carthage copy-frameworks conditionally Xcode build step

carthage.copy-frameworks.rb

built_products_dir = ENV["BUILT_PRODUCTS_DIR"]
frameworks_folder_path = ENV["FRAMEWORKS_FOLDER_PATH"]
srcroot = ENV["SRCROOT"]
dest = File.join(built_products_dir, frameworks_folder_path)
platform = ENV["PLATFORM_DISPLAY_NAME"]

carthage_frameworks_dir = File.join(srcroot, 'Carthage', 'Build', platform)
input_file_count = ENV["SCRIPT_INPUT_FILE_COUNT"].to_i

env = {"SCRIPT_INPUT_FILE_COUNT" => "0"}

for n in 0...input_file_count do
  input_file = ENV["SCRIPT_INPUT_FILE_" + n.to_s]
  framework_name = File.basename(input_file)
  destination = File.join(dest, framework_name)
  if File.exists?(destination) && File.mtime(input_file) <= File.mtime(destination)
    puts "#{framework_name} already exists and is not older than the source. Skipping copy."
  else
    puts "Copying #{framework_name}."
    current_count = env["SCRIPT_INPUT_FILE_COUNT"].to_i
    env["SCRIPT_INPUT_FILE_" + current_count.to_s] = input_file
    env["SCRIPT_INPUT_FILE_COUNT"] = (current_count + 1).to_s
  end
end

system(env, "carthage copy-frameworks")