class Standard::MergesSettings

def call(argv, standard_yaml)
  standard_argv, rubocop_argv = separate_argv(argv)
  standard_cli_flags = parse_standard_argv(standard_argv)
  rubocop_cli_flags, lint_paths = RuboCop::Options.new.parse(rubocop_argv)
  Settings.new(
    determine_command(standard_argv),
    merge(standard_yaml, standard_cli_flags, without_banned(rubocop_cli_flags)),
    lint_paths
  )
end

def determine_command(argv)
  if (argv & ["--help", "-h"]).any?
    :help
  elsif (argv & ["--version", "-v"]).any?
    :version
  elsif (argv & ["--verbose-version", "-V"]).any?
    :verbose_version
  elsif (argv & ["--generate-todo"]).any?
    :genignore
  elsif (argv & ["--lsp"]).any?
    :lsp
  else
    :rubocop
  end
end

def merge(standard_yaml, standard_cli_flags, rubocop_cli_flags)
  {
    autocorrect: standard_yaml[:fix],
    safe_autocorrect: true,
    formatters: [[standard_yaml[:format] || "Standard::Formatter", nil]],
    parallel: standard_yaml[:parallel],
    todo_file: standard_yaml[:todo_file],
    todo_ignore_files: standard_yaml[:todo_ignore_files]
  }.merge(standard_cli_flags).merge(rubocop_cli_flags)
end

def parse_standard_argv(argv)
  argv.each_with_object({}) do |arg, cli_flags|
    if arg == "--fix"
      cli_flags[:autocorrect] = true
      cli_flags[:safe_autocorrect] = true
    elsif arg == "--fix-unsafely"
      cli_flags[:autocorrect] = true
      cli_flags[:safe_autocorrect] = false
    elsif arg == "--no-fix"
      cli_flags[:autocorrect] = false
      cli_flags[:safe_autocorrect] = false
    end
  end
end

def separate_argv(argv)
  argv.partition do |flag|
    ["--generate-todo", "--fix", "--fix-unsafely", "--no-fix", "--version", "-v", "--verbose-version", "-V", "--help", "-h", "--lsp"].include?(flag)
  end
end

def without_banned(rubocop_cli_flags)
  rubocop_cli_flags.tap do |flags|
    flags.delete(:config)
  end
end