// server.js
const express = require('express');
const multer = require('multer');
const Docxtemplater = require('docxtemplater');
const PizZip = require('pizzip');

const app = express();

// Configure multer to accept any field
const upload = multer({
    storage: multer.memoryStorage(),
}).any();

app.use(express.json());

app.post('/process-template', (req, res) => {
    upload(req, res, function(err) {
        if (err instanceof multer.MulterError) {
            console.error('Multer error:', err);
            return res.status(400).json({ error: 'File upload error', details: err.message });
        } else if (err) {
            console.error('Unknown error:', err);
            return res.status(500).json({ error: 'Unknown error', details: err.message });
        }

        // Log incoming request details
        console.log('Files received:', req.files);
        console.log('Body received:', req.body);

        try {
            // Find the template file from the uploaded files
            const templateFile = req.files?.find(file => file.fieldname === 'template');
            const templateData = req.body?.data ? JSON.parse(req.body.data) : null;
		console.log(templateData)
            if (!templateFile || !templateData) {
                return res.status(400).json({
                    error: 'Missing required fields',
                    received: {
                        templateFile: !!templateFile,
                        templateData: !!templateData
                    }
                });
            }

            // Get the template file buffer
            const content = templateFile.buffer;

            // Create a new PizZip instance with the template content
            const zip = new PizZip(content);

            // Create the template processor
            const doc = new Docxtemplater(zip, {
                paragraphLoop: true,
                linebreaks: true,
            });

            // Render the document with the provided data
            doc.render(templateData);

            // Generate the document as a buffer
            const buffer = doc.getZip().generate({
                type: 'nodebuffer',
                compression: 'DEFLATE',
            });

            // Set response headers for file download
            res.setHeader('Content-Type', 'application/vnd.openxmlformats-officedocument.wordprocessingml.document');
            res.setHeader('Content-Disposition', 'attachment; filename=generated-document.docx');

            // Send the generated document
            res.send(buffer);

        } catch (error) {
            console.error('Processing error:', error);
            res.status(500).json({ error: 'Processing error', details: error.message });
        }
    });
});

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
    console.log(`Server is running on port ${PORT}`);
});