#pragma once

#include "envoy/extensions/filters/udp/udp_proxy/v3/udp_proxy.pb.h"

#include "envoy/udp/hash_policy.h"

#include "source/common/common/hash.h"

namespace Envoy {

namespace Extensions {

namespace UdpFilters {

namespace UdpProxy {

using namespace envoy::extensions::filters::udp::udp_proxy::v3;

/**

 * Implementation of HashPolicy that reads from the UDP proxy filter config.

 */

class HashPolicyImpl : public Udp::HashPolicy {

public:

  explicit HashPolicyImpl(const absl::Span<const UdpProxyConfig::HashPolicy* const>& hash_policies);

  // Udp::HashPolicy

  absl::optional<uint64_t>

  generateHash(const Network::Address::Instance& downstream_addr) const override;

  class HashMethod {

  public:

    virtual ~HashMethod() = default;

    virtual absl::optional<uint64_t>

    evaluate(const Network::Address::Instance& downstream_addr) const PURE;

  };

  using HashMethodPtr = std::unique_ptr<HashMethod>;

private:

  HashMethodPtr hash_impl_;

};

} // namespace UdpProxy

} // namespace UdpFilters

} // namespace Extensions

} // namespace Envoy