module Dry::CLI::Banner

def self.arguments(command)
  required_arguments = command.required_arguments
  optional_arguments = command.optional_arguments
  required = required_arguments.map { |arg| arg.name.upcase }.join(" ") if required_arguments.any?
  optional = optional_arguments.map { |arg| "[#{arg.name.upcase}]" }.join(" ") if optional_arguments.any?
  result = [required, optional].compact
  " #{result.join(" ")}" unless result.empty?
end

def self.build_subcommands_list(subcommands)
  subcommands.map do |subcommand_name, subcommand|
    "  #{subcommand_name.ljust(32)}  # #{subcommand.command.description}"
  end.join("\n")
end

def self.call(command, name)
  [
    command_name(name),
    command_name_and_arguments(command, name),
    command_description(command),
    command_subcommands(command),
    command_arguments(command),
    command_options(command),
    command_examples(command, name)
  ].compact.join("\n")
end

def self.command_arguments(command)
  return if command.arguments.empty?
  "\nArguments:\n#{extended_command_arguments(command)}"
end

def self.command_description(command)
  return if command.description.nil?
  "\nDescription:\n  #{command.description}"
end

def self.command_examples(command, name)
  return if command.examples.empty?
  "\nExamples:\n#{command.examples.map { |example| "  #{name} #{example}" }.join("\n")}"
end

def self.command_name(name)
  "Command:\n  #{name}"
end

def self.command_name_and_arguments(command, name)
  usage = "\nUsage:\n  #{name}#{arguments(command)}"
  return usage + " | #{name} SUBCOMMAND" if command.subcommands.any?
  usage
end

def self.command_options(command)
  "\nOptions:\n#{extended_command_options(command)}"
end

def self.command_subcommands(command)
  return if command.subcommands.empty?
  "\nSubcommands:\n#{build_subcommands_list(command.subcommands)}"
end

def self.extended_command_arguments(command)
  command.arguments.map do |argument|
    "  #{argument.name.to_s.upcase.ljust(32)}  # #{"REQUIRED " if argument.required?}#{argument.desc}"
  end.join("\n")
end

def self.extended_command_options(command)
  result = command.options.map do |option|
    name = Inflector.dasherize(option.name)
    name = if option.boolean?
             "[no-]#{name}"
           elsif option.flag?
             name
           elsif option.array?
             "#{name}=VALUE1,VALUE2,.."
           else
             "#{name}=VALUE"
           end
    name = "#{name}, #{option.alias_names.join(", ")}" if option.aliases.any?
    name = "  --#{name.ljust(30)}"
    name = "#{name}  # #{option.desc}"
    name = "#{name}, default: #{option.default.inspect}" unless option.default.nil?
    name
  end
  result << "  --#{"help, -h".ljust(30)}  # Print this help"
  result.join("\n")
end