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/* mbed Microcontroller Library
 * Copyright (c) 2006-2015 ARM Limited
 *
 * 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 "mbed.h"
#include "ble/BLE.h"
#include "ble/DiscoveredCharacteristic.h"
#include "ble/DiscoveredService.h"

#include "ble_gatt.h"

BLE ble;

Gap::Handle_t connectionHandle = 0xFFFF;

DigitalOut alivenessLED(LED1, 1);
bool foundButtonCharacteristic = false;
DiscoveredCharacteristic buttonCharacteristic;

void periodicCallback(void) {
    alivenessLED = !alivenessLED; /* Do blinky on LED1 while we're waiting for BLE events */
}

void advertisementCallback(const Gap::AdvertisementCallbackParams_t *params) {
    if (params->peerAddr[0] != 0x29) { /* !ALERT! Update this filter to suit your device. */
        return;
    }
    printf("adv peerAddr[%02x %02x %02x %02x %02x %02x] rssi %d, isScanResponse %u, AdvertisementType %u\r\n",
           params->peerAddr[5], params->peerAddr[4], params->peerAddr[3], params->peerAddr[2], params->peerAddr[1], params->peerAddr[0],
           params->rssi, params->isScanResponse, params->type);

    ble.gap().connect(params->peerAddr, Gap::ADDR_TYPE_RANDOM_STATIC, NULL, NULL);
}

void serviceDiscoveryCallback(const DiscoveredService *service) {
    if (service->getUUID().shortOrLong() == UUID::UUID_TYPE_SHORT) {
        printf("S UUID-%x attrs[%u %u]\r\n", service->getUUID().getShortUUID(), service->getStartHandle(), service->getEndHandle());
    } else {
        printf("S UUID-");
        const uint8_t *longUUIDBytes = service->getUUID().getBaseUUID();
        for (unsigned i = 0; i < UUID::LENGTH_OF_LONG_UUID; i++) {
            printf("%02x", longUUIDBytes[i]);
        }
        printf(" attrs[%u %u]\r\n", service->getStartHandle(), service->getEndHandle());
    }
}

void characteristicDiscoveryCallback(const DiscoveredCharacteristic *characteristicP) {
    printf("  C UUID-%x valueAttr[%u] props[%x]\r\n", characteristicP->getShortUUID(), characteristicP->getValueHandle(), (uint8_t)characteristicP->getProperties().broadcast());
    if (characteristicP->getShortUUID() == 0xa001) { /* !ALERT! Update this filter to suit your device. */
        buttonCharacteristic      = *characteristicP;
        foundButtonCharacteristic = true;
    }
}

void discoveryTerminationCallback(Gap::Handle_t connectionHandle) {
    printf("terminated SD for handle %u\r\n", connectionHandle);
}

void connectionCallback(const Gap::ConnectionCallbackParams_t *params) {
    if (params->role == Gap::CENTRAL) {
        connectionHandle = params->handle;
        ble.gattClient().onServiceDiscoveryTermination(discoveryTerminationCallback);
        ble.gattClient().launchServiceDiscovery(params->handle, serviceDiscoveryCallback, characteristicDiscoveryCallback/*, 0xa000, 0xa001*/);
    }
}

void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason) {
    printf("disconnected\r\n");
}

void hvxCallback(const GattHVXCallbackParams *params) {
    printf("received HVX callback for handle %u; type %s\r\n", params->handle, (params->type == BLE_HVX_NOTIFICATION) ? "notification" : "indication");
    for (unsigned index = 0; index < params->len; index++) {
        printf(" %02x", params->data[index]);
    }
    printf("\r\n");
}

int main(void) {
    Ticker ticker;
    ticker.attach(periodicCallback, 1);

    ble.init();
    ble.gap().onConnection(connectionCallback);
    ble.gap().onDisconnection(disconnectionCallback);

    ble.gap().setScanParams(500, 400);
    ble.gap().startScan(advertisementCallback);

    ble.gattClient().onHVX(hvxCallback);

    while (true) {
        if (foundButtonCharacteristic && !ble.gattClient().isServiceDiscoveryActive()) {
            foundButtonCharacteristic = false; /* need to do the following only once */

            /* Note: Yuckiness alert! The following needs to be encapsulated in a neat API.
             * It isn't clear whether we should provide a DiscoveredCharacteristic::enableNoticiation() or
             * DiscoveredCharacteristic::discoverDescriptors() followed by DiscoveredDescriptor::write(...). */
            uint16_t value = BLE_HVX_NOTIFICATION;
            ble.gattClient().write(GattClient::GATT_OP_WRITE_REQ,
                                   connectionHandle,
                                   buttonCharacteristic.getValueHandle() + 1, /* HACK Alert. We're assuming that CCCD descriptor immediately follows the value attribute. */
                                   sizeof(uint16_t),                          /* HACK Alert! size should be made into a BLE_API constant. */
                                   reinterpret_cast<const uint8_t *>(&value));
        }
        ble.waitForEvent();
    }
}