#!ruby
# frozen_string_literal: true

require_relative "../lib/right_speed/env"
require_relative "../lib/right_speed/server"
require "getoptlong"

module RightSpeed
  module Command
    Options = Struct.new(
      :rackup, :port, :backlog,
      :workers, :worker_type,
      keyword_init: true,
    )

    COMMAND_OPTIONS = [
      ['--config', '-c', GetoptLong::REQUIRED_ARGUMENT],
      ['--port', '-p', GetoptLong::REQUIRED_ARGUMENT],
      ['--backlog', GetoptLong::REQUIRED_ARGUMENT],
      ['--workers', GetoptLong::REQUIRED_ARGUMENT],
      ['--worker-type', GetoptLong::REQUIRED_ARGUMENT],
      ['--help', GetoptLong::NO_ARGUMENT],
    ]

    DEFAULT_RACKUP_PATH = 'config.ru'
    DEFAULT_PORT = Server::DEFAULT_PORT
    DEFAULT_WORKERS = Env.processors
    DEFAULT_WORKER_TYPE = Server::DEFAULT_WORKER_TYPE

    AVAILABLE_WORKER_TYPES = Server::AVAILABLE_WORKER_TYPES.map(&:to_s).join('/')

    def self.show_help(error: false, error_message: nil)
      STDERR.puts(error_message, "\n") if error_message
      STDERR.puts <<~EOS
        Usage: right_speed [options]

        OPTIONS
          --config, -c PATH     The path of the rackup configuration file (default: #{DEFAULT_RACKUP_PATH})
          --port, -p PORT       The port number to listen (default: #{DEFAULT_PORT})
          --backlog NUM         The number of backlog
          --workers NUM         The number of Ractors (default: CPU cores, #{DEFAULT_WORKERS})
          --worker-type TYPE    The type of workers (available: #{AVAILABLE_WORKER_TYPES}, default: #{DEFAULT_WORKER_TYPE})
          --help                Show this message
      EOS
      exit(error ? 1 : 0)
    end

    def self.integer_value(value, name)
      Integer(value)
    rescue
      show_help(error: true, error_message: "#{name} should be an Integer: #{value}")
    end

    def self.parse_command_line_options
      optparse = GetoptLong.new
      optparse.set_options(*COMMAND_OPTIONS)
      options = Options.new(
        rackup: DEFAULT_RACKUP_PATH,
        port: DEFAULT_PORT,
        backlog: nil,
        workers: DEFAULT_WORKERS,
        worker_type: DEFAULT_WORKER_TYPE,
      )
      worker_type = :read
      optparse.each_option do |name, value|
        case name
        when '--config'
          options.rackup = value
        when '--port'
          options.port = integer_value(value, "Port number")
        when '--backlog'
          options.backlog = integer_value(value, "Backlog")
        when '--workers'
          options.workers = integer_value(value, "Workers")
        when '--worker-type'
          options.worker_type = value.to_sym
        when '--help'
          show_help
        else
          show_help(error: true, error_messsage: "Unknown option: #{name}")
        end
      end
      options
    end

    def self.start
      options = parse_command_line_options
      server = begin
                 RightSpeed::Server.new(
                   port: options.port,
                   app: options.rackup,
                   backlog: options.backlog,
                   workers: options.workers,
                   worker_type: options.worker_type,
                 )
               rescue => e
                 show_help(error: true, error_message: "Failed to launch the server, " + e.message)
               end
      server.run
    end
  end
end

RightSpeed::Command.start