google-drive: Change folders fix from content to background script.HEADmagister

This also removes helpers for blocking CSS from `background.js' (nothing shall
be using them now).

1 files changed, 396 insertions, 0 deletions

diff --git a/background/google-drive-folders.js b/background/google-drive-folders.js
new file mode 100644
index 0000000..4e6a9c6
--- /dev/null
+++ b/background/google-drive-folders.js
@@ -0,0 +1,396 @@
+/**
+ * SPDX-License-Identifier: CC0-1.0
+ *
+ * Copyright (C) 2021, 2026 Woj. Kosior <koszko@koszko.org>
+ */
+
+(() => {
+
+blockJsOnUrl("https://drive.google.com/drive/folders/*");
+
+/* Define how to handle various mime types used by Google. */
+
+const defaultLinkProducer = id => ({
+    view: `https://drive.google.com/file/d/${id}`,
+    download: `https://drive.google.com/uc?export=download&id=${id}`
+});
+
+const knownMimes = {
+    "application/vnd.google-apps.folder": {
+	links: id => ({
+	    view: `https://drive.google.com/drive/folders/${id}`
+	}),
+	type: "folder",
+	is_folder: true
+    },
+    "application/vnd.google-apps.shortcut": {
+	links: id => ({
+	    view: `https://drive.google.com/drive/folders/${id}`
+	}),
+	type: "shortcut",
+	is_folder: true
+    },
+    "application/vnd.google-apps.document": {
+	links: id => ({
+	    view: `https://docs.google.com/document/d/${id}`,
+	    download: `https://docs.google.com/document/d/${id}/export?format=odt`,
+	}),
+	type: "Google text document",
+	newMime: "application/vnd.oasis.opendocument.text"
+    },
+    "application/vnd.google-apps.spreadsheet": {
+	links: id => ({
+	    view: `https://docs.google.com/spreadsheets/d/${id}`,
+	    download: `https://docs.google.com/spreadsheets/d/${id}/export?format=ods`
+	}),
+	type: "Google spreadsheet",
+	newMime: "application/vnd.oasis.opendocument.spreadsheet"
+    },
+    "application/vnd.google-apps.presentation": {
+	links: id => ({
+	    view: `https://docs.google.com/presentation/d/${id}`,
+	    download: `https://docs.google.com/presentation/d/${id}/export/pptx`
+	}),
+	type: "Google presentation",
+	newMime: "application/vnd.openxmlformats-officedocument.presentationml.presentation"
+    },
+    "application/vnd.google-apps.drawing": {
+	links: id => ({
+	    view: `https://docs.google.com/drawings/d/${id}`,
+	    download: `https://docs.google.com/drawings/d/${id}/export/jpeg`
+	}),
+	type: "Google drawing",
+	newMime: "image/jpeg"
+    },
+    "application/vnd.google-apps.script": {
+	links: id => ({
+	    download: `https://script.google.com/feeds/download/export?format=json&id=${id}`
+	}),
+	type: "Google script",
+	newMime: "application/vnd.google-apps.script+json"
+    },
+    "application/vnd.google-apps.jam": {
+	links: id => ({
+	    download: `https://jamboard.google.com/export?id=${id}`
+	}),
+	type: "Google jam",
+	newMime: "application/pdf"
+    },
+    /*
+     * Human-friendly names defined below will be displayed to the user instead
+     * of raw mime types.  Please add more here.
+     */
+    ...[
+        [              "image/jpeg", "JPEG image"],
+        ["application/octet-stream", "binary data"],
+        [         "application/pdf", "PDF document"],
+        [         "application/rar", "RAR archive"],
+        [         "application/zip", "ZIP archive"]
+    ].map(([mime, displayName]) => [
+        mime,
+        {
+	    links: id => defaultLinkProducer,
+	    type: displayName,
+	    newMime: mime
+        }
+    ])
+};
+
+function getMimeInfo(mime) {
+    return knownMimes[mime] || {
+	links: defaultLinkProducer,
+	type: mime || "",
+	newMime: mime || "application/octet-stream"
+    };
+}
+
+function transformDocument(origDoc) {
+    /*
+     * Prepare folder contents data as well as data regarding the folder itself.
+     */
+
+    const contents = new Map();
+
+    function add_contents_item(item)
+    {
+        const old_item = contents.get(item.id) || {};
+        Object.assign(old_item, item);
+        contents.set(item.id, old_item);
+    }
+
+    const this_folder = {};
+
+    function replace_string_escape(match, group)
+    {
+        return String.fromCharCode(`0x${group}`);
+    }
+
+    function try_parse(data, replace_x_escapes)
+    {
+        if (!data)
+	    return null;
+
+        if (replace_x_escapes)
+	    data = data.replaceAll(/\\x([0-9a-f]{2})/g, replace_string_escape);
+
+        try {
+	    return JSON.parse(data);
+        } catch (e) {
+	    console.log(e);
+        }
+
+        return null;
+    }
+
+    function process_file_data(file_data, callback)
+    {
+        if (!Array.isArray(file_data) || !typeof file_data[0] === "string") {
+	    console.log("cannot process the following file data object:",
+		        file_data);
+	    return;
+        }
+
+        const result = {id: file_data[0], folders: []};
+
+        if (Array.isArray(file_data[1])) {
+	    for (const item of file_data[1]) {
+	        if (typeof item === "string" && item !== this_folder.id)
+		    result.folders.push(item);
+	    }
+        }
+        if (typeof file_data[2] === "string")
+	    result.filename = file_data[2];
+        if (typeof file_data[3] === "string" && file_data[3].search("/") >= 0)
+	    result.mime = file_data[3];
+        if (typeof file_data[9] === "number")
+	    result.date1 = new Date(file_data[9]);
+        if (typeof file_data[10] === "number")
+	    result.date2 = new Date(file_data[10]);
+
+        callback(result);
+    }
+
+    /*
+     * By searching for scripts with calls to AF_initDataCallback we get about 7
+     * matches. All arguments to this function seem to be arrays parseable as
+     * JSON, but their contents are very different and only two of those ~7
+     * arrays actually hold some data useful to us. Here we try to filter out
+     * the other cases and then extract the useful data.
+     */
+    function process_af_init_data(data)
+    {
+        if (!Array.isArray(data) || !/^driveweb/.test(data[0]) ||
+	    !Array.isArray(data[1]))
+	    return;
+
+        /*
+         * First useful "kind" of object we can encounter is this folder's data.
+         */
+        if (typeof data[1][0] === "string") {
+	    process_file_data(data[1], item => Object.assign(this_folder, item));
+	    return;
+        }
+
+        /*
+         * Second "kind" of object holds data about all items in the folder.
+         * Folders and Files are stored in separate lists (doesn't matter to us,
+         * since we distinguish them based on mime type anyway).
+         */
+        for (const data_sub of data[1]) {
+	    if (!Array.isArray(data_sub) || !/^driveweb/.test(data_sub[0]) ||
+	        !Array.isArray(data_sub[1]))
+	        continue;
+	    for (const item of data_sub[1])
+	        process_file_data(item, add_contents_item);
+        }
+    }
+
+    /*
+     * Folder items data actually exists in both of the 2 kinds of scripts we
+     * search for. In case of both of the regexes below we call
+     * `process_file_data' in the end. As a result, we process the same file
+     * multiple time as it appears in 2 scripts. This is, however, a good thing,
+     * because it makes a change less likely to break our fix.
+     */
+
+    const ivd_data_regex =
+          /\s*window\s*\['_DRIVE_ivd'\]\s*=\s*'(\\x5b[^']+)'(.*)$/;
+    const af_init_data_regex =
+          /AF_initDataCallback\s*\(.+data\s*:\s*(\[.*\])[^\]]+$/;
+
+    for (const script of origDoc.scripts) {
+        const ivd_data_match = ivd_data_regex.exec(script.textContent);
+        if (ivd_data_match) {
+	    const ivd_data = try_parse(ivd_data_match[1], true);
+	    if (ivd_data && Array.isArray(ivd_data) &&
+                Array.isArray(ivd_data[0])) {
+	        for (const item of ivd_data[0])
+		    process_file_data(item, add_contents_item);
+	    }
+        }
+
+        const af_init_data_match = af_init_data_regex.exec(script.textContent);
+        if (af_init_data_match) {
+	    const af_init_data = try_parse(af_init_data_match[1], false);
+	    if (af_init_data)
+	        process_af_init_data(af_init_data);
+        }
+    }
+
+    /* Construct our own user interface. */
+
+    const newDoc = new DOMParser().parseFromString('<html>', 'text/html');
+
+    const body = newDoc.createElement("body");
+    const folders = newDoc.createElement("div");
+    const files = newDoc.createElement("div");
+    const folders_heading = newDoc.createElement("h2");
+    const files_heading = newDoc.createElement("h2");
+
+    folders_heading.textContent = "Folders";
+    files_heading.textContent = "Files";
+
+    let has_folders = false;
+    let has_files = false;
+
+    folders.appendChild(folders_heading);
+    files.appendChild(files_heading);
+
+    body.setAttribute("style", "width: 100vw; height: 100vh; overflow: scroll; color: #555; margin: 15px; -webkit-user-select: initial;");
+
+    const drive_folder_regex = /application\/vnd.google-apps.(folder|shortcut)/;
+
+    function add_item_to_view(item_data)
+    {
+        const item_div = newDoc.createElement("div");
+        const item_heading = newDoc.createElement("h4");
+
+        item_div.setAttribute("style", "border: 2px solid #999; border-radius: 8px; padding: 10px; display: inline-block; margin: 2px;");
+
+        let item_heading_style = "margin: 8px 4px;";
+
+        if (item_data.filename) {
+	    item_heading.textContent = item_data.filename;
+        } else {
+	    item_heading.textContent = "(no name)";
+	    item_heading_style += " font-style:italic;";
+        }
+        item_heading.setAttribute("style", item_heading_style);
+        item_div.appendChild(item_heading);
+
+        const mime_info = getMimeInfo(item_data.mime);
+
+        if (mime_info.type) {
+	    const type_div = newDoc.createElement("div");
+	    type_div.setAttribute("style", "margin-bottom: 5px;");
+	    type_div.textContent = mime_info.type;
+
+	    item_div.appendChild(type_div);
+        }
+
+        if (mime_info.is_folder)
+	    has_folders = true;
+        else
+	    has_files = true;
+
+        const links = {};
+        if (item_data.id)
+	    Object.assign(links, mime_info.links(item_data.id));
+
+        if (links.view) {
+	    const view_button = newDoc.createElement("a");
+	    view_button.setAttribute("style", "border-radius: 5px; padding: 10px; color: #333; background-color: lightgreen; text-decoration: none; box-shadow: -4px 8px 8px #888; display: inline-block; margin: 5px;");
+	    view_button.textContent = "view";
+	    view_button.href = links.view;
+
+	    item_div.appendChild(view_button);
+        }
+
+        if (links.download) {
+	    const download_button = newDoc.createElement("a");
+	    download_button.setAttribute("style", "border-radius: 5px; padding: 10px; color: #333; background-color: lightgreen; text-decoration: none; box-shadow: -4px 8px 8px #888; display: inline-block; margin: 5px;");
+	    download_button.textContent = "download";
+	    download_button.href = links.download;
+	    download_button.type = mime_info.newMime;
+
+	    item_div.appendChild(download_button);
+        }
+
+        (mime_info.is_folder ? folders : files).appendChild(item_div);
+    }
+
+    for (const item of contents.values())
+        add_item_to_view(item);
+
+    if (this_folder.filename) {
+        const heading = newDoc.createElement("h1");
+        heading.textContent = this_folder.filename;
+        body.appendChild(heading);
+    }
+    if (this_folder.folders && this_folder.folders.length > 0) {
+        for (const parent_id of this_folder.folders) {
+	    const up_button = newDoc.createElement("a");
+	    let text = "go up";
+
+	    up_button.setAttribute("style", "border-radius: 5px; padding: 10px; color: #333; background-color: lightgreen; text-decoration: none; box-shadow: -4px 8px 8px #888; display: inline-block; margin: 5px;");
+	    up_button.href = `https://drive.google.com/drive/folders/${parent_id}`;
+	    if (this_folder.folders.length > 1)
+	        text = `${text} (${parent_id})`;
+	    up_button.textContent = text;
+
+	    body.appendChild(up_button);
+        }
+    }
+    if (has_folders)
+        body.appendChild(folders);
+    if (has_files)
+        body.appendChild(files);
+    if (!(has_files || has_folders)) {
+        const no_files_message = newDoc.createElement("h3");
+        no_files_message.textContent = "No files found.";
+        body.appendChild(no_files_message);
+    }
+
+    newDoc.documentElement.replaceChild(body, newDoc.body);
+
+    return '<!DOCTYPE html>\n' + newDoc.documentElement.outerHTML;
+}
+
+function alterGoogleDriveFolderResponse(details) {
+    if (String(details.statusCode)[0] !== '2')
+        return;
+
+    for (const header of details.responseHeaders) {
+        if (/^content-type$/i.test(header.name) &&
+            !/^text[/]html; *charset *= *utf-8/i.test(header.value))
+            return;
+    }
+
+    const filter = browser.webRequest.filterResponseData(details.requestId);
+
+    const decoder = new TextDecoder("utf-8");
+
+    const pieces = [];
+
+    filter.ondata = event => pieces.push(
+        decoder.decode(event.data, { stream: true })
+    );
+
+    filter.onstop = event => {
+        const origDoc = new DOMParser()
+              .parseFromString(pieces.join(''), 'text/html');
+        filter.write(new TextEncoder().encode(transformDocument(origDoc)));
+        filter.close();
+    };
+}
+
+browser.webRequest.onHeadersReceived.addListener(
+    alterGoogleDriveFolderResponse,
+    {
+        urls: ["https://drive.google.com/drive/folders/*"],
+        types: ["main_frame", "sub_frame"]
+    },
+    ["blocking", "responseHeaders"]
+);
+
+})();