function downloadData(data, filename, type) {
    const blob = new Blob([data], { type: type });
    const url = URL.createObjectURL(blob);
    const a = document.createElement("a");
    a.href = url;
    a.download = filename;
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
    URL.revokeObjectURL(url);
}

function escapeCSV(cell) {
    let cellStr = cell ? String(cell) : "";
    if (cellStr.includes(",") || cellStr.includes("\n") || cellStr.includes('"')) {
        cellStr = '"' + cellStr.replace(/"/g, '""') + '"';
    }
    return cellStr;
}

function convertToCSV(items) {
    if (items.length === 0) return "";
    const headers = ["Word", "Type", "Pronunciation", "Definition", "Examples", "ImageURL", "UKAudioURL", "USAudioURL"];
    let csv = headers.join(",") + "\n";
    
    items.forEach(item => {
        let row = [
            item.word,
            item.type,
            item.pronunciation,
            item.definition,
            item.examples.join(" | "),
            item.imageUrl,
            item.audio.uk,
            item.audio.us
        ].map(escapeCSV);
        csv += row.join(",") + "\n";
    });
    return csv;
}

function convertToAnkiCSV(items) {
    if (items.length === 0) return "";
    let csv = "";
    
    items.forEach(item => {
        let imgTag = "";
        if (item.imageUrl) {
            let filename = item.imageUrl.split('/').pop().split('?')[0];
            // ensure filename doesn't have weird chars
            filename = decodeURIComponent(filename);
            imgTag = `<img src="${filename}">`;
        }
        
        let ukTag = "";
        if (item.audio.uk) {
            let params = new URLSearchParams(item.audio.uk.split('?')[1]);
            let q = params.get('q') ? params.get('q').replace(/ /g, '_') : 'uk';
            ukTag = `[sound:${q}_uk.mp3]`;
        }
        
        let usTag = "";
        if (item.audio.us) {
            let params = new URLSearchParams(item.audio.us.split('?')[1]);
            let q = params.get('q') ? params.get('q').replace(/ /g, '_') : 'us';
            usTag = `[sound:${q}_us.mp3]`;
        }
        
        let row = [
            item.word,
            item.type,
            item.pronunciation,
            item.definition,
            item.examples.join("<br>"),
            imgTag,
            ukTag,
            usTag
        ].map(escapeCSV);
        csv += row.join(",") + "\n";
    });
    return csv;
}

document.getElementById('scrape-json').addEventListener('click', () => triggerScrape('json'));
document.getElementById('scrape-csv').addEventListener('click', () => triggerScrape('csv'));
if (document.getElementById('scrape-anki')) {
    document.getElementById('scrape-anki').addEventListener('click', () => triggerScrape('anki'));
}

async function fetchAsBlob(url) {
    const response = await fetch(url);
    if (!response.ok) throw new Error(`HTTP error! status: ${response.status}`);
    return await response.blob();
}

async function triggerScrape(format) {
    const statusDiv = document.getElementById('status');
    statusDiv.textContent = "Đang xử lý...";

    try {
        let [tab] = await chrome.tabs.query({ active: true, currentWindow: true });

        const results = await chrome.scripting.executeScript({
            target: { tabId: tab.id },
            files: ['content.js']
        });

        if (results && results[0] && results[0].result) {
            const data = results[0].result;
            
            if (data.error) {
                statusDiv.textContent = "Lỗi: " + data.error;
                return;
            }
            
            if (data.length === 0) {
                statusDiv.textContent = "Không tìm thấy từ vựng nào trên trang này.";
                return;
            }

            if (format === 'json') {
                statusDiv.textContent = `Đã tìm thấy ${data.length} từ. Đang tải xuống JSON...`;
                const jsonStr = JSON.stringify(data, null, 2);
                downloadData(jsonStr, 'study4_vocab.json', 'application/json');
                setTimeout(() => { statusDiv.textContent = "Hoàn tất!"; }, 2000);
            } else if (format === 'csv') {
                statusDiv.textContent = `Đã tìm thấy ${data.length} từ. Đang tải xuống CSV...`;
                const csvStr = convertToCSV(data);
                downloadData("\uFEFF" + csvStr, 'study4_vocab.csv', 'text/csv;charset=utf-8');
                setTimeout(() => { statusDiv.textContent = "Hoàn tất!"; }, 2000);
            } else if (format === 'anki') {
                statusDiv.textContent = `Đã tìm thấy ${data.length} từ. Đang chuẩn bị Media (có thể mất ít phút)...`;
                
                const zip = new JSZip();
                
                // 1. Add CSV
                const csvStr = convertToAnkiCSV(data);
                zip.file("study4_anki.csv", "\uFEFF" + csvStr);
                
                let count = 0;
                let total = data.length * 3; // roughly 3 media per word (img, uk, us)
                
                for (let i = 0; i < data.length; i++) {
                    const item = data[i];
                    statusDiv.textContent = `Đang tải hình/âm thanh ${i+1}/${data.length}...`;
                    
                    if (item.imageUrl) {
                        try {
                            let filename = decodeURIComponent(item.imageUrl.split('/').pop().split('?')[0]);
                            const blob = await fetchAsBlob(item.imageUrl);
                            zip.file(filename, blob);
                        } catch (e) {
                            console.error("Failed to load image", item.imageUrl, e);
                        }
                    }
                    
                    if (item.audio.uk) {
                        try {
                            let params = new URLSearchParams(item.audio.uk.split('?')[1]);
                            let q = params.get('q') ? params.get('q').replace(/ /g, '_') : 'uk';
                            const blob = await fetchAsBlob(item.audio.uk);
                            zip.file(`${q}_uk.mp3`, blob);
                        } catch (e) {
                            console.error("Failed to load UK audio", item.audio.uk, e);
                        }
                    }
                    
                    if (item.audio.us) {
                        try {
                            let params = new URLSearchParams(item.audio.us.split('?')[1]);
                            let q = params.get('q') ? params.get('q').replace(/ /g, '_') : 'us';
                            const blob = await fetchAsBlob(item.audio.us);
                            zip.file(`${q}_us.mp3`, blob);
                        } catch (e) {
                            console.error("Failed to load US audio", item.audio.us, e);
                        }
                    }
                }
                
                statusDiv.textContent = `Đang nén file ZIP...`;
                const content = await zip.generateAsync({type:"blob"});
                const url = URL.createObjectURL(content);
                const a = document.createElement("a");
                a.href = url;
                a.download = "study4_anki_deck.zip";
                document.body.appendChild(a);
                a.click();
                document.body.removeChild(a);
                URL.revokeObjectURL(url);
                
                statusDiv.textContent = "Hoàn tất! Hãy giải nén file ZIP, copy hình và âm thanh vào thư mục Anki collection.media, sau đó import file study4_anki.csv";
            }
        } else {
            statusDiv.textContent = "Không thể lấy dữ liệu. Hãy đảm bảo bạn đang ở trang chứa Flashcard Study4.";
        }
    } catch (e) {
        statusDiv.textContent = "Lỗi: " + e.message;
        console.error(e);
    }
}