(function() {
    // 'use strict';
    function isShareLink(url) {
        // test if input is a share link, return True or False
        const regex = /https:\/\/youtu\.be\/[A-Za-z0-9\_-]+\?si=.+/i;
        const isShareLink = regex.test(url);
        return(isShareLink)
    }

    function cleanUrl(url){
        // clean tracker from URL if it is a share link
        if (isShareLink(url)) {
            // replace tracker portion with empty string
            const cleanedUrl = url.replace(/\?si=[^&]+&?/, "");
            return(cleanedUrl)
        }
        // return original url if it is not a share link
        console.log("Not a share link, clipboard contents unmodified.")
        return(url)
    }

    function sleep(ms) {
        return new Promise(resolve => setTimeout(resolve, ms));
    }

    async function onMouseUp() {
        // wait half a second after clicking before reading clipboard
        await sleep(500);
        
        let clipText = await navigator.clipboard.readText();
        let newText = cleanUrl(clipText);

        if (clipText !== newText) {
            const newClip = await navigator.clipboard.writeText(newText);
            console.log("Modified clipboard with cleaned share link: %o", newText);
            clipText = undefined;
            newText = undefined;
        }
        clipText = undefined;
        newText = undefined;
    }

    document.addEventListener('mouseup', onMouseUp, false);
})();