// ==UserScript==
// @name         屏幕录像机
// @namespace    https://scriptcat.org/zh-CN/users/13895
// @version      0.1
// @description  在任何网页上添加屏幕录制功能
// @author       you
// @match        *://*/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // 创建控制界面元素
    const createControlPanel = () => {
        const panel = document.createElement('div');
        panel.style.position = 'fixed';
        panel.style.bottom = '20px';
        panel.style.right = '20px';
        panel.style.zIndex = '999999';
        panel.style.backgroundColor = 'white';
        panel.style.padding = '1rem';
        panel.style.borderRadius = '8px';
        panel.style.boxShadow = '0 2px 10px rgba(0,0,0,0.2)';
        panel.style.display = 'flex';
        panel.style.flexDirection = 'column';
        panel.style.gap = '0.8rem';

        const title = document.createElement('h3');
        title.textContent = '屏幕录制';
        title.style.margin = '0 0 0.5rem 0';
        title.style.fontSize = '1rem';
        title.style.textAlign = 'center';

        const micToggleContainer = document.createElement('div');
        micToggleContainer.style.display = 'flex';
        micToggleContainer.style.alignItems = 'center';
        micToggleContainer.style.gap = '0.5rem';

        const micLabel = document.createElement('label');
        micLabel.textContent = '启用麦克风';
        micLabel.style.fontSize = '0.9rem';

        const micToggle = document.createElement('input');
        micToggle.type = 'checkbox';
        micToggle.id = 'tm-mic-toggle';

        micToggleContainer.appendChild(micLabel);
        micToggleContainer.appendChild(micToggle);

        const startBtn = document.createElement('button');
        startBtn.id = 'tm-start-btn';
        startBtn.textContent = '开始录制';
        startBtn.style.padding = '0.5rem';
        startBtn.style.backgroundColor = '#28a745';
        startBtn.style.color = 'white';
        startBtn.style.border = 'none';
        startBtn.style.borderRadius = '4px';
        startBtn.style.cursor = 'pointer';

        const stopBtn = document.createElement('button');
        stopBtn.id = 'tm-stop-btn';
        stopBtn.textContent = '停止录制';
        stopBtn.style.padding = '0.5rem';
        stopBtn.style.backgroundColor = '#dc3545';
        stopBtn.style.color = 'white';
        stopBtn.style.border = 'none';
        stopBtn.style.borderRadius = '4px';
        stopBtn.style.cursor = 'pointer';
        stopBtn.style.display = 'none';

        panel.appendChild(title);
        panel.appendChild(micToggleContainer);
        panel.appendChild(startBtn);
        panel.appendChild(stopBtn);

        document.body.appendChild(panel);

        return {
            micToggle,
            startBtn,
            stopBtn
        };
    };

    // 获取DOM元素
    const { micToggle, startBtn, stopBtn } = createControlPanel();

    // 状态变量
    let mediaRecorder = null;
    let recordedChunks = [];
    let mediaStream = null;

    // 事件监听器
    startBtn.addEventListener('click', startRecording);
    stopBtn.addEventListener('click', stopRecording);

    /**
     * 开始屏幕和音频录制
     */
    async function startRecording() {
        try {
            // 获取屏幕捕获流
            const displayVideoConstraints = { cursor: 'always' };
            const displayStream = await navigator.mediaDevices.getDisplayMedia({
                video: displayVideoConstraints,
                audio: false,
            });

            let audioStream = null;
            // 如果麦克风开关开启，获取音频流
            if (micToggle.checked) {
                audioStream = await navigator.mediaDevices.getUserMedia({
                    audio: {
                        echoCancellation: true,
                        noiseSuppression: true,
                        sampleRate: 44100,
                    },
                });
            }

            // 合并视频和音频轨道
            const videoTrack = displayStream.getVideoTracks()[0];
            const audioTrack = audioStream ? audioStream.getAudioTracks()[0] : null;

            mediaStream = new MediaStream();
            mediaStream.addTrack(videoTrack);
            if (audioTrack) {
                mediaStream.addTrack(audioTrack);
            }

            // 当用户停止分享时停止录制
            videoTrack.onended = () => {
                stopRecording();
            };

            // 配置MediaRecorder
            recordedChunks = [];

            // 尝试使用MP4格式
            let mimeType = 'video/mp4; codecs="avc1.42E01E, mp4a.40.2"';

            // 检查浏览器支持
            if (!MediaRecorder.isTypeSupported(mimeType)) {
                alert(`您的浏览器不支持MP4格式，将使用WebM格式。`);
                mimeType = 'video/webm';
            }

            mediaRecorder = new MediaRecorder(mediaStream, { mimeType });

            // 处理录制数据
            mediaRecorder.ondataavailable = (event) => {
                if (event.data.size > 0) {
                    recordedChunks.push(event.data);
                }
            };

            // 录制停止时下载
            mediaRecorder.onstop = downloadRecording;

            // 开始录制并更新UI
            mediaRecorder.start();
            updateUIVisibility(true);

        } catch (error) {
            console.error('开始录制时出错:', error);
            alert('无法开始录制，请确保您授予了屏幕和麦克风权限。');
        }
    }

    /**
     * 停止录制并释放资源
     */
    function stopRecording() {
        if (mediaRecorder && mediaRecorder.state === 'recording') {
            mediaRecorder.stop();
        }

        // 停止所有轨道以释放资源
        mediaStream?.getTracks().forEach(track => track.stop());

        // 更新UI
        updateUIVisibility(false);
    }

    /**
     * 下载录制的视频
     */
    function downloadRecording() {
        if (recordedChunks.length === 0) {
            console.warn('没有录制数据，下载已中止。');
            return;
        }

        // 确定文件格式
        const mimeType = mediaRecorder?.mimeType || 'video/mp4';
        const fileExtension = mimeType.includes('mp4') ? 'mp4' : 'webm';

        // 创建Blob并下载
        const recordingBlob = new Blob(recordedChunks, { type: mimeType });
        const url = URL.createObjectURL(recordingBlob);
        const a = document.createElement('a');
        a.style.display = 'none';
        a.href = url;
        a.download = `screen-recording-${new Date().toISOString()}.${fileExtension}`;
        document.body.appendChild(a);
        a.click();
        window.URL.revokeObjectURL(url);
        document.body.removeChild(a);

        // 重置
        recordedChunks = [];
    }

    /**
     * 更新UI可见性
     */
    function updateUIVisibility(isRecording) {
        startBtn.style.display = isRecording ? 'none' : 'block';
        stopBtn.style.display = isRecording ? 'block' : 'none';
        micToggle.disabled = isRecording;
    }
})();