//
//
// Copyright 2018 gRPC authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
//

#include "src/core/tsi/alts/handshaker/transport_security_common_api.h"

#include <grpc/support/port_platform.h>

#include "absl/log/log.h"
#include "upb/mem/arena.hpp"

bool grpc_gcp_rpc_protocol_versions_set_max(
    grpc_gcp_rpc_protocol_versions* versions, uint32_t max_major,
    uint32_t max_minor) {
  if (versions == nullptr) {
    LOG(ERROR)
        << "versions is nullptr in grpc_gcp_rpc_protocol_versions_set_max().";
    return false;
  }
  versions->max_rpc_version.major = max_major;
  versions->max_rpc_version.minor = max_minor;
  return true;
}

bool grpc_gcp_rpc_protocol_versions_set_min(
    grpc_gcp_rpc_protocol_versions* versions, uint32_t min_major,
    uint32_t min_minor) {
  if (versions == nullptr) {
    LOG(ERROR)
        << "versions is nullptr in grpc_gcp_rpc_protocol_versions_set_min().";
    return false;
  }
  versions->min_rpc_version.major = min_major;
  versions->min_rpc_version.minor = min_minor;
  return true;
}

bool grpc_gcp_rpc_protocol_versions_encode(
    const grpc_gcp_rpc_protocol_versions* versions, grpc_slice* slice) {
  if (versions == nullptr || slice == nullptr) {
    LOG(ERROR) << "Invalid nullptr arguments to "
                  "grpc_gcp_rpc_protocol_versions_encode().";
    return false;
  }
  upb::Arena arena;
  grpc_gcp_RpcProtocolVersions* versions_msg =
      grpc_gcp_RpcProtocolVersions_new(arena.ptr());
  grpc_gcp_RpcProtocolVersions_assign_from_struct(versions_msg, arena.ptr(),
                                                  versions);
  return grpc_gcp_rpc_protocol_versions_encode(versions_msg, arena.ptr(),
                                               slice);
}

bool grpc_gcp_rpc_protocol_versions_encode(
    const grpc_gcp_RpcProtocolVersions* versions, upb_Arena* arena,
    grpc_slice* slice) {
  if (versions == nullptr || arena == nullptr || slice == nullptr) {
    LOG(ERROR) << "Invalid nullptr arguments to "
                  "grpc_gcp_rpc_protocol_versions_encode().";
    return false;
  }
  size_t buf_length;
  char* buf =
      grpc_gcp_RpcProtocolVersions_serialize(versions, arena, &buf_length);
  if (buf == nullptr) {
    return false;
  }
  *slice = grpc_slice_from_copied_buffer(buf, buf_length);
  return true;
}

bool grpc_gcp_rpc_protocol_versions_decode(
    const grpc_slice& slice, grpc_gcp_rpc_protocol_versions* versions) {
  if (versions == nullptr) {
    LOG(ERROR)
        << "version is nullptr in grpc_gcp_rpc_protocol_versions_decode().";
    return false;
  }
  upb::Arena arena;
  grpc_gcp_RpcProtocolVersions* versions_msg =
      grpc_gcp_RpcProtocolVersions_parse(
          reinterpret_cast<const char*>(GRPC_SLICE_START_PTR(slice)),
          GRPC_SLICE_LENGTH(slice), arena.ptr());
  if (versions_msg == nullptr) {
    LOG(ERROR) << "cannot deserialize RpcProtocolVersions message";
    return false;
  }
  grpc_gcp_rpc_protocol_versions_assign_from_upb(versions, versions_msg);
  return true;
}

void grpc_gcp_rpc_protocol_versions_assign_from_upb(
    grpc_gcp_rpc_protocol_versions* versions,
    const grpc_gcp_RpcProtocolVersions* value) {
  const grpc_gcp_RpcProtocolVersions_Version* max_version_msg =
      grpc_gcp_RpcProtocolVersions_max_rpc_version(value);
  if (max_version_msg != nullptr) {
    versions->max_rpc_version.major =
        grpc_gcp_RpcProtocolVersions_Version_major(max_version_msg);
    versions->max_rpc_version.minor =
        grpc_gcp_RpcProtocolVersions_Version_minor(max_version_msg);
  } else {
    versions->max_rpc_version.major = 0;
    versions->max_rpc_version.minor = 0;
  }
  const grpc_gcp_RpcProtocolVersions_Version* min_version_msg =
      grpc_gcp_RpcProtocolVersions_min_rpc_version(value);
  if (min_version_msg != nullptr) {
    versions->min_rpc_version.major =
        grpc_gcp_RpcProtocolVersions_Version_major(min_version_msg);
    versions->min_rpc_version.minor =
        grpc_gcp_RpcProtocolVersions_Version_minor(min_version_msg);
  } else {
    versions->min_rpc_version.major = 0;
    versions->min_rpc_version.minor = 0;
  }
}

void grpc_gcp_RpcProtocolVersions_assign_from_struct(
    grpc_gcp_RpcProtocolVersions* versions, upb_Arena* arena,
    const grpc_gcp_rpc_protocol_versions* value) {
  grpc_gcp_RpcProtocolVersions_Version* max_version_msg =
      grpc_gcp_RpcProtocolVersions_mutable_max_rpc_version(versions, arena);
  grpc_gcp_RpcProtocolVersions_Version_set_major(max_version_msg,
                                                 value->max_rpc_version.major);
  grpc_gcp_RpcProtocolVersions_Version_set_minor(max_version_msg,
                                                 value->max_rpc_version.minor);
  grpc_gcp_RpcProtocolVersions_Version* min_version_msg =
      grpc_gcp_RpcProtocolVersions_mutable_min_rpc_version(versions, arena);
  grpc_gcp_RpcProtocolVersions_Version_set_major(min_version_msg,
                                                 value->min_rpc_version.major);
  grpc_gcp_RpcProtocolVersions_Version_set_minor(min_version_msg,
                                                 value->min_rpc_version.minor);
}

bool grpc_gcp_rpc_protocol_versions_copy(
    const grpc_gcp_rpc_protocol_versions* src,
    grpc_gcp_rpc_protocol_versions* dst) {
  if ((src == nullptr && dst != nullptr) ||
      (src != nullptr && dst == nullptr)) {
    LOG(ERROR) << "Invalid arguments to grpc_gcp_rpc_protocol_versions_copy().";
    return false;
  }
  if (src == nullptr) {
    return true;
  }
  grpc_gcp_rpc_protocol_versions_set_max(dst, src->max_rpc_version.major,
                                         src->max_rpc_version.minor);
  grpc_gcp_rpc_protocol_versions_set_min(dst, src->min_rpc_version.major,
                                         src->min_rpc_version.minor);
  return true;
}

namespace grpc_core {
namespace internal {

int grpc_gcp_rpc_protocol_version_compare(
    const grpc_gcp_rpc_protocol_versions_version* v1,
    const grpc_gcp_rpc_protocol_versions_version* v2) {
  if ((v1->major > v2->major) ||
      (v1->major == v2->major && v1->minor > v2->minor)) {
    return 1;
  }
  if ((v1->major < v2->major) ||
      (v1->major == v2->major && v1->minor < v2->minor)) {
    return -1;
  }
  return 0;
}

}  // namespace internal
}  // namespace grpc_core

bool grpc_gcp_rpc_protocol_versions_check(
    const grpc_gcp_rpc_protocol_versions* local_versions,
    const grpc_gcp_rpc_protocol_versions* peer_versions,
    grpc_gcp_rpc_protocol_versions_version* highest_common_version) {
  if (local_versions == nullptr || peer_versions == nullptr) {
    LOG(ERROR)
        << "Invalid arguments to grpc_gcp_rpc_protocol_versions_check().";
    return false;
  }
  // max_common_version is MIN(local.max, peer.max)
  const grpc_gcp_rpc_protocol_versions_version* max_common_version =
      grpc_core::internal::grpc_gcp_rpc_protocol_version_compare(
          &local_versions->max_rpc_version, &peer_versions->max_rpc_version) > 0
          ? &peer_versions->max_rpc_version
          : &local_versions->max_rpc_version;
  // min_common_version is MAX(local.min, peer.min)
  const grpc_gcp_rpc_protocol_versions_version* min_common_version =
      grpc_core::internal::grpc_gcp_rpc_protocol_version_compare(
          &local_versions->min_rpc_version, &peer_versions->min_rpc_version) > 0
          ? &local_versions->min_rpc_version
          : &peer_versions->min_rpc_version;
  bool result = grpc_core::internal::grpc_gcp_rpc_protocol_version_compare(
                    max_common_version, min_common_version) >= 0;
  if (result && highest_common_version != nullptr) {
    memcpy(highest_common_version, max_common_version,
           sizeof(grpc_gcp_rpc_protocol_versions_version));
  }
  return result;
}
