#pragma once

#include <cstdint>

#include <limits>

namespace Envoy {

namespace Http2 {

namespace Utility {

// Limits and defaults for `envoy::config::core::v3::Http2ProtocolOptions` protos.

struct OptionsLimits {

  // disable HPACK compression

  static const uint32_t MIN_HPACK_TABLE_SIZE = 0;

  // initial value from HTTP/2 spec, same as NGHTTP2_DEFAULT_HEADER_TABLE_SIZE from nghttp2

  static const uint32_t DEFAULT_HPACK_TABLE_SIZE = (1 << 12);

  // no maximum from HTTP/2 spec, use unsigned 32-bit maximum

  static const uint32_t MAX_HPACK_TABLE_SIZE = std::numeric_limits<uint32_t>::max();

  // TODO(jwfang): make this 0, the HTTP/2 spec minimum

  static const uint32_t MIN_MAX_CONCURRENT_STREAMS = 1;

  // defaults to maximum, same as nghttp2

  static const uint32_t DEFAULT_MAX_CONCURRENT_STREAMS_LEGACY = (1U << 31) - 1;

  // Defaults to 1024 for safety and enough for most use cases.

  static const uint32_t DEFAULT_MAX_CONCURRENT_STREAMS = 1024;

  // no maximum from HTTP/2 spec, total streams is unsigned 32-bit maximum,

  // one-side (client/server) is half that, and we need to exclude stream 0.

  // same as NGHTTP2_INITIAL_MAX_CONCURRENT_STREAMS from nghttp2

  static const uint32_t MAX_MAX_CONCURRENT_STREAMS = (1U << 31) - 1;

  // initial value from HTTP/2 spec, same as NGHTTP2_INITIAL_WINDOW_SIZE from nghttp2

  // NOTE: we only support increasing window size now, so this is also the minimum

  // TODO(jwfang): make this 0 to support decrease window size

  static const uint32_t MIN_INITIAL_STREAM_WINDOW_SIZE = (1 << 16) - 1;

  // Initial value from HTTP/2 spec is 65535 (64KiB - 1) and we want more (16MiB).

  static const uint32_t DEFAULT_INITIAL_STREAM_WINDOW_SIZE = 16 * 1024 * 1024;

  static const uint32_t DEFAULT_INITIAL_STREAM_WINDOW_SIZE_LEGACY = 256 * 1024 * 1024;

  // maximum from HTTP/2 spec, same as NGHTTP2_MAX_WINDOW_SIZE from nghttp2

  static const uint32_t MAX_INITIAL_STREAM_WINDOW_SIZE = (1U << 31) - 1;

  // CONNECTION_WINDOW_SIZE is similar to STREAM_WINDOW_SIZE, but for connection-level window

  // TODO(jwfang): make this 0 to support decrease window size

  static const uint32_t MIN_INITIAL_CONNECTION_WINDOW_SIZE = (1 << 16) - 1;

  static const uint32_t DEFAULT_INITIAL_CONNECTION_WINDOW_SIZE = 24 * 1024 * 1024;

  static const uint32_t DEFAULT_INITIAL_CONNECTION_WINDOW_SIZE_LEGACY = 256 * 1024 * 1024;

  static const uint32_t MAX_INITIAL_CONNECTION_WINDOW_SIZE = (1U << 31) - 1;

  // Default limit on the number of outbound frames of all types.

  static const uint32_t DEFAULT_MAX_OUTBOUND_FRAMES = 10000;

  // Default limit on the number of outbound frames of types PING, SETTINGS and RST_STREAM.

  static const uint32_t DEFAULT_MAX_OUTBOUND_CONTROL_FRAMES = 1000;

  // Default limit on the number of consecutive inbound frames with an empty payload

  // and no end stream flag.

  static const uint32_t DEFAULT_MAX_CONSECUTIVE_INBOUND_FRAMES_WITH_EMPTY_PAYLOAD = 1;

  // Default limit on the number of inbound frames of type PRIORITY (per stream).

  static const uint32_t DEFAULT_MAX_INBOUND_PRIORITY_FRAMES_PER_STREAM = 100;

  // Default limit on the number of inbound frames of type WINDOW_UPDATE (per DATA frame sent).

  static const uint32_t DEFAULT_MAX_INBOUND_WINDOW_UPDATE_FRAMES_PER_DATA_FRAME_SENT = 10;

};

} // namespace Utility

} // namespace Http2

namespace Http3 {

namespace Utility {

// Limits and defaults for `envoy::config::core::v3::Http3ProtocolOptions` protos.

struct OptionsLimits {

  // The same as kStreamReceiveWindowLimit in QUICHE which is the maximum supported by QUICHE.

  static const uint32_t DEFAULT_INITIAL_STREAM_WINDOW_SIZE = 16 * 1024 * 1024;

  // The same as kSessionReceiveWindowLimit in QUICHE which is the maximum supported by QUICHE.

  static const uint32_t DEFAULT_INITIAL_CONNECTION_WINDOW_SIZE = 24 * 1024 * 1024;

};

} // namespace Utility

} // namespace Http3

} // namespace Envoy