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Telegram Media Downloader

Download images, GIFs, videos, and voice messages on the Telegram webapp from private channels that disable downloading and restrict saving content

このスクリプトの質問や評価の投稿はこちら通報はこちらへお寄せください。
// ==UserScript==
// @name         Telegram Media Downloader
// @name:zh-CN   Telegram图片视频下载器
// @version      1.202
// @namespace    https://github.com/Neet-Nestor/Telegram-Media-Downloader
// @description  Download images, GIFs, videos, and voice messages on the Telegram webapp from private channels that disable downloading and restrict saving content
// @description:zh-cn 从禁止下载的Telegram频道中下载图片、视频及语音消息
// @author       Nestor Qin
// @license      GNU GPLv3
// @website      https://github.com/Neet-Nestor/Telegram-Media-Downloader
// @match        https://web.telegram.org/*
// @match        https://webk.telegram.org/*
// @match        https://webz.telegram.org/*
// @icon         https://img.icons8.com/color/452/telegram-app--v5.png
// ==/UserScript==

(function () {
  const logger = {
    info: (message, fileName = null) => {
      console.log(
        `[Tel Download] ${fileName ? `${fileName}: ` : ""}${message}`
      );
    },
    error: (message, fileName = null) => {
      console.error(
        `[Tel Download] ${fileName ? `${fileName}: ` : ""}${message}`
      );
    },
  };
  // Unicode values for icons (used in /k/ app)
  const DOWNLOAD_ICON = "\uE94E";
  const FORWARD_ICON = "\uE960";
  const contentRangeRegex = /^bytes (\d+)-(\d+)\/(\d+)$/;
  const REFRESH_DELAY = 500;
  const hashCode = (s) => {
    var h = 0,
      l = s.length,
      i = 0;
    if (l > 0) {
      while (i < l) {
        h = ((h << 5) - h + s.charCodeAt(i++)) | 0;
      }
    }
    return h >>> 0;
  };

  const createProgressBar = (videoId, fileName) => {
    const isDarkMode =
      document.querySelector("html").classList.contains("night") ||
      document.querySelector("html").classList.contains("theme-dark");
    const container = document.getElementById(
      "tel-downloader-progress-bar-container"
    );
    const innerContainer = document.createElement("div");
    innerContainer.id = "tel-downloader-progress-" + videoId;
    innerContainer.style.width = "20rem";
    innerContainer.style.marginTop = "0.4rem";
    innerContainer.style.padding = "0.6rem";
    innerContainer.style.backgroundColor = isDarkMode
      ? "rgba(0,0,0,0.3)"
      : "rgba(0,0,0,0.6)";

    const flexContainer = document.createElement("div");
    flexContainer.style.display = "flex";
    flexContainer.style.justifyContent = "space-between";

    const title = document.createElement("p");
    title.className = "filename";
    title.style.margin = 0;
    title.style.color = "white";
    title.innerText = fileName;

    const closeButton = document.createElement("div");
    closeButton.style.cursor = "pointer";
    closeButton.style.fontSize = "1.2rem";
    closeButton.style.color = isDarkMode ? "#8a8a8a" : "white";
    closeButton.innerHTML = "&times;";
    closeButton.onclick = function () {
      container.removeChild(innerContainer);
    };

    const progressBar = document.createElement("div");
    progressBar.className = "progress";
    progressBar.style.backgroundColor = "#e2e2e2";
    progressBar.style.position = "relative";
    progressBar.style.width = "100%";
    progressBar.style.height = "1.6rem";
    progressBar.style.borderRadius = "2rem";
    progressBar.style.overflow = "hidden";

    const counter = document.createElement("p");
    counter.style.position = "absolute";
    counter.style.zIndex = 5;
    counter.style.left = "50%";
    counter.style.top = "50%";
    counter.style.transform = "translate(-50%, -50%)";
    counter.style.margin = 0;
    counter.style.color = "black";
    const progress = document.createElement("div");
    progress.style.position = "absolute";
    progress.style.height = "100%";
    progress.style.width = "0%";
    progress.style.backgroundColor = "#6093B5";

    progressBar.appendChild(counter);
    progressBar.appendChild(progress);
    flexContainer.appendChild(title);
    flexContainer.appendChild(closeButton);
    innerContainer.appendChild(flexContainer);
    innerContainer.appendChild(progressBar);
    container.appendChild(innerContainer);
  };

  const updateProgress = (videoId, fileName, progress) => {
    const innerContainer = document.getElementById(
      "tel-downloader-progress-" + videoId
    );
    innerContainer.querySelector("p.filename").innerText = fileName;
    const progressBar = innerContainer.querySelector("div.progress");
    progressBar.querySelector("p").innerText = progress + "%";
    progressBar.querySelector("div").style.width = progress + "%";
  };

  const completeProgress = (videoId) => {
    const progressBar = document
      .getElementById("tel-downloader-progress-" + videoId)
      .querySelector("div.progress");
    progressBar.querySelector("p").innerText = "Completed";
    progressBar.querySelector("div").style.backgroundColor = "#B6C649";
    progressBar.querySelector("div").style.width = "100%";
  };

  const AbortProgress = (videoId) => {
    const progressBar = document
      .getElementById("tel-downloader-progress-" + videoId)
      .querySelector("div.progress");
    progressBar.querySelector("p").innerText = "Aborted";
    progressBar.querySelector("div").style.backgroundColor = "#D16666";
    progressBar.querySelector("div").style.width = "100%";
  };

  const tel_download_video = (url) => {
    let _blobs = [];
    let _next_offset = 0;
    let _total_size = null;
    let _file_extension = "mp4";

    const videoId =
      (Math.random() + 1).toString(36).substring(2, 10) +
      "_" +
      Date.now().toString();
    let fileName = hashCode(url).toString(36) + "." + _file_extension;

    // Some video src is in format:
    // 'stream/{"dcId":5,"location":{...},"size":...,"mimeType":"video/mp4","fileName":"xxxx.MP4"}'
    try {
      const metadata = JSON.parse(
        decodeURIComponent(url.split("/")[url.split("/").length - 1])
      );
      if (metadata.fileName) {
        fileName = metadata.fileName;
      }
    } catch (e) {
      // Invalid JSON string, pass extracting fileName
    }
    logger.info(`URL: ${url}`, fileName);

    const fetchNextPart = (_writable) => {
      fetch(url, {
        method: "GET",
        headers: {
          Range: `bytes=${_next_offset}-`,
        },
        "User-Agent":
          "User-Agent Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/117.0",
      })
        .then((res) => {
          if (![200, 206].includes(res.status)) {
            throw new Error("Non 200/206 response was received: " + res.status);
          }
          const mime = res.headers.get("Content-Type").split(";")[0];
          if (!mime.startsWith("video/")) {
            throw new Error("Get non video response with MIME type " + mime);
          }
          _file_extension = mime.split("/")[1];
          fileName =
            fileName.substring(0, fileName.indexOf(".") + 1) + _file_extension;

          const match = res.headers
            .get("Content-Range")
            .match(contentRangeRegex);

          const startOffset = parseInt(match[1]);
          const endOffset = parseInt(match[2]);
          const totalSize = parseInt(match[3]);

          if (startOffset !== _next_offset) {
            logger.error("Gap detected between responses.", fileName);
            logger.info("Last offset: " + _next_offset, fileName);
            logger.info("New start offset " + match[1], fileName);
            throw "Gap detected between responses.";
          }
          if (_total_size && totalSize !== _total_size) {
            logger.error("Total size differs", fileName);
            throw "Total size differs";
          }

          _next_offset = endOffset + 1;
          _total_size = totalSize;

          logger.info(
            `Get response: ${res.headers.get(
              "Content-Length"
            )} bytes data from ${res.headers.get("Content-Range")}`,
            fileName
          );
          logger.info(
            `Progress: ${((_next_offset * 100) / _total_size).toFixed(0)}%`,
            fileName
          );
          updateProgress(
            videoId,
            fileName,
            ((_next_offset * 100) / _total_size).toFixed(0)
          );
          return res.blob();
        })
        .then((resBlob) => {
          if (_writable !== null) {
            _writable.write(resBlob).then(() => {});
          } else {
            _blobs.push(resBlob);
          }
        })
        .then(() => {
          if (!_total_size) {
            throw new Error("_total_size is NULL");
          }

          if (_next_offset < _total_size) {
            fetchNextPart(_writable);
          } else {
            if (_writable !== null) {
              _writable.close().then(() => {
                logger.info("Download finished", fileName);
              });
            } else {
              save();
            }
            completeProgress(videoId);
          }
        })
        .catch((reason) => {
          logger.error(reason, fileName);
          AbortProgress(videoId);
        });
    };

    const save = () => {
      logger.info("Finish downloading blobs", fileName);
      logger.info("Concatenating blobs and downloading...", fileName);

      const blob = new Blob(_blobs, { type: "video/mp4" });
      const blobUrl = window.URL.createObjectURL(blob);

      logger.info("Final blob size: " + blob.size + " bytes", fileName);

      const a = document.createElement("a");
      document.body.appendChild(a);
      a.href = blobUrl;
      a.download = fileName;
      a.click();
      document.body.removeChild(a);
      window.URL.revokeObjectURL(blobUrl);

      logger.info("Download triggered", fileName);
    };

    const supportsFileSystemAccess =
      "showSaveFilePicker" in unsafeWindow &&
      (() => {
        try {
          return unsafeWindow.self === unsafeWindow.top;
        } catch {
          return false;
        }
      })();
    if (supportsFileSystemAccess) {
      unsafeWindow
        .showSaveFilePicker({
          suggestedName: fileName,
        })
        .then((handle) => {
          handle
            .createWritable()
            .then((writable) => {
              fetchNextPart(writable);
              createProgressBar(videoId);
            })
            .catch((err) => {
              console.error(err.name, err.message);
            });
        })
        .catch((err) => {
          if (err.name !== "AbortError") {
            console.error(err.name, err.message);
          }
        });
    } else {
      fetchNextPart(null);
      createProgressBar(videoId);
    }
  };

  const tel_download_audio = (url) => {
    let _blobs = [];
    let _next_offset = 0;
    let _total_size = null;
    const fileName = hashCode(url).toString(36) + ".ogg";

    const fetchNextPart = (_writable) => {
      fetch(url, {
        method: "GET",
        headers: {
          Range: `bytes=${_next_offset}-`,
        },
      })
        .then((res) => {
          if (res.status !== 206 && res.status !== 200) {
            logger.error(
              "Non 200/206 response was received: " + res.status,
              fileName
            );
            return;
          }

          const mime = res.headers.get("Content-Type").split(";")[0];
          if (!mime.startsWith("audio/")) {
            logger.error(
              "Get non audio response with MIME type " + mime,
              fileName
            );
            throw "Get non audio response with MIME type " + mime;
          }

          try {
            const match = res.headers
              .get("Content-Range")
              .match(contentRangeRegex);

            const startOffset = parseInt(match[1]);
            const endOffset = parseInt(match[2]);
            const totalSize = parseInt(match[3]);

            if (startOffset !== _next_offset) {
              logger.error("Gap detected between responses.");
              logger.info("Last offset: " + _next_offset);
              logger.info("New start offset " + match[1]);
              throw "Gap detected between responses.";
            }
            if (_total_size && totalSize !== _total_size) {
              logger.error("Total size differs");
              throw "Total size differs";
            }

            _next_offset = endOffset + 1;
            _total_size = totalSize;
          } finally {
            logger.info(
              `Get response: ${res.headers.get(
                "Content-Length"
              )} bytes data from ${res.headers.get("Content-Range")}`
            );
            return res.blob();
          }
        })
        .then((resBlob) => {
          if (_writable !== null) {
            _writable.write(resBlob).then(() => {});
          } else {
            _blobs.push(resBlob);
          }
        })
        .then(() => {
          if (_next_offset < _total_size) {
            fetchNextPart(_writable);
          } else {
            if (_writable !== null) {
              _writable.close().then(() => {
                logger.info("Download finished", fileName);
              });
            } else {
              save();
            }
          }
        })
        .catch((reason) => {
          logger.error(reason, fileName);
        });
    };

    const save = () => {
      logger.info(
        "Finish downloading blobs. Concatenating blobs and downloading...",
        fileName
      );

      let blob = new Blob(_blobs, { type: "audio/ogg" });
      const blobUrl = window.URL.createObjectURL(blob);

      logger.info("Final blob size in bytes: " + blob.size, fileName);

      blob = 0;

      const a = document.createElement("a");
      document.body.appendChild(a);
      a.href = blobUrl;
      a.download = fileName;
      a.click();
      document.body.removeChild(a);
      window.URL.revokeObjectURL(blobUrl);

      logger.info("Download triggered", fileName);
    };

    const supportsFileSystemAccess =
      "showSaveFilePicker" in unsafeWindow &&
      (() => {
        try {
          return unsafeWindow.self === unsafeWindow.top;
        } catch {
          return false;
        }
      })();
    if (supportsFileSystemAccess) {
      unsafeWindow
        .showSaveFilePicker({
          suggestedName: fileName,
        })
        .then((handle) => {
          handle
            .createWritable()
            .then((writable) => {
              fetchNextPart(writable);
            })
            .catch((err) => {
              console.error(err.name, err.message);
            });
        })
        .catch((err) => {
          if (err.name !== "AbortError") {
            console.error(err.name, err.message);
          }
        });
    } else {
      fetchNextPart(null);
    }
  };

  const tel_download_image = (imageUrl) => {
    const fileName =
      (Math.random() + 1).toString(36).substring(2, 10) + ".jpeg"; // assume jpeg

    const a = document.createElement("a");
    document.body.appendChild(a);
    a.href = imageUrl;
    a.download = fileName;
    a.click();
    document.body.removeChild(a);

    logger.info("Download triggered", fileName);
  };

  logger.info("Initialized");

  // For webz /a/ webapp
  setInterval(() => {
    // Stories
    const storiesContainer = document.getElementById("StoryViewer");
    if (storiesContainer) {
      console.log("storiesContainer");
      const createDownloadButton = () => {
        console.log("createDownloadButton");
        const downloadIcon = document.createElement("i");
        downloadIcon.className = "icon icon-download";
        const downloadButton = document.createElement("button");
        downloadButton.className =
          "Button TkphaPyQ tiny translucent-white round tel-download";
        downloadButton.appendChild(downloadIcon);
        downloadButton.setAttribute("type", "button");
        downloadButton.setAttribute("title", "Download");
        downloadButton.setAttribute("aria-label", "Download");
        downloadButton.onclick = () => {
          // 1. Story with video
          const video = storiesContainer.querySelector("video");
          const videoSrc =
            video?.src ||
            video?.currentSrc ||
            video?.querySelector("source")?.src;
          if (videoSrc) {
            tel_download_video(videoSrc);
          } else {
            // 2. Story with image
            const images = storiesContainer.querySelectorAll("img.PVZ8TOWS");
            if (images.length > 0) {
              const imageSrc = images[images.length - 1]?.src;
              if (imageSrc) tel_download_image(imageSrc);
            }
          }
        };
        return downloadButton;
      };

      const storyHeader =
        storiesContainer.querySelector(".GrsJNw3y") ||
        storiesContainer.querySelector(".DropdownMenu").parentNode;
      if (storyHeader && !storyHeader.querySelector(".tel-download")) {
        console.log("storyHeader");
        storyHeader.insertBefore(
          createDownloadButton(),
          storyHeader.querySelector("button")
        );
      }
    }

    // All media opened are located in .media-viewer-movers > .media-viewer-aspecter
    const mediaContainer = document.querySelector(
      "#MediaViewer .MediaViewerSlide--active"
    );
    const mediaViewerActions = document.querySelector(
      "#MediaViewer .MediaViewerActions"
    );
    if (!mediaContainer || !mediaViewerActions) return;

    // Videos in channels
    const videoPlayer = mediaContainer.querySelector(
      ".MediaViewerContent > .VideoPlayer"
    );
    const img = mediaContainer.querySelector(".MediaViewerContent > div > img");
    // 1. Video player detected - Video or GIF
    // container > .MediaViewerSlides > .MediaViewerSlide > .MediaViewerContent > .VideoPlayer > video[src]
    const downloadIcon = document.createElement("i");
    downloadIcon.className = "icon icon-download";
    const downloadButton = document.createElement("button");
    downloadButton.className =
      "Button smaller translucent-white round tel-download";
    downloadButton.setAttribute("type", "button");
    downloadButton.setAttribute("title", "Download");
    downloadButton.setAttribute("aria-label", "Download");
    if (videoPlayer) {
      const videoUrl = videoPlayer.querySelector("video").currentSrc;
      downloadButton.setAttribute("data-tel-download-url", videoUrl);
      downloadButton.appendChild(downloadIcon);
      downloadButton.onclick = () => {
        tel_download_video(videoPlayer.querySelector("video").currentSrc);
      };

      // Add download button to video controls
      const controls = videoPlayer.querySelector(".VideoPlayerControls");
      if (controls) {
        const buttons = controls.querySelector(".buttons");
        if (!buttons.querySelector("button.tel-download")) {
          const spacer = buttons.querySelector(".spacer");
          spacer.after(downloadButton);
        }
      }

      // Add/Update/Remove download button to topbar
      if (mediaViewerActions.querySelector("button.tel-download")) {
        const telDownloadButton = mediaViewerActions.querySelector(
          "button.tel-download"
        );
        if (
          mediaViewerActions.querySelectorAll('button[title="Download"]')
            .length > 1
        ) {
          // There's existing download button, remove ours
          mediaViewerActions.querySelector("button.tel-download").remove();
        } else if (
          telDownloadButton.getAttribute("data-tel-download-url") !== videoUrl
        ) {
          // Update existing button
          telDownloadButton.onclick = () => {
            tel_download_video(videoPlayer.querySelector("video").currentSrc);
          };
          telDownloadButton.setAttribute("data-tel-download-url", videoUrl);
        }
      } else if (
        !mediaViewerActions.querySelector('button[title="Download"]')
      ) {
        // Add the button if there's no download button at all
        mediaViewerActions.prepend(downloadButton);
      }
    } else if (img && img.src) {
      downloadButton.setAttribute("data-tel-download-url", img.src);
      downloadButton.appendChild(downloadIcon);
      downloadButton.onclick = () => {
        tel_download_image(img.src);
      };

      // Add/Update/Remove download button to topbar
      if (mediaViewerActions.querySelector("button.tel-download")) {
        const telDownloadButton = mediaViewerActions.querySelector(
          "button.tel-download"
        );
        if (
          mediaViewerActions.querySelectorAll('button[title="Download"]')
            .length > 1
        ) {
          // There's existing download button, remove ours
          mediaViewerActions.querySelector("button.tel-download").remove();
        } else if (
          telDownloadButton.getAttribute("data-tel-download-url") !== img.src
        ) {
          // Update existing button
          telDownloadButton.onclick = () => {
            tel_download_image(img.src);
          };
          telDownloadButton.setAttribute("data-tel-download-url", img.src);
        }
      } else if (
        !mediaViewerActions.querySelector('button[title="Download"]')
      ) {
        // Add the button if there's no download button at all
        mediaViewerActions.prepend(downloadButton);
      }
    }
  }, REFRESH_DELAY);

  // For webk /k/ webapp
  setInterval(() => {
    /* Voice Message */
    const pinnedAudio = document.body.querySelector(".pinned-audio");
    let dataMid;
    let downloadButtonPinnedAudio =
      document.body.querySelector("._tel_download_button_pinned_container") ||
      document.createElement("button");
    if (pinnedAudio) {
      dataMid = pinnedAudio.getAttribute("data-mid");
      downloadButtonPinnedAudio.className =
        "btn-icon tgico-download _tel_download_button_pinned_container";
      downloadButtonPinnedAudio.innerHTML = `<span class="tgico button-icon">${DOWNLOAD_ICON}</span>`;
    }
    const voiceMessages = document.body.querySelectorAll("audio-element");
    voiceMessages.forEach((voiceMessage) => {
      const bubble = voiceMessage.closest(".bubble");
      if (
        !bubble ||
        bubble.querySelector("._tel_download_button_pinned_container")
      ) {
        return; /* Skip if there's already a download button */
      }
      if (
        dataMid &&
        downloadButtonPinnedAudio.getAttribute("data-mid") !== dataMid &&
        voiceMessage.getAttribute("data-mid") === dataMid
      ) {
        downloadButtonPinnedAudio.onclick = (e) => {
          e.stopPropagation();
          tel_download_audio(link);
        };
        downloadButtonPinnedAudio.setAttribute("data-mid", dataMid);
        const link =
          voiceMessage.audio && voiceMessage.audio.getAttribute("src");
        if (link) {
          pinnedAudio
            .querySelector(".pinned-container-wrapper-utils")
            .appendChild(downloadButtonPinnedAudio);
        }
      }
    });

    // Stories
    const storiesContainer = document.getElementById("stories-viewer");
    if (storiesContainer) {
      const createDownloadButton = () => {
        const downloadButton = document.createElement("button");
        downloadButton.className = "btn-icon rp tel-download";
        downloadButton.innerHTML = `<span class="tgico">${DOWNLOAD_ICON}</span><div class="c-ripple"></div>`;
        downloadButton.setAttribute("type", "button");
        downloadButton.setAttribute("title", "Download");
        downloadButton.setAttribute("aria-label", "Download");
        downloadButton.onclick = () => {
          // 1. Story with video
          const video = storiesContainer.querySelector("video.media-video");
          const videoSrc =
            video?.src ||
            video?.currentSrc ||
            video?.querySelector("source")?.src;
          if (videoSrc) {
            tel_download_video(videoSrc);
          } else {
            // 2. Story with image
            const imageSrc =
              storiesContainer.querySelector("img.media-photo")?.src;
            if (imageSrc) tel_download_image(imageSrc);
          }
        };
        return downloadButton;
      };

      const storyHeader = storiesContainer.querySelector(
        "[class^='_ViewerStoryHeaderRight']"
      );
      if (storyHeader && !storyHeader.querySelector(".tel-download")) {
        storyHeader.prepend(createDownloadButton());
      }

      const storyFooter = storiesContainer.querySelector(
        "[class^='_ViewerStoryFooterRight']"
      );
      if (storyFooter && !storyFooter.querySelector(".tel-download")) {
        storyFooter.prepend(createDownloadButton());
      }
    }

    // All media opened are located in .media-viewer-movers > .media-viewer-aspecter
    const mediaContainer = document.querySelector(".media-viewer-whole");
    if (!mediaContainer) return;
    const mediaAspecter = mediaContainer.querySelector(
      ".media-viewer-movers .media-viewer-aspecter"
    );
    const mediaButtons = mediaContainer.querySelector(
      ".media-viewer-topbar .media-viewer-buttons"
    );
    if (!mediaAspecter || !mediaButtons) return;

    // Query hidden buttons and unhide them
    const hiddenButtons = mediaButtons.querySelectorAll("button.btn-icon.hide");
    let onDownload = null;
    for (const btn of hiddenButtons) {
      btn.classList.remove("hide");
      if (btn.textContent === FORWARD_ICON) {
        btn.classList.add("tgico-forward");
      }
      if (btn.textContent === DOWNLOAD_ICON) {
        btn.classList.add("tgico-download");
        // Use official download buttons
        onDownload = () => {
          btn.click();
        };
        logger.info("onDownload", onDownload);
      }
    }

    if (mediaAspecter.querySelector(".ckin__player")) {
      // 1. Video player detected - Video and it has finished initial loading
      // container > .ckin__player > video[src]

      // add download button to videos
      const controls = mediaAspecter.querySelector(
        ".default__controls.ckin__controls"
      );
      if (controls && !controls.querySelector(".tel-download")) {
        const brControls = controls.querySelector(
          ".bottom-controls .right-controls"
        );
        const downloadButton = document.createElement("button");
        downloadButton.className =
          "btn-icon default__button tgico-download tel-download";
        downloadButton.innerHTML = `<span class="tgico">${DOWNLOAD_ICON}</span>`;
        downloadButton.setAttribute("type", "button");
        downloadButton.setAttribute("title", "Download");
        downloadButton.setAttribute("aria-label", "Download");
        if (onDownload) {
          downloadButton.onclick = onDownload;
        } else {
          downloadButton.onclick = () => {
            tel_download_video(mediaAspecter.querySelector("video").src);
          };
        }
        brControls.prepend(downloadButton);
      }
    } else if (
      mediaAspecter.querySelector("video") &&
      mediaAspecter.querySelector("video") &&
      !mediaButtons.querySelector("button.btn-icon.tgico-download")
    ) {
      // 2. Video HTML element detected, could be either GIF or unloaded video
      // container > video[src]
      const downloadButton = document.createElement("button");
      downloadButton.className = "btn-icon tgico-download tel-download";
      downloadButton.innerHTML = `<span class="tgico button-icon">${DOWNLOAD_ICON}</span>`;
      downloadButton.setAttribute("type", "button");
      downloadButton.setAttribute("title", "Download");
      downloadButton.setAttribute("aria-label", "Download");
      if (onDownload) {
        downloadButton.onclick = onDownload;
      } else {
        downloadButton.onclick = () => {
          tel_download_video(mediaAspecter.querySelector("video").src);
        };
      }
      mediaButtons.prepend(downloadButton);
    } else if (!mediaButtons.querySelector("button.btn-icon.tgico-download")) {
      // 3. Image without download button detected
      // container > img.thumbnail
      if (
        !mediaAspecter.querySelector("img.thumbnail") ||
        !mediaAspecter.querySelector("img.thumbnail").src
      ) {
        return;
      }
      const downloadButton = document.createElement("button");
      downloadButton.className = "btn-icon tgico-download tel-download";
      downloadButton.innerHTML = `<span class="tgico button-icon">${DOWNLOAD_ICON}</span>`;
      downloadButton.setAttribute("type", "button");
      downloadButton.setAttribute("title", "Download");
      downloadButton.setAttribute("aria-label", "Download");
      if (onDownload) {
        downloadButton.onclick = onDownload;
      } else {
        downloadButton.onclick = () => {
          tel_download_image(mediaAspecter.querySelector("img.thumbnail").src);
        };
      }
      mediaButtons.prepend(downloadButton);
    }
  }, REFRESH_DELAY);

  // Progress bar container setup
  (function setupProgressBar() {
    const body = document.querySelector("body");
    const container = document.createElement("div");
    container.id = "tel-downloader-progress-bar-container";
    container.style.position = "fixed";
    container.style.bottom = 0;
    container.style.right = 0;
    if (location.pathname.startsWith("/k/")) {
      container.style.zIndex = 4;
    } else {
      container.style.zIndex = 1600;
    }
    body.appendChild(container);
  })();
})();