document.addEventListener('DOMContentLoaded', function() {
    const uploadBtn = document.getElementById('uploadBtn');
    const fileInput = document.getElementById('fileInput');
    const filePreviewList = document.getElementById('filePreviewList');
    const filePreviewContainer = document.getElementById('filePreviewContainer');
    const processBtn = document.getElementById('processBtn');
    const outputFormat = document.getElementById('outputFormat');
    const resultsContainer = document.getElementById('resultsContainer');
    const resultsSection = document.getElementById('resultsSection');
    const downloadAllBtn = document.getElementById('downloadAllBtn');
    
    let files = [];
    let processedResults = [];
    
    // Set PDF.js worker path
    pdfjsLib.GlobalWorkerOptions.workerSrc = 'https://cdnjs.cloudflare.com/ajax/libs/pdf.js/2.11.338/pdf.worker.min.js';
    
    // Handle file selection
    uploadBtn.addEventListener('click', () => fileInput.click());
    
    fileInput.addEventListener('change', handleFileSelection);
    
    function handleFileSelection(e) {
        files = Array.from(e.target.files);
        filePreviewList.innerHTML = '';
        
        if (files.length === 0) {
            filePreviewContainer.classList.add('hidden');
            return;
        }
        
        files.forEach((file, index) => {
            const filePreview = createFilePreview(file, index);
            filePreviewList.appendChild(filePreview);
        });
        
        filePreviewContainer.classList.remove('hidden');
    }
    
    function createFilePreview(file, index) {
        const card = document.createElement('div');
        card.className = 'file-card bg-gray-50 rounded-lg p-4 flex items-center justify-between';
        
        const fileInfo = document.createElement('div');
        fileInfo.className = 'flex items-center';
        
        const icon = document.createElement('div');
        icon.className = 'bg-gray-200 p-2 rounded-full mr-3';
        
        const fileIcon = document.createElement('i');
        fileIcon.dataset.feather = getFileIcon(file);
        icon.appendChild(fileIcon);
        
        const fileName = document.createElement('span');
        fileName.className = 'font-medium text-gray-800';
        fileName.textContent = file.name;
        
        fileInfo.appendChild(icon);
        fileInfo.appendChild(fileName);
        
        const fileSize = document.createElement('span');
        fileSize.className = 'text-gray-500 text-sm';
        fileSize.textContent = formatFileSize(file.size);
        
        card.appendChild(fileInfo);
        card.appendChild(fileSize);
        
        feather.replace();
        return card;
    }
    
    function getFileIcon(file) {
        if (file.type.includes('pdf')) return 'file';
        if (file.type.includes('word') || file.type.includes('document')) return 'file-text';
        if (file.type.includes('excel') || file.type.includes('spreadsheet')) return 'file-text';
        if (file.type.includes('image')) return 'image';
        return 'file';
    }
    
    function formatFileSize(bytes) {
        if (bytes === 0) return '0 Bytes';
        const k = 1024;
        const sizes = ['Bytes', 'KB', 'MB', 'GB'];
        const i = Math.floor(Math.log(bytes) / Math.log(k));
        return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
    }
    
    // Process files
    processBtn.addEventListener('click', async function() {
        if (files.length === 0) {
            alert('Please select at least one file');
            return;
        }
        
        resultsContainer.innerHTML = '';
        processedResults = [];
        processBtn.disabled = true;
        processBtn.innerHTML = '<i data-feather="loader" class="spinner mr-2"></i> Processing...';
        feather.replace();
        
        try {
            for (const file of files) {
                const result = await processFile(file);
                processedResults.push(result);
                displayResult(result);
            }
            
            resultsSection.classList.remove('hidden');
        } catch (error) {
            console.error('Error processing files:', error);
            alert('An error occurred while processing files: ' + error.message);
        } finally {
            processBtn.disabled = false;
            processBtn.innerHTML = '<i data-feather="cpu" class="mr-2"></i> Process Files';
            feather.replace();
        }
    });
    
    async function processFile(file) {
        const format = outputFormat.value;
        let content;
        
        if (file.type.includes('pdf')) {
            content = await extractTextFromPDF(file);
        } else if (file.type.includes('word') || file.type.includes('document') || 
                   file.name.endsWith('.docx') || file.name.endsWith('.doc')) {
            content = await extractTextFromWord(file);
        } else if (file.type.includes('excel') || file.type.includes('spreadsheet') || 
                   file.name.endsWith('.xlsx') || file.name.endsWith('.xls')) {
            content = await extractTextFromExcel(file);
        } else if (file.type.includes('image')) {
            content = await extractTextFromImage(file);
        } else {
            throw new Error('Unsupported file type: ' + file.type);
        }
        
        // Convert content to requested format
        let formattedContent;
        if (format === 'json') {
            formattedContent = {
                fileName: file.name,
                fileType: file.type,
                fileSize: file.size,
                content: content,
                extractedAt: new Date().toISOString()
            };
            formattedContent = JSON.stringify(formattedContent, null, 2);
        } else if (format === 'markdown') {
            formattedContent = `# ${file.name}\n\n`;
            if (typeof content === 'string') {
                formattedContent += content;
            } else {
                formattedContent += JSON.stringify(content, null, 2)
                    .replace(/\n/g, '\n\n')
                    .replace(/"([^"]+)":/g, '**$1**:');
            }
        } else {
            // Plain text
            if (typeof content === 'string') {
                formattedContent = content;
            } else {
                formattedContent = JSON.stringify(content, null, 2);
            }
        }
        
        return {
            fileName: file.name,
            content: formattedContent,
            format: format
        };
    }
    
    async function extractTextFromPDF(file) {
        return new Promise((resolve, reject) => {
            const reader = new FileReader();
            
            reader.onload = async function(event) {
                try {
                    const typedArray = new Uint8Array(event.target.result);
                    const pdf = await pdfjsLib.getDocument(typedArray).promise;
                    let text = '';
                    
                    for (let i = 1; i <= pdf.numPages; i++) {
                        const page = await pdf.getPage(i);
                        const content = await page.getTextContent();
                        const strings = content.items.map(item => item.str);
                        text += strings.join(' ') + '\n\n';
                    }
                    
                    resolve(text);
                } catch (error) {
                    reject(error);
                }
            };
            
            reader.onerror = reject;
            reader.readAsArrayBuffer(file);
        });
    }
    
    async function extractTextFromWord(file) {
        return new Promise((resolve, reject) => {
            const reader = new FileReader();
            
            reader.onload = function(event) {
                mammoth.extractRawText({ arrayBuffer: event.target.result })
                    .then(function(result) {
                        resolve(result.value);
                    })
                    .catch(reject);
            };
            
            reader.onerror = reject;
            reader.readAsArrayBuffer(file);
        });
    }
    
    async function extractTextFromExcel(file) {
        return new Promise((resolve, reject) => {
            const reader = new FileReader();
            
            reader.onload = function(event) {
                try {
                    const data = new Uint8Array(event.target.result);
                    const workbook = XLSX.read(data, { type: 'array' });
                    const result = {};
                    
                    workbook.SheetNames.forEach(sheetName => {
                        const worksheet = workbook.Sheets[sheetName];
                        result[sheetName] = XLSX.utils.sheet_to_json(worksheet, { header: 1 });
                    });
                    
                    resolve(result);
                } catch (error) {
                    reject(error);
                }
            };
            
            reader.onerror = reject;
            reader.readAsArrayBuffer(file);
        });
    }
async function extractTextFromImage(file) {
        return new Promise((resolve, reject) => {
            Tesseract.recognize(
                file,
                'tur+eng', // Turkish + English languages
                { 
                    logger: m => console.log(m),
                    preserve_interword_spaces: true,
                    tessedit_pageseg_mode: 6, // Assume a single uniform block of text 
                    tessedit_char_whitelist: 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789.,!?-(){}[]/\\\'" ',
                    tessedit_create_hocr: 1 // Include formatting info
                }
            ).then(({ data: { text, hocr } }) => {
                if (outputFormat.value === 'formatted') {
                    // Process formatted output similar to Adobe/Abbyy
                    const formatted = processFormattedOCR(hocr);
                    resolve(formatted);
                } else {
                    resolve(text);
                }
            }).catch(reject);
        });

        function processFormattedOCR(hocr) {
            // Parse hOCR output to preserve formatting and layout
            const parser = new DOMParser();
            const doc = parser.parseFromString(hocr, 'text/html');
            const paragraphs = doc.querySelectorAll('.ocr_par');
            
            let formattedText = '';
            
            paragraphs.forEach(par => {
                const lines = par.querySelectorAll('.ocr_line');
                lines.forEach(line => {
                    const words = line.querySelectorAll('.ocrx_word');
                    let lineText = '';
                    
                    words.forEach((word, index) => {
                        const wordText = word.textContent || '';
                        const wordConfidence = parseFloat(word.getAttribute('title')
                            .match(/x_wconf (\d+)/)[1]);
                        
                        // Apply formatting based on confidence and context
                        if (wordConfidence < 60) {
                            lineText += `[${wordText}] `;
                        } else if (wordConfidence < 80 && index > 0) {
                            lineText += `${wordText}`;
                        } else {
                            lineText += `${wordText} `;
                        }
                    });
                    
                    formattedText += lineText.trim() + '\n';
                });
                
                formattedText += '\n';
            });
            
            return formattedText;
        }
}
    
    function displayResult(result) {
        const resultCard = document.createElement('div');
        resultCard.className = 'bg-gray-50 rounded-lg p-4 shadow-sm';
        
        const header = document.createElement('div');
        header.className = 'flex justify-between items-center mb-3';
        
        const title = document.createElement('h3');
        title.className = 'font-semibold text-lg text-gray-800 truncate';
        title.textContent = result.fileName;
        
        const downloadBtn = document.createElement('button');
        downloadBtn.className = 'bg-indigo-600 hover:bg-indigo-700 text-white font-medium py-1 px-3 rounded transition duration-200 flex items-center text-sm';
        downloadBtn.innerHTML = '<i data-feather="download" class="mr-1"></i> Download';
        downloadBtn.addEventListener('click', () => downloadResult(result));
        
        header.appendChild(title);
        header.appendChild(downloadBtn);
        
        const content = document.createElement('div');
        
        if (result.format === 'json') {
            const pre = document.createElement('pre');
            pre.textContent = result.content;
            content.appendChild(pre);
        } else {
            const pre = document.createElement('pre');
            pre.textContent = result.content;
            content.appendChild(pre);
        }
        
        resultCard.appendChild(header);
        resultCard.appendChild(content);
        
        resultsContainer.appendChild(resultCard);
        feather.replace();
    }
    
    function downloadResult(result) {
        const blob = new Blob([result.content], { type: 'text/plain' });
        const url = URL.createObjectURL(blob);
        const a = document.createElement('a');
        a.href = url;
        a.download = `${result.fileName.split('.')[0]}.${result.format}`;
        document.body.appendChild(a);
        a.click();
        document.body.removeChild(a);
        URL.revokeObjectURL(url);
    }
    
    downloadAllBtn.addEventListener('click', () => {
        processedResults.forEach(result => {
            downloadResult(result);
        });
    });
});