class Telegram::Bot::Client

def self.run(*args, &block)
  new(*args).run(&block)
end

def default_options
  {
    offset: 0,
    timeout: 20,
    logger: NullLogger.new,
    url: 'https://api.telegram.org',
    environment: :production
  }
end

def fetch_updates
  response = api.getUpdates(options)
  return unless response['ok']
  response['result'].each do |data|
    yield handle_update(Types::Update.new(data))
  end
rescue Faraday::TimeoutError, Faraday::ConnectionFailed
  retry
end

def handle_update(update)
  @options[:offset] = update.update_id.next
  message = update.current_message
  log_incoming_message(message)
  message
end

def initialize(token, hash = {})
  @options = default_options.merge(hash)
  @api = Api.new(token, url: options.delete(:url), environment: options.delete(:environment))
  @logger = options.delete(:logger)
end

def listen(&block)
  logger.info('Starting bot')
  running = true
  Signal.trap('INT') { running = false }
  fetch_updates(&block) while running
  exit
end

def log_incoming_message(message)
  uid = message.respond_to?(:from) && message.from ? message.from.id : nil
  logger.info(
    format('Incoming message: text="%<message>s" uid=%<uid>s', message: message, uid: uid)
  )
end

def run
  yield self
end