/**
 * Document Handler Module (PDF, DOCX, DOC)
 * UPDATED: Updates workflow progress after document load
 */

function initPdfHandler() {
    const uploadZone = document.getElementById('uploadZone');
    const docInput = document.getElementById('docInput');
    
    if (!uploadZone || !docInput) return;
    
    uploadZone.addEventListener('click', (e) => {
        if (e.target.closest('button')) return;
        docInput.click();
    });
    
    docInput.addEventListener('change', (e) => {
        const file = e.target.files[0];
        if (file) {
            handleDocumentFile(file);
        }
    });
    
    uploadZone.addEventListener('dragover', (e) => {
        e.preventDefault();
        uploadZone.classList.add('drag-over');
    });
    
    uploadZone.addEventListener('dragleave', () => {
        uploadZone.classList.remove('drag-over');
    });
    
    uploadZone.addEventListener('drop', (e) => {
        e.preventDefault();
        uploadZone.classList.remove('drag-over');
        
        const files = e.dataTransfer.files;
        if (files.length > 0) {
            const file = files[0];
            const name = file.name.toLowerCase();
            
            if (name.endsWith('.pdf') || name.endsWith('.docx') || name.endsWith('.doc')) {
                handleDocumentFile(file);
            } else {
                alert('Please drop a valid PDF, DOCX, or DOC file.');
            }
        }
    });
    
    console.log('📄 Document handler initialized (PDF, DOCX, DOC)');
}

function handleDocumentFile(file) {
    const name = file.name.toLowerCase();
    
    if (name.endsWith('.pdf')) {
        handlePdfFile(file);
    } else if (name.endsWith('.docx') || name.endsWith('.doc')) {
        handleWordFile(file);
    } else {
        alert('Unsupported file type. Please upload a PDF, DOCX, or DOC file.');
    }
}

async function handlePdfFile(file) {
    if (!file.name.toLowerCase().endsWith('.pdf')) {
        alert('Please select a valid PDF file.');
        return;
    }
    
    showLoader('Processing PDF...', `Extracting content from ${file.name}`);
    
    const formData = new FormData();
    formData.append('file', file);
    
    try {
        const response = await fetch('/api/upload-pdf', {
            method: 'POST',
            body: formData
        });
        
        const data = await response.json();
        
        if (data.error) {
            throw new Error(data.error);
        }
        
        console.log(`✅ PDF processed: ${data.page_count} pages, ${data.blocks.length} blocks`);
        
        const projectName = file.name.replace('.pdf', '');
        document.getElementById('projectName').value = projectName;
        currentProject.name = projectName;
        
        renderDocumentBlocks(data.blocks);
        
        document.getElementById('uploadSection').style.display = 'none';
        document.getElementById('editorSection').style.display = 'block';
        
        hideLoader();
        showNotification(`PDF processed: ${data.blocks.length} blocks extracted`, 'success');
        updateWorkflowProgress('edit');
        
    } catch (error) {
        hideLoader();
        console.error('PDF processing error:', error);
        alert('Failed to process PDF: ' + error.message);
    }
}

async function handleWordFile(file) {
    const name = file.name.toLowerCase();
    if (!name.endsWith('.docx') && !name.endsWith('.doc')) {
        alert('Please select a valid DOCX or DOC file.');
        return;
    }
    
    const fileType = name.endsWith('.docx') ? 'DOCX' : 'DOC';
    showLoader(`Processing ${fileType}...`, `Extracting content from ${file.name}`);
    
    const formData = new FormData();
    formData.append('file', file);
    
    try {
        const response = await fetch('/api/upload-docx', {
            method: 'POST',
            body: formData
        });
        
        const data = await response.json();
        
        if (data.error) {
            throw new Error(data.error);
        }
        
        console.log(`✅ ${fileType} processed: ${data.blocks.length} blocks`);
        
        const projectName = file.name.replace(/\.(docx|doc)$/i, '');
        document.getElementById('projectName').value = projectName;
        currentProject.name = projectName;
        
        renderDocumentBlocks(data.blocks);
        
        document.getElementById('uploadSection').style.display = 'none';
        document.getElementById('editorSection').style.display = 'block';
        
        hideLoader();
        showNotification(`${fileType} processed: ${data.blocks.length} blocks extracted`, 'success');
        updateWorkflowProgress('edit');
        
    } catch (error) {
        hideLoader();
        console.error(`${fileType} processing error:`, error);
        alert(`Failed to process ${fileType}: ` + error.message);
    }
}

function renderDocumentBlocks(blocks) {
    const editor = document.getElementById('markdownEditor');
    editor.innerHTML = '';
    editorBlocks = [];
    
    const emptyMessage = document.getElementById('emptyEditorMessage');
    if (emptyMessage) {
        emptyMessage.style.display = 'none';
    }
    
    addChapterMarker(1);
    
    for (const block of blocks) {
        let type = 'paragraph';
        let content = block.content || '';
        
        if (block.type === 'image') {
            type = 'image';
        } else if (block.type === 'heading1' || content.startsWith('# ')) {
            type = 'heading1';
        } else if (block.type === 'heading2' || content.startsWith('## ')) {
            type = 'heading2';
        } else if (block.type === 'heading3' || content.startsWith('### ')) {
            type = 'heading3';
        } else if (block.type === 'list_item' || content.startsWith('- ')) {
            type = 'bulletList';
        } else if (block.type === 'quote' || content.startsWith('> ')) {
            type = 'quote';
        } else if (block.type === 'table') {
            type = 'table';
        }
        
        let images = [];
        if (block.type === 'image' && block.data) {
            images = [{
                data: block.data,
                format: block.format || 'png',
                alt_text: 'Document Image',
                position: 'before'
            }];
            content = `![Document Image](embedded-image.${block.format || 'png'})`;
        }
        
        const lastChild = editor.lastElementChild;
        const blockId = addBlock(type, content, lastChild, images);
        
        if (block.type === 'image' && block.data) {
            const blockEl = document.getElementById(blockId);
            if (blockEl) {
                const contentDiv = blockEl.querySelector('.md-block-content');
                if (contentDiv) {
                    contentDiv.innerHTML = `
                        <div class="image-block">
                            <img src="data:image/${block.format || 'png'};base64,${block.data}" alt="Document Image">
                        </div>
                    `;
                }
            }
        }
        
        const blockEl = document.getElementById(blockId);
        if (blockEl) {
            ensureNewBlockLineAfter(blockEl);
        }
    }
    
    repairAllNewBlockLines();
}

function renderPdfBlocks(blocks) {
    renderDocumentBlocks(blocks);
}