#pragma once

#include "envoy/extensions/matching/actions/transform_stat/v3/transform_stat.pb.h"

#include "envoy/stats/tag.h"

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

#include "source/common/protobuf/utility.h"

#include "source/common/stats/symbol_table.h"

namespace Envoy {

namespace Extensions {

namespace Matching {

namespace Actions {

namespace TransformStat {

using ProtoTransformStat = envoy::extensions::matching::actions::transform_stat::v3::TransformStat;

struct ActionContext {

  Envoy::Stats::StatNamePool& pool_;

};

class TransformStatAction {

public:

  /**

   * The result of the action application.

   */

  enum class Result {

    // The stat should be kept (emitted).

    Keep,

    // The stat should be dropped (not emitted).

    DropStat,

    // The tag should be dropped.

    DropTag,

  };

  /**

   * Apply the action to the supplied tags.

   * @param tags supplied the tags to be applied.

   * @return Result result of the action.

   */

  virtual Result apply(std::string& tag_value) const PURE;

};

class DropStat : public Matcher::ActionBase<ProtoTransformStat>, public TransformStatAction {

public:

  Result apply(std::string&) const override;

};

class UpdateTag : public Matcher::ActionBase<ProtoTransformStat>, public TransformStatAction {

public:

  explicit UpdateTag(const std::string& tag_value);

  Result apply(std::string& tag_value) const override;

private:

  const std::string tag_value_;

};

class DropTag : public Matcher::ActionBase<ProtoTransformStat>, public TransformStatAction {

public:

  Result apply(std::string& tag_value) const override;

};

class NoOpAction : public Matcher::ActionBase<ProtoTransformStat>, public TransformStatAction {

public:

  Result apply(std::string&) const override;

};

} // namespace TransformStat

} // namespace Actions

} // namespace Matching

} // namespace Extensions

} // namespace Envoy