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

app.use(express.json());

// Health check endpoint
app.get('/ping', (req, res) => {
	res.send('pong');
});

// Main inference endpoint (OpenAI-compatible format)
app.post('/v1/messages', async (req, res) => {
	const { messages } = req.body;
	
	if (!messages || !Array.isArray(messages) || messages.length === 0) {
		return res.status(400).json({
			error: {
				message: 'Invalid request: messages array required'
			}
		});
	}
	
	// Extract the last user message as the prompt
	const lastMessage = messages[messages.length - 1];
	const prompt = lastMessage.content;
	
	console.log('━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━');
	console.log('Request from:', req.ip);
	console.log('Prompt length:', prompt.length, 'chars');
	console.log('Prompt preview:', prompt.substring(0, 150) + '...');
	console.log('━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━');
	
	// Spawn Claude CLI process
	const claude = spawn('claude', [], {
		stdio: ['pipe', 'pipe', 'pipe']
	});
	
	let output = '';
	let errorOutput = '';
	
	claude.stdout.on('data', (data) => {
		output += data.toString();
		process.stdout.write('.');
	});
	
	claude.stderr.on('data', (data) => {
		errorOutput += data.toString();
		console.error('Claude stderr:', data.toString());
	});
	
	claude.on('close', (code) => {
		console.log('\n━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━');
		console.log('Claude exit code:', code);
		console.log('Response length:', output.length, 'chars');
		console.log('━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n');
		
		if (code !== 0 || !output.trim()) {
			return res.status(500).json({
				error: {
					message: 'Claude CLI error',
					details: errorOutput || 'No response from Claude'
				}
			});
		}
		
		// Return OpenAI-compatible response format
		res.json({
			id: 'local-' + Date.now(),
			object: 'chat.completion',
			created: Math.floor(Date.now() / 1000),
			model: 'claude-local',
			choices: [{
				index: 0,
				message: {
					role: 'assistant',
					content: output.trim()
				},
				finish_reason: 'stop'
			}],
			usage: {
				prompt_tokens: 0,
				completion_tokens: 0,
				total_tokens: 0
			}
		});
	});
	
	claude.on('error', (err) => {
		console.error('Failed to spawn Claude CLI:', err);
		res.status(500).json({
			error: {
				message: 'Failed to spawn Claude CLI',
				details: err.message
			}
		});
	});
	
	// Send prompt to Claude after brief pause
	setTimeout(() => {
		claude.stdin.write(prompt + '\n');
		claude.stdin.end();
	}, 100);
});

const PORT = process.env.PORT || 8080;
app.listen(PORT, '0.0.0.0', () => {
	console.log('═══════════════════════════════════════════════════');
	console.log('🚀 Agentic Writer Local Backend Started!');
	console.log('═══════════════════════════════════════════════════');
	console.log(`Local:   http://localhost:${PORT}`);
	console.log(`Network: http://YOUR-IP:${PORT}`);
	console.log('');
	console.log('Plugin Configuration:');
	console.log(`  Base URL: http://YOUR-IP:${PORT}`);
	console.log(`  API Key:  dummy`);
	console.log(`  Model:    claude-local`);
	console.log('');
	console.log('Health check: GET /ping');
	console.log('Inference:    POST /v1/messages');
	console.log('═══════════════════════════════════════════════════');
});