/**
 * Client MCP - Streamable HTTP transport (MCP 2025-03-26)
 * La réponse initialize est en SSE, les suivantes aussi.
 */
import http from 'http';

const MCP_HOST = '192.168.1.150';
const MCP_PORT = 9002;

let sessionId = null;
let msgId = 1;

function postMCP(body) {
  return new Promise((resolve, reject) => {
    const payload = JSON.stringify(body);
    const headers = {
      'Content-Type': 'application/json',
      'Content-Length': Buffer.byteLength(payload),
      'Accept': 'application/json, text/event-stream',
    };
    if (sessionId) headers['mcp-session-id'] = sessionId;

    const req = http.request({
      hostname: MCP_HOST, port: MCP_PORT, path: '/mcp', method: 'POST', headers
    }, res => {
      // Récupère session ID depuis header
      if (res.headers['mcp-session-id']) sessionId = res.headers['mcp-session-id'];

      let data = '';
      res.setEncoding('utf8');
      res.on('data', c => data += c);
      res.on('end', () => {
        const ct = res.headers['content-type'] || '';

        if (ct.includes('text/event-stream')) {
          // Parser SSE
          let result = null;
          let error = null;
          for (const line of data.split('\n')) {
            if (line.startsWith('data:')) {
              const raw = line.slice(5).trim();
              if (!raw || raw === '[DONE]') continue;
              try {
                const j = JSON.parse(raw);
                if (j.result !== undefined) result = j.result;
                if (j.error) error = j.error;
              } catch {}
            }
          }
          if (error) reject(new Error(JSON.stringify(error)));
          else resolve(result);
        } else {
          // JSON direct
          try {
            const j = JSON.parse(data);
            if (j.error) reject(new Error(JSON.stringify(j.error)));
            else resolve(j.result ?? j);
          } catch { resolve(data || null); }
        }
      });
    });
    req.on('error', reject);
    req.write(payload);
    req.end();
  });
}

export async function init() {
  await postMCP({
    jsonrpc: '2.0', id: msgId++, method: 'initialize',
    params: { protocolVersion: '2025-03-26', capabilities: {}, clientInfo: { name: 'nox', version: '1.0' } }
  });
  // Notification initialized
  await postMCP({ jsonrpc: '2.0', method: 'notifications/initialized', params: {} }).catch(() => {});
  console.log('✅ MCP Session:', sessionId);
}

export async function toolRaw(name, args = {}) {
  return postMCP({ jsonrpc: '2.0', id: msgId++, method: 'tools/call', params: { name, arguments: args } });
}

export async function tool(name, args = {}) {
  const result = await toolRaw(name, args);
  if (!result) return null;
  if (result.content && result.content[0]) {
    const text = result.content[0].text;
    try { return JSON.parse(text); } catch { return text; }
  }
  return result;
}

export { sessionId };