hooopo/second_level_cache

# frozen_string_literal: true

module SecondLevelCache
  module ActiveRecord
    module FetchByUniqKey
      def fetch_by_uniq_keys(where_values)
        cache_key = cache_uniq_key(where_values)
        obj_id = SecondLevelCache.cache_store.read(cache_key)

        if obj_id
          record = begin
            find(obj_id)
          rescue
            nil
          end
        end
        return record if record_attributes_equal_where_values?(record, where_values)
        record = where(where_values).first
        if record
          SecondLevelCache.cache_store.write(cache_key, record.id)
          record
        else
          SecondLevelCache.cache_store.delete(cache_key)
          nil
        end
      end

      def fetch_by_uniq_keys!(where_values)
        fetch_by_uniq_keys(where_values) || raise(::ActiveRecord::RecordNotFound)
      end

      def fetch_by_uniq_key(value, uniq_key_name)
        # puts "[Deprecated] will remove in the future,
        # use fetch_by_uniq_keys method instead."
        fetch_by_uniq_keys(uniq_key_name => value)
      end

      def fetch_by_uniq_key!(value, uniq_key_name)
        # puts "[Deprecated] will remove in the future,
        # use fetch_by_uniq_keys! method instead."
        fetch_by_uniq_key(value, uniq_key_name) || raise(::ActiveRecord::RecordNotFound)
      end

      private

      def cache_uniq_key(where_values)
        keys = where_values.collect do |k, v|
          v = Digest::MD5.hexdigest(v) if v.respond_to?(:size) && v.size >= 32
          [k, v].join("_")
        end

        ext_key = keys.join(",")
        "#{SecondLevelCache.configure.cache_key_prefix}/uniq_key_#{name}_#{ext_key}"
      end

      def record_attributes_equal_where_values?(record, where_values)
        # https://api.rubyonrails.org/classes/ActiveRecord/ModelSchema/ClassMethods.html#method-i-type_for_attribute
        where_values.all? { |k, v| record&.read_attribute(k) == type_for_attribute(k).cast(v) }
      end
    end
  end
end