# frozen_string_literal: true

module Plutonium
  module Resource
    # Resource register manages the registration and lookup of resources.
    class Register
      # include Plutonium::Lib::SmartCache

      # Custom error class for frozen register operations
      class FrozenRegisterError < StandardError; end

      def initialize
        @resources = Set.new
        @frozen = false
      end

      # Registers a new resource with the register.
      #
      # @param resource [Class] The resource class to be registered.
      # @raise [FrozenRegisterError] If the register is frozen.
      # @return [void]
      def register(resource)
        raise FrozenRegisterError, "Cannot modify frozen resource register" if @frozen
        unless resource.include?(Plutonium::Resource::Record)
          raise ArgumentError, "#{resource} must include Plutonium::Resource::Record before being registered"
        end

        @resources.add(resource.to_s)
      end

      # Returns an array of all registered resource classes and freezes the register.
      #
      # @return [Array<Class>] An array of registered resource classes.
      def resources
        freeze
        @resources.map(&:constantize)
      end
      # memoize_unless_reloading :resources

      # Returns a hash mapping route keys to their corresponding resource classes.
      # This method will freeze the register if it hasn't been frozen already.
      #
      # @return [Hash{Symbol => Class}] A hash where keys are route keys and values are resource classes.
      def route_key_lookup
        freeze
        resources.to_h do |resource|
          [resource.model_name.singular_route_key.to_sym, resource]
        end
      end
      # memoize_unless_reloading :route_key_lookup

      # Clears all registered resources and invalidates the cache.
      #
      # @return [void]
      def clear
        @resources.clear
        @frozen = false
        invalidate_cache
      end

      # Checks if the register is frozen.
      #
      # @return [Boolean] True if the register is frozen, false otherwise.
      def frozen?
        @frozen
      end

      private

      # Freezes the register
      #
      # @return [Boolean] Always returns true
      def freeze
        @frozen ||= true
      end

      # Invalidates the memoization cache
      #
      # @return [void]
      def invalidate_cache
        # flush_smart_cache
      end
    end
  end
end