/*
* Copyright (C) 2014 Invensense, Inc.
*
* 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.
*/

#define FUNC_LOG LOGV("%s", __PRETTY_FUNCTION__)

#include <hardware_legacy/power.h>
#include <hardware/sensors.h>
#include <fcntl.h>
#include <errno.h>
#include <dirent.h>
#include <math.h>
#include <poll.h>
#include <pthread.h>
#include <stdlib.h>

#include <sys/queue.h>

#include <linux/input.h>

#include <cutils/atomic.h>
#include <utils/Log.h>
#include <utils/SystemClock.h>

#include "sensors.h"
#include "MPLSensor.h"

/*
 * Vendor-defined Accel Load Calibration File Method
 * @param[out] Accel bias, length 3.  In HW units scaled by 2^16 in body frame
 * @return '0' for a successful load, '1' otherwise
 * example: int AccelLoadConfig(long* offset);
 * End of Vendor-defined Accel Load Cal Method
 */

/*****************************************************************************/
/* The SENSORS Module */

#ifdef ENABLE_DMP_SCREEN_AUTO_ROTATION
#define LOCAL_SENSORS (NumSensors + 1)
#else
#define LOCAL_SENSORS (NumSensors)
#endif

struct handle_entry {
    SIMPLEQ_ENTRY(handle_entry) entries;
    int handle;
};

static SIMPLEQ_HEAD(simplehead, handle_entry) pending_flush_items_head;
struct simplehead *headp;
static pthread_mutex_t flush_handles_mutex = PTHREAD_MUTEX_INITIALIZER;

static const char *smdWakelockStr = "significant motion";

static struct sensor_t sSensorList[LOCAL_SENSORS];
static int sensors = (sizeof(sSensorList) / sizeof(sensor_t));

static int open_sensors(const struct hw_module_t* module, const char* id,
                        struct hw_device_t** device);

static int sensors__get_sensors_list(struct sensors_module_t* module,
                                     struct sensor_t const** list)
{
    *list = sSensorList;
    return sensors;
}

static struct hw_module_methods_t sensors_module_methods = {
        open: open_sensors
};

static int sensors_set_operation_mode(unsigned int mode)
{
    LOGI("%s", __FUNCTION__);
    LOGI("%s: stub function: ignoring mode request (%d)", __FUNCTION__,
                 mode);
    return 0;
}

struct sensors_module_t HAL_MODULE_INFO_SYM = {
        common: {
                tag: HARDWARE_MODULE_TAG,
                version_major: 1,
                version_minor: 0,
                id: SENSORS_HARDWARE_MODULE_ID,
                name: "Invensense module",
                author: "Invensense Inc.",
                methods: &sensors_module_methods,
                dso: NULL,
                reserved: {0}
        },
        get_sensors_list: sensors__get_sensors_list,
        set_operation_mode: sensors_set_operation_mode
};

struct sensors_poll_context_t {
    sensors_poll_device_1_t device; // must be first

    sensors_poll_context_t();
    ~sensors_poll_context_t();
    int activate(int handle, int enabled);
    int setDelay(int handle, int64_t ns);
    int pollEvents(sensors_event_t* data, int count);
    int query(int what, int *value);
    int batch(int handle, int flags, int64_t period_ns, int64_t timeout);
#if defined ANDROID_KITKAT || defined ANDROID_LOLLIPOP
    int flush(int handle);
#endif
    int64_t getTimestamp();

private:
    enum {
        mpl = 0,
        compass,
        dmpOrient,
        dmpSign,
        dmpPed,
        numSensorDrivers,
        numFds,
    };

    struct pollfd mPollFds[numFds];
    SensorBase *mSensor;
    CompassSensor *mCompassSensor;

    /* Significant Motion wakelock support */
    bool mSMDWakelockHeld;
};

/******************************************************************************/

sensors_poll_context_t::sensors_poll_context_t() {
    VFUNC_LOG;

    /* TODO: Handle external pressure sensor */
    mCompassSensor = new CompassSensor();
    MPLSensor *mplSensor = new MPLSensor(mCompassSensor);

    /* No significant motion events pending yet */
    mSMDWakelockHeld = false;

   /* For Vendor-defined Accel Calibration File Load
    * Use the Following Constructor and Pass Your Load Cal File Function
    *
    * MPLSensor *mplSensor = new MPLSensor(mCompassSensor, AccelLoadConfig);
    */

    // Initialize pending flush queue
    SIMPLEQ_INIT(&pending_flush_items_head);

    // populate the sensor list
    sensors =
            mplSensor->populateSensorList(sSensorList, sizeof(sSensorList));

    mSensor = mplSensor;
    mPollFds[mpl].fd = mSensor->getFd();
    mPollFds[mpl].events = POLLIN;
    mPollFds[mpl].revents = 0;

    mPollFds[compass].fd = mCompassSensor->getFd();
    mPollFds[compass].events = POLLIN;
    mPollFds[compass].revents = 0;

    mPollFds[dmpOrient].fd = ((MPLSensor*) mSensor)->getDmpOrientFd();
    mPollFds[dmpOrient].events = POLLPRI;
    mPollFds[dmpOrient].revents = 0;

    mPollFds[dmpSign].fd = ((MPLSensor*) mSensor)->getDmpSignificantMotionFd();
    mPollFds[dmpSign].events = POLLPRI;
    mPollFds[dmpSign].revents = 0;

    mPollFds[dmpPed].fd = ((MPLSensor*) mSensor)->getDmpPedometerFd();
    mPollFds[dmpPed].events = POLLPRI;
    mPollFds[dmpPed].revents = 0;
}

sensors_poll_context_t::~sensors_poll_context_t() {
    FUNC_LOG;
    delete mSensor;
    delete mCompassSensor;
    for (int i = 0; i < numSensorDrivers; i++) {
        close(mPollFds[i].fd);
    }
}

int sensors_poll_context_t::activate(int handle, int enabled) {
    FUNC_LOG;

    int err;
    err = mSensor->enable(handle, enabled);
    return err;
}

int sensors_poll_context_t::setDelay(int handle, int64_t ns)
{
    FUNC_LOG;
    return mSensor->setDelay(handle, ns);
}

int64_t sensors_poll_context_t::getTimestamp()
{
    return android::elapsedRealtimeNano();
}

int sensors_poll_context_t::pollEvents(sensors_event_t *data, int count)
{
    VHANDLER_LOG;

    int nbEvents = 0;
    int nb, polltime = -1;

    if (mSMDWakelockHeld) {
        mSMDWakelockHeld = false;
        release_wake_lock(smdWakelockStr);
    }

    struct handle_entry *handle_element;
    pthread_mutex_lock(&flush_handles_mutex);
    if (!SIMPLEQ_EMPTY(&pending_flush_items_head)) {
        sensors_event_t flushCompleteEvent;
        flushCompleteEvent.type = SENSOR_TYPE_META_DATA;
        flushCompleteEvent.sensor = 0;
        handle_element = SIMPLEQ_FIRST(&pending_flush_items_head);
        flushCompleteEvent.meta_data.sensor = handle_element->handle;
        SIMPLEQ_REMOVE_HEAD(&pending_flush_items_head, entries);
        free(handle_element);
        memcpy(data, (void *) &flushCompleteEvent, sizeof(flushCompleteEvent));
        LOGI_IF(1, "pollEvents() Returning fake flush event completion for handle %d",
                flushCompleteEvent.meta_data.sensor);
        pthread_mutex_unlock(&flush_handles_mutex);
        return 1;
    }
    pthread_mutex_unlock(&flush_handles_mutex);

    polltime = ((MPLSensor*) mSensor)->getStepCountPollTime();

    // look for new events
    nb = poll(mPollFds, numSensorDrivers, polltime);
    LOGI_IF(0, "poll nb=%d, count=%d, pt=%d ts=%lld", nb, count, polltime, getTimestamp());
    if (nb == 0 && count > 0) {
        /* to see if any step counter events */
        if(((MPLSensor*) mSensor)->hasStepCountPendingEvents() == true) {
            nb = ((MPLSensor*) mSensor)->readDmpPedometerEvents(
                            data, count, ID_SC, 0);
            LOGI_IF(SensorBase::HANDLER_DATA, "sensors_mpl:readStepCount() - "
                    "nb=%d, count=%d, nbEvents=%d, data->timestamp=%lld, ",
                    nb, count, nbEvents, data->timestamp);
            if (nb > 0) {
                count -= nb;
                nbEvents += nb;
                data += nb;
            }
        }
    } else while (nb > 0) {
        for (int i = 0; count && i < numSensorDrivers; i++) {
            if (mPollFds[i].revents & (POLLIN | POLLPRI)) {
                nb = 0;
                if (i == mpl) {
                    ((MPLSensor*) mSensor)->buildMpuEvent();
                    mPollFds[i].revents = 0;
                } else if (i == compass) {
                    ((MPLSensor*) mSensor)->buildCompassEvent();
                    mPollFds[i].revents = 0;
                } else if (i == dmpOrient) {
                    nb = ((MPLSensor*)mSensor)->
                                        readDmpOrientEvents(data, count);
                    mPollFds[dmpOrient].revents= 0;
                    if (isDmpScreenAutoRotationEnabled() && nb > 0) {
                        count -= nb;
                        nbEvents += nb;
                        data += nb;
                    }
                } else if (i == dmpSign) {
                    nb = ((MPLSensor*) mSensor)->
                                    readDmpSignificantMotionEvents(data, count);
                    mPollFds[i].revents = 0;
                    if (nb) {
                        if (!mSMDWakelockHeld) {
                            /* Hold wakelock until Sensor Services reads event */
                            acquire_wake_lock(PARTIAL_WAKE_LOCK, smdWakelockStr);
                            LOGI_IF(1, "HAL: grabbed %s wakelock", smdWakelockStr);
                            mSMDWakelockHeld = true;
                        }

                        count -= nb;
                        nbEvents += nb;
                        data += nb;
                    }
                } else if (i == dmpPed) {
                    nb = ((MPLSensor*) mSensor)->readDmpPedometerEvents(
                            data, count, ID_P, 0);
                    mPollFds[i].revents = 0;
                    count -= nb;
                    nbEvents += nb;
                    data += nb;
                }

                if(nb == 0) {
                    nb = ((MPLSensor*) mSensor)->readEvents(data, count);
                    LOGI_IF(0, "sensors_mpl:readEvents() - "
                            "i=%d, nb=%d, count=%d, nbEvents=%d, "
                            "data->timestamp=%lld, data->data[0]=%f,",
                            i, nb, count, nbEvents, data->timestamp,
                            data->data[0]);
                    if (nb > 0) {
                        count -= nb;
                        nbEvents += nb;
                        data += nb;
                    }
                }
            }
        }

        /* to see if any step counter events */
        if(((MPLSensor*) mSensor)->hasStepCountPendingEvents() == true) {
            nb = 0;
            nb = ((MPLSensor*) mSensor)->readDmpPedometerEvents(
                            data, count, ID_SC, 0);
            LOGI_IF(SensorBase::HANDLER_DATA, "sensors_mpl:readStepCount() - "
                    "nb=%d, count=%d, nbEvents=%d, data->timestamp=%lld, ",
                    nb, count, nbEvents, data->timestamp);
            if (nb > 0) {
                count -= nb;
                nbEvents += nb;
                data += nb;
            }
        }
        if (count > 0) {
            // We still have room for more events, try an immediate poll for more data
            nb = poll(mPollFds, numSensorDrivers, 0);
        } else {
            nb = 0;
        }
    }
    return nbEvents;
}

int sensors_poll_context_t::query(int what, int* value)
{
    FUNC_LOG;
    return mSensor->query(what, value);
}

int sensors_poll_context_t::batch(int handle, int flags, int64_t period_ns,
                                  int64_t timeout)
{
    FUNC_LOG;
    return mSensor->batch(handle, flags, period_ns, timeout);
}

#if defined ANDROID_KITKAT || defined ANDROID_LOLLIPOP

void inv_pending_flush(int handle) {
    struct handle_entry *the_entry;
    pthread_mutex_lock(&flush_handles_mutex);
    the_entry = (struct handle_entry*) malloc(sizeof(struct handle_entry));
    if (the_entry != NULL) {
        LOGI_IF(0, "Inserting %d into pending list", handle);
        the_entry->handle = handle;
        SIMPLEQ_INSERT_TAIL(&pending_flush_items_head, the_entry, entries);
    } else {
        LOGE("ERROR malloc'ing space for pending handler flush entry");
    }
    pthread_mutex_unlock(&flush_handles_mutex);
}

int sensors_poll_context_t::flush(int handle)
{
    FUNC_LOG;
    return mSensor->flush(handle);
}
#endif

/******************************************************************************/

static int poll__close(struct hw_device_t *dev)
{
    FUNC_LOG;
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    if (ctx) {
        delete ctx;
    }
    return 0;
}

static int poll__activate(struct sensors_poll_device_t *dev,
                          int handle, int enabled)
{
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    return ctx->activate(handle, enabled);
}

static int poll__setDelay(struct sensors_poll_device_t *dev,
                          int handle, int64_t ns)
{
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    int s= ctx->setDelay(handle, ns);
    return s;
}

static int poll__poll(struct sensors_poll_device_t *dev,
                      sensors_event_t* data, int count)
{
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    return ctx->pollEvents(data, count);
}

static int poll__query(struct sensors_poll_device_1 *dev,
                      int what, int *value)
{
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    return ctx->query(what, value);
}

static int poll__batch(struct sensors_poll_device_1 *dev,
                      int handle, int flags, int64_t period_ns, int64_t timeout)
{
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    return ctx->batch(handle, flags, period_ns, timeout);
}

#if defined ANDROID_KITKAT || defined ANDROID_LOLLIPOP
static int poll__flush(struct sensors_poll_device_1 *dev,
                      int handle)
{
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    int status = ctx->flush(handle);
    if (handle == SENSORS_STEP_COUNTER_HANDLE) {
        LOGI_IF(0, "creating flush completion event for handle %d", handle);
        inv_pending_flush(handle);
        return 0;
    }
    return status;
}
#endif
/******************************************************************************/

/** Open a new instance of a sensor device using name */
static int open_sensors(const struct hw_module_t* module, const char* id,
                        struct hw_device_t** device)
{
    FUNC_LOG;
    int status = -EINVAL;
    sensors_poll_context_t *dev = new sensors_poll_context_t();

    memset(&dev->device, 0, sizeof(sensors_poll_device_1));

    dev->device.common.tag = HARDWARE_DEVICE_TAG;
    dev->device.common.version  = SENSORS_DEVICE_API_VERSION_1_3;
    dev->device.flush           = poll__flush;
    dev->device.common.module   = const_cast<hw_module_t*>(module);
    dev->device.common.close    = poll__close;
    dev->device.activate        = poll__activate;
    dev->device.setDelay        = poll__setDelay;
    dev->device.poll            = poll__poll;
    dev->device.batch           = poll__batch;

    *device = &dev->device.common;
    status = 0;

    return status;
}