/*
 * Copyright (C) 2015 Intel Corp
 *
 * 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 <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 <string.h>
#include <linux/input.h>
#include <utils/Atomic.h>
#include <utils/Log.h>

#include "sensors.h"
#include "AlsSensor.h"

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

#define DELAY_OUT_TIME          0x7FFFFFFF
#define LIGHT_SENSOR_POLLTIME   2000000000

#define SENSORS_LIGHT_HANDLE    (ID_L)
#define SENSORS_TILT_HANDLE     (ID_T)
/*****************************************************************************/

/* The SENSORS Module */
static struct sensor_t sSensorList[] = {
        { "TSL2584 Ambient light sensor",
          "ams, ltd.",
          1, SENSORS_LIGHT_HANDLE,
          SENSOR_TYPE_LIGHT, 65535.0f, 1.0f, 0.015f,
          0, 0, 0, SENSOR_STRING_TYPE_LIGHT, NULL,
          5000000, SENSOR_FLAG_ON_CHANGE_MODE, { } },
};

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 ARRAY_SIZE(sSensorList);
}

static struct hw_module_methods_t sensors_module_methods = {
        open: open_sensors
};

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: "Intel MVN Sensor module",
                author: "Intel MVN Company",
                methods: &sensors_module_methods,
                dso: 0,
                reserved: {},
        },
        get_sensors_list: sensors__get_sensors_list,
};

struct sensors_poll_context_t {
#ifdef HAL_VERSION_GE_1_0
    struct sensors_poll_device_1 device; // must be first
#else
    struct sensors_poll_device_t device; // must be first
#endif
    sensors_poll_context_t();
    ~sensors_poll_context_t();
    int activate(int handle, int enabled);
    int setDelay(int handle, int64_t ns);
#ifdef HAL_VERSION_GT_1_0
    int batch(int handle, int flags, int64_t period_ns, int64_t timeout);
    int flush(int handle);
#endif
    int pollEvents(sensors_event_t* data, int count);
    bool getInitialized() { return mInitialized; };

private:
    bool mInitialized;

    enum {
        light = 0,
        numSensorDrivers,       /* wake pipe goes here */
        flushPipe,              /* flush pipe goes here */
        numFds,
    };

    static const size_t wake = numFds - 2;
    static const char WAKE_MESSAGE = 'W';
    struct pollfd mPollFds[numFds];
    int mWritePipeFd;
    int mFlushWritePipeFd;
    SensorBase* mSensors[numSensorDrivers];

    int handleToDriver(int handle) const {
        switch (handle) {
            case ID_L:
                return light;
        }
        return -EINVAL;
    }
};

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

sensors_poll_context_t::sensors_poll_context_t()
{
    FUNC_LOG;
    mInitialized = false;
    /* Must clean this up early or else the destructor will make a mess */
    memset(mSensors, 0, sizeof(mSensors));

    mSensors[light] = new LightSensor();
    mPollFds[light].fd = mSensors[light]->getFd();
    mPollFds[light].events = POLLIN;
    mPollFds[light].revents = 0;

    int wakeFds[2];
    int result = pipe(wakeFds);
    ALOGE_IF(result<0, "error creating wake pipe (%s)", strerror(errno));
    result = fcntl(wakeFds[0], F_SETFL, O_NONBLOCK);
    ALOGE_IF(result<0, "error setting wakeFds[0] access mode (%s)", strerror(errno));
    result = fcntl(wakeFds[1], F_SETFL, O_NONBLOCK);
    ALOGE_IF(result<0, "error setting wakeFds[1] access mode (%s)", strerror(errno));
    mWritePipeFd = wakeFds[1];

    mPollFds[wake].fd = wakeFds[0];
    mPollFds[wake].events = POLLIN;
    mPollFds[wake].revents = 0;

    int flushFds[2];
    result = pipe(flushFds);
    ALOGE_IF(result<0, "error creating flush pipe (%s)", strerror(errno));
    result = fcntl(flushFds[0], F_SETFL, O_NONBLOCK);
    ALOGE_IF(result<0, "error setting flushFds[0] access mode (%s)", strerror(errno));
    result = fcntl(flushFds[1], F_SETFL, O_NONBLOCK);
    ALOGE_IF(result<0, "error setting flushFds[1] access mode (%s)", strerror(errno));
    mFlushWritePipeFd = flushFds[1];

    mPollFds[flushPipe].fd = flushFds[0];
    mPollFds[flushPipe].events = POLLIN;
    mPollFds[flushPipe].revents = 0;
    mInitialized = true;
}

sensors_poll_context_t::~sensors_poll_context_t()
{
    FUNC_LOG;
    for (int i=0 ; i<numSensorDrivers ; i++) {
        delete mSensors[i];
    }
    close(mPollFds[wake].fd);
    close(mWritePipeFd);
    close(mPollFds[flushPipe].fd);
    close(mFlushWritePipeFd);
    mInitialized = false;
}

int sensors_poll_context_t::activate(int handle, int enabled)
{
    FUNC_LOG;
    if (!mInitialized) return -EINVAL;
    int index = handleToDriver(handle);
    if (index < 0) return index;
    int err =  mSensors[index]->enable(handle, enabled);
    if (!err) {
        const char wakeMessage(WAKE_MESSAGE);
        int result = write(mWritePipeFd, &wakeMessage, 1);
        ALOGE_IF(result<0, "error sending wake message (%s)", strerror(errno));
    }
    return err;
}

int sensors_poll_context_t::setDelay(int handle, int64_t ns)
{
    FUNC_LOG;
    int index = handleToDriver(handle);
    if (index < 0) return index;
    return mSensors[index]->setDelay(handle, ns);
}

#ifdef HAL_VERSION_GT_1_0
int sensors_poll_context_t::batch(int handle, int flags, int64_t period_ns, int64_t timeout)
{
    FUNC_LOG;
    int index = handleToDriver(handle);
    if (index < 0) return index;
    return mSensors[index]->batch(handle, flags, period_ns, timeout);
}

int sensors_poll_context_t::flush(int handle)
{
    FUNC_LOG;
    int result;
    sensors_event_t flush_event_data;

    int index = handleToDriver(handle);
    if (index < 0) return index;

    result = mSensors[index]->isActivated(handle);
    if (!result)
        return -EINVAL;

    flush_event_data.sensor = 0;
    flush_event_data.timestamp = 0;
    flush_event_data.meta_data.sensor = handle;
    flush_event_data.meta_data.what = META_DATA_FLUSH_COMPLETE;
    flush_event_data.type = SENSOR_TYPE_META_DATA;
    flush_event_data.version = META_DATA_VERSION;

    result = write(mFlushWritePipeFd, &flush_event_data, sizeof(sensors_event_t));
    ALOGE_IF(result<0, "error sending flush event data (%s)", strerror(errno));

    return (result >= 0 ? 0 : result);
}
#endif

int sensors_poll_context_t::pollEvents(sensors_event_t* data, int count)
{
    FUNC_LOG;
    int nbEvents = 0;
    int n = 0;
    do {
        for (int i=0 ; count && i<numSensorDrivers; i++) {
            SensorBase* const sensor(mSensors[i]);
            if ((mPollFds[i].revents & POLLIN) || (sensor->hasPendingEvents())) {
                int nb;
                nb = sensor->readEvents(data, count);
                if (nb < count) {
                    mPollFds[i].revents = 0;
                }
                count -= nb;
                nbEvents += nb;
                data += nb;
            }
        }

        /* flush event data */
        if (count) {
            if (mPollFds[flushPipe].revents & POLLIN) {
                int nb = read(mPollFds[flushPipe].fd, data, count * sizeof(sensors_event_t));
                if (nb < 0) {
                    ALOGE("error reading from flush pipe (%s)", strerror(errno));
                    return -errno;
                }
                nb = nb/sizeof(sensors_event_t);
                mPollFds[flushPipe].revents = 0;
                count -= nb;
                nbEvents += nb;
                data += nb;
            }
        }

        if (count) {
            ALOGV("%s: start poll syscall to kernel", __func__);
            n = poll(mPollFds, numFds, nbEvents ? 0 : -1);
            if (n < 0) {
                ALOGE("poll() failed (%s)", strerror(errno));
                return -errno;
            }

            if (mPollFds[wake].revents & POLLIN) {
                char msg;
                int result = read(mPollFds[wake].fd, &msg, 1);
                ALOGE_IF(result<0, "error reading from wake pipe (%s)", strerror(errno));
                ALOGE_IF(msg != WAKE_MESSAGE, "unknown message on wake queue (0x%02x)", int(msg));
                mPollFds[wake].revents = 0;
            }
        }
    } while (n && count);
    return nbEvents;
}

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

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)
{
    FUNC_LOG;
    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)
{
    FUNC_LOG;
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    return ctx->setDelay(handle, ns);
}

#ifdef HAL_VERSION_GT_1_0
static int poll__batch(struct sensors_poll_device_1 *dev,
                       int handle, int flags, int64_t period_ns, int64_t timeout)
{
    FUNC_LOG;
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    return ctx->batch(handle, flags, period_ns, timeout);
}

static int poll_flush(struct sensors_poll_device_1 *dev, int handle)
{
    FUNC_LOG;
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    return ctx->flush(handle);
}
#endif

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

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

/** 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();

    if (!dev->getInitialized()) {
        ALOGE("Failed to open the sensors (%s)", id);
        return status;
    }
#ifdef HAL_VERSION_GE_1_0
    memset(&dev->device, 0, sizeof(sensors_poll_device_1));
#else
    memset(&dev->device, 0, sizeof(sensors_poll_device_t));
#endif

    dev->device.common.tag = HARDWARE_DEVICE_TAG;
#ifdef ANDROID_KK
    dev->device.common.version = SENSORS_DEVICE_API_VERSION_1_1;
#elif defined(ANDROID_JBMR2)
    dev->device.common.version = SENSORS_DEVICE_API_VERSION_1_0;
#else
    dev->device.common.version = SENSORS_DEVICE_API_VERSION_1_3;
#endif
    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;
#ifdef HAL_VERSION_GT_1_0
    dev->device.batch           = poll__batch;
    dev->device.flush           = poll_flush;
#endif
    dev->device.poll            = poll__poll;

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

    return status;
}