class RuboCop::Cop::Generator

def generate(template)
  format(template, department: badge.department.to_s.gsub('/', '::'),
                   cop_name: badge.cop_name)
end

def generated_source
  generate(SOURCE_TEMPLATE)
end

def generated_spec
  generate(SPEC_TEMPLATE)
end

def initialize(name, output: $stdout)
  @badge = Badge.parse(name)
  @output = output
  return if badge.qualified?
  raise ArgumentError, 'Specify a cop name with Department/Name style'
end

def inject_config(config_file_path: 'config/default.yml',
                  version_added: '<<next>>')
  injector =
    ConfigurationInjector.new(configuration_file_path: config_file_path,
                              badge: badge,
                              version_added: version_added)
  injector.inject do # rubocop:disable Lint/UnexpectedBlockArity
    output.puts(format(CONFIGURATION_ADDED_MESSAGE,
                       configuration_file_path: config_file_path))
  end
end

def inject_require(root_file_path: 'lib/rubocop.rb')
  RequireFileInjector.new(source_path: source_path, root_file_path: root_file_path).inject
end

def snake_case(camel_case_string)
  return 'rspec' if camel_case_string == 'RSpec'
  camel_case_string
    .gsub(%r{([^A-Z/])([A-Z]+)}, '\1_\2')
    .gsub(%r{([A-Z])([A-Z][^A-Z\d/]+)}, '\1_\2')
    .downcase
end

def source_path
  File.join(
    'lib',
    'rubocop',
    'cop',
    snake_case(badge.department.to_s),
    "#{snake_case(badge.cop_name.to_s)}.rb"
  )
end

def spec_path
  File.join(
    'spec',
    'rubocop',
    'cop',
    snake_case(badge.department.to_s),
    "#{snake_case(badge.cop_name.to_s)}_spec.rb"
  )
end

def todo
  <<~TODO
    Do 4 steps:
      1. Modify the description of #{badge} in config/default.yml
      2. Implement your new cop in the generated file!
      3. Commit your new cop with a message such as
         e.g. "Add new `#{badge}` cop"
      4. Run `bundle exec rake changelog:new` to generate a changelog entry
         for your new cop.
  TODO
end

def write_source
  write_unless_file_exists(source_path, generated_source)
end

def write_spec
  write_unless_file_exists(spec_path, generated_spec)
end

def write_unless_file_exists(path, contents)
  if File.exist?(path)
    warn "rake new_cop: #{path} already exists!"
    exit!
  end
  dir = File.dirname(path)
  FileUtils.mkdir_p(dir) unless File.exist?(dir)
  File.write(path, contents)
  output.puts "[create] #{path}"
end