(() => {
    const generateRandomString = (length) => {
        const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
        return Array.from({ length }, () => characters.charAt(Math.floor(Math.random() * characters.length))).join('');
    };

    const generateUUID = () => {
        let dt = Date.now();
        return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, (c) => {
            const r = (dt + Math.random() * 16) % 16 | 0;
            dt = Math.floor(dt / 16);
            return (c === 'x' ? r : (r & 0x3 | 0x8)).toString(16);
        });
    };

    const utf8Encode = (str) => {
        return unescape(encodeURIComponent(str));
    };

    const sha256 = async (message) => {
        const msgBuffer = new TextEncoder().encode(message);
        const hashBuffer = await crypto.subtle.digest('SHA-256', msgBuffer);
        const hashArray = Array.from(new Uint8Array(hashBuffer));
        return hashArray.map(b => b.toString(16).padStart(2, '0')).join('');
    };

    const generateMainBytesValue = async (uuid, hsum) => {
        const randomPart = generateRandomString(128);
        const combined = `${uuid}${hsum}${randomPart}`;
        const encoded = utf8Encode(combined);
        return await sha256(encoded);
    };

    const setValues = async () => {
        const uuidElement = document.getElementById('uuid');
        const mainBytesElement = document.getElementById('mainbytes');
        const hsumElement = document.getElementById('hsum');
        
        const uuidValue = generateUUID();
        uuidElement.innerText = uuidValue;
        
        const hsumValue = hsumElement.value;
        const mainBytesValue = await generateMainBytesValue(uuidValue, hsumValue);

        mainBytesElement.value = mainBytesValue;

        console.log('UUID:', uuidValue);
        console.log('MainBytes:', mainBytesValue);
    };

    // Set values on page load
    setValues();
})();