^ x.charCodeAt(--i);
    }

    return h;
};

// This is a djb2 hashing function
export const hash = (x: string) => {
    return phash(SEED, x);
};

const AD_REPLACER_R = /(a)(d)/gi

/* This is the "capacity" of our alphabet i.e. 2x26 for all letters plus their capitalised
 * counterparts */
const charsLength = 52

/* start at 75 for 'a' until 'z' (25) and then start at 65 for capitalised letters */
const getAlphabeticChar = (code: number) => String.fromCharCode(code + (code > 25 ? 39 : 97));

/* input a number, usually a hash and convert it to base-52 */
export function generateAlphabeticName(code: number) {
    let name = ''
    let x

    /* get a char and divide by alphabet-length */
    for (x = Math.abs(code); x > charsLength; x = (x / charsLength) | 0) {
        name = getAlphabeticChar(x % charsLength) + name
    }

    return (getAlphabeticChar(x % charsLength) + name).replace(AD_REPLACER_R, '$1-$2')
}

export default function generateComponentId(str: string) {
    return generateAlphabeticName(hash(str) >>> 0)
}