// Topic-Übersicht erkennen (keine Buttons dort)
function isInTopicList() {
    return document.querySelector('.topics-list, .topic-list, .forums-list, .chat-list .topic') !== null || 
           document.body.classList.contains('topics-mode');
}

// Kleine Helfer-Funktion: freundlich sanitisieren (erhalte Leerzeichen, Klammern, Punkte)
function sanitizeFriendly(name) {
    if (!name) return 'Telegram';
    return name.toString().replace(/[\/\\\?\%\*\:\|\"\<\>]/g, "_").trim();
}

// Extrahiere den Original-Dateinamen aus Telegram-Metadaten
function extractTelegramFilename(element) {
    try {
        const elementUrl = element.currentSrc || element.src;
        
        console.log('=== FILENAME EXTRACTION ===');
        console.log('Element URL:', elementUrl);

        // 1. Suche die Message, die das Element enthält
        const messageContainer = element.closest('.message, .Message, .bubble, .media-container');
        if (!messageContainer) {
            console.warn('No message container found');
            return 'telegram_media_' + Date.now();
        }

        console.log('Message container found');

        // 2. Zuerst: Suche nach .text-content (funktioniert für einzelne Medien)
        const textContent = messageContainer.querySelector('.text-content, .text-content.clearfix');
        if (textContent) {
            const fullText = textContent.innerText || textContent.textContent;
            const firstLine = fullText.split('\n')[0].trim();
            
            if (firstLine.length > 5 && 
                !firstLine.startsWith('@') && 
                !firstLine.startsWith('#') &&
                !firstLine.includes('⬇') &&
                !firstLine.match(/^\d{2}:\d{2}:\d{2}$/)) {
                console.log('Found filename from .text-content:', firstLine);
                return sanitizeFriendly(firstLine);
            }
        }

        // 3. Bei Alben/Serien
        const albumContainer = messageContainer.querySelector('.album, .Album, [class*="album"]');
        if (albumContainer) {
            console.log('Album/Series detected');
            
            let elementContainer = element.closest('.album-item-select-wrapper, .album-item, .media-item');
            if (elementContainer) {
                const allContainers = albumContainer.querySelectorAll('.album-item-select-wrapper, .album-item');
                let elementIndex = -1;
                for (let i = 0; i < allContainers.length; i++) {
                    if (allContainers[i] === elementContainer || allContainers[i].contains(element)) {
                        elementIndex = i;
                        break;
                    }
                }
                
                console.log('Element index in album:', elementIndex);
                
                const contentInner = messageContainer.querySelector('.content-inner, .text, .message-text');
                if (contentInner && elementIndex >= 0) {
                    const fullText = contentInner.innerText || contentInner.textContent;
                    
                    const episodePattern = /S\d{2}E\d{2}\s*-\s*[^\n]+/gi;
                    const episodes = fullText.match(episodePattern);
                    
                    if (episodes && episodes[elementIndex]) {
                        const episodeName = episodes[elementIndex].trim();
                        console.log('Found episode name for index', elementIndex, ':', episodeName);
                        return sanitizeFriendly(episodeName);
                    }
                    
                    const lines = fullText.split('\n').map(l => l.trim()).filter(l => l.length > 5);
                    const episodeLines = lines.filter(line => 
                        /S\d{2}E\d{2}/.test(line) || 
                        (line.includes('-') && line.length > 10 && line.length < 150)
                    );
                    
                    if (episodeLines[elementIndex]) {
                        console.log('Found episode from lines:', episodeLines[elementIndex]);
                        return sanitizeFriendly(episodeLines[elementIndex]);
                    }
                }
            }
        }

        // 4. Weitere Selektoren
        const titleSelectors = [
            '.media-caption-text',
            '.media-caption',
            '.message-title',
            '.video-title',
            '.document-name',
            '.file-name',
            '.name',
            '.title:not(.peer-title):not(.top-bar)'
        ];

        for (const selector of titleSelectors) {
            const el = messageContainer.querySelector(selector);
            if (el) {
                const text = el.innerText?.trim() || el.textContent?.trim();
                if (text && text.length > 0 && text.length < 300) {
                    if (!text.includes('⬇') && 
                        !text.toLowerCase().includes('download') &&
                        !text.match(/^\d{2}:\d{2}:\d{2}$/)) {
                        console.log('Found filename from selector', selector, ':', text);
                        return sanitizeFriendly(text);
                    }
                }
            }
        }

        // 5. Fallbacks
        const match = elementUrl?.match(/document(\d+)/);
        if (match) {
            console.warn('Using document ID as fallback');
            return 'telegram_doc_' + match[1];
        }

        console.warn('Could not extract filename, using timestamp fallback');
        return 'telegram_media_' + Date.now();
        
    } catch (err) {
        console.error('Error extracting filename:', err);
        return 'telegram_media_' + Date.now();
    }
}

// Video-Button
function addVideoDownloadButton(video) {
    if (isInTopicList()) return;
    if (!video || video.tagName !== "VIDEO" || 
        video.classList.contains("sticker-media") || 
        video.classList.contains("media-sticker")) return;
    if (!video.currentSrc && !video.src) return;

    let container = video.parentElement || video.closest('div') || video;
    if (!container || container.querySelector('.tg-video-btn')) return;

    const computed = window.getComputedStyle(container);
    if (computed.position === 'static') container.style.position = 'relative';

    const btn = document.createElement('button');
    btn.className = 'tg-video-btn';
    btn.innerText = '⬇ Download';
    btn.title = 'Video herunterladen';
    btn.style.cssText = `
        position: absolute !important;
        top: 10px !important;
        right: 10px !important;
        z-index: 100000 !important;
        background: #e63946 !important;
        color: white !important;
        border: none !important;
        border-radius: 8px !important;
        padding: 8px 12px !important;
        font-size: 14px !important;
        font-weight: bold !important;
        cursor: pointer !important;
        box-shadow: 0 4px 12px rgba(0,0,0,0.6) !important;
    `;

    btn.addEventListener('click', (e) => {
        e.stopPropagation();
        e.preventDefault();

        const videoUrl = video.currentSrc || video.src;
        if (!videoUrl) {
            alert('Video-URL nicht verfügbar.');
            return;
        }

        const autoName = extractTelegramFilename(video);
        console.log('=== VIDEO DOWNLOAD ===', autoName);

        const event = new CustomEvent('downloadRequested', {
            detail: { url: videoUrl, name: autoName, version: location.pathname }
        });
        document.dispatchEvent(event);
    });

    container.appendChild(btn);
}

// Bild-Button
function addImageDownloadButton(img) {
    if (isInTopicList()) return;
    if (!img || img.tagName !== "IMG") return;
    if (img.classList.contains('emoji') || img.classList.contains('thumbnail') ||
        img.width < 100 || img.height < 100) return;
    
    let container = img.closest('.media-inner') || img.closest('.Message') || img.parentElement;
    if (!container || container.querySelector('.tg-img-btn')) return;

    if (window.getComputedStyle(container).position === 'static') {
        container.style.position = 'relative';
    }

    const btn = document.createElement('button');
    btn.className = 'tg-img-btn';
    btn.innerText = '⬇';
    btn.title = 'Bild herunterladen';
    btn.style.cssText = `
        position: absolute !important;
        top: 5px !important;
        left: 5px !important;
        z-index: 999999 !important;
        background: rgba(42, 157, 143, 0.95) !important;
        color: white !important;
        border: 2px solid white !important;
        border-radius: 50% !important;
        width: 44px !important;
        height: 44px !important;
        font-size: 22px !important;
        cursor: pointer !important;
        box-shadow: 0 2px 8px rgba(0,0,0,0.8) !important;
        display: flex !important;
        align-items: center !important;
        justify-content: center !important;
        pointer-events: auto !important;
    `;

    btn.onmouseenter = () => btn.style.transform = 'scale(1.15)';
    btn.onmouseleave = () => btn.style.transform = 'scale(1)';

    btn.addEventListener('click', (e) => {
        e.stopPropagation();
        e.preventDefault();

        const imgUrl = img.src || img.currentSrc;
        if (!imgUrl || imgUrl.startsWith('data:')) {
            alert('Bild-URL nicht verfügbar.');
            return;
        }

        const autoName = extractTelegramFilename(img) || 'telegram_image';
        console.log('=== IMAGE DOWNLOAD ===', autoName);

        const event = new CustomEvent('imageDownloadRequested', {
            detail: { url: imgUrl, name: autoName }
        });
        document.dispatchEvent(event);
    });

    container.appendChild(btn);
    console.log('✅ Image button added');
}

// Audio-Button
function addAudioDownloadButton(audioContainer) {
    if (isInTopicList()) return;
    if (!audioContainer || audioContainer.querySelector('.tg-audio-btn')) return;

    const audio = audioContainer.querySelector('audio');
    if (!audio) return;

    if (window.getComputedStyle(audioContainer).position === 'static') {
        audioContainer.style.position = 'relative';
    }

    const btn = document.createElement('button');
    btn.className = 'tg-audio-btn';
    btn.innerText = '⬇ Download';
    btn.title = 'Audio herunterladen';
    btn.style.cssText = `
        position: absolute !important;
        top: 10px !important;
        right: 10px !important;
        z-index: 999999 !important;
        background: rgba(244, 162, 97, 0.95) !important;
        color: white !important;
        border: 2px solid white !important;
        border-radius: 50% !important;
        width: 40px !important;
        height: 40px !important;
        font-size: 20px !important;
        cursor: pointer !important;
        box-shadow: 0 2px 8px rgba(0,0,0,0.8) !important;
        display: flex !important;
        align-items: center !important;
        justify-content: center !important;
        pointer-events: auto !important;
    `;

    btn.onmouseenter = () => btn.style.transform = 'scale(1.15)';
    btn.onmouseleave = () => btn.style.transform = 'scale(1)';

    btn.addEventListener('click', (e) => {
        e.stopPropagation();
        e.preventDefault();

        const audioUrl = audio.currentSrc || audio.src;
        if (!audioUrl) {
            alert('Audio-URL nicht verfügbar.');
            return;
        }

        const autoName = extractTelegramFilename(audioContainer) || 'telegram_audio';
        console.log('=== AUDIO DOWNLOAD ===', autoName);

        const event = new CustomEvent('audioDownloadRequested', {
            detail: { url: audioUrl, name: autoName }
        });
        document.dispatchEvent(event);
    });

    audioContainer.appendChild(btn);
    console.log('✅ Audio button added');
}

// Document-Button (für .mp3, .zip, .pdf, etc.)
function addDocumentDownloadButton(docContainer) {
    if (isInTopicList()) return;
    if (!docContainer || docContainer.querySelector('.tg-doc-btn')) return;

    // Suche nach dem Dateinamen - verschiedene mögliche Selektoren
    const docNameEl = docContainer.querySelector('.file-title, .document-name, .file-name');
    const docName = docNameEl?.innerText?.trim() || docNameEl?.title || '';
    
    // Suche nach File-Extension
    const extEl = docContainer.querySelector('.file-ext');
    const fileExt = extEl?.innerText?.trim()?.toLowerCase() || '';
    
    // Wenn kein Name gefunden wurde, ignoriere
    if (!docName && !fileExt) return;
    
    // Prüfe Dateityp basierend auf Extension oder Name
    const isAudio = /\.(mp3|ogg|wav|m4a|flac|aac|opus)$/i.test(docName) || 
                    ['mp3', 'ogg', 'wav', 'm4a', 'flac', 'aac', 'opus'].includes(fileExt);
    const isArchive = /\.(zip|rar|7z|tar|gz)$/i.test(docName) || 
                      ['zip', 'rar', '7z', 'tar', 'gz'].includes(fileExt);
    const isDocument = /\.(pdf|doc|docx|txt|xlsx|xls|ppt)$/i.test(docName) || 
                       ['pdf', 'doc', 'docx', 'txt', 'xlsx', 'xls', 'ppt'].includes(fileExt);
    
    if (window.getComputedStyle(docContainer).position === 'static') {
        docContainer.style.position = 'relative';
    }

    // Icon und Farbe basierend auf Dateityp
    let icon = '⬇';
    let bgColor = 'rgba(168, 85, 247, 0.95)';
    let title = 'Datei herunterladen';
    
    if (isAudio) {
        icon = '⬇';
        bgColor = 'rgba(244, 162, 97, 0.95)';
        title = 'Audio herunterladen';
    } else if (isArchive) {
        icon = '⬇';
        bgColor = 'rgba(59, 130, 246, 0.95)';
        title = 'Archiv herunterladen';
    } else if (isDocument) {
        icon = '⬇';
        bgColor = 'rgba(168, 85, 247, 0.95)';
        title = 'Dokument herunterladen';
    }

    const btn = document.createElement('button');
    btn.className = 'tg-doc-btn';
    btn.innerText = icon;
    btn.title = title + (docName ? ': ' + docName : '');
    btn.style.cssText = `
        position: absolute !important;
        top: 10px !important;
        right: 10px !important;
        z-index: 999999 !important;
        background: ${bgColor} !important;
        color: white !important;
        border: 2px solid white !important;
        border-radius: 50% !important;
        width: 40px !important;
        height: 40px !important;
        font-size: 20px !important;
        cursor: pointer !important;
        box-shadow: 0 2px 8px rgba(0,0,0,0.8) !important;
        display: flex !important;
        align-items: center !important;
        justify-content: center !important;
        pointer-events: auto !important;
    `;

    btn.onmouseenter = () => btn.style.transform = 'scale(1.15)';
    btn.onmouseleave = () => btn.style.transform = 'scale(1)';

    btn.addEventListener('click', (e) => {
        e.stopPropagation();
        e.preventDefault();

        // Versuche Download-URL zu finden
        let downloadUrl = null;
        
        // Methode 1: Suche nach data-doc-id im File-Element oder Container
        const fileEl = docContainer.querySelector('.File');
        const docId = fileEl?.dataset?.docId || 
                      docContainer.dataset?.docId ||
                      docContainer.closest('[data-doc-id]')?.dataset?.docId;
        
        if (docId) {
            // Konstruiere die Telegram progressive URL
            downloadUrl = `${location.origin}/a/progressive/document${docId}`;
        }
        
        // Methode 2: Suche nach existierendem Download-Link
        if (!downloadUrl) {
            const downloadLink = docContainer.querySelector('a[href*="document"], a[download]');
            if (downloadLink) {
                downloadUrl = downloadLink.href;
            }
        }
        
        // Methode 3: Suche im parent Message nach document-ID
        if (!downloadUrl) {
            const message = docContainer.closest('.Message');
            const messageId = message?.id?.replace('message-', '');
            if (messageId) {
                // Versuche document-ID aus verschiedenen Quellen
                const allDataIds = message.querySelectorAll('[data-doc-id]');
                if (allDataIds.length > 0) {
                    const firstDocId = allDataIds[0].dataset.docId;
                    downloadUrl = `${location.origin}/a/progressive/document${firstDocId}`;
                }
            }
        }

        if (!downloadUrl) {
            alert('Download-URL nicht gefunden. Bitte klicke zuerst auf die Datei um sie zu laden.');
            return;
        }

        const finalName = docName || 'telegram_file';
        console.log('=== DOCUMENT DOWNLOAD ===');
        console.log('Name:', finalName);
        console.log('URL:', downloadUrl);

        const eventName = isAudio ? 'audioDownloadRequested' : 'documentDownloadRequested';
        const event = new CustomEvent(eventName, {
            detail: { url: downloadUrl, name: finalName }
        });
        document.dispatchEvent(event);
    });

    docContainer.appendChild(btn);
    console.log('✅ Document button added:', docName || fileExt);
}

// Alle Medien verarbeiten
function processMedia() {
    if (isInTopicList()) return;
    
    // Videos
    document.querySelectorAll('video:not([data-tg-video])').forEach(video => {
        try {
            video.dataset.tgVideo = 'true';
            addVideoDownloadButton(video);
        } catch (err) {
            console.error('Error processing video', err);
        }
    });

    // Bilder
    document.querySelectorAll('img.full-media').forEach(img => {
        try {
            const container = img.closest('.media-inner, .Message') || img.parentElement;
            if (container && !container.querySelector('.tg-img-btn')) {
                addImageDownloadButton(img);
            }
        } catch (err) {
            console.error('Error processing image', err);
        }
    });

    // Audio mit <audio> Element
    document.querySelectorAll('.Audio, .audio').forEach(container => {
        try {
            if (!container.querySelector('.tg-audio-btn')) {
                const audio = container.querySelector('audio');
                if (audio) addAudioDownloadButton(container);
            }
        } catch (err) {
            console.error('Error processing audio', err);
        }
    });

    // Documents (.mp3, .zip, .pdf, etc.) - erkennbar an .document Container MIT .File Element
    document.querySelectorAll('.document, .Document').forEach(container => {
        try {
            // Prüfe ob es ein .File Element gibt (das ist der Indikator für Documents)
            const fileEl = container.querySelector('.File');
            const fileTitle = container.querySelector('.file-title');
            
            if ((fileEl || fileTitle) && !container.querySelector('.tg-doc-btn')) {
                addDocumentDownloadButton(container);
            }
        } catch (err) {
            console.error('Error processing document', err);
        }
    });
}

const observer = new MutationObserver(processMedia);
observer.observe(document.body, { childList: true, subtree: true });
setInterval(processMedia, 1200);
processMedia();

console.log('✅ TG Downloader loaded - Video, Image & Audio support enabled');

// Event-Weiterleitung
document.addEventListener('telDownloaderCompleted', (e) => {
    try {
        const detail = e.detail || {};
        chrome.runtime.sendMessage(detail.extensionId || chrome.runtime.id, {
            action: detail.action || 'videoProgressCompleted',
            videoId: detail.videoId,
            clientId: detail.clientId,
            name: detail.name,
            version: detail.version,
            locale: detail.locale
        }, () => {
            if (chrome.runtime.lastError) {
                console.error('Error sending message:', chrome.runtime.lastError.message);
            }
        });
    } catch (err) {
        console.error('Failed to forward event:', err);
    }
});

// inject.js laden
const script = document.createElement('script');
script.src = chrome.runtime.getURL('inject.js');
script.setAttribute('data-extension-id', chrome.runtime.id);
(document.head || document.documentElement).appendChild(script);