/**
 * Proxy startup and persisted tunnel restore.
 * Starts the HTTPS and CONNECT proxies after loading persisted settings,
 * then asynchronously restores all tunnels from state.json.
 */

const { log, debugLog } = require('./logger.js');

const PROXY_PORT = 8443;
const CONNECT_PROXY_PORT = 8442;

let proxiesReadyPromise = null;
let tunnelsRestoredPromise = null;

/**
 * Re-start all tunnels that were persisted in state.json.
 * Runs after the proxies are ready so tunnels have a working backend to connect through.
 * Logs per-type success/failure counts but never throws — failures are non-fatal.
 * @param {object} holesailManager - The holesail manager module.
 * @param {object} restored - The persisted state object returned by `holesailManager.restorePersistedState()`.
 * @returns {Promise<void>}
 */
async function restorePersistedTunnels(holesailManager, restored) {
  try {
    debugLog('restorePersistedTunnels: starting');
    const { servers: savedServers, virtualHosts: savedVhosts, serviceTunnels: savedServiceTunnels } = restored;
    log('Restore: loaded', savedServers.length, 'servers,', savedVhosts.length, 'virtual hosts,', savedServiceTunnels.length, 'service tunnels');
    let serverOk = 0, serverFail = 0;
    for (const s of savedServers) {
      const result = await holesailManager.startServer({
        serverId: s.id,
        port: s.port,
        host: s.host || '127.0.0.1',
        secure: s.secure !== false,
        udp: s.udp === true,
        label: s.label || ''
      });
      if (result.ok) serverOk++; else serverFail++;
    }
    let vhostOk = 0, vhostFail = 0;
    for (const v of savedVhosts) {
      const result = await holesailManager.setVirtualHost({ hostname: v.hostname, hsUrl: v.hsUrl, useTls: v.useTls === true });
      if (result.ok) vhostOk++; else vhostFail++;
    }
    let svcOk = 0, svcFail = 0;
    for (const t of savedServiceTunnels) {
      const result = await holesailManager.startServiceTunnel({ tunnelId: t.id, label: t.label, hsUrl: t.hsUrl, localPort: t.localPort });
      if (result.ok) svcOk++; else svcFail++;
    }
    if (savedServers.length || savedVhosts.length || savedServiceTunnels.length) {
      log('Restored on startup: servers', serverOk + '/' + savedServers.length, 'virtual hosts', vhostOk + '/' + savedVhosts.length, 'service tunnels', svcOk + '/' + savedServiceTunnels.length);
      if (serverFail || vhostFail || svcFail) log('Restore failures: servers', serverFail, 'virtual hosts', vhostFail, 'service tunnels', svcFail);
    }
  } catch (e) {
    log('Restore persisted tunnels failed:', e.message);
  }
}

/**
 * Kick off the async startup sequence: restore settings, start the CA, start both
 * proxies, then begin restoring persisted tunnels in the background.
 * Sets `proxiesReadyPromise` which resolves once the proxies are up (or have failed).
 * Sets `tunnelsRestoredPromise` which resolves once all tunnels have been re-started.
 * @param {object} holesailManager
 * @param {object} certificateAuthority
 * @param {object} httpsProxy
 * @param {object} connectProxy
 */
function initStartup(holesailManager, certificateAuthority, httpsProxy, connectProxy) {
  if (typeof setImmediate !== 'function') return;

  proxiesReadyPromise = new Promise((resolve) => {
    setImmediate(async () => {
      try {
        const restored = holesailManager.restorePersistedState();
        const savedProxyPort = (restored.settings && restored.settings.proxyPort) || PROXY_PORT;
        const savedConnectPort = (restored.settings && restored.settings.connectProxyPort) || CONNECT_PROXY_PORT;

        try {
          await certificateAuthority.caReady;
        } catch (e) {
          log('CA generation failed:', e.message, '— HTTPS proxy may not work correctly');
        }

        try {
          await new Promise((res, rej) => {
            httpsProxy.start(savedProxyPort, certificateAuthority, (err) => {
              if (err) return rej(err);
              res();
            });
          });
          log('HTTPS proxy ready on port', savedProxyPort);
        } catch (e) {
          log('HTTPS proxy startup failed:', e.message);
        }

        try {
          await new Promise((res, rej) => {
            const timeout = setTimeout(() => {
              rej(new Error('CONNECT proxy listen timed out after 5s'));
            }, 5000);
            connectProxy.start(savedConnectPort, savedProxyPort, (err) => {
              clearTimeout(timeout);
              if (err) return rej(err);
              res();
            });
          });
          log('CONNECT proxy ready on port', savedConnectPort);
        } catch (e) {
          log('CONNECT proxy startup failed:', e.message);
        }

        log('Proxies startup complete: HTTPS', savedProxyPort, 'CONNECT', connectProxy.getPort() ?? 'FAILED');

        // Assign tunnelsRestoredPromise BEFORE resolving proxiesReadyPromise so
        // that any getState call awaiting proxiesReadyPromise immediately sees the
        // non-null promise rather than the one-microtask window where it is null.
        tunnelsRestoredPromise = restorePersistedTunnels(holesailManager, restored).catch((e) => log('Restore tunnels failed:', e.message));
      } catch (e) {
        log('Unexpected startup error:', e.message);
      } finally {
        resolve();
      }
    });
  });
}

/** @returns {Promise<void>|null} Resolves when both proxies have started (or failed). */
function getProxiesReadyPromise() { return proxiesReadyPromise; }
/** @returns {Promise<void>|null} Resolves when all persisted tunnels have been re-started. */
function getTunnelsRestoredPromise() { return tunnelsRestoredPromise; }
/**
 * Override the tunnels-restored promise (used by message-router to assign it
 * before proxiesReadyPromise resolves, avoiding a one-microtask null window).
 * @param {Promise<void>} p
 */
function setTunnelsRestoredPromise(p) { tunnelsRestoredPromise = p; }

module.exports = {
  initStartup,
  restorePersistedTunnels,
  getProxiesReadyPromise,
  getTunnelsRestoredPromise,
  setTunnelsRestoredPromise
};