class ChefCLI::Command::GeneratorCommands::GeneratorGenerator

def check_for_conflicting_dir(path)
  conflicting_subdir_path = File.join(path, "code_generator")
  if File.exist?(path) &&
      File.directory?(path) &&
      File.exist?(conflicting_subdir_path)
    ui.err("ERROR: file or directory #{conflicting_subdir_path} exists.")
    true
  else
    false
  end
end

def check_for_conflicting_file(path)
  if File.exist?(path) && !File.directory?(path)
    ui.err("ERROR: #{path} exists and is not a directory.")
    true
  else
    false
  end
end

def check_for_missing_parent_dir(path)
  parent = File.dirname(path)
  if !File.exist?(parent)
    ui.err("ERROR: enclosing directory #{parent} does not exist.")
    true
  else
    false
  end
end

def conflicting_file_exists?(path)
  File.exist?(path) && File.file?(path)
end

def cookbook_name
  if custom_cookbook_name?
    File.basename(destination_dir)
  else
    "code_generator"
  end
end

def created_cookbook_path
  if custom_cookbook_name?
    destination_dir
  else
    File.join(destination_dir, "code_generator")
  end
end

def custom_cookbook_name?
  @custom_cookbook_name
end

def initialize(*args)
  super
  @destination_dir = nil
  @ui = UI.new
  @custom_cookbook_name = false
end

def metadata_rb
  <<~METADATA
    name             File.basename(File.dirname(__FILE__))
    description      'Custom code generator cookbook for use with #{ChefCLI::Dist::PRODUCT}'
    version          '0.1.0'
  METADATA
end

def run
  return 1 unless verify_params!
  FileUtils.cp_r(source, destination_dir)
  update_metadata_rb
  ui.msg("Copied built-in generator cookbook to #{created_cookbook_path}")
  ui.msg("Add the following to your config file to enable it:")
  ui.msg("  chefcli.generator_cookbook \"#{created_cookbook_path}\"")
  0
end

def set_destination_dir_from_args(given_path)
  path = File.expand_path(given_path)
  if check_for_conflicting_dir(path) ||
      check_for_conflicting_file(path) ||
      check_for_missing_parent_dir(path)
    false
  else
    @destination_dir = File.expand_path(path)
    @custom_cookbook_name = !File.exist?(destination_dir)
    true
  end
end

def source
  # Hard-coded to the built-in generator, because otherwise setting
  # chefcli.generator_cookbook would make this command copy the custom
  # generator, but that doesn't make sense because the user can easily
  # do that anyway.
  File.expand_path("../../skeletons/code_generator", __dir__)
end

def update_metadata_rb
  File.open(File.join(created_cookbook_path, "metadata.rb"), "w+") do |f|
    f.print(metadata_rb)
  end
end

def verify_params!
  case params.size
  when 0
    @destination_dir = Dir.pwd
    true
  when 1
    set_destination_dir_from_args(params.first)
  else
    ui.err("ERROR: Too many arguments.")
    ui.err(opt_parser)
    false
  end
end