/**
 * Copyright (c) 2014 - 2020, Nordic Semiconductor ASA
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, 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.
 *
 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 *
 * 5. Any software provided in binary form under this license must not be reverse
 *    engineered, decompiled, modified and/or disassembled.
 *
 * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA 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.
 *
 */
/** @file
 *
 * @defgroup ble_sdk_app_proximity_main main.c
 * @{
 * @ingroup ble_sdk_app_proximity_eval
 * @brief Proximity Application main file.
 *
 * This file contains is the source code for a sample proximity application using the
 * Immediate Alert, Link Loss and Tx Power services.
 *
 * This application would accept pairing requests from any peer device.
 *
 * It demonstrates the use of fast and slow advertising intervals.
 */

#include <stdint.h>
#include <string.h>

#include "ble_advertising.h"
#include "nordic_common.h"
#include "nrf.h"
#include "nrf_soc.h"
#include "nrf_drv_saadc.h"
#include "app_error.h"
#include "ble.h"
#include "ble_err.h"
#include "ble_hci.h"
#include "ble_srv_common.h"
#include "ble_advdata.h"
#include "ble_tps.h"
#include "ble_ias.h"
#include "ble_lls.h"
#include "ble_bas.h"
#include "ble_conn_params.h"
#include "sensorsim.h"
#include "nrf_sdh.h"
#include "nrf_sdh_soc.h"
#include "nrf_sdh_ble.h"
#include "app_timer.h"
#include "ble_ias_c.h"
#include "app_util.h"
#include "bsp_btn_ble.h"
#include "ble_db_discovery.h"
#include "peer_manager.h"
#include "peer_manager_handler.h"
#include "fds.h"
#include "ble_conn_state.h"
#include "nrf_ble_gatt.h"
#include "nrf_ble_qwr.h"
#include "nrf_pwr_mgmt.h"

#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"


#define DEVICE_NAME                     "Nordic_Prox"                           /**< Name of device. Will be included in the advertising data. */

#define APP_BLE_OBSERVER_PRIO           3                                       /**< Application's BLE observer priority. You shouldn't need to modify this value. */
#define APP_BLE_CONN_CFG_TAG            1                                       /**< A tag identifying the SoftDevice BLE configuration. */

#define BATTERY_LEVEL_MEAS_INTERVAL     APP_TIMER_TICKS(120000)                 /**< Battery level measurement interval (ticks). This value corresponds to 120 seconds. */

#define MIN_CONN_INTERVAL               MSEC_TO_UNITS(500, UNIT_1_25_MS)        /**< Minimum acceptable connection interval (0.5 seconds).  */
#define MAX_CONN_INTERVAL               MSEC_TO_UNITS(1000, UNIT_1_25_MS)       /**< Maximum acceptable connection interval (1 second). */
#define SLAVE_LATENCY                   0                                       /**< Slave latency. */
#define CONN_SUP_TIMEOUT                MSEC_TO_UNITS(4000, UNIT_10_MS)         /**< Connection supervisory timeout (4 seconds). */

#define APP_ADV_INTERVAL                40                                       /**< The advertising interval (in units of 0.625 ms. This value corresponds to 25 ms). */

#define APP_ADV_DURATION                18000                                    /**< The advertising duration (180 seconds) in units of 10 milliseconds. */

#define FIRST_CONN_PARAMS_UPDATE_DELAY  APP_TIMER_TICKS(5000)                   /**< Time from initiating event (connect or start of notification) to first time sd_ble_gap_conn_param_update is called (5 seconds). */
#define NEXT_CONN_PARAMS_UPDATE_DELAY   APP_TIMER_TICKS(30000)                  /**< Time between each call to sd_ble_gap_conn_param_update after the first call (30 seconds). */
#define MAX_CONN_PARAMS_UPDATE_COUNT    3                                       /**< Number of attempts before giving up the connection parameter negotiation. */

#define SEC_PARAM_BOND                  1                                       /**< Perform bonding. */
#define SEC_PARAM_MITM                  0                                       /**< Man In The Middle protection not required. */
#define SEC_PARAM_LESC                  0                                       /**< LE Secure Connections not enabled. */
#define SEC_PARAM_KEYPRESS              0                                       /**< Keypress notifications not enabled. */
#define SEC_PARAM_IO_CAPABILITIES       BLE_GAP_IO_CAPS_NONE                    /**< No I/O capabilities. */
#define SEC_PARAM_OOB                   0                                       /**< Out Of Band data not available. */
#define SEC_PARAM_MIN_KEY_SIZE          7                                       /**< Minimum encryption key size. */
#define SEC_PARAM_MAX_KEY_SIZE          16                                      /**< Maximum encryption key size. */

#define INITIAL_LLS_ALERT_LEVEL         BLE_CHAR_ALERT_LEVEL_NO_ALERT           /**< Initial value for the Alert Level characteristic in the Link Loss service. */
#define TX_POWER_LEVEL                  (-8)                                    /**< TX Power Level value. This will be set both in the TX Power service, in the advertising data, and also used to set the radio transmit power. */

#define ADC_REF_VOLTAGE_IN_MILLIVOLTS   600                                     /**< Reference voltage (in milli volts) used by ADC while doing conversion. */
#define ADC_PRE_SCALING_COMPENSATION    6                                       /**< The ADC is configured to use VDD with 1/3 prescaling as input. And hence the result of conversion is to be multiplied by 3 to get the actual value of the battery voltage.*/
#define DIODE_FWD_VOLT_DROP_MILLIVOLTS  270                                     /**< Typical forward voltage drop of the diode . */
#define ADC_RES_10BIT                   1024                                    /**< Maximum digital value for 10-bit ADC conversion. */

#define DEAD_BEEF                       0xDEADBEEF                              /**< Value used as error code on stack dump, can be used to identify stack location on stack unwind. */


/**@brief Macro to convert the result of ADC conversion in millivolts.
 *
 * @param[in]  ADC_VALUE   ADC result.
 *
 * @retval     Result converted to millivolts.
 */
#define ADC_RESULT_IN_MILLI_VOLTS(ADC_VALUE)\
        ((((ADC_VALUE) * ADC_REF_VOLTAGE_IN_MILLIVOLTS) / ADC_RES_10BIT) * ADC_PRE_SCALING_COMPENSATION)


APP_TIMER_DEF(m_battery_timer_id);                      /**< Battery measurement timer. */
BLE_TPS_DEF(m_tps);                                     /**< TX Power service instance. */
BLE_IAS_DEF(m_ias, NRF_SDH_BLE_TOTAL_LINK_COUNT);       /**< Immediate Alert service instance. */
BLE_LLS_DEF(m_lls);                                     /**< Link Loss service instance. */
BLE_BAS_DEF(m_bas);                                     /**< Battery service instance. */
BLE_IAS_C_DEF(m_ias_c);                                 /**< Immediate Alert Service client instance. */
NRF_BLE_GATT_DEF(m_gatt);                               /**< GATT module instance. */
NRF_BLE_QWR_DEF(m_qwr);                                 /**< Context for the Queued Write module.*/
BLE_ADVERTISING_DEF(m_advertising);                     /**< Advertising module instance. */
BLE_DB_DISCOVERY_DEF(m_ble_db_discovery);               /**< DB discovery module instance. */
NRF_BLE_GQ_DEF(m_ble_gatt_queue,                        /**< BLE GATT Queue instance. */
               NRF_SDH_BLE_PERIPHERAL_LINK_COUNT,
               NRF_BLE_GQ_QUEUE_SIZE);

static volatile bool m_is_high_alert_signalled;         /**< Variable to indicate whether a high alert has been signalled to the peer. */
static volatile bool m_is_ias_present = false;          /**< Variable to indicate whether the immediate alert service has been discovered at the connected peer. */

static nrf_saadc_value_t adc_buf[2];

static ble_uuid_t m_adv_uuids[] =                       /**< Universally unique service identifiers. */
{
    {BLE_UUID_IMMEDIATE_ALERT_SERVICE, BLE_UUID_TYPE_BLE},
    {BLE_UUID_BATTERY_SERVICE, BLE_UUID_TYPE_BLE},
    {BLE_UUID_TX_POWER_SERVICE, BLE_UUID_TYPE_BLE},
    {BLE_UUID_LINK_LOSS_SERVICE, BLE_UUID_TYPE_BLE}
};


static void on_ias_evt(ble_ias_t * p_ias, ble_ias_evt_t * p_evt);
static void on_lls_evt(ble_lls_t * p_lls, ble_lls_evt_t * p_evt);
static void on_ias_c_evt(ble_ias_c_t * p_lls, ble_ias_c_evt_t * p_evt);
static void on_bas_evt(ble_bas_t * p_bas, ble_bas_evt_t * p_evt);
static void advertising_init(void);
static void advertising_start(bool erase_bonds);


/**@brief Callback function for asserts in the SoftDevice.
 *
 * @details This function will be called in case of an assert in the SoftDevice.
 *
 * @warning This handler is an example only and does not fit a final product. You need to analyze
 *          how your product is supposed to react in case of Assert.
 * @warning On assert from the SoftDevice, the system can only recover on reset.
 *
 * @param[in] line_num   Line number of the failing ASSERT call.
 * @param[in] file_name  File name of the failing ASSERT call.
 */
void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
{
    app_error_handler(DEAD_BEEF, line_num, p_file_name);
}


/**@brief Function for handling Service errors.
 *
 * @details A pointer to this function will be passed to each service which may need to inform the
 *          application about an error.
 *
 * @param[in] nrf_error   Error code containing information about what went wrong.
 */
static void service_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


/**@brief Function for handling Peer Manager events.
 *
 * @param[in] p_evt  Peer Manager event.
 */
static void pm_evt_handler(pm_evt_t const * p_evt)
{
    pm_handler_on_pm_evt(p_evt);
    pm_handler_flash_clean(p_evt);

    switch (p_evt->evt_id)
    {
        case PM_EVT_PEERS_DELETE_SUCCEEDED:
            advertising_start(false);
            break;

        default:
            break;
    }
}


/**@brief Function for handling the ADC interrupt.
 *
 * @details  This function will fetch the conversion result from the ADC, convert the value into
 *           percentage and send it to peer.
 */
void saadc_event_handler(nrf_drv_saadc_evt_t const * p_event)
{
    if (p_event->type == NRF_DRV_SAADC_EVT_DONE)
    {
        nrf_saadc_value_t adc_result;
        uint16_t          batt_lvl_in_milli_volts;
        uint8_t           percentage_batt_lvl;
        uint32_t          err_code;

        adc_result = p_event->data.done.p_buffer[0];

        err_code = nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, 1);
        APP_ERROR_CHECK(err_code);

        batt_lvl_in_milli_volts = ADC_RESULT_IN_MILLI_VOLTS(adc_result) +
                                  DIODE_FWD_VOLT_DROP_MILLIVOLTS;
        percentage_batt_lvl = battery_level_in_percent(batt_lvl_in_milli_volts);

        err_code = ble_bas_battery_level_update(&m_bas, percentage_batt_lvl, BLE_CONN_HANDLE_ALL);
        if ((err_code != NRF_SUCCESS) &&
            (err_code != NRF_ERROR_INVALID_STATE) &&
            (err_code != NRF_ERROR_RESOURCES) &&
            (err_code != NRF_ERROR_BUSY) &&
            (err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)
           )
        {
            APP_ERROR_HANDLER(err_code);
        }
    }
}


/**@brief Function for handling database discovery events.
 *
 * @details This function is callback function to handle events from the database discovery module.
 *          Depending on the UUIDs that are discovered, this function should forward the events
 *          to their respective services.
 *
 * @param[in] p_event  Pointer to the database discovery event.
 */
static void db_disc_handler(ble_db_discovery_evt_t * p_evt)
{
    ble_ias_c_on_db_disc_evt(&m_ias_c, p_evt);
}


/**@brief Function for configuring ADC to do battery level conversion.
 */
static void adc_configure(void)
{
    ret_code_t err_code = nrf_drv_saadc_init(NULL, saadc_event_handler);
    APP_ERROR_CHECK(err_code);

    nrf_saadc_channel_config_t config =
        NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_VDD);
    err_code = nrf_drv_saadc_channel_init(0, &config);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_saadc_buffer_convert(&adc_buf[0], 1);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_saadc_buffer_convert(&adc_buf[1], 1);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling the Battery measurement timer timeout.
 *
 * @details This function will be called each time the battery level measurement timer expires.
 *          This function will start the ADC.
 *
 * @param[in] p_context   Pointer used for passing some arbitrary information (context) from the
 *                        app_start_timer() call to the timeout handler.
 */
static void battery_level_meas_timeout_handler(void * p_context)
{
    UNUSED_PARAMETER(p_context);

    ret_code_t err_code;
    err_code = nrf_drv_saadc_sample();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for the Timer initialization.
 *
 * @details Initializes the timer module. This creates and starts application timers.
 */
static void timers_init(void)
{
    ret_code_t err_code;

    // Initialize timer module.
    err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);

    // Create battery timer.
    err_code = app_timer_create(&m_battery_timer_id,
                                APP_TIMER_MODE_REPEATED,
                                battery_level_meas_timeout_handler);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for the GAP initialization.
 *
 * @details This function sets up all the necessary GAP (Generic Access Profile) parameters of the
 *          device including the device name, appearance, and the preferred connection parameters.
 */
static void gap_params_init(void)
{
    ret_code_t              err_code;
    ble_gap_conn_params_t   gap_conn_params;
    ble_gap_conn_sec_mode_t sec_mode;

    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);

    err_code = sd_ble_gap_device_name_set(&sec_mode,
                                          (const uint8_t *)DEVICE_NAME,
                                          strlen(DEVICE_NAME));
    APP_ERROR_CHECK(err_code);

    err_code = sd_ble_gap_appearance_set(BLE_APPEARANCE_GENERIC_KEYRING);
    APP_ERROR_CHECK(err_code);

    memset(&gap_conn_params, 0, sizeof(gap_conn_params));

    gap_conn_params.min_conn_interval = MIN_CONN_INTERVAL;
    gap_conn_params.max_conn_interval = MAX_CONN_INTERVAL;
    gap_conn_params.slave_latency     = SLAVE_LATENCY;
    gap_conn_params.conn_sup_timeout  = CONN_SUP_TIMEOUT;

    err_code = sd_ble_gap_ppcp_set(&gap_conn_params);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the GATT module.
 */
static void gatt_init(void)
{
    ret_code_t err_code = nrf_ble_gatt_init(&m_gatt, NULL);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for putting the chip into sleep mode.
 *
 * @note This function will not return.
 */
static void sleep_mode_enter(void)
{
    ret_code_t err_code;

    err_code = bsp_indication_set(BSP_INDICATE_IDLE);
    APP_ERROR_CHECK(err_code);

    // Prepare wakeup buttons.
    err_code = bsp_btn_ble_sleep_mode_prepare();
    APP_ERROR_CHECK(err_code);

    // Go to system-off mode (this function will not return; wakeup will cause a reset).
    err_code = sd_power_system_off();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling advertising events.
 *
 * @param[in] ble_adv_evt  Advertising event.
 */
static void on_adv_evt(ble_adv_evt_t ble_adv_evt)
{
    ret_code_t err_code;

    switch (ble_adv_evt)
    {
        case BLE_ADV_EVT_FAST:
            NRF_LOG_INFO("Fast advertising.");
            err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
            APP_ERROR_CHECK(err_code);
            break; // BLE_ADV_EVT_FAST

        case BLE_ADV_EVT_IDLE:
            sleep_mode_enter();
            break; // BLE_ADV_EVT_IDLE

        default:
            break;
    }
}


/**@brief Function for initializing the Advertising functionality.
 *
 * @details Encodes the required advertising data and passes it to the stack.
 *          Also builds a structure to be passed to the stack when starting advertising.
 */
static void advertising_init(void)
{
    ret_code_t             err_code;
    ble_advertising_init_t init;

    memset(&init, 0, sizeof(init));

    init.advdata.name_type               = BLE_ADVDATA_FULL_NAME;
    init.advdata.include_appearance      = true;
    init.advdata.flags                   = BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE;
    init.advdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    init.advdata.uuids_complete.p_uuids  = m_adv_uuids;

    init.config.ble_adv_fast_enabled  = true;
    init.config.ble_adv_fast_interval = APP_ADV_INTERVAL;
    init.config.ble_adv_fast_timeout  = APP_ADV_DURATION;

    init.evt_handler = on_adv_evt;

    err_code = ble_advertising_init(&m_advertising, &init);
    APP_ERROR_CHECK(err_code);

    ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}


/**@brief Function for handling Queued Write Module errors.
 *
 * @details A pointer to this function will be passed to each service which may need to inform the
 *          application about an error.
 *
 * @param[in]   nrf_error   Error code containing information about what went wrong.
 */
static void nrf_qwr_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


/**@brief Function for initializing the Queued Write module.
 */
static void qwr_init(void)
{
    ret_code_t         err_code;
    nrf_ble_qwr_init_t qwr_init_obj = {0};

    // Initialize Queued Write Module.
    qwr_init_obj.error_handler = nrf_qwr_error_handler;

    err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init_obj);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the TX Power Service.
 */
static void tps_init(void)
{
    ret_code_t     err_code;
    ble_tps_init_t tps_init_obj;

    memset(&tps_init_obj, 0, sizeof(tps_init_obj));
    tps_init_obj.initial_tx_power_level = TX_POWER_LEVEL;

    tps_init_obj.tpl_rd_sec = SEC_JUST_WORKS;

    err_code = ble_tps_init(&m_tps, &tps_init_obj);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the Immediate Alert Service.
 */
static void ias_init(void)
{
    ret_code_t     err_code;
    ble_ias_init_t ias_init_obj;

    memset(&ias_init_obj, 0, sizeof(ias_init_obj));
    ias_init_obj.evt_handler  = on_ias_evt;

    ias_init_obj.alert_wr_sec = SEC_JUST_WORKS;

    err_code = ble_ias_init(&m_ias, &ias_init_obj);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the Link Loss Service.
 */
static void lls_init(void)
{
    ret_code_t     err_code;
    ble_lls_init_t lls_init_obj;

    // Initialize Link Loss Service
    memset(&lls_init_obj, 0, sizeof(lls_init_obj));

    lls_init_obj.evt_handler         = on_lls_evt;
    lls_init_obj.error_handler       = service_error_handler;
    lls_init_obj.initial_alert_level = INITIAL_LLS_ALERT_LEVEL;

    lls_init_obj.alert_level_rd_sec = SEC_JUST_WORKS;
    lls_init_obj.alert_level_wr_sec = SEC_JUST_WORKS;

    err_code = ble_lls_init(&m_lls, &lls_init_obj);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the Battery Service.
 */
static void bas_init(void)
{
    ret_code_t     err_code;
    ble_bas_init_t bas_init_obj;

    memset(&bas_init_obj, 0, sizeof(bas_init_obj));

    bas_init_obj.evt_handler          = on_bas_evt;
    bas_init_obj.support_notification = true;
    bas_init_obj.p_report_ref         = NULL;
    bas_init_obj.initial_batt_level   = 100;

    bas_init_obj.bl_rd_sec        = SEC_OPEN;
    bas_init_obj.bl_cccd_wr_sec   = SEC_OPEN;
    bas_init_obj.bl_report_rd_sec = SEC_OPEN;

    err_code = ble_bas_init(&m_bas, &bas_init_obj);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the immediate alert service client.
 *
 * @details This will initialize the client side functionality of the Find Me profile.
 */
static void ias_client_init(void)
{
    ret_code_t       err_code;
    ble_ias_c_init_t ias_c_init_obj;

    memset(&ias_c_init_obj, 0, sizeof(ias_c_init_obj));

    m_is_high_alert_signalled = false;

    ias_c_init_obj.evt_handler   = on_ias_c_evt;
    ias_c_init_obj.error_handler = service_error_handler;
    ias_c_init_obj.p_gatt_queue  = &m_ble_gatt_queue;

    err_code = ble_ias_c_init(&m_ias_c, &ias_c_init_obj);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the services that will be used by the application.
 */
static void services_init(void)
{
    qwr_init();
    tps_init();
    ias_init();
    lls_init();
    bas_init();
    ias_client_init();
}


/** @brief Database discovery module initialization.
 */
static void db_discovery_init(void)
{
    ble_db_discovery_init_t db_init;

    memset(&db_init, 0, sizeof(ble_db_discovery_init_t));

    db_init.evt_handler  = db_disc_handler;
    db_init.p_gatt_queue = &m_ble_gatt_queue;

    ret_code_t err_code = ble_db_discovery_init(&db_init);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling a Connection Parameters error.
 *
 * @param[in] nrf_error  Error code containing information about what went wrong.
 */
static void conn_params_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


/**@brief Function for initializing the Connection Parameters module.
 */
static void conn_params_init(void)
{
    ret_code_t             err_code;
    ble_conn_params_init_t cp_init;

    memset(&cp_init, 0, sizeof(cp_init));

    cp_init.p_conn_params                  = NULL;
    cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
    cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
    cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;
    cp_init.start_on_notify_cccd_handle    = BLE_GATT_HANDLE_INVALID;
    cp_init.disconnect_on_fail             = true;
    cp_init.evt_handler                    = NULL;
    cp_init.error_handler                  = conn_params_error_handler;

    err_code = ble_conn_params_init(&cp_init);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for the Signals alert event from Immediate Alert or Link Loss services.
 *
 * @param[in] alert_level  Requested alert level.
 */
static void alert_signal(uint8_t alert_level)
{
    ret_code_t err_code;

    switch (alert_level)
    {
        case BLE_CHAR_ALERT_LEVEL_NO_ALERT:
            NRF_LOG_INFO("No Alert.");
            err_code = bsp_indication_set(BSP_INDICATE_ALERT_OFF);
            APP_ERROR_CHECK(err_code);
            break; // BLE_CHAR_ALERT_LEVEL_NO_ALERT

        case BLE_CHAR_ALERT_LEVEL_MILD_ALERT:
            NRF_LOG_INFO("Mild Alert.");
            err_code = bsp_indication_set(BSP_INDICATE_ALERT_0);
            APP_ERROR_CHECK(err_code);
            break; // BLE_CHAR_ALERT_LEVEL_MILD_ALERT

        case BLE_CHAR_ALERT_LEVEL_HIGH_ALERT:
            NRF_LOG_INFO("HIGH Alert.");
            err_code = bsp_indication_set(BSP_INDICATE_ALERT_3);
            APP_ERROR_CHECK(err_code);
            break; // BLE_CHAR_ALERT_LEVEL_HIGH_ALERT

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Function for handling Immediate Alert events.
 *
 * @details This function will be called for all Immediate Alert events which are passed to the
 *          application.
 *
 * @param[in] p_ias  Immediate Alert structure.
 * @param[in] p_evt  Event received from the Immediate Alert service.
 */
static void on_ias_evt(ble_ias_t * p_ias, ble_ias_evt_t * p_evt)
{
    switch (p_evt->evt_type)
    {
        case BLE_IAS_EVT_ALERT_LEVEL_UPDATED:
            if (p_evt->p_link_ctx != NULL)
            {
                alert_signal(p_evt->p_link_ctx->alert_level);
            }
            break; // BLE_IAS_EVT_ALERT_LEVEL_UPDATED

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Function for handling Link Loss events.
 *
 * @details This function will be called for all Link Loss events which are passed to the
 *          application.
 *
 * @param[in] p_lls  Link Loss structure.
 * @param[in] p_evt  Event received from the Link Loss service.
 */
static void on_lls_evt(ble_lls_t * p_lls, ble_lls_evt_t * p_evt)
{
    switch (p_evt->evt_type)
    {
        case BLE_LLS_EVT_LINK_LOSS_ALERT:
            alert_signal(p_evt->params.alert_level);
            break; // BLE_LLS_EVT_LINK_LOSS_ALERT

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Function for handling IAS Client events.
 *
 * @details This function will be called for all IAS Client events which are passed to the
 *          application.
 *
 * @param[in] p_ias_c  IAS Client structure.
 * @param[in] p_evt    Event received.
 */
static void on_ias_c_evt(ble_ias_c_t * p_ias_c, ble_ias_c_evt_t * p_evt)
{
    ret_code_t err_code;

    switch (p_evt->evt_type)
    {
        case BLE_IAS_C_EVT_DISCOVERY_COMPLETE:
            // IAS is found on peer. The Find Me Locator functionality of this app will work.
            err_code = ble_ias_c_handles_assign(&m_ias_c,
                                                p_evt->conn_handle,
                                                p_evt->alert_level.handle_value);
            APP_ERROR_CHECK(err_code);

            m_is_ias_present = true;
            break; // BLE_IAS_C_EVT_DISCOVERY_COMPLETE

        case BLE_IAS_C_EVT_DISCOVERY_FAILED:
            // IAS is not found on peer. The Find Me Locator functionality of this app will NOT work.
            break; // BLE_IAS_C_EVT_DISCOVERY_FAILED

        case BLE_IAS_C_EVT_DISCONN_COMPLETE:
            // Disable alert buttons
            m_is_ias_present = false;
            break; // BLE_IAS_C_EVT_DISCONN_COMPLETE

        default:
            break;
    }
}


/**@brief Function for handling the Battery Service events.
 *
 * @details This function will be called for all Battery Service events which are passed to the
 |          application.
 *
 * @param[in] p_bas  Battery Service structure.
 * @param[in] p_evt  Event received from the Battery Service.
 */
static void on_bas_evt(ble_bas_t * p_bas, ble_bas_evt_t * p_evt)
{
    ret_code_t err_code;

    switch (p_evt->evt_type)
    {
        case BLE_BAS_EVT_NOTIFICATION_ENABLED:
            // Start battery timer
            err_code = app_timer_start(m_battery_timer_id, BATTERY_LEVEL_MEAS_INTERVAL, NULL);
            APP_ERROR_CHECK(err_code);
            break; // BLE_BAS_EVT_NOTIFICATION_ENABLED

        case BLE_BAS_EVT_NOTIFICATION_DISABLED:
            err_code = app_timer_stop(m_battery_timer_id);
            APP_ERROR_CHECK(err_code);
            break; // BLE_BAS_EVT_NOTIFICATION_DISABLED

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Function for handling BLE events.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 * @param[in]   p_context   Unused.
 */
static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
{
    ret_code_t err_code = NRF_SUCCESS;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO("Disconnected.");
            // LED indication will be changed when advertising starts.
            break;

        case BLE_GAP_EVT_CONNECTED:
        {
            NRF_LOG_INFO("Connected.");
            err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
            APP_ERROR_CHECK(err_code);

            // Assign connection handle to the Queued Write module.
            err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr, p_ble_evt->evt.gap_evt.conn_handle);
            APP_ERROR_CHECK(err_code);

            // Discover peer's services.
            err_code = ble_db_discovery_start(&m_ble_db_discovery,
                                              p_ble_evt->evt.gap_evt.conn_handle);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
        {
            NRF_LOG_DEBUG("PHY update request.");
            ble_gap_phys_t const phys =
            {
                .rx_phys = BLE_GAP_PHY_AUTO,
                .tx_phys = BLE_GAP_PHY_AUTO,
            };
            err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GATTC_EVT_TIMEOUT:
            // Disconnect on GATT Client timeout event.
            NRF_LOG_DEBUG("GATT Client Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTS_EVT_TIMEOUT:
            // Disconnect on GATT Server timeout event.
            NRF_LOG_DEBUG("GATT Server Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Function for initializing the BLE stack.
 *
 * @details Initializes the SoftDevice and the BLE event interrupt.
 */
static void ble_stack_init(void)
{
    ret_code_t err_code;

    err_code = nrf_sdh_enable_request();
    APP_ERROR_CHECK(err_code);

    // Configure the BLE stack using the default settings.
    // Fetch the start address of the application RAM.
    uint32_t ram_start = 0;
    err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
    APP_ERROR_CHECK(err_code);

    // Enable BLE stack.
    err_code = nrf_sdh_ble_enable(&ram_start);
    APP_ERROR_CHECK(err_code);

    // Register a handler for BLE events.
    NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
}


/**@brief Function for the Peer Manager initialization.
 */
static void peer_manager_init(void)
{
    ble_gap_sec_params_t sec_param;
    ret_code_t           err_code;

    err_code = pm_init();
    APP_ERROR_CHECK(err_code);

    memset(&sec_param, 0, sizeof(ble_gap_sec_params_t));

    // Security parameters to be used for all security procedures.
    sec_param.bond           = SEC_PARAM_BOND;
    sec_param.mitm           = SEC_PARAM_MITM;
    sec_param.lesc           = SEC_PARAM_LESC;
    sec_param.keypress       = SEC_PARAM_KEYPRESS;
    sec_param.io_caps        = SEC_PARAM_IO_CAPABILITIES;
    sec_param.oob            = SEC_PARAM_OOB;
    sec_param.min_key_size   = SEC_PARAM_MIN_KEY_SIZE;
    sec_param.max_key_size   = SEC_PARAM_MAX_KEY_SIZE;
    sec_param.kdist_own.enc  = 1;
    sec_param.kdist_own.id   = 1;
    sec_param.kdist_peer.enc = 1;
    sec_param.kdist_peer.id  = 1;

    err_code = pm_sec_params_set(&sec_param);
    APP_ERROR_CHECK(err_code);

    err_code = pm_register(pm_evt_handler);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling events from the BSP module.
 *
 * @param[in]   event   Event generated when button is pressed.
 */
static void bsp_event_handler(bsp_event_t event)
{
    ret_code_t err_code;

    switch (event)
    {
        case BSP_EVENT_SLEEP:
            sleep_mode_enter();
            break;

        case BSP_EVENT_DISCONNECT:
            err_code = sd_ble_gap_disconnect(m_ias_c.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            if (err_code != NRF_ERROR_INVALID_STATE)
            {
                APP_ERROR_CHECK(err_code);
            }
            break;

        case BSP_EVENT_KEY_0:
        {
            if (m_is_ias_present)
            {
                if (!m_is_high_alert_signalled)
                {
                    err_code =
                        ble_ias_c_send_alert_level(&m_ias_c, BLE_CHAR_ALERT_LEVEL_HIGH_ALERT);
                }
                else
                {
                    err_code = ble_ias_c_send_alert_level(&m_ias_c, BLE_CHAR_ALERT_LEVEL_NO_ALERT);
                }

                if (err_code == NRF_SUCCESS)
                {
                    m_is_high_alert_signalled = !m_is_high_alert_signalled;
                }
                else if (
                    (err_code != NRF_ERROR_RESOURCES)
                    &&
                    (err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)
                    &&
                    (err_code != NRF_ERROR_NOT_FOUND)
                        )
                {
                    APP_ERROR_HANDLER(err_code);
                }
            }
        } break;

        case BSP_EVENT_KEY_1:
            NRF_LOG_INFO("Alert Off.");
            err_code = bsp_indication_set(BSP_INDICATE_ALERT_OFF);
            APP_ERROR_CHECK(err_code);
            break;

        default:
            break;
    }
}


/**@brief Function for initializing buttons and leds.
 *
 * @param[out] p_erase_bonds  Will be true if the clear bonding button was pressed to wake the application up.
 */
static void buttons_leds_init(bool * p_erase_bonds)
{
    ret_code_t err_code;
    bsp_event_t startup_event;

    err_code = bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, bsp_event_handler);
    APP_ERROR_CHECK(err_code);

    err_code = bsp_btn_ble_init(NULL, &startup_event);
    APP_ERROR_CHECK(err_code);

    *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
}


/**@brief Function for initializing the nrf log module.
 */
static void log_init(void)
{
    ret_code_t err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}


/**@brief Function for initializing power management.
 */
static void power_management_init(void)
{
    ret_code_t err_code;
    err_code = nrf_pwr_mgmt_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling the idle state (main loop).
 *
 * @details If there is no pending log operation, then sleep until next the next event occurs.
 */
static void idle_state_handle(void)
{
    if (NRF_LOG_PROCESS() == false)
    {
        nrf_pwr_mgmt_run();
    }
}


/**@brief Clear bond information from persistent storage.
 */
static void delete_bonds(void)
{
    ret_code_t err_code;

    NRF_LOG_INFO("Erase bonds!");

    err_code = pm_peers_delete();
    APP_ERROR_CHECK(err_code);
}



/**@brief Function for starting advertising.
 */
static void advertising_start(bool erase_bonds)
{
    if (erase_bonds == true){
        delete_bonds();
        // Advertising is started by PM_EVT_PEERS_DELETE_SUCEEDED event.
    }
    else
    {
        uint32_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);

        APP_ERROR_CHECK(err_code);
    }
}


/**@brief Function for changing the tx power.
 */
static void tx_power_set(void)
{
    ret_code_t err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_ADV, m_advertising.adv_handle, TX_POWER_LEVEL);
    APP_ERROR_CHECK(err_code);
}

/**@brief Function for application main entry.
 */
int main(void)
{
    bool erase_bonds;

    // Initialize.
    log_init();
    timers_init();
    buttons_leds_init(&erase_bonds);
    power_management_init();
    ble_stack_init();
    adc_configure();
    gap_params_init();
    gatt_init();
    advertising_init();
    db_discovery_init();
    services_init();
    conn_params_init();
    peer_manager_init();

    // Start execution.
    NRF_LOG_INFO("Proximity example started.");
    advertising_start(erase_bonds);
    tx_power_set();

    // Enter main loop.
    for (;;)
    {
        idle_state_handle();
    }
}


/**
 * @}
 */
