#pragma once

#include <chrono>

#include <memory>

#include <vector>

#include "envoy/common/time.h"

#include "envoy/config/route/v3/route_components.pb.h"

#include "envoy/http/header_map.h"

#include "envoy/router/router.h"

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

#include "absl/types/optional.h"

namespace Envoy {

namespace Router {

enum class ResetHeaderFormat { Seconds, UnixTimestamp };

/**

 * A ResetHeaderParser specifies a header name and a format to match against

 * response headers that are used to signal a rate limit interval reset, such

 * as Retry-After or X-RateLimit-Reset.

 */

class ResetHeaderParserImpl : public ResetHeaderParser {

public:

  /**

   * Build a vector of ResetHeaderParserSharedPtr given input config.

   */

  static std::vector<ResetHeaderParserSharedPtr> buildResetHeaderParserVector(

      const Protobuf::RepeatedPtrField<envoy::config::route::v3::RetryPolicy::ResetHeader>&

          reset_headers) {

    std::vector<ResetHeaderParserSharedPtr> ret;

    for (const auto& reset_header : reset_headers) {

      ret.emplace_back(std::make_shared<ResetHeaderParserImpl>(reset_header));

    }

    return ret;

  }

  ResetHeaderParserImpl(const envoy::config::route::v3::RetryPolicy::ResetHeader& config);

  const Http::LowerCaseString& name() const { return name_; }

  ResetHeaderFormat format() const { return format_; }

  /**

   * Iterate over the headers, choose the first one that matches by name, and try to parse its

   * value.

   */

  absl::optional<std::chrono::milliseconds>

  parseInterval(TimeSource& time_source, const Http::HeaderMap& headers) const override;

private:

  const Http::LowerCaseString name_;

  ResetHeaderFormat format_;

};

} // namespace Router

} // namespace Envoy