memory.rb

require 'byebug'
require 'active_support/inflector'
module Sequares
  module Store
    class Memory < Base
      class << self
        def cache_key_for(klass, id)
          inst = klass.with_history(id, [])
          "#{inst.uri}|#{histories}"
        end
      end
      attr_accessor :histories, :locks
      def initialize
        @histories = Hash.new { |hash, key| hash[key] = [] }
        @locks = Hash.new { |hash, key| hash[key] = Mutex.new }
      end

      def filter_events(*klasses)
        events = Hash.new
        # NOTE: look into https://ruby-doc.org/core-2.0.0/Enumerator/Lazy.html
        @histories.each do |key, value|
          value.each do |event|
            key_split = key.split('|')
            klass = ActiveSupport::Inflector.classify(key_split.first).constantize.new(key_split.last)
            events[klass] = event
          end
        end
        events.sort do |a, b|
          a.last.occurred_at <=> b.last.occurred_at
        end.bsearch do |key, value|
          klasses.flatten.any? do |klass|
            value.is_a?(klass) || value.class.to_s.split("::").first.eql?(klass.to_s)
          end
        end
      end

      def cache_key_for(klass, id)
        inst = klass.with_history(id, [])
        [inst.uri, histories[inst.uri].length].join('#')
      end

      def save_history_for_aggregate(obj)
        histories[obj.uri] = obj.history
      end

      def fetch_history_for_aggregate(obj)
        histories[obj.uri]
      end

      def lock(obj)
        raise ::Sequares::Entity::AlreadyLocked unless locks[obj.uri].try_lock
      end

      def unlock(obj)
        locks[obj.uri].unlock
      end
    end
  end
end