# frozen_string_literal: true
require 'ostruct'
module Blacklight
  ##
  # An OpenStruct refinement that converts any hash-keys into
  # additional instances of NestedOpenStructWithHashAccess
  class NestedOpenStructWithHashAccess < OpenStructWithHashAccess
    attr_reader :nested_class
    delegate :default_proc=, to: :to_h

    def initialize(klass, hash = {})
      @nested_class = klass
      value = hash.transform_values do |v|
        if v.is_a? Hash
          nested_class.new(v)
        else
          v
        end
      end

      super value
      set_default_proc!
    end

    ##
    # Add an new key to the object, with a default default
    def << key
      @table[key]
    end

    ##
    # Add a new key/value to the object; if it's a Hash, turn it
    # into another NestedOpenStructWithHashAccess
    def []=(key, value)
      if value.is_a? Hash
        send "#{key}=", nested_class.new(value)
      else
        super
      end
    end

    ##
    # Before serializing, we need to reset the default proc
    # so it can be serialized appropriately
    def marshal_dump
      h = to_h.dup
      h.default = nil

      [nested_class, h]
    end

    ##
    # After deserializing, we need to re-add the default proc
    # to the internal hash
    def marshal_load x
      @nested_class = x.first
      super x.last
      set_default_proc!
    end

    def deep_dup
      self.class.new nested_class, @table.deep_dup
    end

    def select *args, &block
      self.class.new nested_class, to_h.select(*args, &block)
    end

    ##
    # Merge the values of this OpenStruct with another OpenStruct or Hash
    # @param [Hash,#to_h] other_hash
    # @return [OpenStructWithHashAccess] a new instance of an OpenStructWithHashAccess
    def merge other_hash
      self.class.new nested_class, to_h.merge((other_hash if other_hash.is_a? Hash) || other_hash.to_h)
    end

    ##
    # Merge the values of another OpenStruct or Hash into this object
    # @param [Hash,#to_h] other_hash
    # @return [OpenStructWithHashAccess] a new instance of an OpenStructWithHashAccess
    def merge! other_hash
      @table.merge!(nested_class, (other_hash if other_hash.is_a? Hash) || other_hash.to_h)
    end

    ##
    # Override #method_missing from OpenStruct to ensure the default_proc logic
    # gets triggered.
    def method_missing(mid, *args)
      len = args.length

      if len.zero?
        new_ostruct_member(mid)
        @table[mid]
      else
        super
      end
    end

    private

    def set_default_proc!
      self.default_proc = lambda do |hash, key|
        hash[key] = nested_class.new
      end
    end
  end
end