script.js

let mediaInfoInstance = null;
let currentFileData = null;

// ===== 新增：读取网址参数 =====
const urlParams = new URLSearchParams(window.location.search);
const fileParam = urlParams.get('file');

// 初始化 MediaInfo
async function initMediaInfo() {
    try {
        // 优先使用 UMD 的 MediaInfo 对象；兼容不同的导出形式
        const MediaInfoFactory =
            (typeof MediaInfo !== 'undefined' && (MediaInfo.default || MediaInfo)) || null;
        if (!MediaInfoFactory) throw new Error('MediaInfo 库未加载');

        mediaInfoInstance = await MediaInfoFactory({
            locateFile: (path) => 'https://unpkg.com/mediainfo.js/dist/' + path
        });
        console.log('MediaInfo 初始化完成');
    } catch (error) {
        console.error('MediaInfo 初始化失败:', error);
        alert('分析库加载失败，请检查网络后刷新。');
    }
}

// 页面加载
window.addEventListener('load', () => {
    initMediaInfo().then(() => {
        initEventListeners();
        // 如果网址里带了 file 参数，自动分析
        if (fileParam) {
            document.getElementById('uploadSection').style.display = 'none';
            showLoading();
            updateProgress(0, '正在从网址读取文件...');
            analyzeUrl(fileParam);
        }
    });
});

// 事件监听
function initEventListeners() {
    const uploadArea = document.getElementById('uploadArea');
    const fileInput = document.getElementById('fileInput');

    uploadArea.addEventListener('dragover', (e) => {
        e.preventDefault();
        uploadArea.classList.add('drag-over');
    });

    uploadArea.addEventListener('dragleave', () => {
        uploadArea.classList.remove('drag-over');
    });

    uploadArea.addEventListener('drop', (e) => {
        e.preventDefault();
        uploadArea.classList.remove('drag-over');
        const files = e.dataTransfer.files;
        if (files.length > 0) handleFile(files[0]);
    });

    fileInput.addEventListener('change', (e) => {
        if (e.target.files.length > 0) handleFile(e.target.files[0]);
    });
}

// ===== 新增：从网址分析文件 =====
async function analyzeUrl(url) {
    if (!mediaInfoInstance) {
        // 还没初始化完，稍后重试
        setTimeout(() => analyzeUrl(url), 500);
        return;
    }

    try {
        updateProgress(5, '正在获取文件信息...');

        // 先用 HEAD 拿文件大小
        let fileSize = 0;
        try {
            const headResp = await fetch(url, { method: 'HEAD' });
            if (!headResp.ok) throw new Error('HTTP ' + headResp.status);
            fileSize = parseInt(headResp.headers.get('content-length') || '0', 10);
        } catch (e) {
            throw new Error('无法访问文件（可能是跨域 CORS 限制）：' + e.message);
        }

        if (!fileSize) throw new Error('无法获取文件大小，服务器未返回 Content-Length。');

        updateProgress(10, `文件大小：${formatFileSize(fileSize)}，开始分析...`);

        const getSize = () => fileSize;
        const readChunk = async (size, offset) => {
            const end = Math.min(offset + size, fileSize) - 1;
            const resp = await fetch(url, {
                headers: { 'Range': `bytes=${offset}-${end}` }
            });
            if (!resp.ok && resp.status !== 206) {
                throw new Error('分段读取失败：HTTP ' + resp.status);
            }
            const buf = await resp.arrayBuffer();
            return new Uint8Array(buf);
        };

        const result = await mediaInfoInstance.analyzeData(getSize, readChunk);
        updateProgress(100, '分析完成');

        // 构造一个类似 File 的对象，供 displayResults 使用
        const nameFromUrl = decodeURIComponent(
            (url.split('/').pop() || 'video').split('?')[0]
        );
        const fakeFile = {
            name: nameFromUrl,
            size: fileSize,
            type: ''
        };

        setTimeout(() => displayResults(fakeFile, result), 300);
    } catch (error) {
        console.error('分析网址失败：', error);
        document.getElementById('loadingSection').innerHTML =
            '<p style="color:#c00;line-height:1.8;">' +
            '❌ 分析失败：' + error.message +
            '<br><br>最常见原因：<b>跨域（CORS）限制</b>。<br>' +
            '浏览器不允许本页读取另一个域名的视频文件。<br>' +
            '请确认 OpenList（或其反向代理）返回了 ' +
            '<code>Access-Control-Allow-Origin</code> 头。' +
            '</p>';
    }
}

// 处理本地拖入的文件
async function handleFile(file) {
    if (!mediaInfoInstance) {
        alert('分析库还没加载完，请稍后再试。');
        return;
    }

    const maxSize = 24 * 1024 * 1024 * 1024; // 24GB
    if (file.size > maxSize) {
        alert('文件太大，最大支持 24GB。');
        return;
    }

    currentFileData = file;
    showLoading();
    updateProgress(0, '准备分析...');

    try {
        const isLargeFile = file.size > 100 * 1024 * 1024;
        let result;

        if (isLargeFile) {
            result = await analyzeFileInChunks(file);
        } else {
            updateProgress(50, '读取文件...');
            const arrayBuffer = await file.arrayBuffer();
            const uint8Array = new Uint8Array(arrayBuffer);

            updateProgress(80, '分析中...');
            result = await mediaInfoInstance.analyzeData(
                () => uint8Array.length,
                (size, offset) => uint8Array.slice(offset, offset + size)
            );
        }

        updateProgress(100, '分析完成');
        setTimeout(() => displayResults(file, result), 300);
    } catch (error) {
        console.error('分析本地文件失败：', error);
        alert('分析失败：' + error.message);
        hideLoading();
    }
}

// 大文件分段分析
async function analyzeFileInChunks(file) {
    let chunkSize;
    if (file.size > 1024 * 1024 * 1024) chunkSize = 1024 * 1024;
    else if (file.size > 500 * 1024 * 1024) chunkSize = 512 * 1024;
    else chunkSize = 64 * 1024;

    const fileSize = file.size;

    updateProgress(10, '分析大文件...');

    const getSize = () => fileSize;
    const readChunk = async (size, fileOffset) => {
        const progress = Math.min(10 + (fileOffset / fileSize) * 70, 80);
        updateProgress(progress, `处理中：${formatFileSize(fileOffset)} / ${formatFileSize(fileSize)}`);
        const start = fileOffset;
        const end = Math.min(start + size, fileSize);
        const chunk = file.slice(start, end);
        const arrayBuffer = await chunk.arrayBuffer();
        return new Uint8Array(arrayBuffer);
    };

    return await mediaInfoInstance.analyzeData(getSize, readChunk);
}

// 显示结果
function displayResults(file, mediaInfo) {
    hideLoading();
    document.getElementById('uploadSection').style.display = 'none';

    document.getElementById('fileName').textContent = file.name;
    document.getElementById('fileSize').textContent = formatFileSize(file.size);
    document.getElementById('fileType').textContent = file.type || '未知';

    const tracks = parseMediaInfo(mediaInfo);

    fillSummaryInfo(tracks);
    fillGeneralInfo(tracks.general);
    fillVideoInfo(tracks.video);
    fillAudioInfo(tracks.audio);
    fillRawInfo(mediaInfo);

    document.getElementById('resultsSection').style.display = 'block';
}

// 解析 MediaInfo 结果
function parseMediaInfo(mediaInfo) {
    const tracks = { general: [], video: [], audio: [] };

    if (mediaInfo && mediaInfo.media && mediaInfo.media.track) {
        mediaInfo.media.track.forEach(track => {
            const t = track['@type'];
            if (t === 'General') tracks.general.push(track);
            else if (t === 'Video') tracks.video.push(track);
            else if (t === 'Audio') tracks.audio.push(track);
        });
    }
    return tracks;
}

// 摘要信息
function fillSummaryInfo(tracks) {
    const container = document.getElementById('summaryInfo');
    container.innerHTML = '';

    if (tracks.video.length > 0) {
        tracks.video.forEach((track, index) => {
            const section = document.createElement('div');
            section.className = 'summary-section';

            const title = document.createElement('h4');
            title.innerHTML = `🎥 视频${tracks.video.length > 1 ? ' ' + (index + 1) : ''}`;
            section.appendChild(title);

            const text = document.createElement('div');
            text.className = 'summary-text';

            const parts = [];
            if (track.Format) {
                let codec = track.Format;
                if (track.Format_Profile) codec += ` (${track.Format_Profile})`;
                parts.push(`编码：${codec}`);
            }
            if (track.Width && track.Height) {
                let res = `${track.Width}×${track.Height}`;
                if (track.DisplayAspectRatio) res += ` (${formatAspectRatio(track.DisplayAspectRatio)})`;
                parts.push(`分辨率：${res}`);
            }
            if (track.FrameRate) parts.push(`帧率：${formatValue('FrameRate', track.FrameRate)}`);
            if (track.BitRate) parts.push(`码率：${formatValue('BitRate', track.BitRate)}`);

            text.textContent = parts.length ? parts.join('，') : '无数据';
            if (!parts.length) text.className += ' no-data';
            section.appendChild(text);
            container.appendChild(section);
        });
    }

    if (tracks.audio.length > 0) {
        tracks.audio.forEach((track, index) => {
            const section = document.createElement('div');
            section.className = 'summary-section';

            const title = document.createElement('h4');
            title.innerHTML = `🔊 音频${tracks.audio.length > 1 ? ' ' + (index + 1) : ''}`;
            section.appendChild(title);

            const text = document.createElement('div');
            text.className = 'summary-text';

            const parts = [];
            if (track.Format) {
                let codec = track.Format;
                if (track.Format_Profile) codec += ` (${track.Format_Profile})`;
                parts.push(`编码：${codec}`);
            }
            if (track.SamplingRate) parts.push(`采样率：${formatValue('SamplingRate', track.SamplingRate)}`);
            if (track.Channel_s_) {
                let ch = `${track.Channel_s_} 声道`;
                if (track.ChannelLayout) ch += ` (${track.ChannelLayout})`;
                parts.push(`声道：${ch}`);
            } else if (track.ChannelLayout) {
                parts.push(`声道：${track.ChannelLayout}`);
            }
            if (track.BitRate) parts.push(`码率：${formatValue('BitRate', track.BitRate)}`);

            text.textContent = parts.length ? parts.join('，') : '无数据';
            if (!parts.length) text.className += ' no-data';
            section.appendChild(text);
            container.appendChild(section);
        });
    }

    if (tracks.video.length === 0 && tracks.audio.length === 0) {
        const section = document.createElement('div');
        section.className = 'summary-section';
        section.innerHTML = '<div class="summary-text no-data">未找到视频/音频轨</div>';
        container.appendChild(section);
    }
}

// 常规信息
function fillGeneralInfo(generalTracks) {
    const container = document.getElementById('generalInfo');
    container.innerHTML = '';

    if (generalTracks.length === 0) {
        container.innerHTML = '<p>无常规信息</p>';
        return;
    }

    const track = generalTracks[0];
    const fields = [
        { key: 'CompleteName', label: '完整名称' },
        { key: 'Format', label: '格式' },
        { key: 'Format_Version', label: '格式版本' },
        { key: 'FileSize', label: '文件大小' },
        { key: 'Duration', label: '时长' },
        { key: 'OverallBitRate', label: '总码率' },
        { key: 'Encoded_Date', label: '编码日期' },
        { key: 'Tagged_Date', label: '标记日期' }
    ];

    const grid = document.createElement('div');
    grid.className = 'info-grid';

    fields.forEach(f => {
        const value = track[f.key];
        if (value) grid.appendChild(createInfoItem(f.label, formatValue(f.key, value)));
    });

    container.appendChild(grid);
}

// 视频信息
function fillVideoInfo(videoTracks) {
    const container = document.getElementById('videoInfo');
    container.innerHTML = '';

    if (videoTracks.length === 0) {
        container.innerHTML = '<p>未找到视频轨</p>';
        return;
    }

    videoTracks.forEach((track, index) => {
        const div = document.createElement('div');
        div.className = 'track-info';

        if (videoTracks.length > 1) {
            const h = document.createElement('h4');
            h.textContent = `视频轨 ${index + 1}`;
            div.appendChild(h);
        }

        const fields = [
            { key: 'Format', label: '格式' },
            { key: 'Format_Profile', label: '格式配置' },
            { key: 'Width', label: '宽度' },
            { key: 'Height', label: '高度' },
            { key: 'DisplayAspectRatio', label: '宽高比' },
            { key: 'FrameRate', label: '帧率' },
            { key: 'BitRate', label: '码率' },
            { key: 'ColorSpace', label: '色彩空间' },
            { key: 'BitDepth', label: '位深' },
            { key: 'Duration', label: '时长' }
        ];

        const grid = document.createElement('div');
        grid.className = 'info-grid';

        fields.forEach(f => {
            const value = track[f.key];
            if (value) grid.appendChild(createInfoItem(f.label, formatValue(f.key, value)));
        });

        div.appendChild(grid);
        container.appendChild(div);
    });
}

// 音频信息
function fillAudioInfo(audioTracks) {
    const container = document.getElementById('audioInfo');
    container.innerHTML = '';

    if (audioTracks.length === 0) {
        container.innerHTML = '<p>未找到音频轨</p>';
        return;
    }

    audioTracks.forEach((track, index) => {
        const div = document.createElement('div');
        div.className = 'track-info';

        if (audioTracks.length > 1) {
            const h = document.createElement('h4');
            h.textContent = `音频轨 ${index + 1}`;
            div.appendChild(h);
        }

        const fields = [
            { key: 'Format', label: '格式' },
            { key: 'Format_Profile', label: '格式配置' },
            { key: 'Duration', label: '时长' },
            { key: 'BitRate', label: '码率' },
            { key: 'Channel_s_', label: '声道数' },
            { key: 'ChannelLayout', label: '声道布局' },
            { key: 'SamplingRate', label: '采样率' },
            { key: 'BitDepth', label: '位深' },
            { key: 'Language', label: '语言' }
        ];

        const grid = document.createElement('div');
        grid.className = 'info-grid';

        fields.forEach(f => {
            const value = track[f.key];
            if (value) grid.appendChild(createInfoItem(f.label, formatValue(f.key, value)));
        });

        div.appendChild(grid);
        container.appendChild(div);
    });
}

// 原始数据
function fillRawInfo(mediaInfo) {
    document.getElementById('rawInfo').textContent = JSON.stringify(mediaInfo, null, 2);
}

// 值格式化
function formatValue(key, value) {
    if (!value && value !== 0) return '';

    if (key === 'Duration') return formatDuration(value);

    if (key === 'FileSize' && !isNaN(value)) return formatFileSize(parseInt(value, 10));

    if ((key === 'BitRate' || key === 'OverallBitRate') && !isNaN(value))
        return Math.round(parseInt(value, 10) / 1000) + ' kbps';

    if (key === 'SamplingRate' && !isNaN(value))
        return Math.round(parseInt(value, 10) / 1000) + ' kHz';

    if (key === 'FrameRate' && !isNaN(value))
        return parseFloat(value).toFixed(3) + ' fps';

    if ((key === 'Width' || key === 'Height') && !isNaN(value))
        return value + ' px';

    if (key === 'DisplayAspectRatio') return formatAspectRatio(value);

    return value.toString();
}

// 时长格式化
function formatDuration(duration) {
    if (!duration) return '';

    if (typeof duration === 'string' && (duration.includes('h') || duration.includes(':')))
        return duration;

    let totalSeconds;
    if (typeof duration === 'string') {
        const parsed = parseFloat(duration);
        if (isNaN(parsed)) return duration;
        totalSeconds = parsed;
    } else {
        totalSeconds = parseFloat(duration);
    }

    if (totalSeconds > 3600000) totalSeconds = totalSeconds / 1000;

    const hours = Math.floor(totalSeconds / 3600);
    const minutes = Math.floor((totalSeconds % 3600) / 60);
    const seconds = Math.floor(totalSeconds % 60);

    if (hours > 0) {
        return `${hours}:${minutes.toString().padStart(2, '0')}:${seconds.toString().padStart(2, '0')}`;
    }
    return `${minutes}:${seconds.toString().padStart(2, '0')}`;
}

// 宽高比格式化
function formatAspectRatio(ratio) {
    if (!ratio) return '';
    if (typeof ratio === 'string' && ratio.includes(':')) return ratio;

    const numericRatio = parseFloat(ratio);
    if (isNaN(numericRatio)) return ratio;

    const commonRatios = [
        { ratio: 16 / 9, display: '16:9' },
        { ratio: 4 / 3, display: '4:3' },
        { ratio: 21 / 9, display: '21:9' },
        { ratio: 1.85, display: '1.85:1' },
        { ratio: 2.35, display: '2.35:1' },
        { ratio: 2.39, display: '2.39:1' },
        { ratio: 1, display: '1:1' },
        { ratio: 3 / 2, display: '3:2' },
        { ratio: 5 / 4, display: '5:4' },
        { ratio: 16 / 10, display: '16:10' }
    ];

    let closest = commonRatios[0];
    let minDiff = Math.abs(numericRatio - closest.ratio);

    commonRatios.forEach(r => {
        const d = Math.abs(numericRatio - r.ratio);
        if (d < minDiff) { minDiff = d; closest = r; }
    });

    if (minDiff < 0.01) return closest.display;

    const simplified = simplifyRatio(numericRatio);
    if (simplified) return simplified;

    return numericRatio.toFixed(2) + ':1';
}

function simplifyRatio(decimal) {
    for (let denominator = 1; denominator <= 20; denominator++) {
        const numerator = Math.round(decimal * denominator);
        if (Math.abs(numerator / denominator - decimal) < 0.005) {
            const gcd = findGCD(numerator, denominator);
            const num = numerator / gcd;
            const den = denominator / gcd;
            if (num <= 50 && den <= 50) return `${num}:${den}`;
        }
    }
    return null;
}

function findGCD(a, b) {
    while (b !== 0) {
        const t = b;
        b = a % b;
        a = t;
    }
    return a;
}

// 创建信息项
function createInfoItem(label, value) {
    const item = document.createElement('div');
    item.className = 'info-item';

    const labelSpan = document.createElement('span');
    labelSpan.className = 'label';
    labelSpan.textContent = label + '：';

    const valueSpan = document.createElement('span');
    valueSpan.className = 'value';
    valueSpan.textContent = value;

    item.appendChild(labelSpan);
    item.appendChild(valueSpan);
    return item;
}

// 切换标签
function showTab(tabName) {
    document.querySelectorAll('.tab-pane').forEach(el => el.classList.remove('active'));
    document.querySelectorAll('.tab-btn').forEach(el => el.classList.remove('active'));
    document.getElementById(tabName + '-tab').classList.add('active');
    if (window.event && window.event.target) window.event.target.classList.add('active');
}

// 加载状态
function showLoading() {
    document.getElementById('loadingSection').style.display = 'block';
    document.getElementById('resultsSection').style.display = 'none';

    if (!document.getElementById('progressBar')) {
        const section = document.getElementById('loadingSection');
        const wrap = document.createElement('div');
        wrap.className = 'progress-container';
        wrap.innerHTML = `
            <div class="progress-bar-container">
                <div class="progress-bar" id="progressBar"></div>
            </div>
            <div class="progress-text" id="progressText">初始化...</div>
        `;
        section.appendChild(wrap);
    }
}

function updateProgress(percent, text) {
    const bar = document.getElementById('progressBar');
    const txt = document.getElementById('progressText');
    const loadingText = document.getElementById('loadingText');

    if (bar) bar.style.width = percent + '%';
    if (txt) txt.textContent = text || `${Math.round(percent)}%`;
    if (loadingText && text) loadingText.textContent = text;
}

function hideLoading() {
    document.getElementById('loadingSection').style.display = 'none';
}

// 重置
function resetAnalyzer() {
    document.getElementById('resultsSection').style.display = 'none';
    document.getElementById('uploadSection').style.display = 'block';
    document.getElementById('fileInput').value = '';
    currentFileData = null;

    const pc = document.querySelector('.progress-container');
    if (pc) pc.remove();
}

// 导出结果
function exportResults() {
    if (!currentFileData) return;
    const raw = document.getElementById('rawInfo').textContent;
    const blob = new Blob([raw], { type: 'application/json' });
    const url = URL.createObjectURL(blob);

    const a = document.createElement('a');
    a.href = url;
    a.download = (currentFileData.name || 'video') + '_mediainfo.json';
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
    URL.revokeObjectURL(url);
}

// 文件大小格式化
function formatFileSize(bytes) {
    if (bytes === 0) return '0 Bytes';
    const k = 1024;
    const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
    const i = Math.floor(Math.log(bytes) / Math.log(k));
    return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
}