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 = 3001; // Node.js Server läuft auf einem anderen Port als React (3000)

// Middleware
app.use(cors()); // Ermöglicht Cross-Origin-Requests von der React-App
app.use(bodyParser.json()); // Parst JSON-Anfragen

// API-Endpunkt für generateSearchStrategy
app.post('/api/generate-search-strategy', async (req, res) => {
    console.log(`[${new Date().toISOString()}] HIT: /api/generate-search-strategy`);
    const { referenceUrl, contextContent } = req.body;

    if (!referenceUrl || !contextContent) {
        console.error('Validation Error: Missing referenceUrl or contextContent.');
        return res.status(400).json({ error: 'Missing referenceUrl or contextContent' });
    }

    const tempContextFilePath = path.join(__dirname, 'tmp', `context_${Date.now()}.md`);
    const tmpDir = path.join(__dirname, 'tmp');
    if (!fs.existsSync(tmpDir)) {
        fs.mkdirSync(tmpDir);
    }

    try {
        fs.writeFileSync(tempContextFilePath, contextContent);
        console.log(`Successfully wrote context to ${tempContextFilePath}`);

        const pythonExecutable = path.join(__dirname, '..', '.venv', 'bin', 'python3');
        const pythonScript = path.join(__dirname, '..', 'market_intel_orchestrator.py');
        const scriptArgs = [pythonScript, '--mode', 'generate_strategy', '--reference_url', referenceUrl, '--context_file', tempContextFilePath];
        
        console.log(`Spawning command: ${pythonExecutable}`);
        console.log(`With arguments: ${JSON.stringify(scriptArgs)}`);

        const pythonProcess = spawn(pythonExecutable, scriptArgs, {
            env: { ...process.env, PYTHONPATH: path.join(__dirname, '..', '.venv', 'lib', 'python3.11', 'site-packages') }
        });

        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(`Python script finished with exit code: ${code}`);
            console.log(`--- STDOUT ---`);
            console.log(pythonOutput);
            console.log(`--- STDERR ---`);
            console.log(pythonError);
            console.log(`----------------`);

            fs.unlinkSync(tempContextFilePath);

            if (code !== 0) {
                console.error(`Python script exited with error.`);
                return res.status(500).json({ error: 'Python script failed', details: pythonError });
            }
            try {
                const result = JSON.parse(pythonOutput);
                res.json(result);
            } catch (parseError) {
                console.error('Failed to parse Python output as JSON:', parseError);
                res.status(500).json({ error: 'Invalid JSON from Python script', rawOutput: pythonOutput, details: pythonError });
            }
        });

        pythonProcess.on('error', (err) => {
            console.error('FATAL: Failed to start python process itself.', err);
            if (fs.existsSync(tempContextFilePath)) {
                fs.unlinkSync(tempContextFilePath);
            }
            res.status(500).json({ error: 'Failed to start Python process', details: err.message });
        });

    } catch (writeError) {
        console.error('Failed to write temporary context file:', writeError);
        res.status(500).json({ error: 'Failed to write temporary file', details: writeError.message });
    }
});

// Start des Servers
app.listen(PORT, () => {
    console.log(`Node.js API Bridge running on http://localhost:${PORT}`);
});