export {
    onlyUnique,
    shuffle,
    download,
    urlContentToDataUri,
    getBase64Async,
    getStringHash,
    debounce,
    delay,
    isSubsetOf,
};

/// UTILS
function onlyUnique(value, index, array) {
    return array.indexOf(value) === index;
}

function shuffle(array) {
    let currentIndex = array.length,
        randomIndex;

    while (currentIndex != 0) {
        randomIndex = Math.floor(Math.random() * currentIndex);
        currentIndex--;
        [array[currentIndex], array[randomIndex]] = [
            array[randomIndex],
            array[currentIndex],
        ];
    }
    return array;
}

function download(content, fileName, contentType) {
    const a = document.createElement("a");
    const file = new Blob([content], { type: contentType });
    a.href = URL.createObjectURL(file);
    a.download = fileName;
    a.click();
}

async function urlContentToDataUri(url, params) {
    const response = await fetch(url, params);
    const blob = await response.blob();
    return await new Promise(callback => {
        let reader = new FileReader();
        reader.onload = function () { callback(this.result); };
        reader.readAsDataURL(blob);
    });
}

function getBase64Async(file) {
    return new Promise((resolve, reject) => {
        const reader = new FileReader();
        reader.readAsDataURL(file);
        reader.onload = function () {
            resolve(reader.result);
        };
        reader.onerror = function (error) {
            reject(error);
        };
    });
}

function getStringHash(str, seed = 0) {
    let h1 = 0xdeadbeef ^ seed,
        h2 = 0x41c6ce57 ^ seed;
    for (let i = 0, ch; i < str.length; i++) {
        ch = str.charCodeAt(i);
        h1 = Math.imul(h1 ^ ch, 2654435761);
        h2 = Math.imul(h2 ^ ch, 1597334677);
    }

    h1 = Math.imul(h1 ^ (h1 >>> 16), 2246822507) ^ Math.imul(h2 ^ (h2 >>> 13), 3266489909);
    h2 = Math.imul(h2 ^ (h2 >>> 16), 2246822507) ^ Math.imul(h1 ^ (h1 >>> 13), 3266489909);

    return 4294967296 * (2097151 & h2) + (h1 >>> 0);
};

function debounce(func, timeout = 300) {
    let timer;
    return (...args) => {
        clearTimeout(timer);
        timer = setTimeout(() => { func.apply(this, args); }, timeout);
    };
}

const delay = (ms) => new Promise((res) => setTimeout(res, ms));
const isSubsetOf = (a, b) => (Array.isArray(a) && Array.isArray(b)) ? b.every(val => a.includes(val)) : false;
