class RuboCop::Cop::Generator

def generate(template)
  format(template, department: badge.department, cop_name: badge.cop_name)
end

def generated_source
  generate(SOURCE_TEMPLATE)
end

def generated_spec
  generate(SPEC_TEMPLATE)
end

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

def inject_require
  RequireFileInjector.new(require_path).inject
end

def require_path
  source_path.sub('lib/', '').sub('.rb', '')
end

def snake_case(camel_case_string)
  camel_case_string
    .gsub(/([^A-Z])([A-Z]+)/, '\1_\2')
    .gsub(/([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.strip_indent
    Files created:
      - #{source_path}
      - #{spec_path}
    Do 3 steps:
      1. Add an entry to the "New features" section in CHANGELOG.md,
         e.g. "Add new `#{badge}` cop. ([@your_id][])"
      2. Add an entry into config/enabled.yml or config/disabled.yml
      3. Implement your new cop in the generated file!
  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)
  raise "#{path} already exists!" if File.exist?(path)
  dir = File.dirname(path)
  FileUtils.mkdir_p(dir) unless File.exist?(dir)
  File.write(path, contents)
end