module ActiveSupport::Cache::Strategy::LocalCache

def bypass_local_cache(&block)
  use_temporary_local_cache(nil, &block)
end

def cleanup(options = nil) # :nodoc:
  return super unless cache = local_cache
  cache.clear(options)
  super
end

def clear(options = nil) # :nodoc:
  return super unless cache = local_cache
  cache.clear(options)
  super
end

def decrement(name, amount = 1, **options) # :nodoc:
  return super unless local_cache
  value = bypass_local_cache { super }
  write_cache_value(name, value, raw: true, **options)
  value
end

def delete_entry(key, **)
  local_cache.delete_entry(key) if local_cache
  super
end

def delete_matched(matcher, options = nil) # :nodoc:
  return super unless cache = local_cache
  cache.clear(options)
  super
end

def fetch_multi(*names, &block) # :nodoc:
  return super if local_cache.nil? || names.empty?
  options = names.extract_options!
  options = merged_options(options)
  keys_to_names = names.index_by { |name| normalize_key(name, options) }
  local_entries = local_cache.read_multi_entries(keys_to_names.keys)
  results = local_entries.each_with_object({}) do |(key, value), result|
    # If we recorded a miss in the local cache, `#fetch_multi` will forward
    # that key to the real store, and the entry will be replaced
    # local_cache.delete_entry(key)
    next if value.nil?
    entry = deserialize_entry(value, **options)
    normalized_key = keys_to_names[key]
    if entry.nil?
      result[normalized_key] = nil
    elsif entry.expired? || entry.mismatched?(normalize_version(normalized_key, options))
      local_cache.delete_entry(key)
    else
      result[normalized_key] = entry.value
    end
  end
  if results.size < names.size
    results.merge!(super(*(names - results.keys), options, &block))
  end
  results
end

def increment(name, amount = 1, **options) # :nodoc:
  return super unless local_cache
  value = bypass_local_cache { super }
  write_cache_value(name, value, raw: true, **options)
  value
end

def local_cache
  LocalCacheRegistry.cache_for(local_cache_key)
end

def local_cache_key
  @local_cache_key ||= "#{self.class.name.underscore}_local_cache_#{object_id}".gsub(/[\/-]/, "_").to_sym
end

def middleware
  @middleware ||= Middleware.new(
    "ActiveSupport::Cache::Strategy::LocalCache",
    local_cache_key)
end

def read_multi_entries(names, **options)
  return super unless local_cache
  keys_to_names = names.index_by { |name| normalize_key(name, options) }
  local_entries = local_cache.read_multi_entries(keys_to_names.keys)
  results = local_entries.each_with_object({}) do |(key, value), result|
    next if value.nil? # recorded cache miss
    entry = deserialize_entry(value, **options)
    normalized_key = keys_to_names[key]
    if entry.nil?
      result[normalized_key] = nil
    elsif entry.expired? || entry.mismatched?(normalize_version(normalized_key, options))
      local_cache.delete_entry(key)
    else
      result[normalized_key] = entry.value
    end
  end
  if results.size < names.size
    results.merge!(super(names - results.keys, **options))
  end
  results
end

def read_serialized_entry(key, raw: false, **options)
  if cache = local_cache
    hit = true
    entry = cache.fetch_entry(key) do
      hit = false
      super
    end
    options[:event][:store] = cache.class.name if hit && options[:event]
    entry
  else
    super
  end
end

def use_temporary_local_cache(temporary_cache)
  save_cache = LocalCacheRegistry.cache_for(local_cache_key)
  begin
    LocalCacheRegistry.set_cache_for(local_cache_key, temporary_cache)
    yield
  ensure
    LocalCacheRegistry.set_cache_for(local_cache_key, save_cache)
  end
end

def with_local_cache(&block)
  use_temporary_local_cache(LocalStore.new, &block)
end

def write_cache_value(name, value, **options)
  name = normalize_key(name, options)
  cache = local_cache
  if value
    cache.write_entry(name, serialize_entry(new_entry(value, **options), **options))
  else
    cache.delete_entry(name)
  end
end

def write_serialized_entry(key, payload, **)
  if return_value = super
    local_cache.write_entry(key, payload) if local_cache
  else
    local_cache.delete_entry(key) if local_cache
  end
  return_value
end