/**
 * Keyboard Interactive Handler - Shared state for keyboard-interactive authentication
 * This module provides a centralized storage for keyboard-interactive auth requests
 * used by SSH, SFTP, and Port Forwarding bridges.
 */

// Keyboard-interactive authentication pending requests
// Map of requestId -> { finishCallback, webContentsId, sessionId, createdAt, timeoutId }
const { randomUUID } = require("node:crypto");

const keyboardInteractiveRequests = new Map();

// TTL for abandoned requests (5 minutes)
const REQUEST_TTL_MS = 5 * 60 * 1000;

/**
 * Generate a unique request ID for keyboard-interactive requests
 */
function generateRequestId(prefix = 'ki') {
  return `${prefix}-${randomUUID()}`;
}

/**
 * Store a keyboard-interactive request with TTL cleanup
 */
function storeRequest(requestId, finishCallback, webContentsId, sessionId, sender) {
  // Set up TTL timeout to clean up abandoned requests
  const timeoutId = setTimeout(() => {
    const pending = keyboardInteractiveRequests.get(requestId);
    if (pending) {
      console.warn(`[KeyboardInteractive] Request ${requestId} timed out after ${REQUEST_TTL_MS / 1000}s, cleaning up`);
      keyboardInteractiveRequests.delete(requestId);
      // Call finish with empty responses to abort the authentication
      try {
        pending.finishCallback([]);
      } catch (err) {
        console.warn(`[KeyboardInteractive] Failed to call finishCallback for timed out request:`, err.message);
      }
      notifyCancellation(pending, requestId, "timeout");
    }
  }, REQUEST_TTL_MS);

  keyboardInteractiveRequests.set(requestId, {
    finishCallback,
    webContentsId,
    sessionId,
    sender,
    createdAt: Date.now(),
    timeoutId,
  });
}

/**
 * Handle keyboard-interactive authentication response from renderer
 */
function handleResponse(_event, payload) {
  console.log(`[KeyboardInteractive] handleResponse called`, {
    requestId: payload?.requestId,
    cancelled: Boolean(payload?.cancelled),
    responsesCount: Array.isArray(payload?.responses) ? payload.responses.length : 0,
  });

  const { requestId, responses, cancelled } = payload;
  const pending = keyboardInteractiveRequests.get(requestId);

  console.log(`[KeyboardInteractive] Looking for request ${requestId}, found:`, !!pending);
  console.log(`[KeyboardInteractive] Current pending requests:`, Array.from(keyboardInteractiveRequests.keys()));

  if (!pending) {
    console.warn(`[KeyboardInteractive] No pending request for ${requestId}`);
    return { success: false, error: 'Request not found' };
  }

  if (_event?.sender?.id !== pending.webContentsId) {
    console.warn(`[KeyboardInteractive] Wrong sender for request ${requestId}`);
    return { success: false, error: 'Wrong sender' };
  }

  if (pending.timeoutId) clearTimeout(pending.timeoutId);
  keyboardInteractiveRequests.delete(requestId);

  try {
    if (cancelled) {
      console.log(`[KeyboardInteractive] Auth cancelled for ${requestId}`);
      pending.finishCallback([]); // Empty responses to cancel
    } else {
      console.log(`[KeyboardInteractive] Auth response received for ${requestId}, responses count:`, responses?.length);
      pending.finishCallback(responses);
    }
  } catch (err) {
    console.warn(`[KeyboardInteractive] Failed to deliver response for ${requestId}:`, err?.message);
    notifyCancellation(pending, requestId, "delivery-failed");
    return { success: false, error: "Failed to deliver response" };
  }

  return { success: true };
}

/**
 * Cancel every pending request owned by a session or external operation.
 */
function notifyCancellation(pending, requestId, reason) {
  try {
    if (!pending.sender?.isDestroyed?.()) {
      pending.sender?.send?.("netcatty:keyboard-interactive-cancelled", {
        requestId,
        sessionId: pending.sessionId,
        reason,
      });
    }
  } catch (err) {
    console.warn(`[KeyboardInteractive] Failed to notify cancellation for ${requestId}:`, err.message);
  }
}

function cancelRequestsForSession(sessionId, reason = "cancelled") {
  let cancelled = 0;
  for (const [requestId, pending] of keyboardInteractiveRequests) {
    if (pending.sessionId !== sessionId) continue;
    if (pending.timeoutId) {
      clearTimeout(pending.timeoutId);
    }
    keyboardInteractiveRequests.delete(requestId);
    try {
      pending.finishCallback([]);
    } catch (err) {
      console.warn(`[KeyboardInteractive] Failed to cancel request ${requestId}:`, err.message);
    }
    notifyCancellation(pending, requestId, reason);
    cancelled += 1;
  }
  return cancelled;
}

/**
 * Get the requests map (for debugging/testing)
 */
function getRequests() {
  return keyboardInteractiveRequests;
}

/**
 * Register IPC handler for keyboard-interactive responses
 */
function registerHandler(ipcMain) {
  ipcMain.handle("netcatty:keyboard-interactive:respond", handleResponse);
}

module.exports = {
  generateRequestId,
  storeRequest,
  handleResponse,
  cancelRequestsForSession,
  getRequests,
  registerHandler,
};