/*
 * 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 <cinttypes>

#include <chre.h>

#include "calibration/nano_calibration/aosp_nano_cal_parameters.h"
#include "calibration/nano_calibration/nano_calibration.h"
#include "calibration/online_calibration/accelerometer/accel_offset_cal/accel_offset_cal.h"
#include "calibration/online_calibration/gyroscope/gyro_offset_over_temp_cal/gyro_offset_over_temp_cal.h"
#include "calibration/online_calibration/magnetometer/mag_diverse_cal/mag_diverse_cal.h"
#include "chre/util/macros.h"
#include "chre/util/nanoapp/log.h"
#include "chre/util/nanoapp/sensor.h"
#include "chre/util/time.h"

#define LOG_TAG "[ImuCal]"

using chre::Milliseconds;
using chre::Seconds;

namespace {

struct SensorState {
  uint32_t handle;
  const uint8_t type;
  bool isInitialized;
  bool enable;
  // Sample interval/latency defined in nanoseconds
  uint64_t interval;
  uint64_t highPerformanceLatency;
  uint64_t standByLatency;
};

// Dynamic sensor latency settings.
constexpr uint64_t kDefaultHighPerformanceLatency =
    Milliseconds(500).toRawNanoseconds();

constexpr uint64_t kDefaultStandByLatency = Seconds(1).toRawNanoseconds();

// Tracks the ON/OFF state of the gyro.
bool gGyroEnabled = false;

// Defines the indices for the following sensor array definition.
enum SensorIndex {
  SENSOR_INDEX_TEMP = 0,
  SENSOR_INDEX_ACCEL = 1,
  SENSOR_INDEX_GYRO = 2,
  SENSOR_INDEX_MAG = 3,
};

SensorState gSensor[] = {
    [SENSOR_INDEX_TEMP] =
        {
            .type = CHRE_SENSOR_TYPE_ACCELEROMETER_TEMPERATURE,
            .enable = true,
            .interval = Milliseconds(500).toRawNanoseconds(),
            .highPerformanceLatency = 0,
            // TODO(b/63908396): this sensor should be disabled in stand-by mode
            .standByLatency = Seconds(60).toRawNanoseconds(),
        },
    [SENSOR_INDEX_ACCEL] =
        {
            .type = CHRE_SENSOR_TYPE_UNCALIBRATED_ACCELEROMETER,
            .enable = true,
            .interval = Milliseconds(10).toRawNanoseconds(),
            .highPerformanceLatency = kDefaultHighPerformanceLatency,
            .standByLatency = kDefaultStandByLatency,
        },
    [SENSOR_INDEX_GYRO] =
        {
            .type = CHRE_SENSOR_TYPE_UNCALIBRATED_GYROSCOPE,
            .enable = true,
            .interval = Milliseconds(10).toRawNanoseconds(),
            .highPerformanceLatency = kDefaultHighPerformanceLatency,
            .standByLatency = kDefaultHighPerformanceLatency,
        },
    [SENSOR_INDEX_MAG] =
        {
            .type = CHRE_SENSOR_TYPE_UNCALIBRATED_GEOMAGNETIC_FIELD,
            .enable = true,
            .interval = Milliseconds(20).toRawNanoseconds(),
            .highPerformanceLatency = kDefaultHighPerformanceLatency,
            .standByLatency = kDefaultStandByLatency,
        },
};

// Container for all runtime calibration algorithms.
nano_calibration::NanoSensorCal gNanoCal;

// Runtime calibration algorithm objects used in gNanoCal.
online_calibration::AccelOffsetCal gAccelCal;
online_calibration::GyroOffsetOtcCal gGyroCal;
online_calibration::MagDiverseCal gMagCal;

// Runtime calibration initialization state.
bool gNanoCalInitialized = false;

// Configures the Nanoapp's sensors with special adjustment of accel/gyro/mag
// sensor latency based on whether high-performance mode is requested.
void nanoappDynamicConfigure(bool highPerformance) {
  LOGD("Dynamic sensor configuration: %s.",
       (highPerformance) ? "high-performance" : "stand-by");

  // Configures all sensors.
  for (size_t i = 0; i < ARRAY_SIZE(gSensor); i++) {
    SensorState &sensor = gSensor[i];
    if (!sensor.enable || !sensor.isInitialized) {
      // Only configure enabled sensors.
      continue;
    }

    // Update the requested latency according to the requested mode.
    uint64_t latency = (highPerformance) ? sensor.highPerformanceLatency
                                         : sensor.standByLatency;

    bool configStatus = chreSensorConfigure(
        sensor.handle, CHRE_SENSOR_CONFIGURE_MODE_PASSIVE_CONTINUOUS,
        sensor.interval, latency);

    if (!configStatus) {
      LOGE("Requested config. failed: handle %" PRIu32 ", interval %" PRIu64
           " nanos, latency %" PRIu64 " nanos",
           sensor.handle, sensor.interval, latency);
    }
  }
}
}  // namespace

bool nanoappStart() {
  LOGI("App started on platform ID %" PRIx64, chreGetPlatformId());
  gNanoCalInitialized = false;

  // Initialize all sensors to populate their handles.
  for (size_t i = 0; i < ARRAY_SIZE(gSensor); i++) {
    SensorState &sensor = gSensor[i];
    sensor.isInitialized = chreSensorFindDefault(sensor.type, &sensor.handle);

    // TODO: Handle error condition.
    if (!sensor.isInitialized) {
      LOGE("Sensor handle %" PRIu32 " failed to initialize.", sensor.handle);
    }
  }

  // Determine initial gyro state
  struct chreSensorSamplingStatus status;
  if (chreGetSensorSamplingStatus(gSensor[SENSOR_INDEX_GYRO].handle, &status)) {
    gGyroEnabled = status.enabled;
  } else {
    LOGE("Failed to get gyro sampling status.");
  }

  // Configure the Nanoapp's sensors.
  nanoappDynamicConfigure(gGyroEnabled);

  // Checks to see if the accelerometer and magnetometer were initialized.
  bool accelIsInitialized = gSensor[SENSOR_INDEX_ACCEL].isInitialized;
  bool magIsInitialized = gSensor[SENSOR_INDEX_MAG].isInitialized;

  // Checks for the minimimal conditions for a gNanoCal to have an active
  // calibration algorithm running.
  //  Sensor Requirements:
  //  - GyroCal:  accelerometer, gyroscope, magnetometer [optional]
  //  - OTC-Gyro: GyroCal required sensors + temperature
  //  - AccelCal: accelerometer
  //  - MagCal:   magnetometer
  if (accelIsInitialized || magIsInitialized) {
    // Initializes the calibration algorithms with their respective tuning
    // parameters.
    gAccelCal.Initialize(nano_calibration::kAccelCalParameters);
    gGyroCal.Initialize(nano_calibration::kGyroCalParameters,
                        nano_calibration::kGyroOtcParameters);
    gMagCal.Initialize(nano_calibration::kMagCalParameters,
                       nano_calibration::kMagDiversityParameters);

    // Initializes the NanoSensorCal wrapper.
    gNanoCal.Initialize(&gAccelCal, &gGyroCal, &gMagCal);
    gNanoCalInitialized = true;
    LOGI("Runtime calibration algorithms initialized.");
  } else {
    LOGE(
        "None of the required sensors to enable a runtime calibration were "
        "successfully initialized.");
  }

  return true;
}

void nanoappHandleEvent(uint32_t senderInstanceId, uint16_t eventType,
                        const void *eventData) {
  if (!gNanoCalInitialized) {
    return;
  }

  switch (eventType) {
    case CHRE_EVENT_SENSOR_UNCALIBRATED_ACCELEROMETER_DATA:
    case CHRE_EVENT_SENSOR_UNCALIBRATED_GYROSCOPE_DATA:
    case CHRE_EVENT_SENSOR_UNCALIBRATED_GEOMAGNETIC_FIELD_DATA: {
      gNanoCal.HandleSensorSamples(
          eventType, static_cast<const chreSensorThreeAxisData *>(eventData));
      break;
    }

    case CHRE_EVENT_SENSOR_ACCELEROMETER_TEMPERATURE_DATA: {
      gNanoCal.HandleTemperatureSamples(
          eventType, static_cast<const chreSensorFloatData *>(eventData));
      break;
    }

    case CHRE_EVENT_SENSOR_SAMPLING_CHANGE: {
      const auto *ev =
          static_cast<const chreSensorSamplingStatusEvent *>(eventData);

      // Is this the gyro? Check the handle.
      if (gSensor[SENSOR_INDEX_GYRO].isInitialized &&
          ev->sensorHandle == gSensor[SENSOR_INDEX_GYRO].handle &&
          ev->status.enabled != gGyroEnabled) {
        // Modify sensor latency based on whether Gyro is enabled.
        gGyroEnabled = ev->status.enabled;
        nanoappDynamicConfigure(gGyroEnabled);
      }
      break;
    }

    default:
      LOGW("Unhandled event %d", eventType);
      break;
  }
}

void nanoappEnd() {
  // TODO: Unsubscribe to sensors
  LOGI("Stopped");
}