Youtube - Resumer

Store video.currentTime locally

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Youtube - Resumer
// @namespace    http://tampermonkey.net/
// @version      1.2
// @description  Store video.currentTime locally
// @author       You
// @match        https://www.youtube.com/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// @grant        GM.setValue
// @grant        GM.getValue
// @grant        GM_addStyle
// @license      MIT
// ==/UserScript==


function l(...args){
    console.log('[Resumer]', ...args)
}

function videoId(url=document.URL){
    return new URL(url).searchParams.get('v')
}

let lastTimeInSeconds
function save(video, id){
    const seconds = Math.floor(video.currentTime)
    if(lastTimeInSeconds != seconds){ // save less often
        let completion = video.currentTime / video.duration
        GM.setValue(id, video.currentTime)
        GM.setValue(id + '-completion', completion)
    }
    lastTimeInSeconds = seconds
}

function findVideo(onVideoFound){
    const observer = new MutationObserver((mutations, observer) => {
        // Keep trying to find video
        let video = document.querySelector('video.video-stream')
        if(video){
            onVideoFound(video)
            observer.disconnect()
        }
    })
    observer.observe(document, {childList:true, subtree:true})
}


let id = videoId() //if you use the miniplayer the url no longer includes the video id
function listen(video){
    let lastSrc

    function handleTimeUpdate(){
        //Video source is '' and duration is NaN when going back to the home page
        //When loading a new video, the event is fired with currentTime 0 and duration NaN
        if(video.src && !isNaN(video.duration)){
            l('timeupdate', id, lastId, video.src, lastSrc)
            if(id){
                save(video, id)
                lastSrc = video.src
            }else if(video.src === lastSrc){ //in case you click another video while using the miniplayer
                save(video, lastId) //save even if in miniplayer
            }
        }
    }

    video.addEventListener('timeupdate', handleTimeUpdate)
    return () => {
        video.removeEventListener('timeupdate', handleTimeUpdate)
    }
}

async function resume(video){
    id = videoId() // set id here because in firefox the url changes before navigate-finish completes
    let lastTime = await GM.getValue(id)
    if(lastTime){
        if(lastTime < video.duration - 1){
          l('resuming', id, video.currentTime, lastTime)
          video.currentTime = lastTime
        }else{
          l('nearly complete, skipping resume for', id);
        }
    }else{
        l('new video', video.currentTime)
    }
}

function cleanUrl(){
    //Remove t paramater when opening a video that had a progress bar
    let url = new URL(document.URL)
    url.searchParams.delete('t')
    window.history.replaceState(null, null, url)
}

let lastId // don't resume if going back to same page from miniplayer

// Event for each page change
document.addEventListener("yt-navigate-finish", () => {
    l('navigate-finish', lastId, videoId())
    // video page
    if(videoId() && lastId !== videoId()) {
        lastId = videoId()
        cleanUrl()

        let removeListeners
        findVideo(video => {
            resume(video)

            // clean previous listeners
            if(removeListeners) removeListeners()
            removeListeners = listen(video)
        })
    }
})

/////////////////////


function addProgressBar(thumbnail, completion){
    let overlays = thumbnail.querySelector('#overlays')
    let existingProgressBar = thumbnail.querySelector('ytd-thumbnail-overlay-resume-playback-renderer')
    if(!existingProgressBar) {
        let parent = document.createElement('div')
        parent.innerHTML = `
        <ytd-thumbnail-overlay-resume-playback-renderer class="style-scope ytd-thumbnail">
             <div id="progress" class="style-scope ytd-thumbnail-overlay-resume-playback-renderer" style="width: 100%"></div>
        </ytd-thumbnail-overlay-resume-playback-renderer>
        `
        overlays.appendChild(parent.children[0])
    }

    // style
    let progress = overlays.querySelector('#progress')
    let width = parseInt(completion * 100)
    progress.style.width = `${width}%`
    progress.style.backgroundColor = 'blue'
}

function progressBars(){
    // Add progress bars in the related section
    const observer = new MutationObserver(async (mutations, observer) => {
        for(let mutation of mutations){
            if(mutation.addedNodes.length > 0) {
                let thumbnails = mutation.target.querySelectorAll('a.ytd-thumbnail')
                for(let thumbnail of thumbnails){
                    let href = thumbnail.href
                    if(href) {
                        let id = videoId(href)
                        let completion = await GM.getValue(id + '-completion')
                        if(completion) {
                            addProgressBar(thumbnail, completion)
                        }
                    }
                }
            }
        }
    })
    observer.observe(document, {childList:true, subtree:true})
}

progressBars() // TODO doesn't always work