class HTTPX::Plugins::ResponseCache::Store

def cache(request, response)
  return unless ResponseCache.cacheable_request?(request) && ResponseCache.cacheable_response?(response)
  responses = (@store[request.response_cache_key] ||= [])
  responses.reject!(&method(:match_by_vary?).curry(2)[request])
  responses << response
end

def cached?(request)
  lookup(request)
end

def initialize
  @store = {}
end

def lookup(request)
  responses = @store[request.response_cache_key]
  return unless responses
  response = responses.find(&method(:match_by_vary?).curry(2)[request])
  return unless response && response.fresh?
  response
end

def match_by_vary?(request, response)
  vary = response.vary
  return true unless vary
  original_request = response.instance_variable_get(:@request)
  return request.headers.same_headers?(original_request.headers) if vary == %w[*]
  vary.all? do |cache_field|
    cache_field.downcase!
    !original_request.headers.key?(cache_field) || request.headers[cache_field] == original_request.headers[cache_field]
  end
end

def prepare(request)
  cached_response = lookup(request)
  return unless cached_response
  return unless match_by_vary?(request, cached_response)
  if !request.headers.key?("if-modified-since") && (last_modified = cached_response.headers["last-modified"])
    request.headers.add("if-modified-since", last_modified)
  end
  if !request.headers.key?("if-none-match") && (etag = cached_response.headers["etag"]) # rubocop:disable Style/GuardClause
    request.headers.add("if-none-match", etag)
  end
end