#!/usr/bin/env node
/** CLI entry point for @geepers/chat server mode */

import { createServer } from './server.js';
import { detectProviders, checkOllama } from './detect.js';
import type { DetectedProvider, ServerConfig } from './types.js';
import { exec } from 'node:child_process';
import { platform } from 'node:os';
import net from 'node:net';

// ---- Arg parsing (no deps) ----

function parseArgs(): { port: number; gateway: string | null; noOpen: boolean; host: string } {
  const args = process.argv.slice(2);
  let port = 3456;
  let gateway: string | null = null;
  let noOpen = false;
  let host = '127.0.0.1';

  for (let i = 0; i < args.length; i++) {
    const arg = args[i];
    if (arg === '--port' && args[i + 1]) { port = parseInt(args[++i], 10); }
    else if (arg === '--gateway') {
      gateway = (args[i + 1] && !args[i + 1].startsWith('--'))
        ? args[++i]
        : 'https://api.dr.eamer.dev/v1';
    }
    else if (arg === '--no-open') { noOpen = true; }
    else if (arg === '--host' && args[i + 1]) { host = args[++i]; }
    else if (arg === '--help' || arg === '-h') {
      console.log(`
  @geepers/chat — Multi-provider LLM chat

  Usage: npx @geepers/chat [options]

  Options:
    --port <n>       Port to listen on (default: 3456)
    --host <addr>    Bind address (default: 127.0.0.1)
    --gateway [url]  Use gateway mode (default: https://api.dr.eamer.dev/v1)
    --no-open        Don't open browser automatically
    --help           Show this help

  Environment:
    Set provider API keys to enable direct mode:
      OPENAI_API_KEY, ANTHROPIC_API_KEY, XAI_API_KEY,
      MISTRAL_API_KEY, COHERE_API_KEY, GEMINI_API_KEY,
      PERPLEXITY_API_KEY, GROQ_API_KEY, HF_API_KEY

    Or use gateway mode:
      GATEWAY_API_KEY    Key for the gateway API
`);
      process.exit(0);
    }
  }

  return { port, gateway, noOpen, host };
}

// ---- Port finding ----

function isPortAvailable(port: number, host: string): Promise<boolean> {
  return new Promise(resolve => {
    const server = net.createServer();
    server.once('error', () => resolve(false));
    server.once('listening', () => { server.close(); resolve(true); });
    server.listen(port, host);
  });
}

async function findPort(preferred: number, host: string): Promise<number> {
  for (let p = preferred; p < preferred + 20; p++) {
    if (await isPortAvailable(p, host)) return p;
  }
  return 0; // Let OS pick
}

// ---- Browser open ----

function openBrowser(url: string): void {
  const os = platform();
  const cmd = os === 'darwin' ? 'open' : os === 'win32' ? 'start' : 'xdg-open';
  exec(`${cmd} ${url}`, () => {}); // Ignore errors
}

// ---- Main ----

async function main(): Promise<void> {
  const opts = parseArgs();

  // Detect providers
  const providers: DetectedProvider[] = detectProviders();
  const ollama = await checkOllama(process.env.OLLAMA_HOST);
  if (ollama) providers.push(ollama);

  // Determine mode
  const mode = opts.gateway || providers.length === 0 ? 'gateway' : 'direct';
  const gatewayUrl = opts.gateway || 'https://api.dr.eamer.dev/v1';

  const port = await findPort(opts.port, opts.host);

  const config: ServerConfig = {
    port,
    host: opts.host,
    mode,
    providers,
    gatewayUrl,
    openBrowser: !opts.noOpen,
  };

  const app = createServer(config);

  app.listen(port, opts.host, () => {
    const url = `http://${opts.host === '0.0.0.0' ? 'localhost' : opts.host}:${port}`;

    console.log(`
  \x1b[1m@geepers/chat\x1b[0m

  Mode:      ${mode === 'direct' ? `Direct (${providers.length} provider${providers.length !== 1 ? 's' : ''})` : `Gateway (${gatewayUrl})`}
  Providers: ${providers.length > 0 ? providers.map(p => p.name).join(', ') : 'none (gateway handles routing)'}
  URL:       ${url}

  Press Ctrl+C to stop
`);

    if (config.openBrowser) openBrowser(url);
  });
}

main().catch(err => {
  console.error('Failed to start:', err);
  process.exit(1);
});