// ==UserScript==
// @name        Mark Watched YouTube Videos
// @namespace   MarkWatchedYouTubeVideos
// @version     1.1.28
// @license     AGPL v3
// @author      jcunews
// @description Add an indicator for watched videos on YouTube. Use GM menus to display history statistics, backup history, and restore history.
// @website     https://greasyfork.org/en/users/85671-jcunews
// @match       *://www.youtube.com/*
// @grant       GM_getValue
// @grant       GM_registerMenuCommand
// @grant       GM_setValue
// @run-at      document-start
// @downloadURL none
// ==/UserScript==

/*
- Use ALT+LeftClick or ALT+RightClick on a video list item to manually toggle the watched marker. The mouse button is defined in the script and can be changed.
- For restoring history, source file can also be a list of YouTube video URLs, but timestamps will be set to current time.
*/

(() => {
  
  //=== config start ===
  var maxWatchedVideoAge   = 5 * 365; //number of days. set to zero to disable (not recommended)
  var pageLoadMarkDelay    = 400;     //number of milliseconds to wait before marking video items on page load phase (increase if slow network/browser)
  var contentLoadMarkDelay = 600;     //number of milliseconds to wait before marking video items on content load phase (increase if slow network/browser)
  var markerMouseButtons   = [0, 1];  //one or more mouse buttons to use for manual marker toggle. 0=left, 1=right, 2=middle. e.g.:
                                      //if `[0]`, only left button is used, which is ALT+LeftClick.
                                      //if `[1]`, only right button is used, which is ALT+RightClick.
                                      //if `[0,1]`, any left or right button can be used, which is: ALT+LeftClick or ALT+RightClick.
  //=== config end ===

  var watchedVideos, ageMultiplier = 24 * 60 * 60 * 1000, xu = /\/watch(?:\?|.*?&)v=([^&]+)/;

  function getVideoId(url) {
    var vid = url.match(xu);
    if (vid) vid = vid[1] || vid[2];
    return vid;
  }

  function watched(vid) {
    return !!watchedVideos.entries[vid];
  }

  function processVideoItems(selector) {
    var items = document.querySelectorAll(selector), i, link;
    for (i = items.length-1; i >= 0; i--) {
      if (link = items[i].querySelector("A")) {
        if (watched(getVideoId(link.href))) {
          items[i].classList.add("watched");
        } else items[i].classList.remove("watched");
      }
    }
  }

  function processAllVideoItems() {
    //home page
    processVideoItems(".yt-uix-shelfslider-list>.yt-shelf-grid-item");
    processVideoItems("#contents.ytd-rich-grid-renderer>ytd-rich-item-renderer,#contents.ytd-rich-shelf-renderer ytd-rich-item-renderer.ytd-rich-shelf-renderer");
    //subscriptions page
    processVideoItems(".multirow-shelf>.shelf-content>.yt-shelf-grid-item");
    //history:watch page
    processVideoItems('ytd-section-list-renderer[page-subtype="history"] .ytd-item-section-renderer>ytd-video-renderer');
    //channel/user home page
    processVideoItems("#contents>.ytd-item-section-renderer>.ytd-newspaper-renderer,#items>.yt-horizontal-list-renderer"); //old
    processVideoItems("#contents>.ytd-channel-featured-content-renderer,#contents>.ytd-shelf-renderer>#grid-container>.ytd-expanded-shelf-contents-renderer"); //new
    //channel/user video page
    processVideoItems(".yt-uix-slider-list>.featured-content-item,#items>.ytd-grid-renderer");
    //channel/user playlist page
    processVideoItems(".expanded-shelf>.expanded-shelf-content-list>.expanded-shelf-content-item-wrapper,.ytd-playlist-video-renderer");
    //channel/user playlist item page
    processVideoItems(".pl-video-list .pl-video-table .pl-video,ytd-playlist-panel-video-renderer");
    //channel/user videos page
    processVideoItems(".channels-browse-content-grid>.channels-content-item");
    //channel/user search page
    if (/^\/(?:channel|user)\/.*?\/search/.test(location.pathname)) {
      processVideoItems(".ytd-browse #contents>.ytd-item-section-renderer"); //new
    }
    //search page
    processVideoItems("#results>.section-list .item-section>li,#browse-items-primary>.browse-list-item-container"); //old
    processVideoItems(".ytd-search #contents>.ytd-item-section-renderer"); //new
    //video page sidebar
    processVideoItems(".watch-sidebar-body>.video-list>.video-list-item,.playlist-videos-container>.playlist-videos-list>li"); //old
    processVideoItems(".ytd-compact-video-renderer"); //new
  }

  function addHistory(vid, time, noSave) {
    watchedVideos.entries[vid] = time;
    watchedVideos.index.push(vid);
    if (!noSave) GM_setValue("watchedVideos", JSON.stringify(watchedVideos));
  }

  function delHistory(index, noSave) {
    delete watchedVideos.entries[watchedVideos.index[index]];
    watchedVideos.index.splice(index, 1);
    if (!noSave) GM_setValue("watchedVideos", JSON.stringify(watchedVideos));
  }

  function parseData(s, a) {
    try {
      s = JSON.parse(s);
      //convert to new format if old format.
      //old: [{id:<strVID>, timestamp:<numDate>}, ...]
      //new: {entries:{<stdVID>:<numDate>, ...}, index:[<strVID>, ...]}
      if (Array.isArray(s)) {
        a = s;
        s = {entries: {}, index: []};
        a.forEach(o => {
          s.entries[o.id] = o.timestamp;
          s.index.push(o.id);
        });
      } else if (("object" !== typeof s) || ("object" !== typeof s.entries) || !Array.isArray(s.index)) return null;
      return s;
    } catch(z) {
      return null;
    }
  }

  function getHistory(a, b) {
    a = GM_getValue("watchedVideos") || '{"entries": {}, "index": []}';
    if (b = parseData(a)) {
      watchedVideos = b;
    } else a = JSON.stringify(watchedVideos = {entries: {}, index: []});
    GM_setValue("watchedVideos", a);
  }

  function doProcessPage() {
    //get list of watched videos
    getHistory();

    //remove old watched video history
    var now = (new Date()).valueOf(), changed, vid;
    if (maxWatchedVideoAge > 0) {
      while (watchedVideos.index.length) {
        if (((now - watchedVideos.entries[watchedVideos.index[0]]) / ageMultiplier) > maxWatchedVideoAge) {
          delHistory(0, false);
          changed = true;
        } else break;
      }
      if (changed) GM_setValue("watchedVideos", JSON.stringify(watchedVideos));
    }

    //check and remember current video
    if ((vid = getVideoId(location.href)) && !watched(vid)) addHistory(vid, now);

    //mark watched videos
    processAllVideoItems();
  }

  function processPage() {
    setTimeout(doProcessPage, 200);
  }

  function toggleMarker(ele, i) {
    if (ele) {
      if (ele.href) {
        i = getVideoId(ele.href);
      } else {
        ele = ele.parentNode;
        while (ele) {
          if (ele.tagName === "A") {
            i = getVideoId(ele.href);
            break;
          }
          ele = ele.parentNode;
        }
      }
      if (i) {
        if ((ele = watchedVideos.index.indexOf(i)) >= 0) {
          delHistory(ele);
        } else addHistory(i, (new Date()).valueOf());
        processAllVideoItems();
      }
    }
  }

  var xhropen = XMLHttpRequest.prototype.open, xhrsend = XMLHttpRequest.prototype.send;
  XMLHttpRequest.prototype.open = function(method, url) {
    this.url_mwyv = url;
    return xhropen.apply(this, arguments);
  };
  XMLHttpRequest.prototype.send = function(method, url) {
    if ((/\/\w+_ajax\?|\/results\?search_query/).test(this.url_mwyv) && !this.listened_mwyv) {
      this.listened_mwyv = 1;
      this.addEventListener("load", () => {
        setTimeout(processPage, Math.floor(pageLoadMarkDelay / 2));
      });
    }
    return xhrsend.apply(this, arguments);
  };

  addEventListener("DOMContentLoaded", sty => {
    sty = document.createElement("STYLE");
    sty.innerHTML = `
.watched, .watched .yt-ui-ellipsis
  { background-color: #cec !important }
html[dark] .watched, html[dark] .watched .yt-ui-ellipsis,
.playlist-videos-container>.playlist-videos-list>li.watched,
.playlist-videos-container>.playlist-videos-list>li.watched>a,
.playlist-videos-container>.playlist-videos-list>li.watched .yt-ui-ellipsis
  { background-color: #030 !important }`;
    document.head.appendChild(sty);
  });

  var lastFocusState = document.hasFocus();
  addEventListener("blur", () => {
    lastFocusState = false;
  });
  addEventListener("focus", () => {
    if (!lastFocusState) processPage();
    lastFocusState = true;
  });
  addEventListener("click", (ev) => {
    if ((markerMouseButtons.indexOf(ev.button) >= 0) && ev.altKey) toggleMarker(ev.target);
  });
  if (markerMouseButtons.indexOf(1) >= 0) {
    addEventListener("contextmenu", (ev) => {
      if (ev.altKey) toggleMarker(ev.target);
    });
  }
  if (window["body-container"]) { //old
    addEventListener("spfdone", processPage);
    processPage();
  } else { //new
    var t = 0;
    function pl() {
      clearTimeout(t);
      t = setTimeout(processPage, 300);
    }
    (function init(vm) {
      if (vm = document.getElementById("visibility-monitor")) {
        vm.addEventListener("viewport-load", pl);
      } else setTimeout(init, 100);
    })();
    (function init2(mh) {
      if (mh = document.getElementById("masthead")) {
        mh.addEventListener("yt-rendererstamper-finished", pl);
      } else setTimeout(init2, 100);
    })();
    addEventListener("load", () => {
      setTimeout(processPage, pageLoadMarkDelay);
    });
    addEventListener("spfprocess", () => {
      setTimeout(processPage, contentLoadMarkDelay);
    });
  }
  GM_registerMenuCommand("Display History Statistics", () => {
    function sum(r, v) {
      return r + v;
    }
    function avg(arr) {
      return arr ? Math.round(arr.reduce(sum, 0) / arr.length) : "(n/a)";
    }
    var pd, pm, py, ld = [], lm = [], ly = [];
    getHistory();
    Object.keys(watchedVideos.entries).forEach((k, t) => {
      t = new Date(watchedVideos.entries[k]);
      if (!pd || (pd !== t.getDate())) {
        ld.push(1);
        pd = t.getDate();
      } else ld[ld.length - 1]++;
      if (!pm || (pm !== (t.getMonth() + 1))) {
        lm.push(1);
        pm = t.getMonth() + 1;
      } else lm[lm.length - 1]++;
      if (!py || (py !== t.getFullYear())) {
        ly.push(1);
        py = t.getFullYear();
      } else ly[ly.length - 1]++;
    });
    if (watchedVideos.index.length) {
      pd = (new Date(watchedVideos.entries[watchedVideos.index[0]])).toLocaleString();
      pm = (new Date(watchedVideos.entries[watchedVideos.index[watchedVideos.index.length - 1]])).toLocaleString();
    } else {
      pd = "(n/a)";
      pm = "(n/a)";
    }
    alert(`\
Number of entries: ${watchedVideos.index.length}
Oldest entry: ${pd}
Newest entry: ${pm}

Average viewed videos per day: ${avg(ld)}
Average viewed videos per month: ${avg(lm)}
Average viewed videos per year: ${avg(ly)}\
`);
  });
  GM_registerMenuCommand("Backup History Data", (a, b) => {
    document.body.appendChild(a = document.createElement("A")).href = URL.createObjectURL(new Blob([JSON.stringify(watchedVideos)], {type: "application/json"}));
    a.download = `MarkWatchedYouTubeVideos_${(new Date()).toISOString()}.json`;
    a.click();
    a.remove();
    URL.revokeObjectURL(a.href);
  });
  GM_registerMenuCommand("Restore History Data", (a, b) => {
    function askRestore(r, o) {
      if (confirm(`Selected history data file contains ${o.index.length} entries.\n\nRestore from this data?`)) {
        watchedVideos = o;
        GM_setValue("watchedVideos", r);
        a.remove();
        doProcessPage();
      }
    }
    (a = document.createElement("DIV")).id = "mwyvrh_ujs";
    a.innerHTML = `<style>
#mwyvrh_ujs{
  display:flex;position:fixed;z-index:99999;left:0;top:0;right:0;bottom:0;margin:0;border:none;padding:0;background:rgb(0,0,0,0.5);
  color:#000;font-family:sans-serif;font-size:12pt;line-height:12pt;font-weight:normal;cursor:pointer;
}
#mwyvrhb_ujs{
  margin:auto;border:.3rem solid #007;border-radius:.3rem;padding:.5rem;background-color:#fff;cursor:auto;
}
#mwyvrht_ujs{margin-bottom:1rem;font-size:14pt;line-height:14pt;font-weight:bold}
#mwyvrhi_ujs{display:block;margin:1rem auto .5rem auto;width:12rem;overflow:hidden}
</style>
<div id="mwyvrhb_ujs">
  <div id="mwyvrht_ujs">Mark Watched YouTube Videos</div>
  Please select a file to restore history data from.
  <input id="mwyvrhi_ujs" type="file" multiple />
</div>`;
    a.onclick = e => {
      (e.target === a) && a.remove();
    };
    (b = a.querySelector("#mwyvrhi_ujs")).onchange = r => {
      r = new FileReader();
      r.onload = (o, t) => {
        if (o = parseData(r = r.result)) { //parse as native format
          if (o.index.length) {
            askRestore(r, o);
          } else alert("File doesn't have any history entry.");
        } else { //parse as URL list
          o = {entries: {}, index: []};
          t = (new Date()).getTime();
          r = r.replace(/\r/g, "").split("\n");
          while (r.length && !r[0].trim()) r.shift();
          if (r.length && xu.test(r[0])) {
            r.forEach(s => {
              if (s = s.match(xu)) {
                o.entries[s[1]] = t;
                o.index.push(s[1]);
              }
            });
            if (o.index.length) {
              askRestore(JSON.stringify(o), o);
            } else alert("File doesn't have any history entry.");
          } else alert("Invalid history data file.");
        }
      };
      r.readAsText(b.files[0]);
    };
    document.documentElement.appendChild(a);
    b.click();
  });
})();