const { test } = require('node:test');
const assert = require('node:assert/strict');
const path = require('node:path');
const Module = require('node:module');

// The MCP server closes its Nextcloud client only when a session ends. These tests
// pin the teardown, because without it expired sessions leak sockets until the
// server exhausts its file descriptors and every clinical search fails.
function loadClientWithFakeAxios(calls) {
  const axiosStub = {
    post: async function(url, payload, config) {
      calls.push({ method: 'POST', url, payload, headers: (config || {}).headers || {} });
      return {
        status: 200,
        config: { url },
        headers: { 'mcp-session-id': 'session-' + calls.filter(c => c.payload && c.payload.method === 'initialize').length },
        data: JSON.stringify({ jsonrpc: '2.0', result: { content: [] } })
      };
    },
    delete: async function(url, config) {
      calls.push({ method: 'DELETE', url, headers: (config || {}).headers || {} });
      return { status: 204 };
    },
    get: async function(url) { calls.push({ method: 'GET', url }); return { status: 200, data: {} }; }
  };

  const target = require.resolve('../src/utils/clinicalMcpClient');
  delete require.cache[target];
  const original = Module._load;
  Module._load = function(request, parent, isMain) {
    if (request === 'axios') return axiosStub;
    return original.apply(this, arguments);
  };
  try { return require(target); } finally { Module._load = original; }
}

test('an expired session is closed when it is replaced, not abandoned', async () => {
  const calls = [];
  process.env.CLINICAL_ASSISTANT_MCP_SESSION_TTL_MS = '1';
  const client = loadClientWithFakeAxios(calls);

  await client.semanticSearch('bronchiolitis', { limit: 4 });
  await new Promise(resolve => setTimeout(resolve, 5)); // let the 1ms TTL lapse
  await client.semanticSearch('croup', { limit: 4 });

  const deletes = calls.filter(c => c.method === 'DELETE');
  assert.equal(deletes.length, 1, 'the expired session should be deleted exactly once');
  assert.equal(deletes[0].headers['mcp-session-id'], 'session-1');

  const initializes = calls.filter(c => c.payload && c.payload.method === 'initialize');
  assert.equal(initializes.length, 2, 'a lapsed TTL should open a fresh session');
  delete process.env.CLINICAL_ASSISTANT_MCP_SESSION_TTL_MS;
});

test('a live session is reused and never closed between calls', async () => {
  const calls = [];
  process.env.CLINICAL_ASSISTANT_MCP_SESSION_TTL_MS = String(10 * 60 * 1000);
  const client = loadClientWithFakeAxios(calls);

  await client.semanticSearch('asthma', { limit: 4 });
  await client.semanticSearch('sepsis', { limit: 4 });

  assert.equal(calls.filter(c => c.method === 'DELETE').length, 0,
    'deleting a session still in use would force a re-initialize on every search');
  assert.equal(calls.filter(c => c.payload && c.payload.method === 'initialize').length, 1);
  delete process.env.CLINICAL_ASSISTANT_MCP_SESSION_TTL_MS;
});