//
// Copyright 2017 The Android Open Source Project
//
// 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 "hci_packetizer_hikey.h"

#include <sys/ioctl.h>
#include <utils/Log.h>

#include <android-base/logging.h>

namespace {

const size_t preamble_size_for_type[] = {
    0, HCI_COMMAND_PREAMBLE_SIZE, HCI_ACL_PREAMBLE_SIZE, HCI_SCO_PREAMBLE_SIZE,
    HCI_EVENT_PREAMBLE_SIZE};
const size_t packet_length_offset_for_type[] = {
    0, HCI_LENGTH_OFFSET_CMD, HCI_LENGTH_OFFSET_ACL, HCI_LENGTH_OFFSET_SCO,
    HCI_LENGTH_OFFSET_EVT};

size_t HciGetPacketLengthForType(HciPacketType type, const uint8_t* preamble) {
  size_t offset = packet_length_offset_for_type[type];
  if (type != HCI_PACKET_TYPE_ACL_DATA) return preamble[offset];
  return (((preamble[offset + 1]) << 8) | preamble[offset]);
}

}  // namespace

namespace android {
namespace hardware {
namespace bluetooth {
namespace V1_0 {
namespace hikey {

void HciPacketizerHikey::OnDataReadyHikey(int fd) {
  int tty_bytes = 0;
  if (ioctl(fd, FIONREAD, &tty_bytes) == -1)
    ALOGE("%s:FIONREAD %s", __func__, strerror(errno));
  ALOGV("%s:tty_bytes = %d", __func__, tty_bytes);
  uint8_t* tmp_buffer = new uint8_t[tty_bytes];
  size_t bytes_read = TEMP_FAILURE_RETRY(read(fd, tmp_buffer, tty_bytes));
  CHECK(static_cast<int>(bytes_read) == tty_bytes);

  size_t index = 0;
  while (index < bytes_read - 1) {
    switch (hci_parser_state_) {
      case HCI_IDLE: {
        hci_packet_type_ = static_cast<HciPacketType>(tmp_buffer[index++]);
        CHECK(hci_packet_type_ >= HCI_PACKET_TYPE_ACL_DATA &&
              hci_packet_type_ <= HCI_PACKET_TYPE_EVENT)
            << "hci_packet_type_ = "
            << static_cast<unsigned int>(hci_packet_type_);
        hci_parser_state_ = HCI_TYPE_READY;
        hci_packet_bytes_remaining_ = preamble_size_for_type[hci_packet_type_];
        hci_packet_bytes_read_ = 0;
        break;
      }

      case HCI_TYPE_READY: {
        size_t bytes_to_copy = (bytes_read - index < hci_packet_bytes_remaining_
                                    ? bytes_read - index
                                    : hci_packet_bytes_remaining_);
        memcpy(hci_packet_preamble_ + hci_packet_bytes_read_,
               &tmp_buffer[index], bytes_to_copy);
        hci_packet_bytes_remaining_ -= bytes_to_copy;
        hci_packet_bytes_read_ += bytes_to_copy;
        index += bytes_to_copy;
        ALOGV("%s:TYPE index = %d", __func__, static_cast<int>(index));
        if (hci_packet_bytes_remaining_ == 0) {
          size_t packet_length =
              HciGetPacketLengthForType(hci_packet_type_, hci_packet_preamble_);
          hci_packet_.resize(preamble_size_for_type[hci_packet_type_] +
                             packet_length);
          memcpy(hci_packet_.data(), hci_packet_preamble_,
                 preamble_size_for_type[hci_packet_type_]);
          hci_packet_bytes_remaining_ = packet_length;
          hci_parser_state_ = HCI_PAYLOAD;
          hci_packet_bytes_read_ = 0;
        }
        break;
      }

      case HCI_PAYLOAD: {
        size_t bytes_to_copy = (bytes_read - index < hci_packet_bytes_remaining_
                                    ? bytes_read - index
                                    : hci_packet_bytes_remaining_);
        memcpy(hci_packet_.data() + preamble_size_for_type[hci_packet_type_] +
                   hci_packet_bytes_read_,
               &tmp_buffer[index], bytes_to_copy);
        hci_packet_bytes_remaining_ -= bytes_to_copy;
        hci_packet_bytes_read_ += bytes_to_copy;
        index += bytes_to_copy;
        ALOGV("%s:PAYLOAD index = %d", __func__, static_cast<int>(index));
        if (hci_packet_bytes_remaining_ == 0) {
          hci_packet_ready_cb_();
          hci_parser_state_ = HCI_IDLE;
        }
        break;
      }
    }
  }
  delete[] tmp_buffer;
}

}  // namespace hikey
}  // namespace V1_0
}  // namespace bluetooth
}  // namespace hardware
}  // namespace android