Seo/Template-04/server.ts

import express from 'express';
import { createServer as createViteServer } from 'vite';
import { GoogleGenAI } from "@google/genai";
import path from 'path';
import cors from 'cors';

async function startServer() {
  const app = express();
  const PORT = 3000;

  app.use(express.json());
  app.use(cors());

  // Lazy Gemini Setup
  let ai: GoogleGenAI | null = null;
  
  const getAI = () => {
    const apiKey = process.env.GEMINI_API_KEY;
    if (!apiKey) {
      throw new Error("GEMINI_API_KEY environment variable is required");
    }
    if (!ai) {
      ai = new GoogleGenAI({ apiKey });
    }
    return ai;
  };

  // Translation API
  app.post('/api/translate', async (req, res) => {
    const { text, targetLang, context, isObject } = req.body;
    
    try {
      const client = getAI();
      
      let prompt = "";
      if (isObject) {
        prompt = `Translate the following JSON object values to ${targetLang}. 
        Keep the keys exactly the same. 
        Preserve markdown formatting in values.
        Return ONLY the translated JSON object.
        
        Object:
        ${JSON.stringify(text)}`;
      } else {
        prompt = `Translate the following ${context || 'text'} to ${targetLang}. 
        Preserve all markdown formatting, technical terms, and HTML structures if present. 
        Do not add any commentary or prefix. Return only the translated string.
        
        Content:
        ${text}`;
      }

      const response = await client.models.generateContent({
        model: "gemini-3-flash-preview",
        contents: prompt,
        config: isObject ? { responseMimeType: "application/json" } : undefined
      });

      let resultText = response.text || '';
      
      if (isObject) {
        try {
          res.json({ translatedText: JSON.parse(resultText) });
        } catch (e) {
          console.error("Parse Error:", resultText);
          res.json({ translatedText: text }); // Fallback to original if parse fails
        }
      } else {
        res.json({ translatedText: resultText });
      }
    } catch (error) {
      console.error("Translation Error:", error);
      res.status(500).json({ error: error instanceof Error ? error.message : "Failed to translate" });
    }
  });

  // Vite Integration
  if (process.env.NODE_ENV !== "production") {
    const vite = await createViteServer({
      server: { middlewareMode: true },
      appType: "spa",
    });
    app.use(vite.middlewares);
  } else {
    const distPath = path.join(process.cwd(), 'dist');
    app.use(express.static(distPath));
    app.get('*', (req, res) => {
      res.sendFile(path.join(distPath, 'index.html'));
    });
  }

  app.listen(PORT, "0.0.0.0", () => {
    console.log(`Server running at http://0.0.0.0:${PORT}`);
  });
}

startServer();