// ==UserScript==
// @name         屏蔽所有网站的图片和图标 (支持 Alt+P 切换及状态保存)
// @namespace    http://tampermonkey.net/
// @version      1.3
// @description  强制隐藏所有网站图片和图标。按 Alt+P 快捷键可随时开启或关闭，状态全局保存。
// @author       Panda-Young
// @license      MIT
// @match        *://*/*
// @run-at       document-start
// @grant        GM_setValue
// @grant        GM_getValue
// @grant        GM_addValueChangeListener
// @grant        GM_info
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';

    const STORAGE_KEY = 'global_image_block_state';

    // 双重存储读取逻辑：优先使用油猴 API，如果由于某种原因 API 失效，退化为 localStorage
    let isBlocked = true;
    try {
        if (typeof GM_getValue === 'function') {
            isBlocked = GM_getValue(STORAGE_KEY, true);
        } else {
            let localVal = localStorage.getItem(STORAGE_KEY);
            isBlocked = localVal !== null ? (localVal === 'true') : true;
        }
    } catch (e) {
        console.warn("读取状态失败，采用默认值(开启屏蔽)");
    }

    // 定义要注入的全局 CSS
    const blockStyle = `
        img, picture, svg, canvas, video, image {
            display: none !important;
            opacity: 0 !important;
            visibility: hidden !important;
            width: 0 !important;
            height: 0 !important;
            max-width: 0 !important;
            max-height: 0 !important;
        }
        * { background-image: none !important; }
        [class*="icon" i], [id*="icon" i],
        [class*="logo" i], [id*="logo" i],
        [class*="avatar" i], [id*="avatar" i],
        [class*="img" i], [id*="img" i],
        [class*="fa-" i], [class^="el-icon" i], [class^="glyphicon" i] {
            display: none !important;
            background-image: none !important;
        }
        *::before, *::after { background-image: none !important; }
    `;

    // 注入或更新样式的函数
    function injectOrUpdateStyles() {
        let styleNode = document.getElementById('no-images-strict-style');
        if (!styleNode) {
            styleNode = document.createElement('style');
            styleNode.id = 'no-images-strict-style';
            styleNode.type = 'text/css';
            (document.head || document.documentElement).appendChild(styleNode);
        }
        styleNode.textContent = isBlocked ? blockStyle : '';
    }

    // 屏幕中央顶部提示框（Toast）
    function showToast(message) {
        let toast = document.getElementById('no-images-toast');
        if (!toast) {
            toast = document.createElement('div');
            toast.id = 'no-images-toast';
            toast.style.cssText = `
                position: fixed; top: 20px; left: 50%; transform: translateX(-50%);
                padding: 10px 20px; background: rgba(0, 0, 0, 0.75); color: #fff;
                font-size: 14px; font-family: sans-serif; border-radius: 6px;
                z-index: 2147483647; pointer-events: none; transition: opacity 0.3s ease;
            `;
            document.documentElement.appendChild(toast);
        }
        toast.textContent = message;
        toast.style.opacity = '1';
        clearTimeout(toast.timer);
        toast.timer = setTimeout(() => { toast.style.opacity = '0'; }, 2000);
    }

    // 保存状态到本地的函数
    function saveState(state) {
        isBlocked = state;
        try {
            if (typeof GM_setValue === 'function') {
                GM_setValue(STORAGE_KEY, state);
            }
            localStorage.setItem(STORAGE_KEY, state);
        } catch (e) {}
    }

    // 初始化执行
    injectOrUpdateStyles();
    document.addEventListener('DOMContentLoaded', injectOrUpdateStyles);

    const observer = new MutationObserver(() => {
        if (!document.getElementById('no-images-strict-style')) {
            injectOrUpdateStyles();
        }
    });
    observer.observe(document.documentElement, { childList: true, subtree: false });

    // 监听键盘按键，捕获 Alt + P
    window.addEventListener('keydown', (e) => {
        if (e.altKey && e.key.toLowerCase() === 'p') {
            e.preventDefault(); 
            let newState = !isBlocked;
            saveState(newState); // 永久保存新状态
            injectOrUpdateStyles(); 
            showToast(newState ? '🚫 已开启：屏蔽所有图片和图标' : '🖼️ 已关闭：恢复显示图片和图标');
        }
    }, true); 

    // 跨标签页状态同步
    if (typeof GM_addValueChangeListener === 'function') {
        GM_addValueChangeListener(STORAGE_KEY, function(name, old_value, new_value, remote) {
            if (remote && isBlocked !== new_value) { 
                isBlocked = new_value;
                injectOrUpdateStyles();
                showToast(isBlocked ? '🔄 同步开启：屏蔽所有图片' : '🔄 同步关闭：恢复显示图片');
            }
        });
    }
})();