3 files changed, 384 insertions, 0 deletions
diff --git a/content/pgoogle_drive_browse/index.json b/content/pgoogle_drive_browse/index.json
new file mode 100644
index 0000000..b1fa688
--- /dev/null
+++ b/content/pgoogle_drive_browse/index.json
@@ -0,0 +1,5 @@
+{
+"type" : "page",
+"pattern" : "https://drive.google.com/drive/folders/***",
+"payload" : ["script", "google_drive_browse"]
+}
diff --git a/content/sgoogle_drive_browse/google_drive_browse_folder.js b/content/sgoogle_drive_browse/google_drive_browse_folder.js
new file mode 100644
index 0000000..7843b15
--- /dev/null
+++ b/content/sgoogle_drive_browse/google_drive_browse_folder.js
@@ -0,0 +1,373 @@
+/**
+ * Copyright 2021 Wojtek Kosior
+ *
+ * This program is free software; you can redistribute it
+ * and/or modify it under the terms of either:
+ * - the GNU General Public License as published by the Free
+ *   Software Foundation; either version 3 of the License, or (at
+ *   your option) any later version, or
+ * - the "A" license: <https://koszko.org/alicense.txt>; explained
+ *   at: <https://koszko.org/en/articles/my-new-license.html>
+ *
+ * As additional permission under GNU GPL version 3 section 7, you
+ * may distribute forms of that code without the copy of the GNU
+ * GPL normally required by section 4, provided you include this
+ * license notice and, in case of non-source distribution, a URL
+ * through which recipients can access the Corresponding Source.
+ * If you modify file(s) with this exception, you may extend this
+ * exception to your version of the file(s), but you are not
+ * obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version. If you delete this
+ * exception statement from all source files in the program, then
+ * also delete it here.
+ *
+ * As a special exception to the GPL, any HTML file which merely
+ * makes function calls to this code, and for that purpose
+ * includes it by reference shall be deemed a separate work for
+ * copyright law purposes. If you modify this code, you may extend
+ * this exception to your version of the code, but you are not
+ * obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+/* Use with https://drive.google.com/drive/folders/*** */
+
+/* Define how to handle various mime types used by Google. */
+
+const known_mimes = {
+    "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",
+	new_mime: "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",
+	new_mime: "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",
+	new_mime: "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",
+	new_mime: "image/jpeg"
+    },
+    "application/vnd.google-apps.script": {
+	links: id => ({
+	    download: `https://script.google.com/feeds/download/export?format=json&id=${id}`
+	}),
+	type: "Google script",
+	new_mime: "application/vnd.google-apps.script+json"
+    },
+    "application/vnd.google-apps.jam": {
+	links: id => ({
+	    download: `https://jamboard.google.com/export?id=${id}`
+	}),
+	type: "Google jam",
+	new_mime: "application/pdf"
+    }
+};
+
+/*
+ * Human-friendly names defined here will be displayed to the user instead of
+ * raw mime types. Please add more here.
+ */
+let mime_display_overrides = {
+    "image/jpeg": "JPEG image",
+    "application/octet-stream": "binary data",
+    "application/pdf": "PDF document",
+    "application/rar": "RAR archive",
+    "application/zip": "ZIP archive"
+};
+
+let default_link_producer = id => ({
+    view: `https://drive.google.com/file/d/${id}`,
+    download: `https://drive.google.com/uc?export=download&id=${id}`
+});
+
+for (const [mime, display_name] of Object.entries(mime_display_overrides)) {
+    known_mimes[mime] = {
+	links: default_link_producer,
+	type: display_name,
+	new_mime: mime
+    }
+}
+
+delete mime_display_overrides;
+
+function get_mime_info(mime) {
+    return known_mimes[mime] || {
+	links: default_link_producer,
+	type: mime || "",
+	new_mime: mime || "application/octet-stream"
+    }
+}
+
+/* Prepare folder contents data as well as data regarding the folder itself. */
+
+const content = new Map();
+
+function add_content_item(item)
+{
+    const old_item = content.get(item.id) || {};
+    Object.assign(old_item, item);
+    content.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_content_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 document.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_content_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 body = document.createElement("body");
+const folders = document.createElement("div");
+const files = document.createElement("div");
+const folders_heading = document.createElement("h2");
+const files_heading = document.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 = document.createElement("div");
+    const item_heading = document.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 = get_mime_info(item_data.mime);
+
+    if (mime_info.type) {
+	const type_div = document.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 = document.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 = document.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.new_mime;
+
+	item_div.appendChild(download_button);
+    }
+
+    (mime_info.is_folder ? folders : files).appendChild(item_div);
+}
+
+for (const item of content.values())
+    add_item_to_view(item);
+
+if (this_folder.filename) {
+    const heading = document.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 = document.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 = document.createElement("h3");
+    no_files_message.textContent = "No files found.";
+    body.appendChild(no_files_message);
+}
+
+if (document.body.firstChild.id !== "af-error-container")
+    document.documentElement.replaceChild(body, document.body);
diff --git a/content/sgoogle_drive_browse/index.json b/content/sgoogle_drive_browse/index.json
new file mode 100644
index 0000000..148ab65
--- /dev/null
+++ b/content/sgoogle_drive_browse/index.json
@@ -0,0 +1,6 @@
+{
+"type" : "script",
+"name" : "google_drive_browse",
+"sha256" : "e1648ba9f01272e2f5594800acf85515346ec0145e90e4dc8557e09f79b17b92",
+"location" : "google_drive_browse_folder.js"
+}