class ERBLint::Linters::FinalNewline

def autocorrect(_processed_source, offense)
  lambda do |corrector|
    if offense.context == :insert
      corrector.insert_after(offense.source_range, "\n")
    else
      corrector.remove_trailing(offense.source_range, offense.source_range.size)
    end
  end
end

def initialize(file_loader, config)
  super
  @new_lines_should_be_present = @config.present?
end

def run(processed_source)
  file_content = processed_source.file_content
  return if file_content.empty?
  match = file_content.match(/(\n+)\z/)
  final_newline = match&.captures&.first || ""
  if @new_lines_should_be_present && final_newline.size != 1
    if final_newline.empty?
      add_offense(
        processed_source.to_source_range(file_content.size...file_content.size),
        "Missing a trailing newline at the end of the file.",
        :insert,
      )
    else
      add_offense(
        processed_source.to_source_range(
          (file_content.size - final_newline.size + 1)...file_content.size,
        ),
        "Remove multiple trailing newline at the end of the file.",
        :remove,
      )
    end
  elsif !@new_lines_should_be_present && !final_newline.empty?
    add_offense(
      processed_source.to_source_range(match.begin(0)...match.end(0)),
      "Remove #{final_newline.size} trailing newline at the end of the file.",
      :remove,
    )
  end
end