// ==UserScript==
// @name         任意网页多快捷键绑定器
// @namespace    http://tampermonkey.net/
// @version      1.0.0
// @description  2秒内按4次ESC唤出可拖动圆形按钮，支持多个按钮，双击按钮删除，每个可绑定不同按键，独立触发点击
// @author       Lin
// @match        *://*/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // --- 存储所有按钮的数组 ---
    let buttons = [];           // 每个元素: { dom, key, selector, waiting }

    // --- ESC组合计数 ---
    let escPressCount = 0;
    let firstEscTime = 0;

    // --- 工具函数：获取元素简洁且尽量唯一的选择器 ---
    function getSelector(el) {
        if (!el || el === document.documentElement) return 'html';
        if (el.id) return `#${el.id}`;
        const path = [];
        while (el && el.nodeType === Node.ELEMENT_NODE && el !== document.body) {
            let selector = el.tagName.toLowerCase();
            const parent = el.parentNode;
            if (parent) {
                const siblings = Array.from(parent.children).filter(c => c.tagName === el.tagName);
                if (siblings.length > 1) {
                    const sameTagIndex = siblings.indexOf(el) + 1;
                    selector += `:nth-of-type(${sameTagIndex})`;
                } else {
                    const allChildren = parent.children;
                    const index = Array.from(allChildren).indexOf(el) + 1;
                    selector = `${el.tagName.toLowerCase()}:nth-child(${index})`;
                }
            }
            path.unshift(selector);
            el = parent;
        }
        if (el === document.body) path.unshift('body');
        return path.join(' > ');
    }

    // --- 移除所有未绑定的按钮 (key === null) ---
    function removeUnboundButtons() {
        for (let i = buttons.length - 1; i >= 0; i--) {
            const btn = buttons[i];
            if (btn.key === null) {
                btn.dom.remove();
                buttons.splice(i, 1);
            }
        }
    }

    // --- 移除指定按钮 (从数组和DOM) ---
    function removeButton(btnObj) {
        const index = buttons.indexOf(btnObj);
        if (index !== -1) {
            btnObj.dom.remove();
            buttons.splice(index, 1);
        }
    }

    // --- 创建新按钮 (屏幕中央) ---
    function createFloatingButton(x, y) {
        // 先清理所有未绑定的按钮
        removeUnboundButtons();

        // 创建DOM
        const btn = document.createElement('div');
        btn.id = 'floating-shortcut-btn-' + Date.now();
        Object.assign(btn.style, {
            position: 'fixed',
            width: '50px',
            height: '50px',
            borderRadius: '50%',
            backgroundColor: '#ff5722',
            color: 'white',
            textAlign: 'center',
            lineHeight: '50px',
            fontSize: '16px',
            fontWeight: 'bold',
            cursor: 'move',
            userSelect: 'none',
            boxShadow: '0 4px 12px rgba(0,0,0,0.3)',
            zIndex: '999999',
            left: (x - 25) + 'px',
            top: (y - 25) + 'px',
            transition: 'box-shadow 0.1s ease',
            fontFamily: 'Arial, sans-serif'
        });
        btn.textContent = '⚡'; // 等待绑定
        btn.title = '双击删除'; // 删除方式提示

        document.documentElement.appendChild(btn);

        // 创建按钮对象
        const btnObj = {
            dom: btn,
            key: null,          // 未绑定
            selector: null,
            waiting: true       // 新按钮进入等待绑定状态
        };
        buttons.push(btnObj);

        // 确保其他按钮退出等待状态 (只能有一个等待)
        buttons.forEach(b => {
            if (b !== btnObj && b.waiting) b.waiting = false;
        });

        // --- 双击删除 ---
        btn.addEventListener('dblclick', (e) => {
            e.stopPropagation();
            removeButton(btnObj);
        });

        // --- 右键菜单：仅阻止默认菜单，不删除 ---
        btn.addEventListener('contextmenu', (e) => {
            e.preventDefault();
            e.stopPropagation();
        });

        // --- 拖拽功能 (左键) ---
        let isDragging = false;
        let offsetX, offsetY;

        const onMouseDown = (e) => {
            if (e.button !== 0) return; // 仅左键
            e.preventDefault();
            isDragging = false;
            const rect = btn.getBoundingClientRect();
            offsetX = e.clientX - rect.left;
            offsetY = e.clientY - rect.top;

            const onMouseMove = (moveEvent) => {
                moveEvent.preventDefault();
                isDragging = true;
                let newLeft = moveEvent.clientX - offsetX;
                let newTop = moveEvent.clientY - offsetY;
                const maxLeft = window.innerWidth - btn.offsetWidth;
                const maxTop = window.innerHeight - btn.offsetHeight;
                newLeft = Math.max(0, Math.min(newLeft, maxLeft));
                newTop = Math.max(0, Math.min(newTop, maxTop));
                btn.style.left = newLeft + 'px';
                btn.style.top = newTop + 'px';
            };

            const onMouseUp = () => {
                document.removeEventListener('mousemove', onMouseMove);
                document.removeEventListener('mouseup', onMouseUp);
                isDragging = false;
            };

            document.addEventListener('mousemove', onMouseMove);
            document.addEventListener('mouseup', onMouseUp);
        };

        btn.addEventListener('mousedown', onMouseDown);
        btn.addEventListener('mouseup', (e) => e.preventDefault());

        return btnObj;
    }

    // --- 辅助：按钮闪烁 ---
    function flashButton(btnObj, text, duration = 300) {
        if (!btnObj || !btnObj.dom) return;
        const dom = btnObj.dom;
        const originalText = dom.textContent;
        const originalBg = dom.style.backgroundColor;
        dom.textContent = text;
        dom.style.backgroundColor = '#4caf50';
        setTimeout(() => {
            if (dom && dom.parentNode) {
                dom.textContent = originalText;
                dom.style.backgroundColor = originalBg;
            }
        }, duration);
    }

    // --- 处理等待状态下的按键绑定 ---
    function handleBindingKey(e) {
        const waitingBtn = buttons.find(b => b.waiting === true);
        if (!waitingBtn) return false;

        const key = e.key;

        // 允许按ESC取消等待并移除按钮
        if (key === 'Escape') {
            e.preventDefault();
            e.stopPropagation();
            removeButton(waitingBtn);
            return true;
        }

        // 忽略修饰键
        const modifierKeys = ['Shift', 'Control', 'Alt', 'Meta', 'OS', 'CapsLock', 'Tab'];
        if (modifierKeys.includes(key)) {
            flashButton(waitingBtn, '🚫');
            return false;
        }

        if (e.ctrlKey || e.altKey || e.metaKey) {
            flashButton(waitingBtn, '组合键');
            return false;
        }

        // 检查按键是否已被其他已绑定的按钮占用
        const existing = buttons.find(b => b.key === key && b !== waitingBtn);
        if (existing) {
            flashButton(waitingBtn, '❌占用');
            return false;
        }

        // 合法按键，进行绑定
        e.preventDefault();
        e.stopPropagation();

        // 获取按钮下方元素
        const rect = waitingBtn.dom.getBoundingClientRect();
        const centerX = rect.left + rect.width / 2;
        const centerY = rect.top + rect.height / 2;

        waitingBtn.dom.style.visibility = 'hidden';
        let elem = document.elementFromPoint(centerX, centerY);
        waitingBtn.dom.style.visibility = 'visible';

        if (!elem || elem === document.documentElement) {
            elem = document.body;
        }

        waitingBtn.key = key;
        waitingBtn.selector = getSelector(elem);
        waitingBtn.waiting = false;
        waitingBtn.dom.textContent = key;

        console.log(`[快捷键] 绑定按键 "${key}" 到元素:`, elem, '选择器:', waitingBtn.selector);
        flashButton(waitingBtn, '✓', 200);
        return true;
    }

    // --- 触发已绑定的快捷键 ---
    function triggerShortcut(e) {
        const key = e.key;
        if (e.ctrlKey || e.altKey || e.metaKey) return false;

        const target = e.target;
        const isInput = target.matches('input, textarea, select, [contenteditable="true"], [contenteditable=""]');
        if (isInput) return false;

        const matchedBtns = buttons.filter(b => b.key === key && !b.waiting);
        if (matchedBtns.length === 0) return false;

        const btnObj = matchedBtns[0];
        if (!btnObj.selector) return false;

        e.preventDefault();
        e.stopPropagation();

        try {
            const element = document.querySelector(btnObj.selector);
            if (element) {
                element.click();
                flashButton(btnObj, '💥', 150);
                console.log(`[快捷键] 触发按键 "${key}"，点击元素:`, element);
            } else {
                console.warn('[快捷键] 绑定的元素未找到，请重新绑定');
                flashButton(btnObj, '❌');
            }
        } catch (err) {
            console.error('[快捷键] 触发错误:', err);
        }
        return true;
    }

    // --- 处理ESC组合唤出 ---
    function handleEscCombo(e) {
        if (e.key !== 'Escape') return;

        const now = Date.now();

        if (escPressCount === 0) {
            firstEscTime = now;
            escPressCount = 1;
        } else {
            if (now - firstEscTime <= 2000) {
                escPressCount++;
            } else {
                firstEscTime = now;
                escPressCount = 1;
            }
        }

        if (escPressCount === 4) {
            e.preventDefault();
            e.stopPropagation();
            createFloatingButton(window.innerWidth / 2, window.innerHeight / 2);
            escPressCount = 0;
            firstEscTime = 0;
        }
    }

    // --- 全局键盘监听 (捕获阶段) ---
    window.addEventListener('keydown', (e) => {
        // 1. 优先处理等待绑定
        if (buttons.some(b => b.waiting)) {
            if (handleBindingKey(e)) return;
        }

        // 2. 触发已绑定的快捷键
        if (triggerShortcut(e)) return;

        // 3. 处理ESC组合唤出
        handleEscCombo(e);
    }, true);

    // --- 清理 (页面卸载时) ---
    window.addEventListener('unload', () => {
        buttons.forEach(b => b.dom.remove());
        buttons = [];
    });
})();