class IRB::Command::Help

# File lib/irb/command/help.rb, line 9
def execute(command_name)
  content =
    if command_name.empty?
      help_message
    else
      if command_class = Command.load_command(command_name)
        command_class.help_message || command_class.description
      else
        "Can't find command `#{command_name}`. Please check the command name and try again.\n\n"
      end
    end
  Pager.page_content(content)
end

# File lib/irb/command/help.rb, line 72
def add_category_to_output(category, cmds, output, longest_cmd_name_length)
  output.puts Color.colorize(category, [:BOLD])

  cmds.each do |cmd|
    output.puts "  #{cmd[:display_name].to_s.ljust(longest_cmd_name_length)}    #{cmd[:description]}"
  end

  output.puts
end

# File lib/irb/command/help.rb, line 25
def help_message
  commands_info = IRB::Command.all_commands_info
  helper_methods_info = IRB::HelperMethod.all_helper_methods_info
  commands_grouped_by_categories = commands_info.group_by { |cmd| cmd[:category] }
  commands_grouped_by_categories["Helper methods"] = helper_methods_info

  if irb_context.with_debugger
    # Remove the original "Debugging" category
    commands_grouped_by_categories.delete("Debugging")
  end

  longest_cmd_name_length = commands_info.map { |c| c[:display_name].length }.max

  output = StringIO.new

  help_cmds = commands_grouped_by_categories.delete("Help")
  no_category_cmds = commands_grouped_by_categories.delete("No category")
  aliases = irb_context.instance_variable_get(:@command_aliases).map do |alias_name, target|
    { display_name: alias_name, description: "Alias for `#{target}`" }
  end

  # Display help commands first
  add_category_to_output("Help", help_cmds, output, longest_cmd_name_length)

  # Display the rest of the commands grouped by categories
  commands_grouped_by_categories.each do |category, cmds|
    add_category_to_output(category, cmds, output, longest_cmd_name_length)
  end

  # Display commands without a category
  if no_category_cmds
    add_category_to_output("No category", no_category_cmds, output, longest_cmd_name_length)
  end

  # Display aliases
  add_category_to_output("Aliases", aliases, output, longest_cmd_name_length)

  # Append the debugger help at the end
  if irb_context.with_debugger
    # Add "Debugging (from debug.gem)" category as title
    add_category_to_output("Debugging (from debug.gem)", [], output, longest_cmd_name_length)
    output.puts DEBUGGER__.help
  end

  output.string
end