krautcomputing/tries

require 'tries/version'
require 'gem_config'

module Tries
  include GemConfig::Base

  with_configuration do
    has :on_error, classes: Proc
  end
end

class Integer
  def tries(options = {}, &block)
    attempts          = 1
    exception_classes = Array(options[:on] || StandardError)
    delay             = options[:delay]
    incremental       = options[:incremental]
    condition         = options[:if]

    begin
      return yield
    rescue *exception_classes => exception
      raise exception if condition && !condition.call(exception)
      next_delay = calculate_delay(delay, attempts, incremental) if delay
      [Tries.configuration.on_error, options[:on_error]].compact.each do |on_error_callback|
        on_error_callback.call(exception, attempts, next_delay)
      end
      Kernel.sleep next_delay if delay
      retry if (attempts += 1) <= self
    end

    yield
  end

  private

    def calculate_delay(delay, attempts, incremental)
      return delay unless incremental
      (delay * attempts * 100).round.to_f / 100
    end
end