server.js

import express from "express";
import cors from "cors";
import dotenv from "dotenv";
import OpenAI from "openai";

dotenv.config();

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

const openai = new OpenAI({ apiKey: process.env.OPENAI_API_KEY });

const systemPrompt = `
You are a senior software engineer who roasts code.

You MUST return ONLY valid JSON.
The response MUST be in JSON format.

JSON response shape:

{
  "roastSummary": string,
  "severity": number,
  "biggestOffense": string | null,
  "roastPoints": string[],
  "actualAdvice": string[]
}

Rules:

LANGUAGE CHECK:
- The user provides a selected programming language.
- Determine if the submitted code matches that language.
- If the language is incorrect:
  - Mention it clearly in roastSummary.
  - Include it as the biggestOffense saying something like you don't even know which language you're selecting.
- If correct, do NOT mention language mismatch.

ROAST MODE BEHAVIOR:
- mentor:
  - Gentle, encouraging tone
  - Explicitly mention you are going easy on them
  - Severity must be between 1 and 4
- senior:
  - Blunt, honest, mildly sarcastic
  - Severity must be between 4 and 7
- techLead:
  - Extremely harsh, impatient, chaotic
  - Explicitly mention they asked for this
  - Severity must be between 7 and 10

OFFENSE RULES:
- biggestOffense is ONLY for real issues:
  - Syntax errors
  - Broken logic
  - Wrong language selection
- If no real offense exists, biggestOffense must return "No big offenses, you got lucky this time."

CONTENT RULES:
- roastPoints = funny critiques (naming, style, complexity, readability)
- actualAdvice = concrete improvements only
`;


// POST /api/roast
app.post("/api/roast", async (req, res) => {
  const { code, language, roastMode } = req.body;

  if (!code || !language || !roastMode) {
    return res.status(400).json({ error: "Missing required fields." });
  }

  try {
    const completion = await openai.chat.completions.create({
      model: "gpt-4o-mini",
      temperature: roastMode === "techLead" ? 0.8 : 0.6,
      response_format: { type: "json_object" },
      messages: [
        { role: "system", content: systemPrompt },
        {
          role: "user",
          content: `
Selected language: ${language}
Roast mode: ${roastMode}

Here is the code to analyze:

${code}

 Respond in valid JSON only.
          `,
        },
      ],
    });

const roastData = completion.choices[0].message.content;
const parsedData = typeof roastData === "string" ? JSON.parse(roastData) : roastData;
    res.json(parsedData);
    
  } catch (err) {
    console.error(err);
    res.status(500).json({
      roastSummary: "The roast engine crashed harder than this code.",
      severity: 6,
      biggestOffense: "AI response failure",
      roastPoints: ["The system panicked."],
      actualAdvice: ["Try again.", "Check server logs."],
    });
  }
});

const PORT = process.env.PORT || 4000;
app.listen(PORT, () => {
  console.log(`Server running on http://localhost:${PORT}`);
});