#pragma once

#include "envoy/config/core/v3/base.pb.h"

#include "envoy/matcher/matcher.h"

#include "envoy/runtime/runtime.h"

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

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

namespace Envoy {

namespace Extensions {

namespace Matching {

namespace InputMatchers {

namespace RuntimeFraction {

class Matcher : public Envoy::Matcher::InputMatcher {

public:

  Matcher(Runtime::Loader& runtime,

          envoy::config::core::v3::RuntimeFractionalPercent runtime_fraction, uint64_t seed)

      : runtime_(runtime), runtime_fraction_(runtime_fraction), seed_(seed) {}

  bool match(const ::Envoy::Matcher::MatchingDataType& input) override {

    // Only match if the value is present.

    if (absl::holds_alternative<absl::monostate>(input)) {

      return false;

    }

    // Otherwise, match if feature is enabled for hash(input).

    const auto hash_value = HashUtil::xxHash64(absl::get<std::string>(input), seed_);

    return runtime_.snapshot().featureEnabled(runtime_fraction_.runtime_key(),

                                              runtime_fraction_.default_value(), hash_value);

  }

private:

  Runtime::Loader& runtime_;

  const envoy::config::core::v3::RuntimeFractionalPercent runtime_fraction_;

  const uint64_t seed_;

};

} // namespace RuntimeFraction

} // namespace InputMatchers

} // namespace Matching

} // namespace Extensions

} // namespace Envoy