# frozen_string_literal: true

module Toys
  module StandardMiddleware
    ##
    # This middleware handles the case of a usage error. If a usage error, such
    # as an unrecognized flag or an unfulfilled required argument, is detected,
    # this middleware intercepts execution and displays the error along with
    # the short help string, and terminates execution with an error code.
    #
    class HandleUsageErrors
      ##
      # Exit code for usage error. (2 by convention)
      # @return [Integer]
      #
      USAGE_ERROR_EXIT_CODE = 2

      ##
      # Create a HandleUsageErrors middleware.
      #
      # @param exit_code [Integer] The exit code to return if a usage error
      #     occurs. Default is {USAGE_ERROR_EXIT_CODE}.
      # @param stream [IO] Output stream to write to. Default is stderr.
      # @param styled_output [Boolean,nil] Cause the tool to display help text
      #     with ansi styles. If `nil`, display styles if the output stream is
      #     a tty. Default is `nil`.
      #
      def initialize(exit_code: nil, stream: $stderr, styled_output: nil)
        @exit_code = exit_code || USAGE_ERROR_EXIT_CODE
        @stream = stream
        @styled_output = styled_output
      end

      ##
      # Intercept and handle usage errors during execution.
      # @private
      #
      def run(context)
        yield
      rescue ArgParsingError => e
        require "toys/utils/terminal"
        require "toys/utils/help_text"
        help_text = Utils::HelpText.from_context(context)
        terminal = Utils::Terminal.new(output: @stream, styled: @styled_output)
        terminal.puts(e.usage_errors.join("\n"), :bright_red, :bold)
        terminal.puts("")
        terminal.puts(help_text.usage_string(wrap_width: terminal.width))
        Context.exit(@exit_code)
      end
    end
  end
end