// ==UserScript==
// @name         yout-ube iframe player
// @namespace    https://example.com/
// @description  Replaces YouTube player with yout-ube iframe and blocks videoplayback on the parent page.
// @match        https://www.youtube.com/*
// @match        https://m.youtube.com/*
// @run-at       document-start
// @grant        none
// ==/UserScript==

(() => {
  "use strict";

  const TARGET_HOST = "www.yout-ube.com";
  const IFRAME_ATTR = "data-gm-yout-ube-iframe";
  const WRAP_ATTR = "data-gm-yout-ube-wrap";

  const BLOCK_PATTERNS = [
    /\/\/[^/]*googlevideo\.com\/videoplayback/i,
    /\/videoplayback(\?|$)/i,
  ];

  const shouldBlockUrl = (url) => {
    try {
      const s = String(url || "");
      return BLOCK_PATTERNS.some((re) => re.test(s));
    } catch {
      return false;
    }
  };

  const buildIframeUrl = () => {
    const u = new URL(location.href);
    u.hostname = TARGET_HOST;
    return u.toString();
  };

  const isWatchPage = () =>
    location.pathname === "/watch" && new URL(location.href).searchParams.has("v");

  const pauseAndNukeMedia = (root = document) => {
    try {
      root.querySelectorAll("video,audio").forEach((el) => {
        try { el.pause?.(); } catch {}
        try { el.muted = true; el.volume = 0; } catch {}
        try {
          el.removeAttribute("src");
          el.querySelectorAll?.("source").forEach((s) => s.remove());
          el.load?.();
        } catch {}
      });
    } catch {}
  };

  const stopAllInjectedIframes = () => {
    document.querySelectorAll(`iframe[${IFRAME_ATTR}]`).forEach((ifr) => {
      try { ifr.src = "about:blank"; } catch {}
      try { ifr.remove(); } catch {}
    });
    document.querySelectorAll(`div[${WRAP_ATTR}]`).forEach((w) => {
      try { w.remove(); } catch {}
    });
  };

  const installBlockers = () => {
    if (typeof window.fetch === "function") {
      const origFetch = window.fetch;
      window.fetch = function (input, init) {
        const url = (typeof input === "string") ? input : (input && input.url);
        if (shouldBlockUrl(url)) {
          return Promise.reject(new TypeError("Blocked by userscript: videoplayback"));
        }
        return origFetch.apply(this, arguments);
      };
    }

    if (window.XMLHttpRequest) {
      const origOpen = XMLHttpRequest.prototype.open;
      const origSend = XMLHttpRequest.prototype.send;

      XMLHttpRequest.prototype.open = function (method, url) {
        this.__gm_blocked_url__ = url;
        return origOpen.apply(this, arguments);
      };

      XMLHttpRequest.prototype.send = function () {
        if (shouldBlockUrl(this.__gm_blocked_url__)) {
          try { this.abort(); } catch {}
          return;
        }
        return origSend.apply(this, arguments);
      };
    }

    const mo = new MutationObserver((mutList) => {
      for (const m of mutList) {
        for (const n of m.addedNodes) {
          if (!(n instanceof Element)) continue;
          if (n.matches?.("video,audio")) pauseAndNukeMedia(n.parentNode || document);
          else if (n.querySelector) {
            if (n.querySelector("video,audio")) pauseAndNukeMedia(n);
          }
        }
      }
    });

    const startObs = () => {
      if (!document.documentElement) return;
      mo.observe(document.documentElement, { childList: true, subtree: true });
    };

    if (document.documentElement) startObs();
    else document.addEventListener("readystatechange", startObs, { once: true });
  };

  const findPlayerHost = () => {
    const selectors = [
      "#player.ytd-watch-flexy",
      "#player-container.ytd-watch-flexy",
      "ytd-player#ytd-player",
      "#movie_player",
      "ytd-watch-flexy #player",
    ];

    for (const sel of selectors) {
      const el = document.querySelector(sel);
      if (el) {
        if (el.id === "movie_player" && el.parentElement) return el.parentElement;
        return el;
      }
    }
    return null;
  };

  const ensureIframePlayer = () => {
    if (!isWatchPage()) return;

    const host = findPlayerHost();
    if (!host) return;

    const desiredSrc = buildIframeUrl();

    const existingIframe = host.querySelector(`iframe[${IFRAME_ATTR}]`);
    if (existingIframe) {
      if (existingIframe.src !== desiredSrc) {
        existingIframe.src = "about:blank";
        existingIframe.src = desiredSrc;
      }
      return;
    }

    host.textContent = "";

    const wrap = document.createElement("div");
    wrap.setAttribute(WRAP_ATTR, "1");
    wrap.style.position = "relative";
    wrap.style.width = "100%";

    wrap.style.aspectRatio = "16 / 9";
    wrap.style.minHeight = "360px";
    host.style.width = "100%";

    const iframe = document.createElement("iframe");
    iframe.setAttribute(IFRAME_ATTR, "1");
    iframe.src = desiredSrc;
    iframe.allow =
      "accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share";
    iframe.allowFullscreen = true;
    iframe.referrerPolicy = "origin-when-cross-origin";
    iframe.loading = "eager";

    iframe.style.position = "absolute";
    iframe.style.inset = "0";
    iframe.style.width = "100%";
    iframe.style.height = "100%";
    iframe.style.border = "0";
    iframe.style.display = "block";

    wrap.appendChild(iframe);
    host.appendChild(wrap);
  };

  const handleRouteChange = () => {
    pauseAndNukeMedia(document);

    if (isWatchPage()) {
      ensureIframePlayer();
    } else {
      stopAllInjectedIframes();
      pauseAndNukeMedia(document);
    }
  };

  const installSpaHooks = () => {
    const schedule = (() => {
      let t = null;
      return () => {
        if (t) clearTimeout(t);
        t = setTimeout(() => {
          t = null;
          handleRouteChange();
        }, 50);
      };
    })();

    window.addEventListener("yt-navigate-start", schedule, true);
    window.addEventListener("yt-navigate-finish", schedule, true);
    window.addEventListener("yt-page-data-updated", schedule, true);
    window.addEventListener("popstate", schedule, true);
    window.addEventListener("hashchange", schedule, true);

    const mo = new MutationObserver(() => {
      if (isWatchPage()) ensureIframePlayer();
    });

    const start = () => {
      if (!document.documentElement) return;
      mo.observe(document.documentElement, { childList: true, subtree: true });
    };

    if (document.documentElement) start();
    else document.addEventListener("readystatechange", start, { once: true });

    let lastHref = location.href;
    setInterval(() => {
      if (location.href !== lastHref) {
        lastHref = location.href;
        handleRouteChange();
      }
    }, 250);

    handleRouteChange();
  };

  installBlockers();
  installSpaHooks();
})();