/* Copyright (c) 2017 The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials provided
 *       with the distribution.
 *     * Neither the name of The Linux Foundation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#define LOG_NDEBUG 0
#define LOG_TAG "LocSvc_LocationAPI"

#include <location_interface.h>
#include <dlfcn.h>
#include <loc_pla.h>
#include <log_util.h>
#include <pthread.h>
#include <map>

typedef void* (getLocationInterface)();
typedef std::map<LocationAPI*, LocationCallbacks> LocationClientMap;
typedef struct {
    LocationClientMap clientData;
    LocationControlAPI* controlAPI;
    LocationControlCallbacks controlCallbacks;
    GnssInterface* gnssInterface;
    GeofenceInterface* geofenceInterface;
    FlpInterface* flpInterface;
} LocationAPIData;
static LocationAPIData gData = {};
static pthread_mutex_t gDataMutex = PTHREAD_MUTEX_INITIALIZER;
static bool gGnssLoadFailed = false;
static bool gFlpLoadFailed = false;
static bool gGeofenceLoadFailed = false;

static bool needsGnssTrackingInfo(LocationCallbacks& locationCallbacks)
{
    return (locationCallbacks.gnssLocationInfoCb != nullptr ||
            locationCallbacks.gnssSvCb != nullptr ||
            locationCallbacks.gnssNmeaCb != nullptr ||
            locationCallbacks.gnssMeasurementsCb != nullptr);
}

static bool isGnssClient(LocationCallbacks& locationCallbacks)
{
    return (locationCallbacks.gnssNiCb != nullptr ||
            locationCallbacks.trackingCb != nullptr ||
            locationCallbacks.gnssMeasurementsCb != nullptr);
}

static bool isFlpClient(LocationCallbacks& locationCallbacks)
{
    return (locationCallbacks.trackingCb != nullptr ||
            locationCallbacks.batchingCb != nullptr);
}

static bool isGeofenceClient(LocationCallbacks& locationCallbacks)
{
    return (locationCallbacks.geofenceBreachCb != nullptr ||
            locationCallbacks.geofenceStatusCb != nullptr);
}

static void* loadLocationInterface(const char* library, const char* name) {
    LOC_LOGD("%s]: loading %s::%s ...", __func__, library, name);
    if (NULL == library || NULL == name) {
        return NULL;
    }
    getLocationInterface* getter = NULL;
    const char *error = NULL;
    dlerror();
    void *handle = dlopen(library, RTLD_NOW);
    if (NULL == handle || (error = dlerror()) != NULL)  {
        LOC_LOGW("dlopen for %s failed, error = %s", library, error);
    } else {
        getter = (getLocationInterface*)dlsym(handle, name);
        if ((error = dlerror()) != NULL)  {
            LOC_LOGW("dlsym for %s::%s failed, error = %s", library, name, error);
            getter = NULL;
        }
    }

    if (NULL == getter) {
        return (void*)getter;
    } else {
        return (*getter)();
    }
}

LocationAPI*
LocationAPI::createInstance(LocationCallbacks& locationCallbacks)
{
    if (nullptr == locationCallbacks.capabilitiesCb ||
        nullptr == locationCallbacks.responseCb ||
        nullptr == locationCallbacks.collectiveResponseCb) {
        return NULL;
    }

    LocationAPI* newLocationAPI = new LocationAPI();
    bool requestedCapabilities = false;

    pthread_mutex_lock(&gDataMutex);

    if (isGnssClient(locationCallbacks)) {
        if (NULL == gData.gnssInterface && !gGnssLoadFailed) {
            gData.gnssInterface =
                (GnssInterface*)loadLocationInterface("libgnss.so", "getGnssInterface");
            if (NULL == gData.gnssInterface) {
                gGnssLoadFailed = true;
                LOC_LOGW("%s:%d]: No gnss interface available", __func__, __LINE__);
            } else {
                gData.gnssInterface->initialize();
            }
        }
        if (NULL != gData.gnssInterface) {
            gData.gnssInterface->addClient(newLocationAPI, locationCallbacks);
            if (!requestedCapabilities) {
                gData.gnssInterface->requestCapabilities(newLocationAPI);
                requestedCapabilities = true;
            }
        }
    }

    if (isFlpClient(locationCallbacks)) {
        if (NULL == gData.flpInterface && !gFlpLoadFailed) {
            gData.flpInterface =
                (FlpInterface*)loadLocationInterface("libflp.so", "getFlpInterface");
            if (NULL == gData.flpInterface) {
                gFlpLoadFailed = true;
                LOC_LOGW("%s:%d]: No flp interface available", __func__, __LINE__);
            } else {
                gData.flpInterface->initialize();
            }
        }
        if (NULL != gData.flpInterface) {
            gData.flpInterface->addClient(newLocationAPI, locationCallbacks);
            if (!requestedCapabilities) {
                gData.flpInterface->requestCapabilities(newLocationAPI);
                requestedCapabilities = true;
            }
        }
    }

    if (isGeofenceClient(locationCallbacks)) {
        if (NULL == gData.geofenceInterface && !gGeofenceLoadFailed) {
            gData.geofenceInterface =
                (GeofenceInterface*)loadLocationInterface("libgeofence.so", "getGeofenceInterface");
            if (NULL == gData.geofenceInterface) {
                gGeofenceLoadFailed = true;
                LOC_LOGW("%s:%d]: No geofence interface available", __func__, __LINE__);
            } else {
                gData.geofenceInterface->initialize();
            }
        }
        if (NULL != gData.geofenceInterface) {
            gData.geofenceInterface->addClient(newLocationAPI, locationCallbacks);
            if (!requestedCapabilities) {
                gData.geofenceInterface->requestCapabilities(newLocationAPI);
                requestedCapabilities = true;
            }
        }
    }

    gData.clientData[newLocationAPI] = locationCallbacks;

    pthread_mutex_unlock(&gDataMutex);

    return newLocationAPI;
}

void
LocationAPI::destroy()
{
    delete this;
}

LocationAPI::LocationAPI()
{
    LOC_LOGD("LOCATION API CONSTRUCTOR");
}

LocationAPI::~LocationAPI()
{
    LOC_LOGD("LOCATION API DESTRUCTOR");
    pthread_mutex_lock(&gDataMutex);

    auto it = gData.clientData.find(this);
    if (it != gData.clientData.end()) {
        if (isGnssClient(it->second) && NULL != gData.gnssInterface) {
            gData.gnssInterface->removeClient(it->first);
        }
        if (isFlpClient(it->second) && NULL != gData.flpInterface) {
            gData.flpInterface->removeClient(it->first);
        }
        if (isGeofenceClient(it->second) && NULL != gData.geofenceInterface) {
            gData.geofenceInterface->removeClient(it->first);
        }
        gData.clientData.erase(it);
    } else {
        LOC_LOGE("%s:%d]: Location API client %p not found in client data",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
}

void
LocationAPI::updateCallbacks(LocationCallbacks& locationCallbacks)
{
    if (nullptr == locationCallbacks.capabilitiesCb ||
        nullptr == locationCallbacks.responseCb ||
        nullptr == locationCallbacks.collectiveResponseCb) {
        return;
    }

    pthread_mutex_lock(&gDataMutex);

    if (isGnssClient(locationCallbacks)) {
        if (NULL == gData.gnssInterface && !gGnssLoadFailed) {
            gData.gnssInterface =
                (GnssInterface*)loadLocationInterface("libgnss.so", "getGnssInterface");
            if (NULL == gData.gnssInterface) {
                gGnssLoadFailed = true;
                LOC_LOGW("%s:%d]: No gnss interface available", __func__, __LINE__);
            } else {
                gData.gnssInterface->initialize();
            }
        }
        if (NULL != gData.gnssInterface) {
            // either adds new Client or updates existing Client
            gData.gnssInterface->addClient(this, locationCallbacks);
        }
    }

    if (isFlpClient(locationCallbacks)) {
        if (NULL == gData.flpInterface && !gFlpLoadFailed) {
            gData.flpInterface =
                (FlpInterface*)loadLocationInterface("libflp.so", "getFlpInterface");
            if (NULL == gData.flpInterface) {
                gFlpLoadFailed = true;
                LOC_LOGW("%s:%d]: No flp interface available", __func__, __LINE__);
            } else {
                gData.flpInterface->initialize();
            }
        }
        if (NULL != gData.flpInterface) {
            // either adds new Client or updates existing Client
            gData.flpInterface->addClient(this, locationCallbacks);
        }
    }

    if (isGeofenceClient(locationCallbacks)) {
        if (NULL == gData.geofenceInterface && !gGeofenceLoadFailed) {
            gData.geofenceInterface =
                (GeofenceInterface*)loadLocationInterface("libgeofence.so", "getGeofenceInterface");
            if (NULL == gData.geofenceInterface) {
                gGeofenceLoadFailed = true;
                LOC_LOGW("%s:%d]: No geofence interface available", __func__, __LINE__);
            } else {
                gData.geofenceInterface->initialize();
            }
        }
        if (NULL != gData.geofenceInterface) {
            // either adds new Client or updates existing Client
            gData.geofenceInterface->addClient(this, locationCallbacks);
        }
    }

    gData.clientData[this] = locationCallbacks;

    pthread_mutex_unlock(&gDataMutex);
}

uint32_t
LocationAPI::startTracking(TrackingOptions& trackingOptions)
{
    uint32_t id = 0;
    pthread_mutex_lock(&gDataMutex);

    auto it = gData.clientData.find(this);
    if (it != gData.clientData.end()) {
        if (NULL != gData.flpInterface && trackingOptions.minDistance > 0) {
            id = gData.flpInterface->startTracking(this, trackingOptions);
        } else if (NULL != gData.gnssInterface && needsGnssTrackingInfo(it->second)) {
            id = gData.gnssInterface->startTracking(this, trackingOptions);
        } else if (NULL != gData.flpInterface) {
            id = gData.flpInterface->startTracking(this, trackingOptions);
        } else if (NULL != gData.gnssInterface) {
            id = gData.gnssInterface->startTracking(this, trackingOptions);
        } else {
            LOC_LOGE("%s:%d]: No gnss/flp interface available for Location API client %p ",
                     __func__, __LINE__, this);
        }
    } else {
        LOC_LOGE("%s:%d]: Location API client %p not found in client data",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
    return id;
}

void
LocationAPI::stopTracking(uint32_t id)
{
    pthread_mutex_lock(&gDataMutex);

    auto it = gData.clientData.find(this);
    if (it != gData.clientData.end()) {
        // we don't know if tracking was started on flp or gnss, so we call stop on both, where
        // stopTracking call to the incorrect interface will fail without response back to client
        if (gData.gnssInterface != NULL) {
            gData.gnssInterface->stopTracking(this, id);
        }
        if (gData.flpInterface != NULL) {
            gData.flpInterface->stopTracking(this, id);
        }
        if (gData.flpInterface == NULL && gData.gnssInterface == NULL) {
            LOC_LOGE("%s:%d]: No gnss/flp interface available for Location API client %p ",
                     __func__, __LINE__, this);
        }
    } else {
        LOC_LOGE("%s:%d]: Location API client %p not found in client data",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
}

void
LocationAPI::updateTrackingOptions(
        uint32_t id, TrackingOptions& trackingOptions)
{
    pthread_mutex_lock(&gDataMutex);

    auto it = gData.clientData.find(this);
    if (it != gData.clientData.end()) {
        // we don't know if tracking was started on flp or gnss, so we call update on both, where
        // updateTracking call to the incorrect interface will fail without response back to client
        if (gData.gnssInterface != NULL) {
            gData.gnssInterface->updateTrackingOptions(this, id, trackingOptions);
        }
        if (gData.flpInterface != NULL) {
            gData.flpInterface->updateTrackingOptions(this, id, trackingOptions);
        }
        if (gData.flpInterface == NULL && gData.gnssInterface == NULL) {
            LOC_LOGE("%s:%d]: No gnss/flp interface available for Location API client %p ",
                     __func__, __LINE__, this);
        }
    } else {
        LOC_LOGE("%s:%d]: Location API client %p not found in client data",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
}

uint32_t
LocationAPI::startBatching(BatchingOptions &batchingOptions)
{
    uint32_t id = 0;
    pthread_mutex_lock(&gDataMutex);

    if (NULL != gData.flpInterface) {
        id = gData.flpInterface->startBatching(this, batchingOptions);
    } else {
        LOC_LOGE("%s:%d]: No flp interface available for Location API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
    return id;
}

void
LocationAPI::stopBatching(uint32_t id)
{
    pthread_mutex_lock(&gDataMutex);

    if (NULL != gData.flpInterface) {
        gData.flpInterface->stopBatching(this, id);
    } else {
        LOC_LOGE("%s:%d]: No flp interface available for Location API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
}

void
LocationAPI::updateBatchingOptions(uint32_t id, BatchingOptions& batchOptions)
{
    pthread_mutex_lock(&gDataMutex);

    if (NULL != gData.flpInterface) {
        gData.flpInterface->updateBatchingOptions(this, id, batchOptions);
    } else {
        LOC_LOGE("%s:%d]: No flp interface available for Location API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
}

void
LocationAPI::getBatchedLocations(uint32_t id, size_t count)
{
    pthread_mutex_lock(&gDataMutex);

    if (gData.flpInterface != NULL) {
        gData.flpInterface->getBatchedLocations(this, id, count);
    } else {
        LOC_LOGE("%s:%d]: No flp interface available for Location API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
}

uint32_t*
LocationAPI::addGeofences(size_t count, GeofenceOption* options, GeofenceInfo* info)
{
    uint32_t* ids = NULL;
    pthread_mutex_lock(&gDataMutex);

    if (gData.geofenceInterface != NULL) {
        ids = gData.geofenceInterface->addGeofences(this, count, options, info);
    } else {
        LOC_LOGE("%s:%d]: No geofence interface available for Location API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
    return ids;
}

void
LocationAPI::removeGeofences(size_t count, uint32_t* ids)
{
    pthread_mutex_lock(&gDataMutex);

    if (gData.geofenceInterface != NULL) {
        gData.geofenceInterface->removeGeofences(this, count, ids);
    } else {
        LOC_LOGE("%s:%d]: No geofence interface available for Location API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
}

void
LocationAPI::modifyGeofences(size_t count, uint32_t* ids, GeofenceOption* options)
{
    pthread_mutex_lock(&gDataMutex);

    if (gData.geofenceInterface != NULL) {
        gData.geofenceInterface->modifyGeofences(this, count, ids, options);
    } else {
        LOC_LOGE("%s:%d]: No geofence interface available for Location API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
}

void
LocationAPI::pauseGeofences(size_t count, uint32_t* ids)
{
    pthread_mutex_lock(&gDataMutex);

    if (gData.geofenceInterface != NULL) {
        gData.geofenceInterface->pauseGeofences(this, count, ids);
    } else {
        LOC_LOGE("%s:%d]: No geofence interface available for Location API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
}

void
LocationAPI::resumeGeofences(size_t count, uint32_t* ids)
{
    pthread_mutex_lock(&gDataMutex);

    if (gData.geofenceInterface != NULL) {
        gData.geofenceInterface->resumeGeofences(this, count, ids);
    } else {
        LOC_LOGE("%s:%d]: No geofence interface available for Location API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
}

void
LocationAPI::gnssNiResponse(uint32_t id, GnssNiResponse response)
{
    pthread_mutex_lock(&gDataMutex);

    if (gData.gnssInterface != NULL) {
        gData.gnssInterface->gnssNiResponse(this, id, response);
    } else {
        LOC_LOGE("%s:%d]: No gnss interface available for Location API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
}

LocationControlAPI*
LocationControlAPI::createInstance(LocationControlCallbacks& locationControlCallbacks)
{
    LocationControlAPI* controlAPI = NULL;
    pthread_mutex_lock(&gDataMutex);

    if (nullptr != locationControlCallbacks.responseCb && NULL == gData.controlAPI) {
        if (NULL == gData.gnssInterface && !gGnssLoadFailed) {
            gData.gnssInterface =
                (GnssInterface*)loadLocationInterface("libgnss.so", "getGnssInterface");
            if (NULL == gData.gnssInterface) {
                gGnssLoadFailed = true;
                LOC_LOGW("%s:%d]: No gnss interface available", __func__, __LINE__);
            } else {
                gData.gnssInterface->initialize();
            }
        }
        if (NULL != gData.gnssInterface) {
            gData.controlAPI = new LocationControlAPI();
            gData.controlCallbacks = locationControlCallbacks;
            gData.gnssInterface->setControlCallbacks(locationControlCallbacks);
            controlAPI = gData.controlAPI;
        }
    }

    pthread_mutex_unlock(&gDataMutex);
    return controlAPI;
}

void
LocationControlAPI::destroy()
{
    delete this;
}

LocationControlAPI::LocationControlAPI()
{
    LOC_LOGD("LOCATION CONTROL API CONSTRUCTOR");
}

LocationControlAPI::~LocationControlAPI()
{
    LOC_LOGD("LOCATION CONTROL API DESTRUCTOR");
    pthread_mutex_lock(&gDataMutex);

    gData.controlAPI = NULL;

    pthread_mutex_unlock(&gDataMutex);
}

uint32_t
LocationControlAPI::enable(LocationTechnologyType techType)
{
    uint32_t id = 0;
    pthread_mutex_lock(&gDataMutex);

    if (gData.gnssInterface != NULL) {
        id = gData.gnssInterface->enable(techType);
    } else {
        LOC_LOGE("%s:%d]: No gnss interface available for Location Control API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
    return id;
}

void
LocationControlAPI::disable(uint32_t id)
{
    pthread_mutex_lock(&gDataMutex);

    if (gData.gnssInterface != NULL) {
        gData.gnssInterface->disable(id);
    } else {
        LOC_LOGE("%s:%d]: No gnss interface available for Location Control API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
}

uint32_t*
LocationControlAPI::gnssUpdateConfig(GnssConfig config)
{
    uint32_t* ids = NULL;
    pthread_mutex_lock(&gDataMutex);

    if (gData.gnssInterface != NULL) {
        ids = gData.gnssInterface->gnssUpdateConfig(config);
    } else {
        LOC_LOGE("%s:%d]: No gnss interface available for Location Control API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
    return ids;
}

uint32_t* LocationControlAPI::gnssGetConfig(GnssConfigFlagsMask mask) {

    uint32_t* ids = NULL;
    pthread_mutex_lock(&gDataMutex);

    if (NULL != gData.gnssInterface) {
        ids = gData.gnssInterface->gnssGetConfig(mask);
    } else {
        LOC_LOGe("No gnss interface available for Control API client %p", this);
    }

    pthread_mutex_unlock(&gDataMutex);
    return ids;
}

uint32_t
LocationControlAPI::gnssDeleteAidingData(GnssAidingData& data)
{
    uint32_t id = 0;
    pthread_mutex_lock(&gDataMutex);

    if (gData.gnssInterface != NULL) {
        id = gData.gnssInterface->gnssDeleteAidingData(data);
    } else {
        LOC_LOGE("%s:%d]: No gnss interface available for Location Control API client %p ",
                 __func__, __LINE__, this);
    }

    pthread_mutex_unlock(&gDataMutex);
    return id;
}