Google Gmail User Account Redirect

Redirect Google Mail to correct user Account

// ==UserScript==
// @name         Google Gmail User Account Redirect
// @description  Redirect Google Mail to correct user Account
// @version      0.1
// @author       Torkelicous
// @icon         https://ssl.gstatic.com/ui/v1/icons/mail/rfr/logo_gmail_lockup_dark_2x_r5.png
// @include      https://mail.google.com/*
// @run-at       document-start
// @grant        GM_setValue
// @grant        GM_getValue
// @license      MIT
// @namespace https://greasyfork.org/users/1403155
// ==/UserScript==

(function() {

    let wantedAccount = GM_getValue('wantedAccount', 1)
    let isUIVisible = GM_getValue('isUIVisible', true);
    let guiContainer;
    let toggleButton;

    var currentUrl = window.location.href;
    var shouldShowUI = !currentUrl.includes('/mail/u/') || currentUrl.includes('#inbox');

    // Create toggle
    function createToggleButton() {
        toggleButton = document.createElement('button');
        toggleButton.textContent = isUIVisible ? '➖' : '➕';
        toggleButton.style.position = 'fixed';
        toggleButton.style.bottom = '10px';
        toggleButton.style.left = '70px';
        toggleButton.style.zIndex = '1000';
        toggleButton.style.padding = '5px';
        toggleButton.style.cursor = 'pointer';
        toggleButton.style.backgroundColor = 'grey';
        toggleButton.style.border = '1px solid grey';
        toggleButton.style.borderRadius = '3px';
        toggleButton.style.fontSize = '16px';

        toggleButton.onclick = function() {
            if (isUIVisible) {
                guiContainer.style.display = 'none';
                toggleButton.textContent = '➕';
            } else {
                guiContainer.style.display = 'block';
                toggleButton.textContent = '➖';
            }
            isUIVisible = !isUIVisible;
            GM_setValue('isUIVisible', isUIVisible);
        };

        document.body.appendChild(toggleButton);
    }

    // GUI for wantedAccount
    function createGUI() {
        // Don't create UI if we're on a specific email URL
        if (!shouldShowUI) {
            return;
        }

        guiContainer = document.createElement('div');
        guiContainer.style.position = 'fixed';
        guiContainer.style.bottom = '10px';
        guiContainer.style.left = '110px';
        guiContainer.style.padding = '10px';
        guiContainer.style.backgroundColor = 'DarkGrey';
        guiContainer.style.border = '1px solid grey';
        guiContainer.style.zIndex = '1000';
        guiContainer.style.display = isUIVisible ? 'block' : 'none'; // Set initial display based on saved state

        const label = document.createElement('label');
        label.textContent = 'Account: ';
        guiContainer.appendChild(label);

        const input = document.createElement('input');
        input.type = 'number';
        input.min = '0';
        input.max = '9';
        input.style.width = '30px';
        input.value = wantedAccount;
        guiContainer.appendChild(input);

        const button = document.createElement('button');
        button.textContent = 'Save';
        button.style.marginLeft = '5px';
        button.onclick = function() {
            GM_setValue('wantedAccount', input.value);
            location.reload();
        };
        guiContainer.appendChild(button);
        document.body.appendChild(guiContainer);
        createToggleButton();
    }
    window.addEventListener('load', createGUI);

    // Redirect logic for Gmail
    var urlPattern = /^https:\/\/mail\.google\.com\/mail\/u\/(\d+)\//;
    var match = currentUrl.match(urlPattern);

    if (match) {
        var currentAccount = match[1];
        if (currentAccount != wantedAccount) {
            var newUrl = currentUrl.replace(/\/u\/\d+\//, `/u/${wantedAccount}/`);
            window.location.replace(newUrl);
        }
    } else {
        if (currentUrl.includes('mail.google.com/mail') && !currentUrl.includes('/u/')) {
            var newUrl = currentUrl.replace('mail.google.com/mail', `mail.google.com/mail/u/${wantedAccount}`);
            window.location.replace(newUrl);
        }
    }

})();