/*
 * Copyright 2024 Google LLC
 *
 * 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.
 */

#if PULSE_EVERYWHERE

#include "pulse_protocol_impl.h"

#include "console/pulse2_transport_impl.h"
#include "system/passert.h"
#include <util/attributes.h>
#include <util/net.h>

#include <stddef.h>
#include <stdint.h>

#define PULSE2_PUSH_TRANSPORT_PROTOCOL (0x5021)

typedef struct PACKED PushPacket {
  net16 protocol;
  net16 length;
  char information[];
} PushPacket;

void *pulse_push_send_begin(uint16_t app_protocol) {
  PushPacket *packet = pulse_link_send_begin(PULSE2_PUSH_TRANSPORT_PROTOCOL);
  packet->protocol = hton16(app_protocol);
  return &packet->information;
}

void pulse_push_send(void *buf, size_t length) {
  PBL_ASSERT(length <= pulse_link_max_send_size() - sizeof(PushPacket),
             "Packet to big to send");
  // We're blindly assuming that buf is the same pointer returned by
  // pulse_push_send_begin. If it isn't, we'll either crash here
  // when trying to dereference it or we'll hit the assert in
  // pulse_link_send.
  PushPacket *packet = (void *)((char *)buf - offsetof(PushPacket,
                                                       information));
  size_t packet_size = length + sizeof(PushPacket);
  packet->length = hton16(packet_size);
  pulse_link_send(packet, packet_size);
}

#endif