// perm-mcp — serveur MCP stdio minimal exposant l'outil `approve` utilisé par
// `claude --permission-prompt-tool mcp__adminka__approve`. Chaque demande de
// permission est relayée au backend admin-ka (long-poll HTTP local) qui la
// transforme en carte Autoriser/Refuser dans le chat.
import readline from 'node:readline';
import dns from 'node:dns';

const PERM_URL = process.env.ADMIN_KA_PERM_URL || 'http://127.0.0.1:3300/internal/perm';
const PERM_TOKEN = process.env.ADMIN_KA_PERM_TOKEN || '';

// fetch (undici) échoue sur les noms Bonjour .local qui résolvent en IPv6
// link-local — on force la résolution IPv4 avant l'appel.
async function resolvedPermUrl() {
  const u = new URL(PERM_URL);
  if (/^\d+\.\d+\.\d+\.\d+$/.test(u.hostname) || u.hostname === 'localhost') return PERM_URL;
  const { address } = await dns.promises.lookup(u.hostname, { family: 4 });
  u.hostname = address;
  return u.toString();
}

const rl = readline.createInterface({ input: process.stdin });

function send(obj) {
  process.stdout.write(JSON.stringify(obj) + '\n');
}

rl.on('line', async (line) => {
  line = line.trim();
  if (!line) return;
  let msg;
  try { msg = JSON.parse(line); } catch { return; }
  const { id, method, params } = msg;
  if (method === 'initialize') {
    send({
      jsonrpc: '2.0', id,
      result: {
        protocolVersion: (params && params.protocolVersion) || '2024-11-05',
        capabilities: { tools: {} },
        serverInfo: { name: 'adminka', version: '1.0.0' },
      },
    });
    return;
  }
  if (method === 'notifications/initialized') return;
  if (method === 'ping') { send({ jsonrpc: '2.0', id, result: {} }); return; }
  if (method === 'tools/list') {
    send({
      jsonrpc: '2.0', id,
      result: {
        tools: [{
          name: 'approve',
          description: 'Demande de permission relayée à administration-ka.com',
          inputSchema: {
            type: 'object',
            properties: {
              tool_name: { type: 'string' },
              input: { type: 'object' },
              tool_use_id: { type: 'string' },
            },
            required: ['tool_name', 'input'],
          },
        }],
      },
    });
    return;
  }
  if (method === 'tools/call' && params && params.name === 'approve') {
    const args = params.arguments || {};
    let decision;
    try {
      const url = await resolvedPermUrl();
      const resp = await fetch(url, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ token: PERM_TOKEN, tool_name: args.tool_name, input: args.input, tool_use_id: args.tool_use_id }),
      });
      decision = await resp.json();
      if (decision.error) decision = { behavior: 'deny', message: 'Erreur backend: ' + decision.error };
    } catch (e) {
      decision = { behavior: 'deny', message: 'Backend admin-ka injoignable: ' + e.message };
    }
    send({
      jsonrpc: '2.0', id,
      result: { content: [{ type: 'text', text: JSON.stringify(decision) }] },
    });
    return;
  }
  if (id !== undefined) {
    send({ jsonrpc: '2.0', id, error: { code: -32601, message: 'method not found: ' + method } });
  }
});