// ==UserScript==
// @name         youtube time rewind
// @version      1.0
// @description  s키로 시간을 저장하고 r로 되돌립니다
// @match        https://www.youtube.com/watch?*
// ==/UserScript==

function toSecond(hms) {
    var p = hms.split(':'),
        s = 0, m = 1;

    while (p.length > 0) {
        s += m * parseInt(p.pop(), 10);
        m *= 60;
    }

    return s;
}

(function() {
    let savetime=0
    window.getKey = function (keyStroke){
        if ((event.srcElement.tagName != 'INPUT') && (event.srcElement.tagName != 'TEXTAREA')) {
            isNetscape = (document.layers);
            eventChooser = (isNetscape) ? keyStroke.which : event.keyCode;
            which = String.fromCharCode(eventChooser).toLowerCase();
            control(which);
        }
    };
    document.onkeypress = getKey;

    window.control = function (key){
        switch(key){
            case 's':
                console.log('time saved')
                savetime=toSecond(document.querySelector('span.ytp-time-current').textContent)
                console.log(savetime)
                break
            case 'r':
                console.log('time rewind')
                let originUrl=location.href
                let rewindUrl

                if(originUrl.includes('t=')){
                    originUrl=originUrl.split('&')[0]
                }
                rewindUrl=originUrl+'&t='+savetime
                location.href=rewindUrl
        }
    };
})();