/**
 * Permission and system checks
 */

import { $ } from 'bun';
import { logger } from '../utils/logger.js';

/**
 * Check if running as root
 */
export function isRoot(): boolean {
  return process.getuid?.() === 0;
}

/**
 * Check if user has sudo access
 */
export async function hasSudoAccess(): Promise<boolean> {
  try {
    await $`sudo -n true`.quiet();
    return true;
  } catch {
    return false;
  }
}

/**
 * Check if usbip kernel modules are loaded
 */
export async function checkModulesLoaded(): Promise<boolean> {
  try {
    const result = await $`lsmod`.text();
    return result.includes('vhci_hcd') || result.includes('usbip_core');
  } catch {
    return false;
  }
}

/**
 * Create escalation script for installing udev rules
 */
export function generateEscalationScript(): string {
  return `#!/bin/bash
# USB/IP Supervisor - Permission Escalation Script

echo "This script will install udev rules and notification scripts for USB/IP Supervisor"
echo "Root access is required."
echo

# Check if running as root
if [ "$EUID" -ne 0 ]; then
  echo "Please run with sudo:"
  echo "  sudo $0"
  exit 1
fi

# Install udev rules
echo "Installing udev rules..."
bunx @siwats/usbip-supervisor server --install-udev

# Load kernel modules
echo "Loading kernel modules..."
modprobe vhci-hcd
modprobe usbip-core

echo
echo "Installation complete!"
echo "You can now run the supervisor without root access."
`;
}

/**
 * Save escalation script
 */
export async function saveEscalationScript(path: string): Promise<void> {
  const script = generateEscalationScript();
  await Bun.write(path, script);
  await $`chmod +x ${path}`.quiet();
  logger.info(`Saved escalation script to ${path}`);
}

/**
 * Verify system requirements
 */
export async function verifySystemRequirements(): Promise<{
  usbipInstalled: boolean;
  modulesLoaded: boolean;
  hasPermissions: boolean;
}> {
  const checks = {
    usbipInstalled: false,
    modulesLoaded: false,
    hasPermissions: false,
  };

  // Check if usbip is installed
  try {
    await $`which usbip`.quiet();
    checks.usbipInstalled = true;
  } catch {
    logger.error('usbip is not installed. Please install usbip-utils package.');
  }

  // Check if modules are loaded
  checks.modulesLoaded = await checkModulesLoaded();
  if (!checks.modulesLoaded) {
    logger.warn('USBIP kernel modules are not loaded. Will attempt to load them.');
  }

  // Check permissions
  checks.hasPermissions = isRoot() || (await hasSudoAccess());
  if (!checks.hasPermissions) {
    logger.warn('No root/sudo access. Some operations may fail.');
  }

  return checks;
}