/*
 * Copyright (C) 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 "chre/platform/slpi/see/see_helper.h"

#include "pb_decode.h"
#include "pb_encode.h"
#include "sns_cal.pb.h"
#include "sns_client.pb.h"
#include "sns_client_api_v01.h"
#include "sns_proximity.pb.h"
#include "sns_rc.h"
#include "sns_remote_proc_state.pb.h"
#include "sns_resampler.pb.h"
#include "sns_std.pb.h"
#include "sns_std_sensor.pb.h"
#include "stringl.h"
#include "timer.h"

#ifdef CHRE_SLPI_DEFAULT_BUILD
#include "sns_amd.pb.h"
#endif

#ifdef CHRE_SLPI_UIMG_ENABLED
#include "sns_qmi_client.h"
#endif

#include <algorithm>
#include <cfloat>
#include <cinttypes>
#include <cmath>

#include "chre/platform/assert.h"
#include "chre/platform/log.h"
#include "chre/platform/slpi/system_time_util.h"
#include "chre/util/lock_guard.h"
#include "chre/util/macros.h"

#ifdef CHREX_SENSOR_SUPPORT
#include "chre/extensions/platform/vendor_sensor_types.h"
#endif  // CHREX_SENSOR_SUPPORT

#define LOG_NANOPB_ERROR(stream) \
    LOGE("Nanopb error: %s:%d", PB_GET_ERROR(stream), __LINE__)

#define LOG_UNHANDLED_MSG(message) \
    LOGW("Unhandled msg ID %" PRIu32 ": line %d", message, __LINE__)

namespace chre {
namespace {

//! Operating mode indicating sensor is disabled.
const char *kOpModeOff = "OFF";

//! The SUID of the look up sensor.
const sns_std_suid kSuidLookup = sns_suid_sensor_init_default;

//! A struct to facilitate SEE response handling
struct SeeRespCbData {
  SeeHelper *seeHelper;
  uint32_t txnId;
};

//! A struct to facilitate pb encode/decode
struct SeeBufArg {
  const void *buf;
  size_t bufLen;
};

//! A struct to facilitate pb decode of sync calls.
struct SeeSyncArg {
  sns_std_suid syncSuid;
  void *syncData;
  const char *syncDataType;
  bool syncIndFound;
};

//! SeeFloatArg can be used to decode a vectorized 3x3 array.
constexpr size_t kSeeFloatArgValLen = 9;

//! A struct to facilitate decoding a float array.
struct SeeFloatArg {
  size_t index;
  float val[kSeeFloatArgValLen];
};

//! A struct to facilitate pb decode of sensor data event.
struct SeeDataArg {
  uint64_t prevTimeNs;
  uint64_t timeNs;
  size_t sampleIndex;
  size_t totalSamples;
  UniquePtr<uint8_t> event;
  UniquePtr<SeeHelperCallbackInterface::SamplingStatusData> status;
  UniquePtr<struct chreSensorThreeAxisData> bias;
  SensorType sensorType;
  bool isHostWakeSuspendEvent;
  bool isHostAwake;
};

//! A struct to facilitate pb decode
struct SeeInfoArg {
  sns_client *client;
  sns_std_suid suid;
  uint32_t msgId;
  SeeSyncArg *sync;
  SeeDataArg *data;
  bool decodeMsgIdOnly;
  Optional<sns_std_suid> *remoteProcSuid;
  SeeCalHelper *calHelper;
};

//! A struct to facilitate decoding sensor attributes.
struct SeeAttrArg {
  union {
    char strVal[kSeeAttrStrValLen];
    bool boolVal;
    struct {
      float fltMin;
      float fltMax;
    };
    int64_t int64;
  };
  bool initialized;
};

/**
 * Copy an encoded pb message to a wrapper proto's field.
 */
bool copyPayload(pb_ostream_t *stream, const pb_field_t *field,
                 void *const *arg) {
  bool success = false;

  auto *data = static_cast<const SeeBufArg *>(*arg);
  if (!pb_encode_tag_for_field(stream, field)) {
    LOG_NANOPB_ERROR(stream);
  } else if (!pb_encode_string(
      stream, static_cast<const pb_byte_t *>(data->buf), data->bufLen)) {
    LOG_NANOPB_ERROR(stream);
  } else {
    success = true;
  }
  return success;
}

/**
 * Encodes sns_std_attr_req pb message.
 *
 * @param msg A non-null pointer to the pb message unique pointer whose object
 *            will be assigned here.
 * @param msgLen A non-null pointer to the size of the encoded pb message.
 *
 * @return true if the pb message and length were obtained.
 */
bool encodeSnsStdAttrReq(UniquePtr<pb_byte_t> *msg, size_t *msgLen) {
  CHRE_ASSERT(msg);
  CHRE_ASSERT(msgLen);

  // Initialize the pb message
  sns_std_attr_req req = {};

  bool success = pb_get_encoded_size(msgLen, sns_std_attr_req_fields, &req);
  if (!success) {
    LOGE("pb_get_encoded_size failed for sns_str_attr_req");
  } else {
    UniquePtr<pb_byte_t> buf(static_cast<pb_byte_t *>(memoryAlloc(*msgLen)));
    *msg = std::move(buf);

    // The encoded size can be 0 as there's only one optional field.
    if (msg->isNull() && *msgLen > 0) {
      LOG_OOM();
    } else {
      pb_ostream_t stream = pb_ostream_from_buffer(msg->get(), *msgLen);

      success = pb_encode(&stream, sns_std_attr_req_fields, &req);
      if (!success) {
        LOG_NANOPB_ERROR(&stream);
      }
    }
  }
  return success;
}

/**
 * Encodes sns_suid_req pb message.
 *
 * @param dataType Sensor data type, "accel" for example.
 * @param msg A non-null pointer to the pb message unique pointer whose object
 *            will be assigned here.
 * @param msgLen A non-null pointer to the size of the encoded pb message.
 *
 * @return true if the pb message and length were obtained.
 */
bool encodeSnsSuidReq(const char *dataType,
                      UniquePtr<pb_byte_t> *msg, size_t *msgLen) {
  CHRE_ASSERT(msg);
  CHRE_ASSERT(msgLen);
  bool success = false;

  // Initialize the pb message
  SeeBufArg data = {
    .buf = dataType,
    .bufLen = strlen(dataType),
  };
  sns_suid_req req = {
    .data_type.funcs.encode = copyPayload,
    .data_type.arg = &data,
  };

  if (!pb_get_encoded_size(msgLen, sns_suid_req_fields, &req)) {
    LOGE("pb_get_encoded_size failed for sns_suid_req: %s", dataType);
  } else if (*msgLen == 0) {
    LOGE("Invalid pb encoded size for sns_suid_req");
  } else {
    UniquePtr<pb_byte_t> buf(static_cast<pb_byte_t *>(memoryAlloc(*msgLen)));
    *msg = std::move(buf);
    if (msg->isNull()) {
      LOG_OOM();
    } else {
      pb_ostream_t stream = pb_ostream_from_buffer(msg->get(), *msgLen);

      success = pb_encode(&stream, sns_suid_req_fields, &req);
      if (!success) {
        LOG_NANOPB_ERROR(&stream);
      }
    }
  }
  return success;
}

/**
 * Encodes sns_resampler_config pb message.
 *
 * @param request The request to be encoded.
 * @param suid The SUID of the physical sensor to be resampled.
 * @param msg A non-null pointer to the pb message unique pointer whose object
 *            will be assigned here.
 * @param msgLen A non-null pointer to the size of the encoded pb message.
 *
 * @return true if the pb message and length were obtained.
 */
bool encodeSnsResamplerConfig(const SeeSensorRequest& request,
                              const sns_std_suid& suid,
                              UniquePtr<pb_byte_t> *msg, size_t *msgLen) {
  CHRE_ASSERT(msg);
  CHRE_ASSERT(msgLen);
  bool success = false;

  // Initialize the pb message
  sns_resampler_config req = {
    .sensor_uid = suid,
    .resampled_rate = request.samplingRateHz,
    .rate_type = SNS_RESAMPLER_RATE_FIXED,
    .filter = true,
    .has_axis_cnt = true,
    .axis_cnt = 3,  // TODO: set this properly.
  };

  if (!pb_get_encoded_size(msgLen, sns_resampler_config_fields, &req)) {
    LOGE("pb_get_encoded_size failed for sns_resampler_config");
  } else if (*msgLen == 0) {
    LOGE("Invalid pb encoded size for sns_resampler_config");
  } else {
    UniquePtr<pb_byte_t> buf(static_cast<pb_byte_t *>(memoryAlloc(*msgLen)));
    *msg = std::move(buf);
    if (msg->isNull()) {
      LOG_OOM();
    } else {
      pb_ostream_t stream = pb_ostream_from_buffer(msg->get(), *msgLen);

      success = pb_encode(&stream, sns_resampler_config_fields, &req);
      if (!success) {
        LOG_NANOPB_ERROR(&stream);
      }
    }
  }
  return success;
}

/**
 * Encodes sns_std_sensor_config pb message.
 *
 * @param request The request to be encoded.
 * @param msg A non-null pointer to the pb message unique pointer whose object
 *            will be assigned here.
 * @param msgLen A non-null pointer to the size of the encoded pb message.
 *
 * @return true if the pb message and length were obtained.
 */
bool encodeSnsStdSensorConfig(const SeeSensorRequest& request,
                              UniquePtr<pb_byte_t> *msg, size_t *msgLen) {
  CHRE_ASSERT(msg);
  CHRE_ASSERT(msgLen);
  bool success = false;

  // Initialize the pb message
  sns_std_sensor_config req = {
    .sample_rate = request.samplingRateHz,
  };

  if (!pb_get_encoded_size(msgLen, sns_std_sensor_config_fields, &req)) {
    LOGE("pb_get_encoded_size failed for sns_std_sensor_config");
  } else if (*msgLen == 0) {
    LOGE("Invalid pb encoded size for sns_std_sensor_config");
  } else {
    UniquePtr<pb_byte_t> buf(static_cast<pb_byte_t *>(memoryAlloc(*msgLen)));
    *msg = std::move(buf);
    if (msg->isNull()) {
      LOG_OOM();
    } else {
      pb_ostream_t stream = pb_ostream_from_buffer(msg->get(), *msgLen);

      success = pb_encode(&stream, sns_std_sensor_config_fields, &req);
      if (!success) {
        LOG_NANOPB_ERROR(&stream);
      }
    }
  }
  return success;
}

bool encodeSnsRemoteProcSensorConfig(pb_byte_t *msgBuffer, size_t msgBufferSize,
                                     size_t *msgLen,
                                     sns_std_client_processor processorType) {
  CHRE_ASSERT(msgBuffer);
  CHRE_ASSERT(msgLen);

  sns_remote_proc_state_config request = {
    .proc_type = processorType,
  };

  pb_ostream_t stream = pb_ostream_from_buffer(msgBuffer, msgBufferSize);
  bool success = pb_encode(
      &stream, sns_remote_proc_state_config_fields, &request);
  if (!success) {
    LOG_NANOPB_ERROR(&stream);
  } else {
    *msgLen = stream.bytes_written;
  }

  return success;
}

/**
 * Prepares a sns_client_req message with provided payload.
 */
bool prepSnsClientReq(sns_std_suid suid, uint32_t msgId,
                      void *payload, size_t payloadLen,
                      bool batchValid, uint32_t batchPeriodUs, bool passive,
                      UniquePtr<sns_client_request_msg> *msg, SeeBufArg *data) {
  CHRE_ASSERT(payload || payloadLen == 0);
  CHRE_ASSERT(msg);
  CHRE_ASSERT(data);
  bool success = false;

  auto req = MakeUniqueZeroFill<sns_client_request_msg>();
  if (req.isNull()) {
    LOG_OOM();
  } else {
    success = true;

    // Initialize sns_client_request_msg to be sent
    data->buf = payload,
    data->bufLen = payloadLen,

    req->suid = suid;
    req->msg_id = msgId;
    req->susp_config.client_proc_type = SNS_STD_CLIENT_PROCESSOR_SSC;
    req->susp_config.delivery_type = SNS_CLIENT_DELIVERY_WAKEUP;
    req->request.has_batching = batchValid;
    req->request.batching.batch_period = batchPeriodUs;
    // TODO: remove flush_period setting after resolving b/110823194.
    req->request.batching.has_flush_period = true;
    req->request.batching.flush_period = batchPeriodUs + 3000000;
    req->request.payload.funcs.encode = copyPayload;
    req->request.payload.arg = data;
    req->request.has_is_passive = true,
    req->request.is_passive = passive,

    *msg = std::move(req);
  }
  return success;
}

/**
 * Helps decode a pb string field and passes the string to the calling function.
 */
bool decodeStringField(pb_istream_t *stream, const pb_field_t *field,
                       void **arg) {
  auto *data = static_cast<SeeBufArg *>(*arg);
  data->bufLen = stream->bytes_left;
  data->buf = stream->state;

  bool success = pb_read(stream, nullptr /* buf */, stream->bytes_left);
  if (!success) {
    LOG_NANOPB_ERROR(stream);
  }
  return success;
}

/**
 * Decodes each SUID.
 */
bool decodeSnsSuidEventSuid(pb_istream_t *stream, const pb_field_t *field,
                            void **arg) {
  sns_std_suid suid = {};
  bool success = pb_decode(stream, sns_std_suid_fields, &suid);
  if (!success) {
    LOG_NANOPB_ERROR(stream);
  } else {
    auto *suids = static_cast<DynamicVector<sns_std_suid> *>(*arg);
    suids->push_back(suid);
  }
  return success;
}

bool decodeSnsSuidEvent(pb_istream_t *stream, const pb_field_t *field,
                        void **arg) {
  auto *info = static_cast<SeeInfoArg *>(*arg);
  if (!suidsMatch(info->suid, kSuidLookup)) {
    LOGE("SNS_SUID_MSGID_SNS_SUID_EVENT with incorrect SUID: 0x%" PRIx64
         " %" PRIx64, info->suid.suid_high, info->suid.suid_low);
  }

  SeeBufArg data;
  DynamicVector<sns_std_suid> suids;
  sns_suid_event event = {
    .data_type.funcs.decode = decodeStringField,
    .data_type.arg = &data,
    .suid.funcs.decode = decodeSnsSuidEventSuid,
    .suid.arg = &suids,
  };

  bool success = pb_decode(stream, sns_suid_event_fields, &event);
  if (!success) {
    LOG_NANOPB_ERROR(stream);
  } else {
    // If syncData == nullptr, this indication is received outside of a sync
    // call. If the decoded data type doesn't match the one we are waiting
    // for, this indication is from a previous call (may be findSuidSync)
    // and happens to arrive between another sync req/ind pair.
    // Note that req/ind misalignment can still happen if findSuidSync is
    // called again with the same data type.
    // Note that there's no need to compare the SUIDs as no other calls
    // but findSuidSync populate mWaitingDataType and can lead to a data
    // type match.
    if (info->sync->syncData == nullptr
        || strncmp(info->sync->syncDataType,
                   static_cast<const char *>(data.buf),
                   std::min(data.bufLen, kSeeAttrStrValLen)) != 0) {
      LOGW("Received late SNS_SUID_MSGID_SNS_SUID_EVENT indication");
    } else {
      info->sync->syncIndFound = true;
      auto *outputSuids = static_cast<DynamicVector<sns_std_suid> *>(
          info->sync->syncData);
      for (const auto& suid : suids) {
        outputSuids->push_back(suid);
      }
    }
  }
  return success;
}

/**
 * Decode messages defined in sns_suid.proto
 */
bool decodeSnsSuidProtoEvent(pb_istream_t *stream, const pb_field_t *field,
                             void **arg) {
  bool success = false;

  auto *info = static_cast<SeeInfoArg *>(*arg);
  switch (info->msgId) {
    case SNS_SUID_MSGID_SNS_SUID_EVENT:
      success = decodeSnsSuidEvent(stream, field, arg);
      break;

    default:
      LOG_UNHANDLED_MSG(info->msgId);
      break;
  }
  return success;
}

/**
 * Defined in sns_std_sensor.pb.h
 */
const char *getAttrNameFromAttrId(int32_t id) {
  switch (id) {
    case SNS_STD_SENSOR_ATTRID_NAME:
      return "NAME";
    case SNS_STD_SENSOR_ATTRID_VENDOR:
      return "VENDOR";
    case SNS_STD_SENSOR_ATTRID_TYPE:
      return "TYPE";
    case SNS_STD_SENSOR_ATTRID_AVAILABLE:
      return "AVAILABLE";
    case SNS_STD_SENSOR_ATTRID_VERSION:
      return "VERSION";
    case SNS_STD_SENSOR_ATTRID_API:
      return "API";
    case SNS_STD_SENSOR_ATTRID_RATES:
      return "RATES";
    case SNS_STD_SENSOR_ATTRID_RESOLUTIONS:
      return "RESOLUTIONS";
    case SNS_STD_SENSOR_ATTRID_FIFO_SIZE:
      return "FIFO_SIZE";
    case SNS_STD_SENSOR_ATTRID_ACTIVE_CURRENT:
      return "ACTIVE_CURRENT";
    case SNS_STD_SENSOR_ATTRID_SLEEP_CURRENT:
      return "SLEEP_CURRENT";
    case SNS_STD_SENSOR_ATTRID_RANGES:
      return "RANGES";
    case SNS_STD_SENSOR_ATTRID_OP_MODES:
      return "OP_MODES";
    case SNS_STD_SENSOR_ATTRID_DRI:
      return "DRI";
    case SNS_STD_SENSOR_ATTRID_STREAM_SYNC:
      return "STREAM_SYNC";
    case SNS_STD_SENSOR_ATTRID_EVENT_SIZE:
      return "EVENT_SIZE";
    case SNS_STD_SENSOR_ATTRID_STREAM_TYPE:
      return "STREAM_TYPE";
    case SNS_STD_SENSOR_ATTRID_DYNAMIC:
      return "DYNAMIC";
    case SNS_STD_SENSOR_ATTRID_HW_ID:
      return "HW_ID";
    case SNS_STD_SENSOR_ATTRID_RIGID_BODY:
      return "RIGID_BODY";
    case SNS_STD_SENSOR_ATTRID_PLACEMENT:
      return "PLACEMENT";
    case SNS_STD_SENSOR_ATTRID_PHYSICAL_SENSOR:
      return "PHYSICAL_SENSOR";
    case SNS_STD_SENSOR_ATTRID_PHYSICAL_SENSOR_TESTS:
      return "PHYSICAL_SENSOR_TESTS";
    case SNS_STD_SENSOR_ATTRID_SELECTED_RESOLUTION:
      return "SELECTED_RESOLUTION";
    case SNS_STD_SENSOR_ATTRID_SELECTED_RANGE:
      return "SELECTED_RANGE";
    case SNS_STD_SENSOR_ATTRID_ADDITIONAL_LOW_LATENCY_RATES:
      return "LOW_LATENCY_RATES";
    case SNS_STD_SENSOR_ATTRID_PASSIVE_REQUEST:
      return "PASSIVE_REQUEST";
    default:
      return "UNKNOWN ATTRIBUTE";
  }
}

/**
 * Decodes each attribute field and passes the value to the calling function.
 * For repeated fields of float or integers, only store the maximum and
 * minimum values for the calling function.
 */
bool decodeSnsStdAttrValue(pb_istream_t *stream, const pb_field_t *field,
                           void **arg) {
  bool success = false;

  struct DecodeData {
    SeeBufArg strData;
    SeeAttrArg subtypeAttrArg;
    sns_std_attr_value_data value;
  };
  auto data = MakeUniqueZeroFill<DecodeData>();

  if (data.isNull()) {
    LOG_OOM();
  } else {
    data->value.str.funcs.decode = decodeStringField;
    data->value.str.arg = &data->strData;
    data->value.subtype.values.funcs.decode = decodeSnsStdAttrValue;
    data->value.subtype.values.arg = &data->subtypeAttrArg;

    success = pb_decode(stream, sns_std_attr_value_data_fields, &data->value);
    if (!success) {
      LOG_NANOPB_ERROR(stream);
    } else {
      auto *attrVal = static_cast<SeeAttrArg *>(*arg);
      if (data->value.has_flt) {
        // If this is a float (repeated) field, initialize the union as floats
        // to store the maximum and minmum values of the repeated fields.
        if (!attrVal->initialized) {
          attrVal->initialized = true;
          attrVal->fltMin = FLT_MAX;
          attrVal->fltMax = FLT_MIN;
        }
        if (data->value.flt < attrVal->fltMin) {
          attrVal->fltMin = data->value.flt;
        }
        if (data->value.flt > attrVal->fltMax) {
          attrVal->fltMax = data->value.flt;
        }
      } else if (data->value.has_sint) {
        attrVal->int64 = data->value.sint;
      } else if (data->value.has_boolean) {
        attrVal->boolVal = data->value.boolean;
      } else if (data->strData.buf != nullptr) {
        strlcpy(attrVal->strVal, static_cast<const char *>(data->strData.buf),
                sizeof(attrVal->strVal));
      } else if (!data->value.has_subtype) {
        LOGW("Unknown attr type");
      }
    }
  }
  return success;
}

bool decodeSnsStrAttr(pb_istream_t *stream, const pb_field_t *field,
                      void **arg) {
  bool success = false;

  struct Decodedata {
    SeeAttrArg attrArg;
    sns_std_attr attr;
  };
  auto data = MakeUniqueZeroFill<Decodedata>();

  if (data.isNull()) {
    LOG_OOM();
  } else {
    data->attr.value.values.funcs.decode = decodeSnsStdAttrValue;
    data->attr.value.values.arg = &data->attrArg;

    success = pb_decode(stream, sns_std_attr_fields, &data->attr);
    if (!success) {
      LOG_NANOPB_ERROR(stream);
    } else {
      auto *attrData = static_cast<SeeAttributes *>(*arg);
      switch (data->attr.attr_id) {
        case SNS_STD_SENSOR_ATTRID_NAME:
          strlcpy(attrData->name, data->attrArg.strVal, sizeof(attrData->name));
          break;
        case SNS_STD_SENSOR_ATTRID_VENDOR:
          strlcpy(attrData->vendor, data->attrArg.strVal,
                  sizeof(attrData->vendor));
          break;
        case SNS_STD_SENSOR_ATTRID_TYPE:
          strlcpy(attrData->type, data->attrArg.strVal, sizeof(attrData->type));
          break;
        case SNS_STD_SENSOR_ATTRID_AVAILABLE:
          if (!data->attrArg.boolVal) {
            LOGW("%s: %d", getAttrNameFromAttrId(data->attr.attr_id),
                 data->attrArg.boolVal);
          }
          break;
        case SNS_STD_SENSOR_ATTRID_RATES:
          attrData->maxSampleRate = data->attrArg.fltMax;
          break;
        case SNS_STD_SENSOR_ATTRID_STREAM_TYPE:
          attrData->streamType = data->attrArg.int64;
          break;
        case SNS_STD_SENSOR_ATTRID_HW_ID:
          attrData->hwId = data->attrArg.int64;
          break;
        case SNS_STD_SENSOR_ATTRID_PASSIVE_REQUEST:
          attrData->passiveRequest = data->attrArg.boolVal;
          break;
        default:
          break;
      }
    }
  }
  return success;
}

bool decodeSnsStdAttrEvent(pb_istream_t *stream, const pb_field_t *field,
                           void **arg) {
  bool success = false;

  struct DecodeData {
    SeeAttributes attr;
    sns_std_attr_event event;
  };
  auto data = MakeUniqueZeroFill<DecodeData>();

  if (data.isNull()) {
    LOG_OOM();
  } else {
    data->event.attributes.funcs.decode = decodeSnsStrAttr;
    data->event.attributes.arg = &data->attr;

    success = pb_decode(stream, sns_std_attr_event_fields, &data->event);
    if (!success) {
      LOG_NANOPB_ERROR(stream);
    } else {
      auto *info = static_cast<SeeInfoArg *>(*arg);

      // If syncData == nullptr, this indication is received outside of a sync
      // call. If the decoded SUID doesn't match the one we are waiting for,
      // this indication is from a previous getAttributes call and happens to
      // arrive between a later findAttributesSync req/ind pair.
      // Note that req/ind misalignment can still happen if getAttributesSync is
      // called again with the same SUID.
      if (info->sync->syncData == nullptr
          || !suidsMatch(info->suid, info->sync->syncSuid)) {
        LOGW("Received late SNS_STD_MSGID_SNS_STD_ATTR_EVENT indication");
      } else {
        info->sync->syncIndFound = true;
        memcpy(info->sync->syncData, &data->attr, sizeof(data->attr));
      }
    }
  }
  return success;
}

/**
 * Decode messages defined in sns_std.proto
 */
bool decodeSnsStdProtoEvent(pb_istream_t *stream, const pb_field_t *field,
                            void **arg) {
  bool success = false;

  auto *info = static_cast<SeeInfoArg *>(*arg);
  switch (info->msgId) {
    case SNS_STD_MSGID_SNS_STD_ATTR_EVENT:
      success = decodeSnsStdAttrEvent(stream, field, arg);
      break;

    case SNS_STD_MSGID_SNS_STD_FLUSH_EVENT:
      // An empty message.
      success = true;
      break;

    case SNS_STD_MSGID_SNS_STD_ERROR_EVENT: {
      sns_std_error_event event = {};
      success = pb_decode(stream, sns_std_error_event_fields, &event);
      if (!success) {
        LOG_NANOPB_ERROR(stream);
      } else {
        LOGW("SNS_STD_MSGID_SNS_STD_ERROR_EVENT: %d", event.error);
      }
      break;
    }

    default:
      LOG_UNHANDLED_MSG(info->msgId);
  }
  return success;
}

void populateEventSample(SeeInfoArg *info, const float *val) {
  SeeDataArg *data = info->data;
  size_t index = data->sampleIndex;
  if (!data->event.isNull() && index < data->totalSamples) {
    SensorSampleType sampleType = getSensorSampleTypeFromSensorType(
        data->sensorType);

    uint32_t *timestampDelta = nullptr;
    switch (sampleType) {
      case SensorSampleType::ThreeAxis: {
        auto *event = reinterpret_cast<chreSensorThreeAxisData *>(
            data->event.get());
        info->calHelper->applyCalibration(
            data->sensorType, val, event->readings[index].values);
        timestampDelta = &event->readings[index].timestampDelta;
        break;
      }

      case SensorSampleType::Float: {
        auto *event = reinterpret_cast<chreSensorFloatData *>(
            data->event.get());
        event->readings[index].value = val[0];
        timestampDelta = &event->readings[index].timestampDelta;
        break;
      }

      case SensorSampleType::Byte: {
        auto *event = reinterpret_cast<chreSensorByteData *>(data->event.get());
        event->readings[index].value = 0;
        event->readings[index].isNear = (val[0] > 0.5f);
        timestampDelta = &event->readings[index].timestampDelta;
        break;
      }

      case SensorSampleType::Occurrence: {
        auto *event = reinterpret_cast<chreSensorOccurrenceData *>(
            data->event.get());
        timestampDelta = &event->readings[index].timestampDelta;
        break;
      }

#ifdef CHREX_SENSOR_SUPPORT
      case SensorSampleType::Vendor0: {
        auto *event = reinterpret_cast<chrexSensorVendor0Data *>(
            data->event.get());
        memcpy(event->readings[index].values, val,
               sizeof(event->readings[index].values));
        timestampDelta = &event->readings[index].timestampDelta;
        break;
      }

      case SensorSampleType::Vendor1: {
        auto *event = reinterpret_cast<chrexSensorVendor1Data *>(
            data->event.get());
        memcpy(event->readings[index].values, val,
               sizeof(event->readings[index].values));
        timestampDelta = &event->readings[index].timestampDelta;
        break;
      }

      case SensorSampleType::Vendor2: {
        auto *event = reinterpret_cast<chrexSensorVendor2Data *>(
            data->event.get());
        event->readings[index].value = *val;
        timestampDelta = &event->readings[index].timestampDelta;
        break;
      }

      case SensorSampleType::Vendor3: {
        auto *event = reinterpret_cast<chrexSensorVendor3Data *>(
            data->event.get());
        memcpy(event->readings[index].values, val,
               sizeof(event->readings[index].values));
        timestampDelta = &event->readings[index].timestampDelta;
        break;
      }

      case SensorSampleType::Vendor4: {
        auto *event = reinterpret_cast<chrexSensorVendor4Data *>(
            data->event.get());
        memcpy(event->readings[index].values, val,
               sizeof(event->readings[index].values));
        timestampDelta = &event->readings[index].timestampDelta;
        break;
      }

      case SensorSampleType::Vendor5: {
        auto *event = reinterpret_cast<chrexSensorVendor5Data *>(
            data->event.get());
        event->readings[index].value = *val;
        timestampDelta = &event->readings[index].timestampDelta;
        break;
      }

      case SensorSampleType::Vendor6: {
        auto *event = reinterpret_cast<chrexSensorVendor6Data *>(
            data->event.get());
        memcpy(event->readings[index].values, val,
               sizeof(event->readings[index].values));
        timestampDelta = &event->readings[index].timestampDelta;
        break;
      }

      case SensorSampleType::Vendor7: {
        auto *event = reinterpret_cast<chrexSensorVendor7Data *>(
            data->event.get());
        memcpy(event->readings[index].values, val,
               sizeof(event->readings[index].values));
        timestampDelta = &event->readings[index].timestampDelta;
        break;
      }

      case SensorSampleType::Vendor8: {
        auto *event = reinterpret_cast<chrexSensorVendor8Data *>(
            data->event.get());
        memcpy(event->readings[index].values, val,
               sizeof(event->readings[index].values));
        timestampDelta = &event->readings[index].timestampDelta;
        break;
      }
#endif  // CHREX_SENSOR_SUPPORT

      default:
        LOGE("Invalid sample type %" PRIu8, static_cast<uint8_t>(sampleType));
    }

    if (data->sampleIndex == 0) {
      auto *header = reinterpret_cast<chreSensorDataHeader *>(
          data->event.get());
      header->baseTimestamp = data->timeNs;
      *timestampDelta = 0;
    } else {
      uint64_t delta = data->timeNs - data->prevTimeNs;
      if (delta > UINT32_MAX) {
        LOGE("Sensor %" PRIu8 " timestampDelta overflow: prev %" PRIu64
             " curr %" PRIu64, static_cast<uint8_t>(data->sensorType),
             data->prevTimeNs, data->timeNs);
        delta = UINT32_MAX;
      }
      *timestampDelta = static_cast<uint32_t>(delta);
    }
    data->prevTimeNs = data->timeNs;
  }
}

/**
 * Decodes a float array and ensures that the data doesn't go out of bound.
 */
bool decodeFloatData(pb_istream_t *stream, const pb_field_t *field,
                     void **arg) {
  auto *data = static_cast<SeeFloatArg *>(*arg);

  float value;
  float *fltPtr = &value;
  if (data->index >= ARRAY_SIZE(data->val)) {
    LOGE("Float array length exceeds %zu", ARRAY_SIZE(data->val));
  } else {
    // Decode to the provided array only if it doesn't go out of bound.
    fltPtr = &(data->val[data->index]);
  }
  // Increment index whether it's gone out of bounds or not.
  (data->index)++;

  bool success = pb_decode_fixed32(stream, fltPtr);
  if (!success) {
    LOG_NANOPB_ERROR(stream);
  }
  return success;
}

bool decodeSnsStdSensorPhysicalConfigEvent(
    pb_istream_t *stream, const pb_field_t *field, void **arg) {
  SeeBufArg data = {};
  sns_std_sensor_physical_config_event event = {
    .operation_mode.funcs.decode = decodeStringField,
    .operation_mode.arg = &data,
  };

  bool success = pb_decode(stream, sns_std_sensor_physical_config_event_fields,
                           &event);
  if (!success) {
    LOG_NANOPB_ERROR(stream);
  } else {
    auto statusData =
        MakeUniqueZeroFill<SeeHelperCallbackInterface::SamplingStatusData>();
    if (statusData.isNull()) {
      LOG_OOM();
    } else {
      struct chreSensorSamplingStatus *status = &statusData->status;

      if (event.has_sample_rate) {
        statusData->intervalValid = true;
        status->interval = static_cast<uint64_t>(
            ceilf(Seconds(1).toRawNanoseconds() / event.sample_rate));
      }

      // If operation_mode is populated, decoded string length will be > 0.
      if (data.bufLen > 0) {
        statusData->enabledValid = true;
        status->enabled =
            (strncmp(static_cast<const char *>(data.buf), kOpModeOff,
                     std::min(data.bufLen, sizeof(kOpModeOff))) != 0);
      }

      if (event.has_sample_rate || data.bufLen > 0) {
        auto *info = static_cast<SeeInfoArg *>(*arg);
        statusData->sensorType = info->data->sensorType;
        info->data->status = std::move(statusData);
      }
    }
  }
  return success;
}

bool decodeSnsStdSensorEvent(pb_istream_t *stream, const pb_field_t *field,
                             void **arg) {
  SeeFloatArg sample = {};
  sns_std_sensor_event event = {
    .data.funcs.decode = decodeFloatData,
    .data.arg = &sample,
  };

  bool success = pb_decode(stream, sns_std_sensor_event_fields, &event);
  if (!success) {
    LOG_NANOPB_ERROR(stream);
  } else {
    auto *info = static_cast<SeeInfoArg *>(*arg);
    populateEventSample(info, sample.val);
  }
  return success;
}

/**
 * Decode messages defined in sns_std_sensor.proto
 */
bool decodeSnsStdSensorProtoEvent(pb_istream_t *stream, const pb_field_t *field,
                                  void **arg) {
  bool success = false;

  auto *info = static_cast<SeeInfoArg *>(*arg);
  switch (info->msgId) {
    case SNS_STD_SENSOR_MSGID_SNS_STD_SENSOR_PHYSICAL_CONFIG_EVENT:
      success = decodeSnsStdSensorPhysicalConfigEvent(stream, field, arg);
      break;

    case SNS_STD_SENSOR_MSGID_SNS_STD_SENSOR_EVENT:
      success = decodeSnsStdSensorEvent(stream, field, arg);
      break;

    default:
      LOG_UNHANDLED_MSG(info->msgId);
  }
  return success;
}

/**
 * Helper function to convert sns_std_sensor_sample_status to
 * CHRE_SENSOR_ACCURACY_* values.
 *
 * @param status the SEE sensor sample status
 *
 * @return the corresponding CHRE_SENSOR_ACCURACY_* value,
 * CHRE_SENSOR_ACCURACY_UNKNOWN if invalid
 */
uint8_t getChreSensorAccuracyFromSeeSampleStatus(
    sns_std_sensor_sample_status status) {
  switch (status) {
    case SNS_STD_SENSOR_SAMPLE_STATUS_UNRELIABLE:
      return CHRE_SENSOR_ACCURACY_UNRELIABLE;
    case SNS_STD_SENSOR_SAMPLE_STATUS_ACCURACY_LOW:
      return CHRE_SENSOR_ACCURACY_LOW;
    case SNS_STD_SENSOR_SAMPLE_STATUS_ACCURACY_MEDIUM:
      return CHRE_SENSOR_ACCURACY_MEDIUM;
    case SNS_STD_SENSOR_SAMPLE_STATUS_ACCURACY_HIGH:
      return CHRE_SENSOR_ACCURACY_HIGH;
    default:
      return CHRE_SENSOR_ACCURACY_UNKNOWN;
  }
}

bool decodeSnsCalEvent(pb_istream_t *stream, const pb_field_t *field,
                       void **arg) {
  SeeFloatArg offset = {};
  SeeFloatArg scale = {};
  SeeFloatArg matrix = {};
  sns_cal_event event = {
    .bias.funcs.decode = decodeFloatData,
    .bias.arg = &offset,
    .scale_factor.funcs.decode = decodeFloatData,
    .scale_factor.arg = &scale,
    .comp_matrix.funcs.decode = decodeFloatData,
    .comp_matrix.arg = &matrix,
  };

  bool success = pb_decode(stream, sns_cal_event_fields, &event);
  if (!success) {
    LOG_NANOPB_ERROR(stream);
  } else {
    auto *info = static_cast<SeeInfoArg *>(*arg);
    SeeCalHelper *calHelper = info->calHelper;

    bool hasBias = (offset.index == 3);
    bool hasScale = (scale.index == 3);
    bool hasMatrix = (matrix.index == 9);
    uint8_t accuracy = getChreSensorAccuracyFromSeeSampleStatus(event.status);

    calHelper->updateCalibration(
        info->suid, hasBias, offset.val, hasScale, scale.val,
        hasMatrix, matrix.val, accuracy, info->data->timeNs);

    SensorType sensorType = calHelper->getSensorTypeFromSuid(info->suid);
    auto biasData = MakeUniqueZeroFill<struct chreSensorThreeAxisData>();
    if (biasData.isNull()) {
      LOG_OOM();
    } else if (calHelper->getBias(sensorType, biasData.get())) {
      info->data->bias = std::move(biasData);
    }
  }
  return success;
}

/**
 * Decode messages defined in sns_cal.proto
 */
bool decodeSnsCalProtoEvent(pb_istream_t *stream, const pb_field_t *field,
                            void **arg) {
  bool success = false;

  auto *info = static_cast<SeeInfoArg *>(*arg);
  switch (info->msgId) {
    case SNS_CAL_MSGID_SNS_CAL_EVENT:
      success = decodeSnsCalEvent(stream, field, arg);
      break;

    default:
      LOG_UNHANDLED_MSG(info->msgId);
  }
  return success;
}

bool decodeSnsProximityEvent(pb_istream_t *stream, const pb_field_t *field,
                             void **arg) {
  sns_proximity_event event = {};

  bool success = pb_decode(stream, sns_proximity_event_fields, &event);
  if (!success) {
    LOG_NANOPB_ERROR(stream);
  } else {
    float value = static_cast<float>(event.proximity_event_type);
    auto *info = static_cast<SeeInfoArg *>(*arg);
    populateEventSample(info, &value);
  }
  return success;
}

/**
 * Decode messages defined in sns_proximity.proto
 */
bool decodeSnsProximityProtoEvent(pb_istream_t *stream, const pb_field_t *field,
                                  void **arg) {
  bool success = false;

  auto *info = static_cast<SeeInfoArg *>(*arg);
  switch (info->msgId) {
    case SNS_PROXIMITY_MSGID_SNS_PROXIMITY_EVENT:
      success = decodeSnsProximityEvent(stream, field, arg);
      break;

    default:
      LOG_UNHANDLED_MSG(info->msgId);
  }
  return success;
}

bool decodeSnsResamplerConfigEvent(pb_istream_t *stream,
                                   const pb_field_t *field, void **arg) {
  sns_resampler_config_event event = {};

  bool success = pb_decode(stream, sns_resampler_config_event_fields, &event);
  if (!success) {
    LOG_NANOPB_ERROR(stream);
  } else {
    auto *info = static_cast<SeeInfoArg *>(*arg);
    LOGD("SensorType %" PRIu8 " resampler quality %" PRIu8,
         static_cast<uint8_t>(info->data->sensorType),
         static_cast<uint8_t>(event.quality));
  }
  return success;
}

/**
 * Decode messages defined in sns_resampler.proto
 */
bool decodeSnsResamplerProtoEvent(pb_istream_t *stream, const pb_field_t *field,
                                  void **arg) {
  bool success = false;

  auto *info = static_cast<SeeInfoArg *>(*arg);
  switch (info->msgId) {
    case SNS_RESAMPLER_MSGID_SNS_RESAMPLER_CONFIG_EVENT:
      success = decodeSnsResamplerConfigEvent(stream, field, arg);
      break;

    default:
      LOG_UNHANDLED_MSG(info->msgId);
  }
  return success;
}

bool decodeSnsRemoteProcStateEvent(
    pb_istream_t *stream, const pb_field_t *field, void **arg) {
  sns_remote_proc_state_event event = sns_remote_proc_state_event_init_default;
  bool success = pb_decode(stream, sns_remote_proc_state_event_fields, &event);
  if (!success) {
    LOG_NANOPB_ERROR(stream);
  } else if (event.proc_type == SNS_STD_CLIENT_PROCESSOR_APSS) {
    auto *info = static_cast<SeeInfoArg *>(*arg);
    info->data->isHostWakeSuspendEvent = true;
    info->data->isHostAwake =
        (event.event_type == SNS_REMOTE_PROC_STATE_AWAKE);
  }
  return success;
}

/**
 * Decode messages defined in sns_remote_proc_state.proto
 */
bool decodeSnsRemoteProcProtoEvent(
    pb_istream_t *stream, const pb_field_t *field, void **arg) {
  bool success = false;
  auto *info = static_cast<SeeInfoArg *>(*arg);
  switch (info->msgId) {
    case SNS_REMOTE_PROC_STATE_MSGID_SNS_REMOTE_PROC_STATE_EVENT:
      success = decodeSnsRemoteProcStateEvent(stream, field, arg);
      break;

    default:
      LOG_UNHANDLED_MSG(info->msgId);
  }
  return success;
}

#ifdef CHRE_SLPI_DEFAULT_BUILD
bool decodeSnsAmdProtoEvent(
    pb_istream_t *stream, const pb_field_t *field, void **arg) {
  bool success = false;
  sns_amd_event event = sns_amd_event_init_default;
  auto *info = static_cast<SeeInfoArg *>(*arg);

  if (!pb_decode(stream, sns_amd_event_fields, &event)) {
    LOG_NANOPB_ERROR(stream);
  } else {
    // Stationary / instant motion share the same suid so modify the sensorType
    // to be the correct type depending on the event.
    if (SNS_AMD_EVENT_TYPE_STATIONARY == event.state) {
      info->data->sensorType = SensorType::StationaryDetect;
    } else if (SNS_AMD_EVENT_TYPE_MOTION == event.state) {
      info->data->sensorType = SensorType::InstantMotion;
    } else {
      CHRE_ASSERT(false);
    }

    float val = 0;
    populateEventSample(info, &val);
    success = true;
  }

  return success;
}
#endif

bool assignPayloadCallback(const SeeInfoArg *info, pb_callback_t *payload) {
  bool success = true;

  payload->arg = const_cast<SeeInfoArg *>(info);

  if (info->remoteProcSuid->has_value()
      && suidsMatch(info->suid, info->remoteProcSuid->value())) {
    payload->funcs.decode = decodeSnsRemoteProcProtoEvent;
  } else if (suidsMatch(info->suid, kSuidLookup)) {
    payload->funcs.decode = decodeSnsSuidProtoEvent;
  } else {
    // Assumed: "real" sensors SUIDs
    switch (info->msgId) {
      case SNS_STD_MSGID_SNS_STD_ATTR_EVENT:
      case SNS_STD_MSGID_SNS_STD_FLUSH_EVENT:
      case SNS_STD_MSGID_SNS_STD_ERROR_EVENT:
        payload->funcs.decode = decodeSnsStdProtoEvent;
        break;

      case SNS_STD_SENSOR_MSGID_SNS_STD_SENSOR_PHYSICAL_CONFIG_EVENT:
      case SNS_STD_SENSOR_MSGID_SNS_STD_SENSOR_EVENT:
        payload->funcs.decode = decodeSnsStdSensorProtoEvent;
        break;

      case SNS_CAL_MSGID_SNS_CAL_EVENT:
        payload->funcs.decode = decodeSnsCalProtoEvent;
        break;

      case SNS_PROXIMITY_MSGID_SNS_PROXIMITY_EVENT:
        payload->funcs.decode = decodeSnsProximityProtoEvent;
        break;

      case SNS_RESAMPLER_MSGID_SNS_RESAMPLER_CONFIG_EVENT:
        payload->funcs.decode = decodeSnsResamplerProtoEvent;
        break;

#ifdef CHRE_SLPI_DEFAULT_BUILD
      case SNS_AMD_MSGID_SNS_AMD_EVENT:
        payload->funcs.decode = decodeSnsAmdProtoEvent;
        break;
#endif

      default:
        success = false;
        LOG_UNHANDLED_MSG(info->msgId);
    }
  }
  return success;
}

/**
 * Decodes only msg_id and timestamp defined in sns_client_event and converts
 * the timestamp to nanoseconds.
 */
bool decodeMsgIdAndTime(pb_istream_t *stream, uint32_t *msgId,
                        uint64_t *timeNs) {
  sns_client_event_msg_sns_client_event event = {};

  bool success = pb_decode(
      stream, sns_client_event_msg_sns_client_event_fields, &event);
  if (!success) {
    LOG_NANOPB_ERROR(stream);
  } else {
    *msgId = event.msg_id;
    *timeNs = getNanosecondsFromQTimerTicks(event.timestamp);
  }
  return success;
}

/**
 * Decodes pb-encoded message
 */
bool decodeSnsClientEventMsg(pb_istream_t *stream, const pb_field_t *field,
                             void **arg) {
  // Make a copy for data decoding.
  pb_istream_t streamCpy = *stream;

  auto *info = static_cast<SeeInfoArg *>(*arg);
  bool success = decodeMsgIdAndTime(stream, &info->msgId, &info->data->timeNs);

  if (success && !info->decodeMsgIdOnly) {
    sns_client_event_msg_sns_client_event event = {};

    // Payload callback must be assigned if and only if we want to decode beyond
    // msg ID.
    success = assignPayloadCallback(info, &event.payload);
    if (!success) {
      LOGE("No pb callback assigned");
    } else {
      success = pb_decode(&streamCpy,
                          sns_client_event_msg_sns_client_event_fields, &event);
      if (!success) {
        LOG_NANOPB_ERROR(&streamCpy);
      }
    }
  }

  // Increment sample count only after sensor event decoding.
  if (success
      && (info->msgId == SNS_STD_SENSOR_MSGID_SNS_STD_SENSOR_EVENT
          || info->msgId == SNS_PROXIMITY_MSGID_SNS_PROXIMITY_EVENT
#ifdef CHRE_SLPI_DEFAULT_BUILD
          || info->msgId == SNS_AMD_MSGID_SNS_AMD_EVENT
#endif
      )) {
    info->data->sampleIndex++;
  }
  return success;
}

/**
 * Obtain the SensorType from the list of registered SensorInfos.
 */
SensorType getSensorTypeFromSensorInfo(
    sns_client *client, const sns_std_suid& suid,
    const DynamicVector<SeeHelper::SensorInfo>& sensorInfos) {
  bool suidFound = false;
  SensorType otherType;
  for (const auto& sensorInfo : sensorInfos) {
    if (suidsMatch(sensorInfo.suid, suid)) {
      suidFound = true;
      if (sensorInfo.client == client) {
        return sensorInfo.sensorType;
      }
      otherType = sensorInfo.sensorType;
    }
  }

  if (suidFound) {
    LOGE("Unmatched client: %p, SUID 0x%016" PRIx64 " %016" PRIx64,
             client, suid.suid_high, suid.suid_low);

    // Return SensorType in the other sns_client that matches the SUID as a
    // backup plan.
    return otherType;
  }
  return SensorType::Unknown;
}

/**
 * Allocate event memory according to SensorType and the number of samples.
 */
void *allocateEvent(SensorType sensorType, size_t numSamples) {
  SensorSampleType sampleType = getSensorSampleTypeFromSensorType(sensorType);
  size_t sampleSize = 0;
  switch (sampleType) {
    case SensorSampleType::ThreeAxis:
      sampleSize = sizeof(
          chreSensorThreeAxisData::chreSensorThreeAxisSampleData);
      break;

    case SensorSampleType::Float:
      sampleSize = sizeof(
          chreSensorFloatData::chreSensorFloatSampleData);
      break;

    case SensorSampleType::Byte:
      sampleSize = sizeof(
          chreSensorByteData::chreSensorByteSampleData);
      break;

    case SensorSampleType::Occurrence:
      sampleSize = sizeof(
          chreSensorOccurrenceData::chreSensorOccurrenceSampleData);
      break;

#ifdef CHREX_SENSOR_SUPPORT
    case SensorSampleType::Vendor0:
      sampleSize = sizeof(chrexSensorVendor0SampleData);
      break;

    case SensorSampleType::Vendor1:
      sampleSize = sizeof(chrexSensorVendor1SampleData);
      break;

    case SensorSampleType::Vendor2:
      sampleSize = sizeof(chrexSensorVendor2SampleData);
      break;

    case SensorSampleType::Vendor3:
      sampleSize = sizeof(chrexSensorVendor3SampleData);
      break;

    case SensorSampleType::Vendor4:
      sampleSize = sizeof(chrexSensorVendor4SampleData);
      break;

    case SensorSampleType::Vendor5:
      sampleSize = sizeof(chrexSensorVendor5SampleData);
      break;

    case SensorSampleType::Vendor6:
      sampleSize = sizeof(chrexSensorVendor6SampleData);
      break;

    case SensorSampleType::Vendor7:
      sampleSize = sizeof(chrexSensorVendor7SampleData);
      break;

    case SensorSampleType::Vendor8:
      sampleSize = sizeof(chrexSensorVendor8SampleData);
      break;
#endif  // CHREX_SENSOR_SUPPORT

    default:
      LOGE("Unhandled SensorSampleType for SensorType %" PRIu8,
           static_cast<uint8_t>(sensorType));
  }

  size_t memorySize = (sampleType == SensorSampleType::Unknown)
      ? 0 : (sizeof(chreSensorDataHeader) + numSamples * sampleSize);
  void *event = (memorySize == 0) ? nullptr : memoryAlloc(memorySize);

  if (event == nullptr && memorySize != 0) {
    LOG_OOM();
  }
  return event;
}

// Allocates the sensor event memory and partially populates the header.
bool prepareSensorEvent(SeeInfoArg& info) {
  bool success = false;

  UniquePtr<uint8_t> buf(static_cast<uint8 *>(
      allocateEvent(info.data->sensorType, info.data->sampleIndex)));
  info.data->event = std::move(buf);

  if (!info.data->event.isNull()) {
    success = true;

    info.data->prevTimeNs = 0;

    auto *header = reinterpret_cast<chreSensorDataHeader *>(
        info.data->event.get());
    header->reserved = 0;
    header->sensorHandle = getSensorHandleFromSensorType(
        info.data->sensorType);
    header->readingCount = info.data->sampleIndex;
    header->accuracy = CHRE_SENSOR_ACCURACY_UNKNOWN;

    // Protect against out of bounds access in data decoding.
    info.data->totalSamples = info.data->sampleIndex;

    // Reset sampleIndex only after memory has been allocated and header
    // populated.
    info.data->sampleIndex = 0;
  }
  return success;
}

}  // anonymous namespace

const SeeHelper::SnsClientApi SeeHelper::kDefaultApi = {
  .sns_client_init   = sns_client_init,
  .sns_client_deinit = sns_client_deinit,
  .sns_client_send   = sns_client_send,
};

#ifdef CHRE_SLPI_UIMG_ENABLED
const SeeHelper::SnsClientApi BigImageSeeHelper::kQmiApi = {
  .sns_client_init   = sns_qmi_client_init,
  .sns_client_deinit = sns_qmi_client_deinit,
  .sns_client_send   = sns_qmi_client_send,
};
#endif  // CHRE_SLPI_UIMG_ENABLED

SeeHelper::SeeHelper() {
  mCalHelper = memoryAlloc<SeeCalHelper>();
  if (mCalHelper == nullptr) {
    FATAL_ERROR("Failed to allocate SeeCalHelper");
  }
  mOwnsCalHelper = true;
}

SeeHelper::SeeHelper(SeeCalHelper *calHelper)
    : mCalHelper(calHelper), mOwnsCalHelper(false) {}

SeeHelper::~SeeHelper() {
  for (auto *client : mSeeClients) {
    int status = mSnsClientApi->sns_client_deinit(client);
    if (status != 0) {
      LOGE("Failed to release sensor client: %d", status);
    }
  }

  if (mOwnsCalHelper) {
    mCalHelper->~SeeCalHelper();
    memoryFree(mCalHelper);
  }
}

void SeeHelper::handleSnsClientEventMsg(
    sns_client *client, const void *payload, size_t payloadLen) {
  CHRE_ASSERT(payload);

  pb_istream_t stream = pb_istream_from_buffer(
      static_cast<const pb_byte_t *>(payload), payloadLen);

  // Make a copy of the stream for sensor data decoding.
  pb_istream_t streamCpy = stream;

  struct DecodeData {
    SeeSyncArg syncArg = {};
    SeeDataArg dataArg = {};
    SeeInfoArg info = {};
    sns_client_event_msg event = {};
  };
  auto data = MakeUnique<DecodeData>();

  if (data.isNull()) {
    LOG_OOM();
  } else {
    // Only initialize fields that are not accessed in the main CHRE thread.
    data->info.client = client;
    data->info.sync = &data->syncArg;
    data->info.data = &data->dataArg;
    data->info.decodeMsgIdOnly = true;
    data->info.remoteProcSuid = &mRemoteProcSuid;
    data->info.calHelper = mCalHelper;
    data->event.events.funcs.decode = decodeSnsClientEventMsg;
    data->event.events.arg = &data->info;

    // Decode only SUID and MSG ID to help further decode.
    if (!pb_decode(&stream, sns_client_event_msg_fields, &data->event)) {
      LOG_NANOPB_ERROR(&stream);
    } else {
      data->info.suid = data->event.suid;
      data->info.decodeMsgIdOnly = false;
      data->info.data->sensorType = getSensorTypeFromSensorInfo(
          data->info.client, data->info.suid, mSensorInfos);

      mMutex.lock();
      bool synchronizedDecode = mWaitingOnInd;
      if (!synchronizedDecode) {
        // Early unlock, we're not going to use anything from the main thread.
        mMutex.unlock();
      } else {
        // Populate fields set by the main thread.
        data->info.sync->syncData = mSyncData;
        data->info.sync->syncDataType = mSyncDataType;
        data->info.sync->syncSuid = mSyncSuid;
      }

      if (data->info.data->sampleIndex > 0) {
        if (data->info.data->sensorType == SensorType::Unknown) {
          LOGE("Unhandled sensor data SUID 0x%016" PRIx64 " %016" PRIx64,
               data->info.suid.suid_high, data->info.suid.suid_low);
        } else if (!prepareSensorEvent(data->info)) {
          LOGE("Failed to prepare sensor event");
        }
      }

      if (!pb_decode(&streamCpy, sns_client_event_msg_fields, &data->event)) {
        LOG_NANOPB_ERROR(&streamCpy);
      } else if (synchronizedDecode && data->info.sync->syncIndFound) {
        mWaitingOnInd = false;
        mCond.notify_one();
      } else {
        if (data->info.msgId == SNS_STD_MSGID_SNS_STD_FLUSH_EVENT) {
          mCbIf->onFlushCompleteEvent(data->info.data->sensorType);
        }
        if (data->info.data->isHostWakeSuspendEvent) {
          mCbIf->onHostWakeSuspendEvent(data->info.data->isHostAwake);
        }
        if (!data->info.data->event.isNull()) {
          mCbIf->onSensorDataEvent(
              data->info.data->sensorType, std::move(data->info.data->event));
        }
        if (!data->info.data->bias.isNull()) {
          mCbIf->onSensorBiasEvent(std::move(data->info.data->bias));
        }
        if (!data->info.data->status.isNull()) {
          if (data->info.data->sensorType == SensorType::Unknown) {
            LOGE("Unhandled sensor status SUID 0x%016" PRIx64 " %016" PRIx64,
                 data->info.suid.suid_high, data->info.suid.suid_low);
          } else {
            mCbIf->onSamplingStatusUpdate(std::move(data->info.data->status));
          }
        }
      }

      if (synchronizedDecode) {
        mMutex.unlock();
      }
    }
  }
}

void SeeHelper::handleSeeResp(uint32_t txnId, sns_std_error error) {
  LockGuard<Mutex> lock(mMutex);
  if (mWaitingOnResp && txnId == mCurrentTxnId) {
    mRespError = error;
    mWaitingOnResp = false;
    mCond.notify_one();
  }
}

bool SeeHelper::findSuidSync(const char *dataType,
                             DynamicVector<sns_std_suid> *suids,
                             uint8_t minNumSuids, uint32_t maxRetries,
                             Milliseconds retryDelay) {
  CHRE_ASSERT(suids != nullptr);
  CHRE_ASSERT(minNumSuids > 0);

  bool success = false;
  if (mSeeClients.empty()) {
    LOGE("Sensor client wasn't initialized");
  } else {
    UniquePtr<pb_byte_t> msg;
    size_t msgLen;
    if (encodeSnsSuidReq(dataType, &msg, &msgLen)) {
      // Sensor client service may come up before SEE sensors are enumerated. A
      // max dwell time is set and retries are performed as currently there's no
      // message indicating that SEE intialization is complete.
      uint32_t trialCount = 0;
      do {
        suids->clear();
        if (++trialCount > 1) {
          timer_sleep(retryDelay.getMilliseconds(), T_MSEC,
                      true /* non_deferrable */);
        }

        // Ignore failures from sendReq, we'll retry anyways (up to maxRetries)
        sendReq(sns_suid_sensor_init_default,
                suids, dataType,
                SNS_SUID_MSGID_SNS_SUID_REQ, msg.get(), msgLen,
                false /* batchValid */, 0 /* batchPeriodUs */,
                false /* passive */, true /* waitForIndication */);
      } while (suids->size() < minNumSuids && trialCount < maxRetries);

      success = (suids->size() >= minNumSuids);
      if (!success) {
        mHaveTimedOutOnSuidLookup = true;
      }
      if (trialCount > 1) {
        LOGD("Waited %" PRIu32 " ms for %s (found %zu, required %" PRIu8 ")",
             static_cast<uint32_t>(trialCount * retryDelay.getMilliseconds()),
             dataType, suids->size(), minNumSuids);
      }
    }
  }

  return success;
}

bool SeeHelper::getAttributesSync(const sns_std_suid& suid,
                                  SeeAttributes *attr) {
  CHRE_ASSERT(attr);
  bool success = false;

  if (mSeeClients.empty()) {
    LOGE("Sensor client wasn't initialized");
  } else {
    UniquePtr<pb_byte_t> msg;
    size_t msgLen;
    success = encodeSnsStdAttrReq(&msg, &msgLen);

    if (success) {
      success = sendReq(suid, attr, nullptr /* syncDataType */,
                        SNS_STD_MSGID_SNS_STD_ATTR_REQ, msg.get(), msgLen,
                        false /* batchValid */, 0 /* batchPeriodUs */,
                        false /* passive */, true /* waitForIndication */);
    }
  }
  return success;
}

bool SeeHelper::init(SeeHelperCallbackInterface *cbIf, Microseconds timeout,
                     bool skipDefaultSensorInit) {
  CHRE_ASSERT(cbIf);

  mCbIf = cbIf;
  sns_client *client;

  // Initialize cal/remote_proc_state sensors before making sensor data request.
  return (waitForService(&client, timeout)
          && mSeeClients.push_back(client)
          && initResamplerSensor()
          && (skipDefaultSensorInit
              || (mCalHelper->registerForCalibrationUpdates(*this)
                  && initRemoteProcSensor())));
}

bool SeeHelper::makeRequest(const SeeSensorRequest& request) {
  bool success = false;

  const SensorInfo *sensorInfo = getSensorInfo(request.sensorType);
  if (sensorInfo == nullptr) {
    LOGE("SensorType %" PRIu8 " hasn't been registered",
         static_cast<uint8_t>(request.sensorType));
  } else {
    uint32_t msgId;
    UniquePtr<pb_byte_t> msg;
    size_t msgLen = 0;

    bool encodeSuccess = true;
    if (!request.enable) {
      // An empty message
      msgId = SNS_CLIENT_MSGID_SNS_CLIENT_DISABLE_REQ;
    } else if (sensorTypeIsContinuous(request.sensorType)) {
      if (suidsMatch(sensorInfo->suid, mResamplerSuid.value())) {
        msgId = SNS_RESAMPLER_MSGID_SNS_RESAMPLER_CONFIG;
        encodeSuccess = encodeSnsResamplerConfig(
            request, sensorInfo->physicalSuid, &msg, &msgLen);
      } else {
        msgId = SNS_STD_SENSOR_MSGID_SNS_STD_SENSOR_CONFIG;
        encodeSuccess = encodeSnsStdSensorConfig(request, &msg, &msgLen);
      }
    } else {
      msgId = SNS_STD_SENSOR_MSGID_SNS_STD_ON_CHANGE_CONFIG;
      // No sample rate needed to configure on-change or one-shot sensors.
    }

    if (encodeSuccess) {
      success = sendReq(sensorInfo->client, sensorInfo->suid,
                        nullptr /* syncData */, nullptr /* syncDataType */,
                        msgId, msg.get(), msgLen,
                        true /* batchValid */, request.batchPeriodUs,
                        request.passive, false /* waitForIndication */);
    }
  }
  return success;
}

bool SeeHelper::flush(SensorType sensorType) {
  bool success = false;

  const SensorInfo *sensorInfo = getSensorInfo(sensorType);
  if (sensorInfo == nullptr) {
    LOGE("SensorType %" PRIu8 " hasn't been registered",
         static_cast<uint8_t>(sensorType));
  } else {
    uint32_t msgId = SNS_STD_MSGID_SNS_STD_FLUSH_REQ;
    success = sendReq(sensorInfo->client, sensorInfo->suid,
                      nullptr /* syncData */, nullptr /* syncDataType */,
                      msgId, nullptr /* msg */, 0 /* msgLen */,
                      false /* batchValid */, 0 /* batchPeriodUs */,
                      false /* passive */, false /* waitForIndication */);
  }
  return success;
}

bool SeeHelper::configureOnChangeSensor(const sns_std_suid& suid, bool enable) {
  uint32_t msgId = (enable)
      ? SNS_STD_SENSOR_MSGID_SNS_STD_ON_CHANGE_CONFIG
      : SNS_CLIENT_MSGID_SNS_CLIENT_DISABLE_REQ;
  return sendReq(
      suid, nullptr /* syncData */, nullptr /* syncDataType */,
      msgId, nullptr /* msg */, 0 /* msgLen */,
      false /* batchValid */, 0 /* batchPeriodUs */,
      false /* passive */, false /* waitForIndication */);
}

/**
 * Sends a request to SEE and waits for the response.
 */
bool SeeHelper::sendSeeReqSync(
    sns_client *client, sns_client_request_msg *req, Nanoseconds timeoutResp) {
  CHRE_ASSERT(client);
  CHRE_ASSERT(req);
  bool success = false;

  auto *cbData = memoryAlloc<SeeRespCbData>();
  if (cbData == nullptr) {
    LOG_OOM();
  } else {
    cbData->seeHelper = this;

    {
      LockGuard<Mutex> lock(mMutex);
      CHRE_ASSERT(!mWaitingOnResp);
      mWaitingOnResp = true;
      cbData->txnId = ++mCurrentTxnId;
    }

    int status = mSnsClientApi->sns_client_send(
        client, req, SeeHelper::seeRespCb, cbData);
    if (status != 0) {
      LOGE("Error sending SEE request %d", status);
      memoryFree(cbData);
    }

    {
      LockGuard<Mutex> lock(mMutex);

      if (status == 0) {
        bool waitSuccess = true;

        while (mWaitingOnResp && waitSuccess) {
          waitSuccess = mCond.wait_for(mMutex, timeoutResp);
        }

        if (!waitSuccess) {
          LOGE("SEE resp timed out after %" PRIu64 " ms",
               Milliseconds(timeoutResp).getMilliseconds());

          if (++mNumMissingResp >= kSeeNumMissingResp) {
            FATAL_ERROR("%" PRIu32 " consecutive missing responses",
                        mNumMissingResp);
          }
        } else {
          mNumMissingResp = 0;
          if (mRespError != SNS_STD_ERROR_NO_ERROR) {
            LOGE("SEE txn ID %" PRIu32 " failed with error %d",
                 mCurrentTxnId, mRespError);
          } else {
            success = true;
          }
        }
      }
      mWaitingOnResp = false;
    }
  }
  return success;
}

bool SeeHelper::sendReq(
    sns_client *client, const sns_std_suid& suid,
    void *syncData, const char *syncDataType,
    uint32_t msgId, void *payload, size_t payloadLen,
    bool batchValid, uint32_t batchPeriodUs, bool passive,
    bool waitForIndication, Nanoseconds timeoutResp, Nanoseconds timeoutInd) {
  UniquePtr<sns_client_request_msg> msg;
  SeeBufArg data;
  bool success = false;

  if (prepSnsClientReq(suid, msgId, payload, payloadLen, batchValid,
                       batchPeriodUs, passive, &msg, &data)) {
    if (waitForIndication) {
      prepareWaitForInd(suid, syncData, syncDataType);
    }

    success = sendSeeReqSync(client, msg.get(), timeoutResp);

    if (waitForIndication) {
      success = waitForInd(success, timeoutInd);
    }
  }
  return success;
}

void SeeHelper::prepareWaitForInd(const sns_std_suid& suid, void *syncData,
                                  const char *syncDataType) {
  LockGuard<Mutex> lock(mMutex);
  CHRE_ASSERT(!mWaitingOnInd);
  mWaitingOnInd = true;

  // Specify members needed for a sync call.
  mSyncSuid = suid;
  mSyncData = syncData;
  mSyncDataType = syncDataType;
}

bool SeeHelper::waitForInd(bool reqSent, Nanoseconds timeoutInd) {
  bool success = reqSent;

  LockGuard<Mutex> lock(mMutex);
  CHRE_ASSERT(!mWaitingOnResp);
  if (reqSent) {
    bool waitSuccess = true;

    while (mWaitingOnInd && waitSuccess) {
      waitSuccess = mCond.wait_for(mMutex, timeoutInd);
    }

    if (!waitSuccess) {
      LOGE("SEE indication timed out after %" PRIu64 " ms",
           Milliseconds(timeoutInd).getMilliseconds());
      success = false;
    }
  }
  mWaitingOnInd = false;

  // Reset members needed for a sync call.
  mSyncSuid = sns_suid_sensor_init_zero;
  mSyncData = nullptr;
  mSyncDataType = nullptr;

  return success;
}

void SeeHelper::seeIndCb(
    sns_client *client, void *msg, uint32_t msgLen, void *cbData) {
  auto *obj = static_cast<SeeHelper *>(cbData);
  obj->handleSnsClientEventMsg(client, msg, msgLen);
}

void SeeHelper::seeRespCb(sns_client *client, sns_std_error error,
                              void *cbData) {
  auto *respCbData = static_cast<SeeRespCbData *>(cbData);
  respCbData->seeHelper->handleSeeResp(respCbData->txnId, error);
  memoryFree(cbData);
}

bool SeeHelper::registerSensor(
    SensorType sensorType, const sns_std_suid& suid, bool resample,
    bool *prevRegistered) {
  CHRE_ASSERT(sensorType != SensorType::Unknown);
  CHRE_ASSERT(prevRegistered != nullptr);
  bool success = false;

  bool doResample = resample && sensorTypeIsContinuous(sensorType);
  if (doResample && !mResamplerSuid.has_value()) {
    LOGE("Unable to use resampler without its SUID");
  } else {
    // The SUID to make request to.
    const sns_std_suid& reqSuid = doResample ? mResamplerSuid.value() : suid;

    // Check whether the SUID/SensorType pair has been previously registered.
    // Also count how many other SensorTypes the SUID has been registered with.
    *prevRegistered = false;
    size_t suidRegCount = 0;
    for (const auto& sensorInfo : mSensorInfos) {
      if (suidsMatch(reqSuid, sensorInfo.suid)) {
        suidRegCount++;
        if (sensorInfo.sensorType == sensorType) {
          *prevRegistered = true;
        }
      }
    }

    // Initialize another SEE client if the SUID has been previously
    // registered with more SensorTypes than the number of SEE clients can
    // disambiguate.
    bool clientAvailable = true;
    if (mSeeClients.size() <= suidRegCount) {
      sns_client *client;
      clientAvailable = waitForService(&client);
      if (clientAvailable) {
        clientAvailable = mSeeClients.push_back(client);
      }
    }

    // Add a new entry only if this SUID/SensorType pair hasn't been registered.
    if (!*prevRegistered && clientAvailable) {
      SensorInfo sensorInfo = {
        .suid = reqSuid,
        .sensorType = sensorType,
        .client = mSeeClients[suidRegCount],
        .physicalSuid = suid,
      };
      success = mSensorInfos.push_back(sensorInfo);
    }
  }
  return success;
}

bool SeeHelper::sensorIsRegistered(SensorType sensorType) const {
  return (getSensorInfo(sensorType) != nullptr);
}

bool SeeHelper::waitForService(sns_client **client,
                               Microseconds timeout) {
  CHRE_ASSERT(client);

  // TODO: add error_cb and error_cb_data.
  int status = mSnsClientApi->sns_client_init(
      client, timeout.getMilliseconds(),
      SeeHelper::seeIndCb, this /* ind_cb_data */,
      nullptr /* error_cb */, nullptr /* error_cb_data */);

  bool success = (status == 0);
  if (!success) {
    LOGE("Failed to initialize the sensor client: %d", status);
  }
  return success;
}

bool SeeHelper::initRemoteProcSensor() {
  bool success = false;

  const char *kRemoteProcType = "remote_proc_state";
  DynamicVector<sns_std_suid> suids;
  if (!findSuidSync(kRemoteProcType, &suids)) {
    LOGE("Failed to find sensor '%s'", kRemoteProcType);
  } else {
    mRemoteProcSuid = suids[0];

    uint32_t msgId = SNS_REMOTE_PROC_STATE_MSGID_SNS_REMOTE_PROC_STATE_CONFIG;
    constexpr size_t kBufferSize = sns_remote_proc_state_config_size;
    pb_byte_t msgBuffer[kBufferSize];
    size_t msgLen;
    if (encodeSnsRemoteProcSensorConfig(msgBuffer, kBufferSize, &msgLen,
                                        SNS_STD_CLIENT_PROCESSOR_APSS)) {
      success = sendReq(mRemoteProcSuid.value(),
                        nullptr /* syncData */, nullptr /* syncDataType */,
                        msgId, msgBuffer, msgLen,
                        false /* batchValid */, 0 /* batchPeriodUs */,
                        false /* passive */, false /* waitForIndication */);
      if (!success) {
        LOGE("Failed to request '%s' config", kRemoteProcType);
      }
    }
  }

  return success;
}

bool SeeHelper::initResamplerSensor() {
  bool success = false;

  const char *kResamplerType = "resampler";
  DynamicVector<sns_std_suid> suids;
  if (!findSuidSync(kResamplerType, &suids)) {
    LOGE("Failed to find sensor '%s'", kResamplerType);
  } else {
    mResamplerSuid = suids[0];
    success = true;
  }
  return success;
}

const SeeHelper::SensorInfo *SeeHelper::getSensorInfo(
    SensorType sensorType) const {
  for (const auto& sensorInfo : mSensorInfos) {
    if (sensorInfo.sensorType == sensorType) {
      return &sensorInfo;
    }
  }
  return nullptr;
}

}  // namespace chre