require 'virtus'
require 'active_support/core_ext/string/inflections'
require 'active_support/core_ext/hash'
require 'active_model'

# check to see how this works with plugins
Dir[File.expand_path('../state_stores/*.rb', File.dirname(__FILE__))].each do |file|
  require file
end

module Covalence
  class StateStore
    include Virtus.model
    include ActiveModel::Validations

    attribute :params, Hash, :writer => :private
    attribute :backend, Object, :writer => :private

    validate :validate_params_has_name,
      :backend_has_state_store

    def initialize(attributes = {}, *args)
      super
      self.valid?
    end

    def name
      params.fetch('name')
    end

    # :reek:FeatureEnvy
    def params=(params)
      super(params.stringify_keys)
    end

    #TODO: prep different backend for plugins
    # :reek:FeatureEnvy
    def backend=(backend_name)
      super("Covalence::#{backend_name.camelize}".constantize)
    end

    def get_config
      backend::get_state_store(@params)
    end

    private
    def validate_params_has_name
      if !params.has_key?('name')
        errors.add(:base,
                   "Params #{params} missing 'name' parameter for the #{backend} state store",
                   strict: true)
      end
    end

    def backend_has_state_store
      backend_has_no_state_store = !backend.has_state_store? rescue true
      if backend_has_no_state_store
        errors.add(:base,
                   "#{backend} backend module does not support state storage",
                   strict: true)
      end
    end
  end
end