const express = require('express');
const { spawn } = require('child_process');
const bodyParser = require('body-parser');
const cors = require('cors');
const fs = require('fs');
const path = require('path');

const app = express();
const PORT = 3002; 
const VERSION = "1.1.0-DEBUG (Timeout 600s)";

// Middleware
app.use(cors());
app.use(bodyParser.json({ limit: '10mb' }));

const PYTHON_EXECUTABLE = 'python3';
const SCRIPT_PATH = path.join(__dirname, 'b2b_marketing_orchestrator.py');
const dbScript = '/app/market_db_manager.py';

// Helper-Funktion zum Ausführen des Python-Skripts
const runPythonScript = (args, res) => {
    console.log(`[${new Date().toISOString()}] Spawning: ${PYTHON_EXECUTABLE} ${args.join(' ')}`);
    const pythonProcess = spawn(PYTHON_EXECUTABLE, args);
    let pythonOutput = '';
    let pythonError = '';

    pythonProcess.stdout.on('data', (data) => { pythonOutput += data.toString(); });
    pythonProcess.stderr.on('data', (data) => { pythonError += data.toString(); });

    pythonProcess.on('close', (code) => {
        console.log(`[${new Date().toISOString()}] Python process exited with code ${code}`);
        if (pythonOutput.length > 0) {
             console.log(`[${new Date().toISOString()}] Stdout (first 500 chars): ${pythonOutput.substring(0, 500)}...`);
        } else {
             console.log(`[${new Date().toISOString()}] Stdout is empty.`);
        }
        if (pythonError.length > 0) {
             console.log(`[${new Date().toISOString()}] Stderr (first 500 chars): ${pythonError.substring(0, 500)}...`);
        }

        if (code !== 0) {
            console.error(`Python error (Code ${code}): ${pythonError}`);
            return res.status(500).json({ error: 'Backend error', details: pythonError, version: VERSION });
        }
        try {
            res.header('X-Server-Timeout', '600000');
            const responseData = JSON.parse(pythonOutput);
            // Add version info to the response if it's an object
            if (typeof responseData === 'object' && responseData !== null) {
                responseData._backend_version = VERSION;
            }
            res.json(responseData);
        } catch (e) {
            console.error(`JSON Parse Error: ${e.message}`);
            console.error(`Raw Output was: ${pythonOutput}`);
            res.status(500).json({ error: 'Invalid JSON', raw: pythonOutput, details: e.message, version: VERSION });
        }
    });
};

// --- API ROUTES ---
const router = express.Router();

router.post('/start-generation', (req, res) => {
    const { companyUrl, language, regions, focus } = req.body;
    const args = [SCRIPT_PATH, '--mode', 'start_generation', '--url', companyUrl, '--language', language];
    if (regions) args.push('--regions', regions);
    if (focus) args.push('--focus', focus);
    runPythonScript(args, res);
});

router.post('/next-step', (req, res) => {
    const { analysisData, language, channels, generationStep, focusIndustry } = req.body;
    const tmpDir = path.join(__dirname, 'tmp');
    if (!fs.existsSync(tmpDir)) fs.mkdirSync(tmpDir);
    const contextFilePath = path.join(tmpDir, `context_${Date.now()}.json`);
    try {
        fs.writeFileSync(contextFilePath, JSON.stringify(analysisData));
        const args = [SCRIPT_PATH, '--mode', 'next_step', '--language', language, '--context_file', contextFilePath, '--generation_step', generationStep.toString()];
        if (channels && Array.isArray(channels)) args.push('--channels', channels.join(','));
        if (focusIndustry) args.push('--focus_industry', focusIndustry);
        
        const originalJson = res.json.bind(res);
        res.json = (data) => {
            if (fs.existsSync(contextFilePath)) fs.unlinkSync(contextFilePath);
            originalJson(data);
        };
        runPythonScript(args, res);
    } catch (e) { res.status(500).json({ error: e.message }); }
});

router.get('/projects', (req, res) => runPythonScript([dbScript, 'list'], res));
router.get('/projects/:id', (req, res) => runPythonScript([dbScript, 'load', req.params.id], res));
router.delete('/projects/:id', (req, res) => runPythonScript([dbScript, 'delete', req.params.id], res));
router.post('/save-project', (req, res) => {
    const tmpDir = path.join(__dirname, 'tmp');
    if (!fs.existsSync(tmpDir)) fs.mkdirSync(tmpDir);
    const tempFilePath = path.join(tmpDir, `save_${Date.now()}.json`);
    try {
        fs.writeFileSync(tempFilePath, JSON.stringify(req.body));
        runPythonScript([dbScript, 'save', tempFilePath], res);
    } catch (e) { res.status(500).json({ error: 'Save failed' }); }
});

// Register API Router
app.use('/api', router);
app.use('/b2b/api', router); // Extra safety for Nginx pathing

// --- SERVE STATIC FRONTEND ---
const distPath = path.join(__dirname, 'dist');
app.use('/b2b', express.static(distPath));
app.use(express.static(distPath));

app.get('*', (req, res) => {
    // If it's an API call that missed the router, don't serve index.html
    if (req.url.startsWith('/api')) return res.status(404).json({ error: 'Not found' });
    res.sendFile(path.join(distPath, 'index.html'));
});

const initializeDatabase = () => {
    console.log(`[${new Date().toISOString()}] Initializing B2B database...`);
    const proc = spawn(PYTHON_EXECUTABLE, [dbScript, 'init']);
    proc.on('close', (code) => console.log(`[${new Date().toISOString()}] DB init finished (Code ${code})`));
};

const server = app.listen(PORT, () => {
    console.log(`B2B Marketing Assistant API Bridge running on port ${PORT} (Version: ${VERSION})`);
    initializeDatabase();
});

// Set timeout to 10 minutes (600s) to handle long AI generation steps
server.setTimeout(600000);
server.keepAliveTimeout = 610000;
server.headersTimeout = 620000;