class Byebug::HelpCommand

def self.description
  <<-DESCRIPTION
    h[elp][ <cmd>[ <subcmd>]]
    #{short_description}
    help                -- prints a summary of all commands
    help <cmd>          -- prints help on command <cmd>
    help <cmd> <subcmd> -- prints help on <cmd>'s subcommand <subcmd>
  DESCRIPTION
end

def self.regexp
  /^\s* h(?:elp)? (?:\s+(\S+))? (?:\s+(\S+))? \s*$/x
end

def self.short_description
  "Helps you using byebug"
end

def command
  @command ||= processor.command_list.match(@match[1])
end

def execute
  return help_for_all unless @match[1]
  return help_for(@match[1], command) unless @match[2]
  help_for(@match[2], subcommand)
end

def help_for(input, cmd)
  raise CommandNotFound.new(input, command) unless cmd
  puts(cmd.help)
end

def help_for_all
  puts(processor.command_list.to_s)
end

def subcommand
  return unless command
  @subcommand ||= command.subcommand_list.match(@match[2])
end