class RuboCop::ConfigLoaderResolver

def base_configs(path, inherit_from, file)
  inherit_froms = Array(inherit_from).compact.flat_map do |f|
    PathUtil.glob?(f) ? Dir.glob(f) : f
  end
  configs = inherit_froms.map do |f|
    ConfigLoader.load_file(inherited_file(path, f, file))
  end
  configs.compact
end

def determine_inherit_mode(hash, key)
  cop_cfg = hash[key]
  local_inherit = cop_cfg['inherit_mode'] if cop_cfg.is_a?(Hash)
  local_inherit || hash['inherit_mode'] || {}
end

def disabled?(hash, department)
  hash[department].is_a?(Hash) && hash[department]['Enabled'] == false
end

def duplicate_setting?(base_hash, derived_hash, key, inherited_file)
  return false if inherited_file.nil? # Not inheritance resolving merge
  return false if inherited_file.start_with?('..') # Legitimate override
  return false if base_hash[key] == derived_hash[key] # Same value
  return false if remote_file?(inherited_file) # Can't change
  Gem.path.none? { |dir| inherited_file.start_with?(dir) } # Can change?
end

def fix_include_paths(base_config_path, hash, path, key, value)
  return unless File.basename(base_config_path).start_with?('.rubocop')
  base_dir = File.dirname(base_config_path)
  derived_dir = File.dirname(path)
  hash[key]['Include'] = value['Include'].map do |include_path|
    PathUtil.relative_path(File.join(base_dir, include_path), derived_dir)
  end
end

def gem_config_path(gem_name, relative_config_path)
  if defined?(Bundler)
    begin
      gem = Bundler.load.specs[gem_name].first
      gem_path = gem.full_gem_path if gem
    rescue Bundler::GemfileNotFound
      # No Gemfile found. Bundler may be loaded manually
    rescue Bundler::GitError
      # The Gemfile exists but contains an uninstalled git source
    end
  end
  gem_path ||= Gem::Specification.find_by_name(gem_name).gem_dir
  File.join(gem_path, relative_config_path)
rescue Gem::LoadError => e
  raise Gem::LoadError, "Unable to find gem #{gem_name}; is the gem installed? #{e}"
end

def handle_disabled_by_default(config, new_default_configuration)
  department_config = config.to_hash.reject { |cop| cop.include?('/') }
  department_config.each do |dept, dept_params|
    next unless dept_params['Enabled']
    new_default_configuration.each do |cop, params|
      next unless cop.start_with?("#{dept}/")
      # Retain original default configuration for cops in the department.
      params['Enabled'] = ConfigLoader.default_configuration[cop]['Enabled']
    end
  end
  transform(config) do |params|
    { 'Enabled' => true }.merge(params) # Set true if not set.
  end
end

def inherited_file(path, inherit_from, file)
  if remote_file?(inherit_from)
    # A remote configuration, e.g. `inherit_from: http://example.com/rubocop.yml`.
    RemoteConfig.new(inherit_from, File.dirname(path))
  elsif Pathname.new(inherit_from).absolute?
    # An absolute path to a config, e.g. `inherit_from: /Users/me/rubocop.yml`.
    # The path may come from `inherit_gem` option, where a gem name is expanded
    # to an absolute path to that gem.
    print 'Inheriting ' if ConfigLoader.debug?
    inherit_from
  elsif file.is_a?(RemoteConfig)
    # A path relative to a URL, e.g. `inherit_from: configs/default.yml`
    # in a config included with `inherit_from: http://example.com/rubocop.yml`
    file.inherit_from_remote(inherit_from, path)
  else
    # A local relative path, e.g. `inherit_from: default.yml`
    print 'Inheriting ' if ConfigLoader.debug?
    File.expand_path(inherit_from, File.dirname(path))
  end
end

def merge(base_hash, derived_hash, **opts)
  result = base_hash.merge(derived_hash)
  keys_appearing_in_both = base_hash.keys & derived_hash.keys
  keys_appearing_in_both.each do |key|
    if opts[:unset_nil] && derived_hash[key].nil?
      result.delete(key)
    elsif merge_hashes?(base_hash, derived_hash, key)
      result[key] = merge(base_hash[key], derived_hash[key], **opts)
    elsif should_union?(derived_hash, base_hash, opts[:inherit_mode], key)
      result[key] = base_hash[key] | derived_hash[key]
    elsif opts[:debug]
      warn_on_duplicate_setting(base_hash, derived_hash, key, **opts)
    end
  end
  result
end

def merge_hashes?(base_hash, derived_hash, key)
  base_hash[key].is_a?(Hash) && derived_hash[key].is_a?(Hash)
end

def merge_with_default(config, config_file, unset_nil:)
  default_configuration = ConfigLoader.default_configuration
  disabled_by_default = config.for_all_cops['DisabledByDefault']
  enabled_by_default = config.for_all_cops['EnabledByDefault']
  if disabled_by_default || enabled_by_default
    default_configuration = transform(default_configuration) do |params|
      params.merge('Enabled' => !disabled_by_default)
    end
  end
  config = handle_disabled_by_default(config, default_configuration) if disabled_by_default
  override_enabled_for_disabled_departments(default_configuration, config)
  opts = { inherit_mode: config['inherit_mode'] || {}, unset_nil: unset_nil }
  Config.new(merge(default_configuration, config, **opts), config_file)
end

def override_department_setting_for_cops(base_hash, derived_hash)
  derived_hash.each_key do |key|
    next unless key =~ %r{(.*)/.*}
    department = Regexp.last_match(1)
    next unless disabled?(derived_hash, department) || disabled?(base_hash, department)
    # The `override_department` setting for the `Enabled` parameter is an
    # internal setting that's not documented in the manual. It will cause a
    # cop to be enabled later, when logic surrounding enabled/disabled it
    # run, even though its department is disabled.
    derived_hash[key]['Enabled'] = 'override_department' if derived_hash[key]['Enabled']
  end
end

def override_enabled_for_disabled_departments(base_hash, derived_hash)
  cops_to_disable = derived_hash.each_key.with_object([]) do |key, cops|
    next unless disabled?(derived_hash, key)
    cops.concat(base_hash.keys.grep(Regexp.new("^#{key}/")))
  end
  cops_to_disable.each do |cop_name|
    next unless base_hash.dig(cop_name, 'Enabled') == true
    derived_hash.replace(merge({ cop_name => { 'Enabled' => false } }, derived_hash))
  end
end

def remote_file?(uri)
  uri.start_with?('http://', 'https://')
end

def resolve_inheritance(path, hash, file, debug) # rubocop:disable Metrics/MethodLength, Metrics/AbcSize
  inherited_files = Array(hash['inherit_from'])
  base_configs(path, inherited_files, file)
    .each_with_index.reverse_each do |base_config, index|
    override_department_setting_for_cops(base_config, hash)
    override_enabled_for_disabled_departments(base_config, hash)
    base_config.each do |k, v|
      next unless v.is_a?(Hash)
      if hash.key?(k)
        v = merge(v, hash[k],
                  cop_name: k, file: file, debug: debug,
                  inherited_file: inherited_files[index],
                  inherit_mode: determine_inherit_mode(hash, k))
      end
      hash[k] = v
      fix_include_paths(base_config.loaded_path, hash, path, k, v) if v.key?('Include')
    end
  end
end

def resolve_inheritance_from_gems(hash)
  gems = hash.delete('inherit_gem')
  (gems || {}).each_pair do |gem_name, config_path|
    if gem_name == 'rubocop'
      raise ArgumentError, "can't inherit configuration from the rubocop gem"
    end
    hash['inherit_from'] = Array(hash['inherit_from'])
    Array(config_path).reverse_each do |path|
      # Put gem configuration first so local configuration overrides it.
      hash['inherit_from'].unshift gem_config_path(gem_name, path)
    end
  end
end

def resolve_requires(path, hash)
  config_dir = File.dirname(path)
  hash.delete('require').tap do |loaded_features|
    Array(loaded_features).each do |feature|
      FeatureLoader.load(config_directory_path: config_dir, feature: feature)
    end
  end
end

def should_merge?(mode, key)
  mode && mode['merge']&.include?(key)
end

def should_override?(mode, key)
  mode && mode['override']&.include?(key)
end

def should_union?(derived_hash, base_hash, root_mode, key)
  return false unless base_hash[key].is_a?(Array)
  derived_mode = derived_hash['inherit_mode']
  return false if should_override?(derived_mode, key)
  return true if should_merge?(derived_mode, key)
  base_mode = base_hash['inherit_mode']
  return false if should_override?(base_mode, key)
  return true if should_merge?(base_mode, key)
  should_merge?(root_mode, key)
end

def transform(config, &block)
  config.transform_values(&block)
end

def warn_on_duplicate_setting(base_hash, derived_hash, key, **opts)
  return unless duplicate_setting?(base_hash, derived_hash, key, opts[:inherited_file])
  inherit_mode = opts[:inherit_mode]['merge'] || opts[:inherit_mode]['override']
  return if base_hash[key].is_a?(Array) && inherit_mode&.include?(key)
  puts "#{PathUtil.smart_path(opts[:file])}: " \
       "#{opts[:cop_name]}:#{key} overrides " \
       "the same parameter in #{opts[:inherited_file]}"
end