// ==UserScript==
// @name         手动全屏
// @namespace    http://tampermonkey.net/
// @version      1.2.2
// @description  添加一个可拖动的全屏按钮，支持触屏设备，全屏切换后自动回位
// @author       youli
// @match        *://*/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // 创建全屏按钮
    var fullScreenButton = document.createElement('button');
    fullScreenButton.textContent = '全屏';
    fullScreenButton.style.position = 'fixed';
    fullScreenButton.style.bottom = '10px'; // 以右下角为起始点
    fullScreenButton.style.right = '10px';
    fullScreenButton.style.zIndex = 9999;
    fullScreenButton.style.cursor = 'pointer';
    fullScreenButton.style.padding = '5px 10px';
    fullScreenButton.style.background = 'rgba(76, 175, 79, 0.14)';
    fullScreenButton.style.color = 'white';
    fullScreenButton.style.border = 'none';
    fullScreenButton.style.borderRadius = '4px';
    fullScreenButton.style.transition = 'background 0.2s';

    // 鼠标悬停效果
    fullScreenButton.addEventListener('mouseover', function() {
        this.style.background = '#45a049';
    });
    fullScreenButton.addEventListener('mouseout', function() {
        this.style.background = 'rgba(76, 175, 80, 0.3)';
    });

    // 重置按钮到右下角
    function resetButtonPosition() {
        fullScreenButton.style.bottom = '10px';
        fullScreenButton.style.right = '10px';
        fullScreenButton.style.left = 'auto';
        fullScreenButton.style.top = 'auto';
    }

    // 初始化拖动变量
    var isDragging = false;
    var startX, startY;
    var offsetX, offsetY;
    var touchMoved = false; // 用于判断触摸是否移动过
    var dragThreshold = 5; // 拖动阈值，超过这个距离才认为是拖动

    // 鼠标/触摸事件处理
    fullScreenButton.addEventListener('mousedown', startDrag);
    fullScreenButton.addEventListener('touchstart', startDrag, { passive: false });

    function startDrag(e) {
        e.preventDefault();
        isDragging = false;
        touchMoved = false;
        
        if (e.type === 'touchstart') {
            startX = e.touches[0].clientX;
            startY = e.touches[0].clientY;
            offsetX = startX - fullScreenButton.getBoundingClientRect().left;
            offsetY = startY - fullScreenButton.getBoundingClientRect().top;
        } else {
            startX = e.clientX;
            startY = e.clientY;
            offsetX = startX - fullScreenButton.getBoundingClientRect().left;
            offsetY = startY - fullScreenButton.getBoundingClientRect().top;
        }

        document.addEventListener('mousemove', drag);
        document.addEventListener('touchmove', drag, { passive: false });
        document.addEventListener('mouseup', stopDrag);
        document.addEventListener('touchend', stopDrag);
    }

    function drag(e) {
        e.preventDefault();
        
        var clientX, clientY;
        if (e.type === 'touchmove') {
            clientX = e.touches[0].clientX;
            clientY = e.touches[0].clientY;
        } else {
            clientX = e.clientX;
            clientY = e.clientY;
        }

        // 计算移动距离
        var diffX = Math.abs(clientX - startX);
        var diffY = Math.abs(clientY - startY);
        
        // 如果移动距离超过阈值，才认为是拖动
        if (diffX > dragThreshold || diffY > dragThreshold) {
            isDragging = true;
            touchMoved = true;
            
            var newX = clientX - offsetX;
            var newY = clientY - offsetY;

            // 限制按钮在视口范围内
            newX = Math.max(0, Math.min(newX, window.innerWidth - fullScreenButton.offsetWidth));
            newY = Math.max(0, Math.min(newY, window.innerHeight - fullScreenButton.offsetHeight));

            fullScreenButton.style.left = newX + 'px';
            fullScreenButton.style.top = newY + 'px';
            fullScreenButton.style.right = 'auto';
            fullScreenButton.style.bottom = 'auto';
        }
    }

    function stopDrag(e) {
        // 如果是触摸结束且没有移动过，则视为点击
        if (e.type === 'touchend' && !touchMoved) {
            toggleFullScreen();
        }
        
        isDragging = false;
        touchMoved = false;
        document.removeEventListener('mousemove', drag);
        document.removeEventListener('touchmove', drag);
        document.removeEventListener('mouseup', stopDrag);
        document.removeEventListener('touchend', stopDrag);
    }

    // 全屏切换功能
    fullScreenButton.addEventListener('click', function() {
        if (!isDragging) {
            toggleFullScreen();
        }
    });

    function toggleFullScreen() {
        if (!document.fullscreenElement &&
            !document.webkitFullscreenElement &&
            !document.mozFullScreenElement &&
            !document.msFullscreenElement) {
            // 进入全屏
            if (document.documentElement.requestFullscreen) {
                document.documentElement.requestFullscreen();
            } else if (document.documentElement.webkitRequestFullscreen) {
                document.documentElement.webkitRequestFullscreen();
            } else if (document.documentElement.mozRequestFullScreen) {
                document.documentElement.mozRequestFullScreen();
            } else if (document.documentElement.msRequestFullscreen) {
                document.documentElement.msRequestFullscreen();
            }
        } else {
            // 退出全屏
            if (document.exitFullscreen) {
                document.exitFullscreen();
            } else if (document.webkitExitFullscreen) {
                document.webkitExitFullscreen();
            } else if (document.mozCancelFullScreen) {
                document.mozCancelFullScreen();
            } else if (document.msExitFullscreen) {
                document.msExitFullscreen();
            }
        }
        // 全屏状态变化后重置按钮位置
        resetButtonPosition();
    }

    // 监听全屏状态变化，更新按钮文本并重置位置
    document.addEventListener('fullscreenchange', handleFullscreenChange);
    document.addEventListener('webkitfullscreenchange', handleFullscreenChange);
    document.addEventListener('mozfullscreenchange', handleFullscreenChange);
    document.addEventListener('MSFullscreenChange', handleFullscreenChange);

    function handleFullscreenChange() {
        // 更新按钮文本
        if (document.fullscreenElement ||
            document.webkitFullscreenElement ||
            document.mozFullScreenElement ||
            document.msFullscreenElement) {
            fullScreenButton.textContent = '退出全屏';
        } else {
            fullScreenButton.textContent = '全屏';
        }
        // 重置按钮位置到右下角
        resetButtonPosition();
    }

    // 添加按钮到页面
    document.body.appendChild(fullScreenButton);
})();