class RuboCop::Cop::Naming::FileName

def allowed_acronyms
  cop_config['AllowedAcronyms'] || []
end

def bad_filename_allowed?
  ignore_executable_scripts? && processed_source.start_with?('#!')
end

def check_definition_path_hierarchy?
  cop_config['CheckDefinitionPathHierarchy']
end

def defined_struct(node)
  namespace, name = *struct_definition(node)
  s(:const, namespace, name) if name
end

def definition_path_hierarchy_roots
  cop_config['CheckDefinitionPathHierarchyRoots'] || []
end

def expect_matching_definition?
  cop_config['ExpectMatchingDefinition']
end

def filename_good?(basename)
  basename = basename.sub(/^\./, '')
  basename = basename.sub(/\.[^.]+$/, '')
  # special handling for Action Pack Variants file names like
  # some_file.xlsx+mobile.axlsx
  basename = basename.sub('+', '_')
  basename.match?(regex || SNAKE_CASE)
end

def find_class_or_module(node, namespace)
  return nil unless node
  name = namespace.pop
  on_node(%i[class module casgn], node) do |child|
    next unless (const = find_definition(child))
    const_namespace, const_name = *const
    next if name != const_name && !match_acronym?(name, const_name)
    next unless namespace.empty? || match_namespace(child, const_namespace, namespace)
    return node
  end
  nil
end

def find_definition(node)
  node.defined_module || defined_struct(node)
end

def for_bad_filename(file_path)
  basename = File.basename(file_path)
  if filename_good?(basename)
    msg = perform_class_and_module_naming_checks(file_path, basename)
  else
    msg = other_message(basename) unless bad_filename_allowed?
  end
  yield source_range(processed_source.buffer, 1, 0), msg if msg
end

def ignore_executable_scripts?
  cop_config['IgnoreExecutableScripts']
end

def match?(expected)
  expected.empty? || expected == [:Object]
end

def match_acronym?(expected, name)
  expected = expected.to_s
  name = name.to_s
  allowed_acronyms.any? { |acronym| expected.gsub(acronym.capitalize, acronym) == name }
end

def match_namespace(node, namespace, expected)
  match_partial = partial_matcher!(expected)
  match_partial.call(namespace)
  node.each_ancestor(:class, :module, :sclass, :casgn) do |ancestor|
    return false if ancestor.sclass_type?
    match_partial.call(ancestor.defined_module)
  end
  match?(expected)
end

def matching_class?(file_name)
  find_class_or_module(processed_source.ast, to_namespace(file_name))
end

def matching_definition?(file_path)
  find_class_or_module(processed_source.ast, to_namespace(file_path))
end

def no_definition_message(basename, file_path)
  format(MSG_NO_DEFINITION,
         basename: basename,
         namespace: to_namespace(file_path).join('::'))
end

def on_new_investigation
  file_path = processed_source.file_path
  return if config.file_to_exclude?(file_path) || config.allowed_camel_case_file?(file_path)
  for_bad_filename(file_path) { |range, msg| add_offense(range, message: msg) }
end

def other_message(basename)
  if regex
    format(MSG_REGEX, basename: basename, regex: regex)
  else
    format(MSG_SNAKE_CASE, basename: basename)
  end
end

def partial_matcher!(expected)
  lambda do |namespace|
    while namespace
      return match?(expected) if namespace.cbase_type?
      namespace, name = *namespace
      expected.pop if name == expected.last || match_acronym?(expected.last, name)
    end
    false
  end
end

def perform_class_and_module_naming_checks(file_path, basename)
  return unless expect_matching_definition?
  if check_definition_path_hierarchy? && !matching_definition?(file_path)
    msg = no_definition_message(basename, file_path)
  elsif !matching_class?(basename)
    msg = no_definition_message(basename, basename)
  end
  msg
end

def regex
  cop_config['Regex']
end

def to_module_name(basename)
  words = basename.sub(/\..*/, '').split('_')
  words.map(&:capitalize).join.to_sym
end

def to_namespace(path) # rubocop:disable Metrics/AbcSize
  components = Pathname(path).each_filename.to_a
  # To convert a pathname to a Ruby namespace, we need a starting point
  # But RC can be run from any working directory, and can check any path
  # We can't assume that the working directory, or any other, is the
  # "starting point" to build a namespace.
  start = definition_path_hierarchy_roots
  start_index = nil
  # To find the closest namespace root take the path components, and
  # then work through them backwards until we find a candidate. This
  # makes sure we work from the actual root in the case of a path like
  # /home/user/src/project_name/lib.
  components.reverse.each_with_index do |c, i|
    if start.include?(c)
      start_index = components.size - i
      break
    end
  end
  if start_index.nil?
    [to_module_name(components.last)]
  else
    components[start_index..-1].map { |c| to_module_name(c) }
  end
end