/**
 * Native messaging port lifecycle: connect to the native host, reconnect with
 * exponential backoff on disconnect, send promise-based requests with timeout,
 * and dispatch incoming responses and events to subscribers.
 * Depends on: state.js, logs.js, proxy.js
 */

const HOST_NAME = 'com.holesail.browser';
const MAX_RECONNECT_DELAY = 30000;
const INITIAL_RECONNECT_DELAY = 100;
const REQUEST_TIMEOUT_MS = 30000;

let port = null;
let reconnectDelay = INITIAL_RECONNECT_DELAY;
let reconnectTimer = null;
const _retryTimers = [];

// Pending requests: id -> { resolve, reject }
const pending = new Map();

// Tabs that have subscribed to native host events (content script registered)
const subscribedTabs = new Set();

/**
 * Send a message to the native host and return a Promise that resolves with the response payload.
 * Rejects if the port is not connected, if the request times out (30 s), or if the
 * response contains an error field.
 * @param {object} msg - Message object; must include a `type` field.
 * @returns {Promise<object>} The response payload from the native host.
 */
function send(msg) {
  const id = msg.id || `req_${Date.now()}_${Math.random().toString(36).slice(2)}`;
  msg.id = id;
  debugLog('send: id=', id, 'type=', msg.type, 'payload=', msg.payload && JSON.stringify(msg.payload));
  debugLog('Sending to native:', msg.type, msg.payload?.swarmId || '', msg.payload?.connId || '');
  return new Promise((resolve, reject) => {
    if (!port) {
      debugLog('send: no port, rejecting');
      reject(new Error('Native host not connected'));
      return;
    }
    const timeoutId = setTimeout(() => {
      if (pending.has(id)) {
        pending.delete(id);
        debugLog('send: timeout for id=', id, 'type=', msg.type);
        reject(new Error('Request timed out: ' + msg.type));
      }
    }, REQUEST_TIMEOUT_MS);
    pending.set(id, {
      resolve: (v) => { clearTimeout(timeoutId); resolve(v); },
      reject:  (e) => { clearTimeout(timeoutId); reject(e); }
    });
    try {
      port.postMessage(msg);
    } catch (e) {
      pending.delete(id);
      clearTimeout(timeoutId);
      debugLog('send: postMessage threw', e.message);
      reject(e);
    }
  });
}

function retryGetStateForConnectProxy(delaySeconds, attempt = 0) {
  const maxAttempts = 3;
  if (attempt >= maxAttempts || !port) return;
  const delayMs = delaySeconds * (attempt + 1) * 1000;
  const timerId = setTimeout(() => {
    const idx = _retryTimers.indexOf(timerId);
    if (idx !== -1) _retryTimers.splice(idx, 1);
    if (!port) return;
    send({ type: 'getState', payload: {} })
      .then((payload) => {
        if (payload && payload.ok && payload.connectProxyPort != null) {
          extensionState.connectProxyPort = payload.connectProxyPort;
          extensionState.proxyPort = payload.proxyPort ?? null;
          extensionState.virtualHosts = payload.virtualHosts || extensionState.virtualHosts;
          applyPAC(getActiveTlds(extensionState.virtualHosts));
        } else if (payload && payload.ok && attempt + 1 < maxAttempts) {
          retryGetStateForConnectProxy(delaySeconds, attempt + 1);
        }
      })
      .catch(() => {});
  }, delayMs);
  _retryTimers.push(timerId);
}

/**
 * Schedule a reconnect attempt after the current backoff delay.
 * Doubles the delay on each call, capped at MAX_RECONNECT_DELAY.
 * No-op if a reconnect is already scheduled.
 */
function scheduleReconnect() {
  if (reconnectTimer) return;
  reconnectTimer = setTimeout(() => {
    reconnectTimer = null;
    connect();
    reconnectDelay = Math.min(reconnectDelay * 2, MAX_RECONNECT_DELAY);
  }, reconnectDelay);
}

/**
 * Open the native messaging port, fetch initial state, apply the PAC proxy,
 * and wire up message and disconnect listeners.
 * On disconnect: rejects all pending requests, clears the PAC, and schedules a reconnect.
 */
function connect() {
  debugLog('connect: attempting connectNative', HOST_NAME);
  try {
    port = browser.runtime.connectNative(HOST_NAME);
    log('Connected to native host');
    debugLog('connect: connected, fetching getState then apply/clear PAC');
    send({ type: 'getState', payload: {} })
      .then((payload) => {
        if (payload && payload.ok) {
          extensionState.proxyPort = payload.proxyPort ?? null;
          extensionState.connectProxyPort = payload.connectProxyPort ?? null;
          extensionState.virtualHosts = payload.virtualHosts || [];
          if (payload.settings && typeof payload.settings.notifyOnDisconnect === 'boolean') {
            notifyOnDisconnect = payload.settings.notifyOnDisconnect;
          }
          if (payload.settings && typeof payload.settings.notifyOnTunnelError === 'boolean') {
            notifyOnTunnelError = payload.settings.notifyOnTunnelError;
          }
          applyPAC(getActiveTlds(extensionState.virtualHosts));
          if (extensionState.connectProxyPort == null) retryGetStateForConnectProxy(2);
        } else {
          applyPAC();
        }
      })
      .catch(() => applyPAC());
  } catch (e) {
    log('connectNative failed:', e);
    debugLog('connect: failed', e.message, e.stack);
    scheduleReconnect();
    return;
  }

  reconnectDelay = INITIAL_RECONNECT_DELAY;

  port.onMessage.addListener((msg) => {
    debugLog('onMessage: full msg=', JSON.stringify(msg));
    debugLog('Received from native:', msg.type, msg.event || '');

    if (msg.type === 'event') {
      const payload = msg.payload || {};
      if (msg.event === 'connection') {
        const connId = payload.connId;
        const swarmId = payload.swarmId;
        const peerInfo = payload.peerInfo || {};
        log('Connection established:', connId, 'peer:', peerInfo.publicKey?.slice(0, 8));
        activeConnections.set(connId, {
          connId,
          swarmId,
          peerKey: peerInfo.publicKey || '',
          createdAt: Date.now()
        });
        updateExtensionState();
      } else if (msg.event === 'error') {
        const connId = payload.connId;
        const errorMsg = payload.message || 'Unknown error';
        log('Connection ERROR:', connId, errorMsg);
        activeConnections.delete(connId);
        updateExtensionState();
      } else if (msg.event === 'end') {
        const connId = payload.connId;
        log('Connection ended:', connId);
        activeConnections.delete(connId);
        updateExtensionState();
      }
    }

    if (msg.type === 'response' && msg.id != null) {
      debugLog('onMessage: response id=', msg.id, 'payloadKeys=', msg.payload && Object.keys(msg.payload), 'payload=', msg.payload && JSON.stringify(msg.payload).slice(0, 300));
      const p = pending.get(msg.id);
      if (p) {
        pending.delete(msg.id);
        if (msg.payload && msg.payload.error) {
          p.reject(new Error(msg.payload.error));
        } else {
          p.resolve(msg.payload);
        }
      } else {
        debugLog('onMessage: response id=', msg.id, 'no pending handler');
      }
      return;
    }
    if (msg.type === 'event') {
      const p = msg.payload || {};
      const eventSwarmId = p.swarmId;
      const isTunnelEvent = msg.event === 'tunnelReady' || msg.event === 'tunnelClosed' || msg.event === 'tunnelError';
      if (isTunnelEvent) {
        log('Broadcasting event to tabs:', msg.event, 'hostname:', p.hostname);
      } else {
        log('Broadcasting event to tabs:', msg.event, 'connId:', p.connId, 'swarmId:', eventSwarmId);
      }
      if (eventSwarmId != null) {
        for (const [tabId, swarmIds] of tabSwarms) {
          if (swarmIds.has(eventSwarmId)) {
            browser.tabs.sendMessage(tabId, { type: 'holesail-event', payload: msg }).catch(() => {});
          }
        }
      }
      if (isTunnelEvent) {
        for (const tabId of subscribedTabs) {
          browser.tabs.sendMessage(tabId, { type: 'holesail-event', payload: msg }).catch(() => {});
        }
        if (msg.event === 'tunnelError' && notifyOnTunnelError && browser.notifications) {
          const label = p.hostname || p.label || p.swarmId || 'tunnel';
          const errMsg = p.error || p.message || 'Tunnel error';
          browser.notifications.create('holesail-tunnel-error-' + Date.now(), {
            type: 'basic',
            title: 'Holesail — Tunnel Error',
            message: label + ': ' + errMsg,
            iconUrl: browser.runtime.getURL('icons/48.png'),
          }).catch(() => {});
        }
      }
    }
  });

  port.onDisconnect.addListener(() => {
    // Reading lastError suppresses the "Unchecked runtime.lastError: Native host has exited"
    // console error that Chrome logs when the host process exits unexpectedly.
    const disconnectReason = browser.runtime.lastError?.message || null;
    if (disconnectReason) {
      debugLog('onDisconnect reason:', disconnectReason);
    }
    log('Native host disconnected');
    extensionState.hostConnected = false;
    activeConnections.clear();
    updateExtensionState();
    clearProxy();
    port = null;
    for (const t of _retryTimers) clearTimeout(t);
    _retryTimers.length = 0;
    if (notifyOnDisconnect && browser.notifications) {
      browser.notifications.create('holesail-host-disconnect', {
        type: 'basic',
        title: 'Holesail Browser',
        message: 'Native host disconnected.',
        iconUrl: browser.runtime.getURL('icons/48.png'),
      }).catch(() => {});
    }
    const err = new Error('Native host disconnected');
    for (const [id, p] of pending) {
      p.reject(err);
    }
    pending.clear();
    for (const tabId of subscribedTabs) {
      browser.tabs.sendMessage(tabId, { type: 'holesail-host-disconnect' }).catch(() => {});
    }
    scheduleReconnect();
  });
}