Hydrilla

/**

 * SPDX-License-Identifier: LicenseRef-GPL-3.0-or-later-WITH-js-exceptions

 *

 * Make spreadsheets on drive.google.com browsable without nonfree js

 *

 * Copyright (C) 2021 Wojtek Kosior <koszko@koszko.org>

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of 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.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * 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.

 *

 * 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.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>.

 *

 * I, Wojtek Kosior, thereby promise not to sue for violation of this file's

 * license. Although I request that you do not make use of this code in a

 * proprietary program, I am not going to enforce this in court.

 */

/* Use with https://docs.google.com/spreadsheets/d/** */

/* Make the view scrollable. */

document.body.setAttribute("style",

			   "width: 100vw; height: 100vh; overflow: scroll;" +

			   (document.body.getAttribute("style") || ""));

let container = document.querySelectorAll(".waffle")[0];

let main_gid = null;

while (container) {

    container = container.parentElement;

    console.log(container);

    if (container === document.body || !container)

	break;

    const match = /([0-9]+)-grid-container/.exec(container.id);

    if (match)

	main_gid = match[1];

    container.setAttribute("style",

			   "width: fit-content; width: -moz-fit-content;");

}

/* Remove editor toolbars and bottom bar - these don't work anyway. */

const docs_chrome = document.getElementById("docs-chrome");

if (docs_chrome)

    docs_chrome.remove();

const grid_bottom_bar = document.getElementById("grid-bottom-bar");

if (grid_bottom_bar)

    grid_bottom_bar.remove();

/* Remove no Javascript warning. */

for (const no_js_warning of document.querySelectorAll("noscript"))

    no_js_warning.remove();

/* Get opengraph data. */

const og = {};

for (const node of document.head.childNodes) {

    if (node.tagName === "STYLE") {

	document.head.removeChild(node);

	continue;

    }

    if (node.tagName !== "META")

	continue;

    const match = /^og:(.+)/.exec(node.getAttribute("property"));

    if (!match)

	continue;

    og[match[1]] = node.getAttribute("content");

}

/* Construct download link. */

let download_link = null;

const match = new RegExp("/spreadsheets/d/([^/]+)").exec(document.URL);

if (match)

    download_link = `https://docs.google.com/spreadsheets/d/${match[1]}/export`;

/* Add title bar with sheet name and download button. */

const title_bar = document.createElement("div");

const title_heading = document.createElement("h1");

const title_text = document.createElement("span");

const main_download_button = document.createElement("a");

main_download_button.textContent = "download";

main_download_button.setAttribute("style", "border-radius: 10px; padding: 20px; color: #333; background-color: lightgreen; text-decoration: none; box-shadow: -4px 8px 8px #888; display: inline-block;");

if (og.title) {

    title_text.textContent = og.title;

    title_heading.appendChild(title_text);

}

title_text.setAttribute("style", "margin-right: 10px;");

if (download_link) {

    main_download_button.setAttribute("href", download_link);

    title_heading.appendChild(main_download_button);

}

title_bar.setAttribute("style", "padding: 0 20px; color: #555;");

title_bar.appendChild(title_heading);

document.body.insertBefore(title_bar, document.body.firstElementChild);

/* Extract sheet data from a script that sets the `bootstrapData' variable. */

let data = null;

for (const script of document.scripts) {

    const match = /bootstrapData = ({([^;]|[^}];)+})/.exec(script.textContent);

    if (!match)

	continue;

    data = JSON.parse(match[1]);

}

/*

 * Add download buttons for individual sheets belonging to this spreadsheet.

 * Data schema has been observed by looking at various spreadsheets.

 */

function add_sheet_download(data)

{

    if (!Array.isArray(data))

	return;

    const gid = data[2];

    if (!["string", "number"].includes(typeof gid))

	return;

    const sheet_download_link = `${download_link}?gid=${gid}`;

    const sheet_download_button = document.createElement("a");

    sheet_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: 0 5px 5px 0;");

    sheet_download_button.setAttribute("href", sheet_download_link);

    let sheet_name = null;

    if (Array.isArray(data[3]) &&

	data[3][0] && typeof data[3][0] === "object"

	&& Array.isArray(data[3][0][1]) &&

	Array.isArray(data[3][0][1][0]) &&

	typeof data[3][0][1][0][2] === "string") {

	const sheet_name = data[3][0][1][0][2];

	sheet_download_button.textContent = sheet_name;

        if (gid == main_gid)

	    title_text.textContent = `${title_text.textContent} - ${sheet_name}`;

    } else {

	sheet_download_button.textContent = `<sheet gid=${gid}>`;

    }

    title_bar.appendChild(sheet_download_button);

}

if (download_link) {

    for (const entry of data.changes.topsnapshot) {

	if (!Array.isArray(entry) || entry[0] !== 21350203 ||

	    typeof entry[1] !== "string")

	    continue;

	let entry_data = null;

	try {

	    entry_data = JSON.parse(entry[1]);

	} catch (e) {

	    console.log(e);

	    continue;

	}

	add_sheet_download(entry_data);

    }

}