require 'open3'

module MacOSSystem
  def os_name
    "macOS"
  end

  def cpus
    stdout, stderr, status = Open3.capture3("sysctl -n hw.ncpu")
    stdout.strip.to_i
  end

  def install(packages)
    missing_packages = packages.reject { |pkg| package_installed?(pkg) }

    if missing_packages.empty?
      puts "All packages are already installed."
      return
    end

    pkg_list = missing_packages.join(' ')
    puts "Installing missing packages: #{pkg_list}"

    success = system("brew install #{pkg_list}")

    unless success
      puts "Failed to install some packages."
    end
  end

  def package_installed?(package)
    system("brew list --formula | grep -qx #{package}")
  end

  def uninstall(packages)
    installed_packages = packages.select { |pkg| package_installed?(pkg) }

    if installed_packages.empty?
      puts "None of the specified packages are installed."
      return
    end

    pkg_list = installed_packages.join(' ')
    puts "Uninstalling packages: #{pkg_list}"

    success = system("brew uninstall #{pkg_list}")

    unless success
      puts "Failed to uninstall some packages."
    end
  end
end