const express = require('express');
const { spawn } = require('child_process');
const path = require('path');
const fs = require('fs');

const app = express();
const port = process.env.PORT || 3006;

// LOGGING SETUP
const LOG_DIR = '/app/Log_from_docker';
if (!fs.existsSync(LOG_DIR)) {
    try {
        fs.mkdirSync(LOG_DIR, { recursive: true });
    } catch (e) {
        console.error("Could not create Log directory:", e);
    }
}
const LOG_FILE = path.join(LOG_DIR, 'content_node_server.log');

function log(message, level = 'INFO') {
    const timestamp = new Date().toISOString();
    const logLine = `[${timestamp}] [${level}] ${message}\n`;
    
    // Console output
    if (level === 'ERROR') console.error(logLine);
    else console.log(logLine);

    // File output
    try {
        fs.appendFileSync(LOG_FILE, logLine);
    } catch (e) {
        console.error("Failed to write to log file:", e);
    }
}

app.use(express.json({ limit: '50mb' }));

// INITIALIZE DATABASE ON START
const dbScript = path.join(__dirname, 'content_db_manager.py');
log(`Initializing database via ${dbScript}...`);
const dbInit = spawn('python3', [dbScript]);

dbInit.stdout.on('data', (data) => log(`DB Init Output: ${data}`));
dbInit.stderr.on('data', (data) => log(`DB Init Error: ${data}`, 'ERROR'));
dbInit.on('close', (code) => log(`DB Init finished with code ${code}`));


// Helper to run python commands
function runPython(mode, payload) {
    return new Promise((resolve, reject) => {
        const payloadFile = path.join(__dirname, `payload_${Date.now()}.json`);
        
        try {
            fs.writeFileSync(payloadFile, JSON.stringify(payload));
            log(`Created payload file: ${payloadFile} for mode: ${mode}`);
        } catch (e) {
            log(`Failed to write payload file: ${e.message}`, 'ERROR');
            return reject(e);
        }

        const scriptPath = path.join(__dirname, 'content_orchestrator.py');
        log(`Spawning Python: python3 ${scriptPath} --mode ${mode} --payload_file ${payloadFile}`);

        const pythonProcess = spawn('python3', [
            scriptPath,
            '--mode', mode,
            '--payload_file', payloadFile
        ]);

        let stdout = '';
        let stderr = '';

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

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

        pythonProcess.on('close', (code) => {
            // Cleanup payload file
            if (fs.existsSync(payloadFile)) {
                try {
                    fs.unlinkSync(payloadFile);
                } catch(e) {
                    log(`Warning: Could not delete payload file: ${e.message}`, 'WARN');
                }
            }

            if (code !== 0) {
                log(`Python script exited with code ${code}. Stderr: ${stderr}`, 'ERROR');
                return reject(stderr || "Unknown Python Error");
            }

            // Log stderr anyway as it might contain debug info (Python logging often goes to stderr)
            if (stderr) {
                log(`Python Stderr (Debug): ${stderr}`);
            }

            try {
                log(`Python Stdout received (${stdout.length} bytes). Parsing JSON...`);
                const parsed = JSON.parse(stdout);
                resolve(parsed);
            } catch (e) {
                log(`Failed to parse JSON output: ${stdout.substring(0, 200)}...`, 'ERROR');
                reject("Failed to parse Python output: " + stdout);
            }
        });
    });
}

app.post('/api/:mode', async (req, res) => {
    const mode = req.params.mode;
    log(`Incoming POST request for mode: ${mode}`);
    try {
        const result = await runPython(mode, req.body);
        log(`Request for ${mode} completed successfully.`);
        res.json(result);
    } catch (error) {
        log(`Request for ${mode} failed: ${error}`, 'ERROR');
        res.status(500).json({ error: error.toString() });
    }
});

// Serve static assets
if (fs.existsSync(path.join(__dirname, 'dist'))) {
    app.use(express.static(path.join(__dirname, 'dist')));
    app.get('*', (req, res) => {
        res.sendFile(path.join(__dirname, 'dist', 'index.html'));
    });
}

app.listen(port, () => {
    log(`Content Engine Server running on port ${port}`);
});