// ==UserScript==
// @name         Gmail Enhanced Toolbar
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  Adds custom buttons to Gmail toolbar with toggleable features.
// @author       Antigravity
// @match        https://mail.google.com/*
// @updateURL    https://raw.githubusercontent.com/nguyenhuy158/tampermonkey-script/main/gmail-enhanced.user.js
// @downloadURL  https://raw.githubusercontent.com/nguyenhuy158/tampermonkey-script/main/gmail-enhanced.user.js
// @grant        GM_registerMenuCommand
// @grant        GM_getValue
// @grant        GM_setValue
// @run-at       document-end
// ==/UserScript==

(function () {
    'use strict';

    // --- Configuration & State Management ---
    const FEATURES = {
        FILTER_NEAR_ARCHIVE: {
            id: 'filterNearArchive',
            name: 'Filter Button (Left of Archive)',
            default: true
        },
        FILTER_NEAR_SELECT: {
            id: 'filterNearSelect',
            name: 'Filter Button (Right of Select)',
            default: true
        }
    };

    const config = {};
    Object.keys(FEATURES).forEach(key => {
        const feature = FEATURES[key];
        config[feature.id] = GM_getValue(feature.id, feature.default);

        GM_registerMenuCommand(`${config[feature.id] ? '✅' : '❌'} ${feature.name}`, () => {
            GM_setValue(feature.id, !config[feature.id]);
            location.reload();
        });
    });

    // --- Utility Functions ---
    function waitForElement(selector, callback, interval = 500, timeout = 10000) {
        const startTime = Date.now();
        const check = () => {
            const el = document.querySelector(selector);
            if (el) {
                callback(el);
            } else if (Date.now() - startTime < timeout) {
                setTimeout(check, interval);
            }
        };
        check();
    }

    function createGmailButton(label, iconHtml, title, onClick) {
        const btn = document.createElement('div');
        btn.className = 'T-I J-J5-Ji T-I-ax7 T-I-Js-IF mA custom-gmail-btn';
        btn.setAttribute('role', 'button');
        btn.setAttribute('tabindex', '0');
        btn.setAttribute('data-tooltip', title);
        btn.setAttribute('aria-label', title);
        btn.style.userSelect = 'none';
        btn.style.marginRight = '4px';
        btn.style.marginLeft = '4px';
        btn.style.display = 'inline-flex';
        btn.style.alignItems = 'center';
        btn.style.justifyContent = 'center';
        btn.title = title;

        const iconContainer = document.createElement('div');
        iconContainer.className = 'asa';
        iconContainer.innerHTML = iconHtml || `<span style="font-family: 'Google Material Icons'; font-size: 20px;">filter_list</span>`;
        btn.appendChild(iconContainer);

        btn.addEventListener('click', (e) => {
            e.stopPropagation();
            onClick();
        });

        // Hover effect
        btn.addEventListener('mouseenter', () => btn.classList.add('T-I-JW'));
        btn.addEventListener('mouseleave', () => btn.classList.remove('T-I-JW'));

        return btn;
    }

    function triggerFilterAction() {
        // Try to trigger the "Filter messages like these" action
        // 1. Find the 'More' button
        const moreBtn = document.querySelector('div[aria-label="More email options"], div[data-tooltip="More"]');
        if (moreBtn) {
            moreBtn.click();
            // Wait for menu to appear and click "Filter messages like these"
            setTimeout(() => {
                const menuItems = document.querySelectorAll('div[role="menuitem"]');
                for (let item of menuItems) {
                    if (item.textContent.includes('Filter messages like these')) {
                        item.click();
                        break;
                    }
                }
            }, 50);
        } else {
            console.warn('More button not found');
        }
    }

    // SVG for the Filter icon (similar to Gmail's style)
    const FILTER_ICON_SVG = `<svg width="20" height="20" viewBox="0 0 24 24" fill="currentColor"><path d="M10 18h4v-2h-4v2zM3 6v2h18V6H3zm3 7h12v-2H6v2z"/></svg>`;

    // --- Main Logic ---
    function injectButtons() {
        // 1. Feature: Filter Button Near Archive
        if (config.filterNearArchive) {
            const archiveBtn = document.querySelector('div[aria-label="Archive"]');
            if (archiveBtn && !document.getElementById('custom-filter-archive')) {
                const filterBtn = createGmailButton('Filter', FILTER_ICON_SVG, 'Filter messages like these', triggerFilterAction);
                filterBtn.id = 'custom-filter-archive';
                archiveBtn.parentNode.insertBefore(filterBtn, archiveBtn);
            }
        }

        // 2. Feature: Filter Button Near Select
        if (config.filterNearSelect) {
            const selectGroup = document.querySelector('div.G-as3') || document.querySelector('div[aria-label="Select"]');
            if (selectGroup && !document.getElementById('custom-filter-select')) {
                const filterBtn = createGmailButton('Filter', FILTER_ICON_SVG, 'Filter messages like these', triggerFilterAction);
                filterBtn.id = 'custom-filter-select';
                // Insert after the select group
                selectGroup.insertAdjacentElement('afterend', filterBtn);
            }
        }
    }

    // Watch for toolbar changes
    const observer = new MutationObserver(() => {
        injectButtons();
    });

    observer.observe(document.body, {
        childList: true,
        subtree: true
    });

    // Initial injection
    injectButtons();

})();