// server.js
import express from 'express';
import bodyParser from 'body-parser';
import cors from 'cors';
import { StateManager } from './stateManager.js';
import { AIEngine } from './aiEngine.js';
import fs from 'fs';

const app = express();
const PORT = process.env.PORT || 7860;

// Load prompts for dynamic usage
const sysPrompts = JSON.parse(fs.readFileSync('./prompts.json', 'utf8'));

app.use(cors());
app.use(bodyParser.json({ limit: '50mb' })); // Increased limit for images

// Middleware: Validate User/Project IDs
const validateRequest = (req, res, next) => {
    const { userId, projectId } = req.body;
    if (!userId || !projectId) {
        return res.status(400).json({ error: "Missing userId or projectId" });
    }
    next();
};

/**
 * 1. NEW PROJECT
 * Flow: PM (GDD) -> PM (Tasks) -> Worker (Task 1)
 */
app.post('/new/project', validateRequest, async (req, res) => {
    const { userId, projectId, description } = req.body;

    try {
        // 1. Generate GDD with PM (High Thinking)
        const pmHistory = [];
        const gddPrompt = `Create a comprehensive GDD for: ${description}`;
        const gddResponse = await AIEngine.callPM(pmHistory, gddPrompt);
        
        pmHistory.push({ role: 'user', parts: [{ text: gddPrompt }] });
        pmHistory.push({ role: 'model', parts: [{ text: gddResponse }] });

        // 2. Generate Initial Tasks
        const taskPrompt = "Based on the GDD, generate a prioritized list of initial technical tasks. Output them as a JSON list.";
        const taskResponse = await AIEngine.callPM(pmHistory, taskPrompt);

        pmHistory.push({ role: 'user', parts: [{ text: taskPrompt }] });
        pmHistory.push({ role: 'model', parts: [{ text: taskResponse }] });

        // 3. Initialize Worker with GDD Context and Execute First Task
        const workerHistory = [];
        const initialWorkerPrompt = `Here is the GDD: ${gddResponse}. \n\n Here are the tasks: ${taskResponse}. \n\n EXECUTE THE FIRST TASK NOW.`;
        const workerResponse = await AIEngine.callWorker(workerHistory, initialWorkerPrompt);

        workerHistory.push({ role: 'user', parts: [{ text: initialWorkerPrompt }] });
        workerHistory.push({ role: 'model', parts: [{ text: workerResponse }] });

        // Save State
        await StateManager.updateProject(projectId, {
            userId,
            pmHistory,
            workerHistory,
            gdd: gddResponse,
            failureCount: 0
        });

        // Queue the result for the plugin
        StateManager.queueCommand(projectId, workerResponse);

        res.json({ success: true, message: "Project initialized", gddPreview: gddResponse.substring(0, 200) });

    } catch (err) {
        console.error(err);
        res.status(500).json({ error: "AI Processing Failed" });
    }
});

/**
 * 2. FEEDBACK (The Main Loop Endpoint)
 * Accepts text + optional image. Hits Worker. Checks for escalation.
 */

app.post('/project/feedback', async (req, res) => {
    const { projectId, prompt, hierarchyContext, scriptContext, logContext, taskComplete } = req.body;
    
    const project = await StateManager.getProject(projectId);
    if (!project) return res.status(404).json({ error: "Project not found." });

    // 1. MISSION COMPLETE: CALL PM & NUKE WORKER
    if (taskComplete) {
        console.log(`[${projectId}] ✅ TASK COMPLETE. Calling PM & Nuking Worker.`);
        
        // A. Notify PM (Add to PM History)
        const summary = `Worker has successfully completed the previous task. Logs: ${logContext?.logs || "Clean"}. Ready for next assignment.`;
        project.pmHistory.push({ role: 'user', parts: [{ text: summary }] });
        
        // B. Nuke Worker (Reset History)
        project.workerHistory = []; 
        
        // C. Update State
        await StateManager.updateProject(projectId, { 
            pmHistory: project.pmHistory,
            workerHistory: [], // THE NUKE
            status: "IDLE"     // Waiting for user or PM to start next task
        });
        
        return res.json({ success: true, message: "Worker Nuked. PM Notified. Loop Stopped." });
    }

    // 2. ERROR DETECTION (Safety Net)
    let isFailure = false;
    if (logContext && logContext.logs) {
        const errorKeywords = ["Infinite yield", "Stack Begin", "Error:", "Exception", "failed"];
        if (errorKeywords.some(keyword => logContext.logs.includes(keyword))) {
            isFailure = true;
            console.log(`[${projectId}] ⚠️ Detected Error in Logs.`);
        }
    }

    // 3. BUILD AI PROMPT
    const fullInput = `USER: ${prompt || "Automatic Feedback"}` + formatContext({ hierarchyContext, scriptContext, logContext });
    
    let finalPrompt = fullInput;
    if (isFailure && (!prompt || prompt.length < 5)) {
        finalPrompt += "\n[SYSTEM ALERT]: Runtime Error detected. Fix the code immediately. Do not use WaitForChild. Do not yield.";
    }

    console.log(`[${projectId}] Processing Feedback...`);

    // 4. CALL AI
    try {
        const response = await AIEngine.callWorker(project.workerHistory, finalPrompt);
        
        // Escalation Logic
        if (response.includes("STATUS: ESCALATE_TO_PM") || (project.failureCount > 2)) {
            console.log(`[${projectId}] Escalating to PM...`);
            const guidance = await AIEngine.callPM(project.pmHistory, `Worker Stuck. Input: ${fullInput}`);
            const fixed = await AIEngine.callWorker(project.workerHistory, `PM GUIDANCE: ${guidance}`);
            
            await StateManager.updateProject(projectId, { failureCount: 0 });
            project.workerHistory.push({ role: 'user', parts: [{ text: fullInput }] });
            project.workerHistory.push({ role: 'model', parts: [{ text: fixed }] });
            await StateManager.queueCommand(projectId, fixed);
            return res.json({ success: true, message: "Escalated & Fixed." });
        }

        project.workerHistory.push({ role: 'user', parts: [{ text: fullInput }] });
        project.workerHistory.push({ role: 'model', parts: [{ text: response }] });
        await StateManager.updateProject(projectId, { workerHistory: project.workerHistory });
        await StateManager.queueCommand(projectId, response);

        res.json({ success: true, message: "Input Processed." });

    } catch (err) {
        console.error("AI Error:", err);
        res.status(500).json({ error: "AI Failed" });
    }
});


/**
 * 3. INTERNAL PING WORKER
 * PM sends guidance to Worker.
 */
app.post('/internal/ping/worker', validateRequest, async (req, res) => {
    const { projectId, guidancePrompt } = req.body;
    const project = await StateManager.getProject(projectId);
    if (!project) return res.status(404).json({ error: "Project not found" });

    // Inject PM Context (GDD/History) into the message if requested
    const fullContextPrompt = `PM CONTEXT: ${JSON.stringify(project.pmHistory)}. \n GUIDANCE: ${guidancePrompt}`;

    const response = await AIEngine.callWorker(project.workerHistory, fullContextPrompt);
    StateManager.queueCommand(projectId, response);
    
    res.json({ success: true, message: "Guidance sent to Worker" });
});

/**
 * 4. INTERNAL PING PM
 * Worker signals distress -> PM responds.
 */
app.post('/internal/ping/pm', validateRequest, async (req, res) => {
    const { projectId, distressMessage } = req.body;
    const project = await StateManager.getProject(projectId);
    
    // PM analyzes distress
    const pmResponse = await AIEngine.callPM(project.pmHistory, `Worker Distress: ${distressMessage}. Provide solution.`);
    
    // Logic: Decide to reset worker OR guide worker
    if (pmResponse.includes("RESET_RECOMMENDED")) {
        // Call reset endpoint logic (internal function call)
        project.workerHistory = [{ role: 'user', parts: [{ text: sysPrompts.worker_reset_prompt.replace('{{INSTRUCTION}}', pmResponse) }] }];
        await StateManager.updateProject(projectId, { workerHistory: project.workerHistory });
        res.json({ action: "RESET", guidance: pmResponse });
    } else {
        // Just guide
        const workerResp = await AIEngine.callWorker(project.workerHistory, `PM FIX: ${pmResponse}`);
        StateManager.queueCommand(projectId, workerResp);
        res.json({ action: "GUIDANCE", guidance: pmResponse });
    }
});

/**
 * 5. PROJECT RESET
 * Resets the worker thread completely.
 */
app.post('/project/reset', validateRequest, async (req, res) => {
    const { projectId } = req.body;
    const project = await StateManager.getProject(projectId);
    
    // Clear history, keep GDD context
    const resetPrompt = `System reset. Current GDD: ${project.gdd}. Await instructions.`;
    
    await StateManager.updateProject(projectId, { 
        workerHistory: [{ role: 'user', parts: [{ text: resetPrompt }] }],
        failureCount: 0 
    });

    res.json({ success: true, message: "Worker thread reset" });
});

/**
 * 6. PROJECT PING (The Roblox Plugin Endpoint)
 * Plugin calls this to fetch executable code.
 */
/*
app.post('/project/ping', validateRequest, async (req, res) => {
    const { projectId } = req.body;
    const project = await StateManager.getProject(projectId);

    if (!project || !project.commandQueue || project.commandQueue.length === 0) {
        return res.json({ status: "IDLE" });
    }

    // Pop the oldest command
    const command = project.commandQueue.shift();
    await StateManager.updateProject(projectId, { commandQueue: project.commandQueue });

    // Return the whole response, but specifically parsed code for execution
    res.json({
        status: "EXECUTE",
        fullResponse: command.raw,
        codeSnippet: command.code // The markdown snippet extracted in StateManager
    });
});
*/

/**
 * 7. INACTIVITY CLEANUP
 */
app.delete('/internal/cleanup', async (req, res) => {
    const count = StateManager.cleanupInactivity();
    res.json({ success: true, removed: count });
});

app.post('/project/ping', async (req, res) => {
    const { projectId } = req.body;
    const command = await StateManager.popCommand(projectId);

    if (command) {
        // Sends: { action: "EXECUTE", target: "...", code: "..." }
        res.json({ 
            action: command.type, 
            target: command.payload, 
            code: command.type === 'EXECUTE' ? command.payload : null 
        });
    } else {
        res.json({ action: "IDLE" });
    }
});

app.listen(PORT, () => {
    console.log(`AI Builder Backend running on port ${PORT}`);
});