/*
 * Copyright (C) 2010 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 <stdint.h>
#include <math.h>
#include <sys/types.h>

#include <utils/Atomic.h>
#include <utils/Errors.h>
#include <utils/Singleton.h>

#include <binder/BinderService.h>
#include <binder/Parcel.h>
#include <binder/IServiceManager.h>

#include <hardware/sensors.h>

#include "SensorDevice.h"
#include "SensorService.h"

#ifdef SYSFS_LIGHT_SENSOR
#include <fcntl.h>
#endif

namespace android {
// ---------------------------------------------------------------------------

ANDROID_SINGLETON_STATIC_INSTANCE(SensorDevice)

#ifdef SYSFS_LIGHT_SENSOR
#define DUMMY_ALS_HANDLE 0xdeadbeef
static ssize_t addDummyLightSensor(sensor_t const **list, ssize_t count) {
    struct sensor_t dummy_light =     {
                  name            : "CyanogenMod dummy light sensor",
                  vendor          : "CyanogenMod",
                  version         : 1,
                  handle          : DUMMY_ALS_HANDLE,
                  type            : SENSOR_TYPE_LIGHT,
                  maxRange        : 20,
                  resolution      : 0.1,
                  power           : 20,
    };
    void * new_list = malloc((count+1)*sizeof(sensor_t));
    new_list = memcpy(new_list, *list, count*sizeof(sensor_t));
    ((sensor_t *)new_list)[count] = dummy_light;
    *list = (sensor_t const *)new_list;
    count++;
    return count;
}
#endif

SensorDevice::SensorDevice()
    :  mSensorDevice(0),
       mSensorModule(0)
{
    status_t err = hw_get_module(SENSORS_HARDWARE_MODULE_ID,
            (hw_module_t const**)&mSensorModule);

    ALOGE_IF(err, "couldn't load %s module (%s)",
            SENSORS_HARDWARE_MODULE_ID, strerror(-err));

    if (mSensorModule) {
        err = sensors_open(&mSensorModule->common, &mSensorDevice);

        ALOGE_IF(err, "couldn't open device for module %s (%s)",
                SENSORS_HARDWARE_MODULE_ID, strerror(-err));

        if (mSensorDevice) {
            sensor_t const* list;
            ssize_t count = mSensorModule->get_sensors_list(mSensorModule, &list);
#ifdef SYSFS_LIGHT_SENSOR
            count = addDummyLightSensor(&list, count);
#endif
            mActivationCount.setCapacity(count);
            Info model;
            for (size_t i=0 ; i<size_t(count) ; i++) {
                mActivationCount.add(list[i].handle, model);
                mSensorDevice->activate(mSensorDevice, list[i].handle, 0);
            }
        }
    }
}

void SensorDevice::dump(String8& result, char* buffer, size_t SIZE)
{
    if (!mSensorModule) return;
    sensor_t const* list;
    ssize_t count = mSensorModule->get_sensors_list(mSensorModule, &list);

    snprintf(buffer, SIZE, "%d h/w sensors:\n", int(count));
    result.append(buffer);

    Mutex::Autolock _l(mLock);
    for (size_t i=0 ; i<size_t(count) ; i++) {
        const Info& info = mActivationCount.valueFor(list[i].handle);
        snprintf(buffer, SIZE, "handle=0x%08x, active-count=%d, rates(ms)={ ",
                list[i].handle,
                info.rates.size());
        result.append(buffer);
        for (size_t j=0 ; j<info.rates.size() ; j++) {
            snprintf(buffer, SIZE, "%4.1f%s",
                    info.rates.valueAt(j) / 1e6f,
                    j<info.rates.size()-1 ? ", " : "");
            result.append(buffer);
        }
        snprintf(buffer, SIZE, " }, selected=%4.1f ms\n",  info.delay / 1e6f);
        result.append(buffer);
    }
}

ssize_t SensorDevice::getSensorList(sensor_t const** list) {
    if (!mSensorModule) return NO_INIT;
    ssize_t count = mSensorModule->get_sensors_list(mSensorModule, list);
#ifdef SYSFS_LIGHT_SENSOR
    return addDummyLightSensor(list, count);
#else
    return count;
#endif
}

status_t SensorDevice::initCheck() const {
    return mSensorDevice && mSensorModule ? NO_ERROR : NO_INIT;
}

ssize_t SensorDevice::poll(sensors_event_t* buffer, size_t count) {
    if (!mSensorDevice) return NO_INIT;
    ssize_t c;
    do {
        c = mSensorDevice->poll(mSensorDevice, buffer, count);
    } while (c == -EINTR);
    return c;
}

status_t SensorDevice::activate(void* ident, int handle, int enabled)
{
    if (!mSensorDevice) return NO_INIT;
    status_t err(NO_ERROR);
    bool actuateHardware = false;

#ifdef SYSFS_LIGHT_SENSOR
    if (handle == DUMMY_ALS_HANDLE) {
        int nwr, ret, fd;
        char value[2];

        fd = open(SYSFS_LIGHT_SENSOR, O_RDWR);
        if(fd < 0)
            return -ENODEV;

        nwr = snprintf(value, 2, "%d\n", enabled ? 1 : 0);
        write(fd, value, nwr);
        close(fd);
        return 0;
    }
#endif

    Info& info( mActivationCount.editValueFor(handle) );


    ALOGD_IF(DEBUG_CONNECTIONS,
            "SensorDevice::activate: ident=%p, handle=0x%08x, enabled=%d, count=%d",
            ident, handle, enabled, info.rates.size());

    if (enabled) {
        Mutex::Autolock _l(mLock);
        ALOGD_IF(DEBUG_CONNECTIONS, "... index=%ld",
                info.rates.indexOfKey(ident));

        if (info.rates.indexOfKey(ident) < 0) {
            info.rates.add(ident, DEFAULT_EVENTS_PERIOD);
            if (info.rates.size() == 1) {
                actuateHardware = true;
            }
        } else {
            // sensor was already activated for this ident
        }
    } else {
        Mutex::Autolock _l(mLock);
        ALOGD_IF(DEBUG_CONNECTIONS, "... index=%ld",
                info.rates.indexOfKey(ident));

        ssize_t idx = info.rates.removeItem(ident);
        if (idx >= 0) {
            if (info.rates.size() == 0) {
                actuateHardware = true;
            }
        } else {
            // sensor wasn't enabled for this ident
        }
    }

    if (actuateHardware) {
        ALOGD_IF(DEBUG_CONNECTIONS, "\t>>> actuating h/w");

        err = mSensorDevice->activate(mSensorDevice, handle, enabled);
        ALOGE_IF(err, "Error %s sensor %d (%s)",
                enabled ? "activating" : "disabling",
                handle, strerror(-err));
    }

    { // scope for the lock
        Mutex::Autolock _l(mLock);
        nsecs_t ns = info.selectDelay();
        mSensorDevice->setDelay(mSensorDevice, handle, ns);
    }

    return err;
}

status_t SensorDevice::setDelay(void* ident, int handle, int64_t ns)
{
    if (!mSensorDevice) return NO_INIT;
    Mutex::Autolock _l(mLock);
    Info& info( mActivationCount.editValueFor(handle) );
    status_t err = info.setDelayForIdent(ident, ns);
    if (err < 0) return err;
    ns = info.selectDelay();
    return mSensorDevice->setDelay(mSensorDevice, handle, ns);
}

// ---------------------------------------------------------------------------

status_t SensorDevice::Info::setDelayForIdent(void* ident, int64_t ns)
{
    ssize_t index = rates.indexOfKey(ident);
    if (index < 0) {
        ALOGE("Info::setDelayForIdent(ident=%p, ns=%lld) failed (%s)",
                ident, ns, strerror(-index));
        return BAD_INDEX;
    }
    rates.editValueAt(index) = ns;
    return NO_ERROR;
}

nsecs_t SensorDevice::Info::selectDelay()
{
    nsecs_t ns = rates.valueAt(0);
    for (size_t i=1 ; i<rates.size() ; i++) {
        nsecs_t cur = rates.valueAt(i);
        if (cur < ns) {
            ns = cur;
        }
    }
    delay = ns;
    return ns;
}

// ---------------------------------------------------------------------------
}; // namespace android