// server.js
import express from "express";
import bodyParser from "body-parser";
import cors from "cors";
import fs from "fs";
import path from "path";
import { fileURLToPath } from "url";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
const PORT = process.env.PORT || 7860;

const app = express();
app.use(cors());
app.use(bodyParser.json({ limit: "50mb" }));

// === DEMO CONTROLLER ===
// CHANGE THIS TO TEST DIFFERENT INTERACTIONS
// Options: 'NONE' (Just save), 'BUILD_PART' (Send Lua Code), 'FETCH_SCRIPT' (Ask for Source)
const DEMO_MODE = 'BUILD_PART'; 

app.post("/api/ai-build", async (req, res) => {
  try {
    const { instruction, state, scriptContext } = req.body;
    
    console.log("📥 Received Request");
    console.log("   Instruction:", instruction);
    
    // 1. Log Payload Size (Check token efficiency)
    if(state && state.flatList) {
        console.log(`   Hierarchy Size: ${state.flatList.length} items (Flat Format)`);
    }

    // 2. IF WE RECEIVED SCRIPT SOURCE (From a previous fetch request)
    if (scriptContext) {
        console.log("   📘 Received Script Source for:", scriptContext.name);
        console.log("   --- START SOURCE ---\n", scriptContext.source.substring(0, 100) + "...", "\n   --- END SOURCE ---");
        // In a real app, you would now feed this to the AI to edit.
        return res.json({ success: true, message: "Source received, analyzing..." });
    }

    // 3. DEMO RESPONSES
    if (DEMO_MODE === 'BUILD_PART') {
        console.log("   👉 Sending Code Demo");
        const luaCode = `
        ```lua
        -- AI Generated Demo
        local p = Instance.new("Part")
        p.Name = "AI_Generated_Cube"
        p.Color = Color3.fromRGB(0, 255, 100)
        p.Size = Vector3.new(4, 4, 4)
        p.Position = Vector3.new(0, 10, 0)
        p.Anchored = true
        p.Parent = workspace
        print("Hello from the Server! I made a part.")
        ```
        `;
        return res.send(luaCode); // Sending raw markdown/text
    } 
    
    else if (DEMO_MODE === 'FETCH_SCRIPT') {
        console.log("   👉 Sending Fetch Request Demo");
        // This tells the plugin to find a script named "BikeLogic" and send it back
        return res.json({
            action: "read_script",
            targetName: "BikeLogic" // CHANGE THIS to a script name that actually exists in your studio
        });
    }

    // Default: Just acknowledge
    return res.json({ success: true, assetId: "req_" + Date.now() });

  } catch (err) {
    console.error("Server Error:", err);
    res.status(500).send("Server Error");
  }
});

app.listen(PORT, () => console.log(`🚀 Server running on port ${PORT}. Demo Mode: ${DEMO_MODE}`));