/**
 * MCP JSON-RPC response parsing. No Bare imports / no network.
 */

function extractJson(text) {
  const raw = String(text || '').trim();
  if (!raw) throw new Error('empty MCP response');
  if (raw[0] === '{' || raw[0] === '[') {
    return JSON.parse(raw);
  }
  const lines = raw.split('\n');
  for (const line of lines) {
    const t = line.trim();
    if (t.indexOf('data:') === 0) {
      const payload = t.slice(5).trim();
      if (payload && payload !== '[DONE]') return JSON.parse(payload);
    }
  }
  const m = raw.match(/\{[\s\S]*\}/);
  if (!m) throw new Error('MCP response was not JSON');
  return JSON.parse(m[0]);
}

function unwrapResult(body) {
  if (body && body.error) {
    const msg = body.error.message || JSON.stringify(body.error);
    throw new Error(String(msg));
  }
  if (body && Object.prototype.hasOwnProperty.call(body, 'result')) return body.result;
  return body;
}

function normalizeTools(result) {
  const list = result && result.tools ? result.tools : Array.isArray(result) ? result : [];
  return list
    .map((t) => {
      if (!t) return null;
      if (typeof t === 'string') return { name: t, description: '' };
      const name = t.name || (t.function && t.function.name);
      if (!name) return null;
      return {
        name: String(name),
        description: String(t.description || (t.function && t.function.description) || ''),
        inputSchema: t.inputSchema || t.parameters || (t.function && t.function.parameters) || undefined,
      };
    })
    .filter(Boolean);
}

module.exports = { extractJson, unwrapResult, normalizeTools };