feat: implement SparkPlug backend API integration for Gemini and Meshy

backend/server.js

@@ -7,6 +7,9 @@ const { v4: uuidv4 } = require('uuid');
 const multer = require('multer');
 const path = require('path');
 const fs = require('fs');
+const pdfParse = require('pdf-parse');
+const { GoogleGenerativeAI } = require('@google/generative-ai');
+const axios = require('axios');
 
 const { db, run, get, all } = require('./database');
 const { sendMail } = require('./mail');
@@ -305,6 +308,176 @@ app.post('/api/upload/complete', authenticate, (req, res) => {
   }
 });
 
+// ==========================================
+// SPARK PLUG WORKFLOW APIS
+// ==========================================
+
+const getKeysFromProfile = async (userId) => {
+  const profile = await get('SELECT api_keys FROM profiles WHERE id = ?', [userId]);
+  if (profile && profile.api_keys) {
+    try {
+      return JSON.parse(profile.api_keys);
+    } catch(e) {}
+  }
+  return {};
+};
+
+// 1. Extract PDF (Gemini)
+app.post('/api/sparkplug/extract', authenticate, upload.single('file'), async (req, res) => {
+  if (!req.file) return res.status(400).json({ error: 'No file uploaded' });
+  
+  try {
+    const keys = await getKeysFromProfile(req.user.id);
+    const geminiKey = keys.GEMINI_API_KEY;
+    if (!geminiKey) return res.status(400).json({ error: 'Gemini API key missing' });
+
+    // Parse PDF
+    const dataBuffer = fs.readFileSync(req.file.path);
+    const pdfData = await pdfParse(dataBuffer);
+    const textContent = pdfData.text;
+
+    // Call Gemini to extract prompt
+    const genAI = new GoogleGenerativeAI(geminiKey);
+    const model = genAI.getGenerativeModel({ model: "gemini-1.5-flash" });
+
+    const prompt = `
+      You are an expert product designer. Read the following text from a product spec PDF and create a highly detailed, concise visual design prompt for an image generation AI.
+      Focus on the object's shape, color, materials, packaging details, and label content. Do not include background details.
+      
+      TEXT:
+      ${textContent.substring(0, 30000)} // Limit to avoid context length issues if massive
+    `;
+
+    const result = await model.generateContent(prompt);
+    const response = await result.response;
+    const extractedPrompt = response.text();
+
+    res.json({ prompt: extractedPrompt });
+  } catch (err) {
+    res.status(500).json({ error: err.message });
+  } finally {
+    if (req.file) {
+      fs.unlinkSync(req.file.path); // cleanup uploaded PDF
+    }
+  }
+});
+
+// 2. Generate Images (Nano Banana / Gemini Imagen)
+app.post('/api/sparkplug/generate-images', authenticate, async (req, res) => {
+  const { prompt } = req.body;
+  if (!prompt) return res.status(400).json({ error: 'No prompt provided' });
+
+  try {
+    const keys = await getKeysFromProfile(req.user.id);
+    const apiKey = keys.NANO_BANANA_API_KEY || keys.GEMINI_API_KEY;
+    if (!apiKey) return res.status(400).json({ error: 'Nano Banana (Gemini) API key missing' });
+
+    // We will use axios to call the Gemini Imagen REST API
+    const baseUrl = 'https://generativelanguage.googleapis.com/v1beta/models/imagen-3.0-generate-001:predict';
+    
+    const views = ['Front view', 'Back view', 'Left side view', 'Right side view'];
+    const imageUrls = [];
+
+    // Run parallel generation for all 4 views
+    const promises = views.map(async (view, index) => {
+      const fullPrompt = `${prompt}. ${view}, isolated on a pure white background, studio lighting.`;
+      
+      const payload = {
+        instances: [
+          {
+            prompt: fullPrompt
+          }
+        ],
+        parameters: {
+          sampleCount: 1,
+          outputOptions: { mimeType: 'image/png' }
+        }
+      };
+
+      const response = await axios.post(`${baseUrl}?key=${apiKey}`, payload, {
+        headers: { 'Content-Type': 'application/json' }
+      });
+
+      const base64Image = response.data.predictions[0].bytesBase64Encoded;
+      const buffer = Buffer.from(base64Image, 'base64');
+      
+      const filename = `sparkplug-${req.user.id}-${Date.now()}-${index}.png`;
+      const filepath = path.join(uploadsDir, filename);
+      fs.writeFileSync(filepath, buffer);
+      
+      return `/uploads/${filename}`;
+    });
+
+    const generatedUrls = await Promise.all(promises);
+    res.json({ images: generatedUrls });
+  } catch (err) {
+    // Gemini HTTP errors usually have response.data.error
+    const errorMsg = err.response?.data?.error?.message || err.message;
+    res.status(500).json({ error: errorMsg });
+  }
+});
+
+// 3. Generate 3D (Meshy)
+app.post('/api/sparkplug/generate-3d', authenticate, async (req, res) => {
+  const { imageUrls } = req.body;
+  if (!imageUrls || imageUrls.length === 0) return res.status(400).json({ error: 'No images provided' });
+
+  try {
+    const keys = await getKeysFromProfile(req.user.id);
+    const meshyKey = keys.MESHY_API_KEY;
+    if (!meshyKey) return res.status(400).json({ error: 'Meshy API key missing' });
+
+    // Assuming imageUrls are local paths like /uploads/...
+    // Meshy requires base64 Data URIs if the images are not publicly accessible URLs.
+    // Our local URLs are not publicly accessible to Meshy's servers! We MUST convert to base64.
+    
+    const base64Images = imageUrls.map(url => {
+      // Extract filename from URL
+      const filename = url.replace('/uploads/', '');
+      const filepath = path.join(uploadsDir, filename);
+      const buffer = fs.readFileSync(filepath);
+      return `data:image/png;base64,${buffer.toString('base64')}`;
+    });
+
+    const response = await axios.post('https://api.meshy.ai/openapi/v1/multi-image-to-3d', {
+      image_urls: base64Images,
+      enable_pbr: true
+    }, {
+      headers: {
+        'Authorization': `Bearer ${meshyKey}`,
+        'Content-Type': 'application/json'
+      }
+    });
+
+    res.json({ taskId: response.data.result });
+  } catch (err) {
+    const errorMsg = err.response?.data?.message || err.message;
+    res.status(500).json({ error: errorMsg });
+  }
+});
+
+// 4. Check 3D Status (Meshy)
+app.get('/api/sparkplug/status-3d/:taskId', authenticate, async (req, res) => {
+  const { taskId } = req.params;
+  
+  try {
+    const keys = await getKeysFromProfile(req.user.id);
+    const meshyKey = keys.MESHY_API_KEY;
+    if (!meshyKey) return res.status(400).json({ error: 'Meshy API key missing' });
+
+    const response = await axios.get(`https://api.meshy.ai/openapi/v1/multi-image-to-3d/${taskId}`, {
+      headers: {
+        'Authorization': `Bearer ${meshyKey}`
+      }
+    });
+
+    res.json(response.data);
+  } catch (err) {
+    const errorMsg = err.response?.data?.message || err.message;
+    res.status(500).json({ error: errorMsg });
+  }
+});
+
 const PORT = process.env.PORT || 3005;
 app.listen(PORT, () => {
   console.log(`Backend server running on port ${PORT}`);