// ==UserScript==
// @name           Persistent Tab Renamer with Position Tracking
// @namespace      https://github.com/YourUsername/
// @version        2.1
// @author         YourName
// @license        MIT
// @compatibility  Firefox 100+
// @include        main
// @run-at         document-start
// ==/UserScript==

(function() {
    // ===== CONFIG ===== //
    const PERSISTENT_MODE_DEFAULT = true;  // Default persistence state
    const CHECK_INTERVAL = 100;            // Enforcement loop interval (ms)
    const BLOCK_TITLE_CHANGES = true;      // Block document.title changes for renamed tabs

    // ===== STATE ===== //
    let persistentMode = PERSISTENT_MODE_DEFAULT;
    const renamedTabs = new Map();  // { tabId: customName }
    let hoveredTab = null;          // Track currently hovered tab

    // ===== CORE FUNCTIONALITY ===== //
    function enforceTabNames() {
        const tabs = gBrowser.tabs || document.querySelectorAll('tab');
        tabs.forEach((tab) => {
            const tabId = tab.getAttribute('linkedpanel') || tab.id;
            if (!tabId) return;

            const customName = renamedTabs.get(tabId);
            if (customName && persistentMode) {
                const label = tab.querySelector('.tab-text, .tab-label');
                if (label && label.textContent !== customName) {
                    label.textContent = customName;
                }
            }
        });
    }

    function startTabRename(tab) {
        if (!tab) return;
        
        const tabId = tab.getAttribute('linkedpanel') || tab.id;
        const label = tab.querySelector('.tab-text, .tab-label');
        if (!label) return;

        const originalText = label.textContent;

        const input = document.createElement('input');
        Object.assign(input.style, {
            width: `${document.documentElement.clientWidth - 4}px`,
            height: `${label.clientHeight}px`,
            backgroundColor: 'var(--toolbar-field-background-color)',
            color: 'var(--toolbar-field-color)',
            border: '1px solid var(--toolbar-field-border-color)',
            borderRadius: '5px',
            padding: '0 2px',
            margin: '0',
            font: 'inherit'
        });
        input.value = originalText;
        
        label.replaceWith(input);
        input.focus();
        input.select();

        const save = () => {
            const newText = input.value.trim();
            if (newText && newText !== originalText) {
                renamedTabs.set(tabId, newText);
                label.textContent = newText;
            }
            input.replaceWith(label);
        };

        input.addEventListener('keydown', (e) => {
            if (e.key === 'Enter') save();
            else if (e.key === 'Escape') input.replaceWith(label);
        });
        input.addEventListener('blur', save);
    }

    function handleTabLabelClick(event) {
        if (event.button !== 0 || event.detail !== 2) return;

        const label = event.target.closest('.tab-text, .tab-label');
        if (!label) return;

        event.preventDefault();
        event.stopPropagation();
        
        const tab = label.closest('tab');
        startTabRename(tab);
    }

    // ===== F2 RENAMING SUPPORT ===== //
    function handleTabHover(event) {
        const tab = event.target.closest('tab');
        hoveredTab = tab || null;
    }

    function handleKeyDown(event) {
        if (event.key === 'F2' && hoveredTab) {
            event.preventDefault();
            event.stopPropagation();
            startTabRename(hoveredTab);
        }
    }

    // ===== TITLE CHANGE BLOCKING ===== //
    function blockTitleChanges() {
        if (!BLOCK_TITLE_CHANGES) return;

        const { content } = Components.utils.Sandbox(gBrowser, {
            sandboxPrototype: gBrowser,
            wantXrays: false
        });

        Object.defineProperty(content.document.wrappedJSObject, 'title', {
            set: function(value) {
                const browser = gBrowser.getBrowserForDocument(this);
                if (browser) {
                    const tabId = browser.outerWindowID;
                    if (renamedTabs.has(tabId)) {
                        return renamedTabs.get(tabId); // Block title change for renamed tabs
                    }
                }
                // Allow title change for non-renamed tabs
                this._title = value;
                return value;
            },
            get: function() {
                return this._title || '';
            },
            configurable: true,
            enumerable: true
        });
    }

    // ===== INIT ===== //
    setInterval(enforceTabNames, CHECK_INTERVAL);
    const tabContainer = document.getElementById('tabbrowser-tabs');
    
    // Event listeners
    tabContainer.addEventListener('click', handleTabLabelClick, true);
    tabContainer.addEventListener('mouseover', handleTabHover);
    tabContainer.addEventListener('mouseout', () => { hoveredTab = null; });
    window.addEventListener('keydown', handleKeyDown, true);

    // Initialize title blocking
    if (BLOCK_TITLE_CHANGES) {
        if (gBrowser) {
            blockTitleChanges();
        } else {
            window.addEventListener('load', blockTitleChanges, { once: true });
        }
    }

    // Cleanup
    window.addEventListener('unload', () => {
        tabContainer.removeEventListener('click', handleTabLabelClick, true);
        tabContainer.removeEventListener('mouseover', handleTabHover);
        tabContainer.removeEventListener('mouseout', () => { hoveredTab = null; });
        window.removeEventListener('keydown', handleKeyDown, true);
    }, { once: true });

})();