// Copyright 2015-2017 Espressif Systems (Shanghai) PTE LTD
//
// 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.



/****************************************************************************
*
* This file is for gatt client. It can scan ble device, connect multiple devices,
* The gattc_multi_connect demo can connect three ble slaves at the same time.
* Modify the name of gatt_server demo named ESP_GATTS_DEMO_a,
* ESP_GATTS_DEMO_b and ESP_GATTS_DEMO_c,then run three demos,the gattc_multi_connect demo will connect
* the three gatt_server demos, and then exchange data.
* Of course you can also modify the code to connect more devices, we default to connect
* up to 4 devices, more than 4 you need to modify menuconfig.
*
****************************************************************************/

#include <stdint.h>
#include <string.h>
#include <stdbool.h>
#include <stdio.h>
#include "nvs.h"
#include "nvs_flash.h"
#include "controller.h"

#include "bt.h"
#include "esp_gap_ble_api.h"
#include "esp_gattc_api.h"
#include "esp_gatt_defs.h"
#include "esp_bt_main.h"
#include "esp_gatt_common_api.h"

#define GATTC_TAG "GATTC_MULTIPLE_DEMO"
#define REMOTE_SERVICE_UUID        0x00FF
#define REMOTE_NOTIFY_CHAR_UUID    0xFF01

///Declare static functions
static void esp_gap_cb(esp_gap_ble_cb_event_t event, esp_ble_gap_cb_param_t *param);
static void esp_gattc_cb(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param);
static void gattc_profile_a_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param);
static void gattc_profile_b_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param);
static void gattc_profile_c_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param);

static esp_gatt_srvc_id_t remote_service_id = {
    .id = {
        .uuid = {
            .len = ESP_UUID_LEN_16,
            .uuid = {.uuid16 = REMOTE_SERVICE_UUID,},
        },
        .inst_id = 0,
    },
    .is_primary = true,
};

static esp_bt_uuid_t remote_filter_service_uuid = {
    .len = ESP_UUID_LEN_16,
    .uuid = {.uuid16 = REMOTE_SERVICE_UUID,},
};

static esp_gatt_id_t notify_descr_id = {
    .uuid = {
        .len = ESP_UUID_LEN_16,
        .uuid = {.uuid16 = ESP_GATT_UUID_CHAR_CLIENT_CONFIG,},
    },
    .inst_id = 0,
};

static bool conn_device_a   = false;
static bool conn_device_b   = false;
static bool conn_device_c   = false;

static bool get_service_a   = false;
static bool get_service_b   = false;
static bool get_service_c   = false;

static bool Isconnecting    = false;
static bool stop_scan_done  = false;

static const char remote_device_name[3][20] = {"ESP_GATTS_DEMO_a", "ESP_GATTS_DEMO_b", "ESP_GATTS_DEMO_c"};

static esp_ble_scan_params_t ble_scan_params = {
    .scan_type              = BLE_SCAN_TYPE_ACTIVE,
    .own_addr_type          = BLE_ADDR_TYPE_PUBLIC,
    .scan_filter_policy     = BLE_SCAN_FILTER_ALLOW_ALL,
    .scan_interval          = 0x50,
    .scan_window            = 0x30
};

//register three profiles, each profile corresponds to one connection,
//which makes it easy to handle each connection event
#define PROFILE_NUM 3
#define PROFILE_A_APP_ID 0
#define PROFILE_B_APP_ID 1
#define PROFILE_C_APP_ID 2


struct gattc_profile_inst {
    esp_gattc_cb_t gattc_cb;
    uint16_t gattc_if;
    uint16_t app_id;
    uint16_t conn_id;
    esp_bd_addr_t remote_bda;
};

/* One gatt-based profile one app_id and one gattc_if, this array will store the gattc_if returned by ESP_GATTS_REG_EVT */
static struct gattc_profile_inst gl_profile_tab[PROFILE_NUM] = {
    [PROFILE_A_APP_ID] = {
        .gattc_cb = gattc_profile_a_event_handler,
        .gattc_if = ESP_GATT_IF_NONE,       /* Not get the gatt_if, so initial is ESP_GATT_IF_NONE */
    },
    [PROFILE_B_APP_ID] = {
        .gattc_cb = gattc_profile_b_event_handler,
        .gattc_if = ESP_GATT_IF_NONE,       /* Not get the gatt_if, so initial is ESP_GATT_IF_NONE */
    },
    [PROFILE_C_APP_ID] = {
        .gattc_cb = gattc_profile_c_event_handler,
        .gattc_if = ESP_GATT_IF_NONE,       /* Not get the gatt_if, so initial is ESP_GATT_IF_NONE */
    },

};

static void start_scan(void)
{
    stop_scan_done = false;
    Isconnecting = false;
    uint32_t duration = 30;
    esp_ble_gap_start_scanning(duration);
}
static void gattc_profile_a_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param)
{

    esp_ble_gattc_cb_param_t *p_data = (esp_ble_gattc_cb_param_t *)param;

    switch (event) {
    case ESP_GATTC_REG_EVT:
        ESP_LOGI(GATTC_TAG, "REG_EVT");
        esp_err_t scan_ret = esp_ble_gap_set_scan_params(&ble_scan_params);
        if (scan_ret){
            ESP_LOGE(GATTC_TAG, "set scan params error, error code = %x", scan_ret);
        }
        break;
    /* one device connect successfully, all profiles callback function will get the ESP_GATTC_CONNECT_EVT,
     so must compare the mac address to check which device is connected, so it is a good choice to use ESP_GATTC_OPEN_EVT. */
    case ESP_GATTC_CONNECT_EVT:
        break;
    case ESP_GATTC_OPEN_EVT:
        if (p_data->open.status != ESP_GATT_OK){
            //open failed, ignore the first device, connect the second device
            ESP_LOGE(GATTC_TAG, "connect device failed, status %d", p_data->open.status);
            conn_device_a = false;
            start_scan();
            break;
        }
        memcpy(gl_profile_tab[PROFILE_A_APP_ID].remote_bda, p_data->open.remote_bda, 6);
        gl_profile_tab[PROFILE_A_APP_ID].conn_id = p_data->open.conn_id;
        ESP_LOGI(GATTC_TAG, "ESP_GATTC_OPEN_EVT conn_id %d, if %d, status %d, mtu %d", p_data->open.conn_id, gattc_if, p_data->open.status, p_data->open.mtu);
        ESP_LOGI(GATTC_TAG, "REMOTE BDA:");
        esp_log_buffer_hex(GATTC_TAG, p_data->open.remote_bda, sizeof(esp_bd_addr_t));
        esp_err_t mtu_ret = esp_ble_gattc_send_mtu_req (gattc_if, p_data->open.conn_id);
        if (mtu_ret){
            ESP_LOGE(GATTC_TAG, "config MTU error, error code = %x", mtu_ret);
        }
        break;
    case ESP_GATTC_CFG_MTU_EVT:
        if (param->cfg_mtu.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG,"Config mtu failed");
        }
        ESP_LOGI(GATTC_TAG, "Status %d, MTU %d, conn_id %d", param->cfg_mtu.status, param->cfg_mtu.mtu, param->cfg_mtu.conn_id);
        esp_ble_gattc_search_service(gattc_if, param->cfg_mtu.conn_id, &remote_filter_service_uuid);
        break;
    case ESP_GATTC_SEARCH_RES_EVT: {
        esp_gatt_srvc_id_t *srvc_id = &p_data->search_res.srvc_id;
        ESP_LOGI(GATTC_TAG, "SEARCH RES: conn_id = %x", p_data->search_res.conn_id);
        if (srvc_id->id.uuid.len == ESP_UUID_LEN_16 && srvc_id->id.uuid.uuid.uuid16 == REMOTE_SERVICE_UUID) {
            ESP_LOGI(GATTC_TAG, "UUID16: %x", srvc_id->id.uuid.uuid.uuid16);
            get_service_a = true;
        }
        break;
    }
    case ESP_GATTC_SEARCH_CMPL_EVT:
        if (p_data->search_cmpl.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "search service failed, error status = %x", p_data->search_cmpl.status);
            break;
        }
        if (get_service_a){
            esp_ble_gattc_get_characteristic(gattc_if, p_data->search_cmpl.conn_id, &remote_service_id, NULL);
        }
        break;
    case ESP_GATTC_GET_CHAR_EVT:
        if (p_data->get_char.status != ESP_GATT_OK) {
            break;
        }
        ESP_LOGI(GATTC_TAG, "GET CHAR: conn_id = %x, status %d", p_data->get_char.conn_id, p_data->get_char.status);
        ESP_LOGI(GATTC_TAG, "GET CHAR: srvc_id = %04x, char_id = %04x", p_data->get_char.srvc_id.id.uuid.uuid.uuid16, p_data->get_char.char_id.uuid.uuid.uuid16);

        if (p_data->get_char.char_id.uuid.uuid.uuid16 == REMOTE_NOTIFY_CHAR_UUID) {
            ESP_LOGI(GATTC_TAG, "register notify");
            esp_ble_gattc_register_for_notify(gattc_if, gl_profile_tab[PROFILE_A_APP_ID].remote_bda, &remote_service_id, &p_data->get_char.char_id);
        }

        esp_ble_gattc_get_characteristic(gattc_if, p_data->get_char.conn_id, &remote_service_id, &p_data->get_char.char_id);
        break;
    case ESP_GATTC_REG_FOR_NOTIFY_EVT: {
        if (p_data->reg_for_notify.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "reg notify failed, error status =%x", p_data->reg_for_notify.status);
            break;
        }
        uint16_t notify_en = 1;
        ESP_LOGI(GATTC_TAG, "REG FOR NOTIFY: status %d, srvc_id = %04x, char_id = %04x",
                p_data->reg_for_notify.status,
                p_data->reg_for_notify.srvc_id.id.uuid.uuid.uuid16,
                p_data->reg_for_notify.char_id.uuid.uuid.uuid16);

        esp_ble_gattc_write_char_descr(gattc_if,
                                       gl_profile_tab[PROFILE_A_APP_ID].conn_id,
                                       &remote_service_id,
                                       &p_data->reg_for_notify.char_id,
                                       &notify_descr_id,
                                       sizeof(notify_en),
                                       (uint8_t *)&notify_en,
                                       ESP_GATT_WRITE_TYPE_RSP,
                                       ESP_GATT_AUTH_REQ_NONE);
        break;
    }
    case ESP_GATTC_NOTIFY_EVT:
        ESP_LOGI(GATTC_TAG, "ESP_GATTC_NOTIFY_EVT, Receive notify value:");
        esp_log_buffer_hex(GATTC_TAG, p_data->notify.value, p_data->notify.value_len);
        //write  back
        esp_ble_gattc_write_char(gattc_if,
                                gl_profile_tab[PROFILE_A_APP_ID].conn_id,
                                &remote_service_id,
                                &p_data->notify.char_id,
                                p_data->notify.value_len,
                                p_data->notify.value,
                                ESP_GATT_WRITE_TYPE_RSP,
                                ESP_GATT_AUTH_REQ_NONE);
        break;
    case ESP_GATTC_WRITE_DESCR_EVT:
        if (p_data->write.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "write descr failed, error status = %x", p_data->write.status);
            break;
        }
        ESP_LOGI(GATTC_TAG, "write descr success");
        break;
    case ESP_GATTC_WRITE_CHAR_EVT:
        if (p_data->write.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "write char failed, error status = %x", p_data->write.status);
        }else{
            ESP_LOGI(GATTC_TAG, "write char success");
        }
        start_scan();
        break;
    case ESP_GATTC_SRVC_CHG_EVT: {
        esp_bd_addr_t bda;
        memcpy(bda, p_data->srvc_chg.remote_bda, sizeof(esp_bd_addr_t));
        ESP_LOGI(GATTC_TAG, "ESP_GATTC_SRVC_CHG_EVT, bd_addr:%08x%04x",(bda[0] << 24) + (bda[1] << 16) + (bda[2] << 8) + bda[3],
                 (bda[4] << 8) + bda[5]);
        break;
    }
    case ESP_GATTC_DISCONNECT_EVT:
        ESP_LOGI(GATTC_TAG,"ESP_GATTC_DISCONNECT_EVT");
        ESP_LOGI(GATTC_TAG, "conn_id %d, if %d", p_data->disconnect.conn_id, gattc_if);
        //Start scanning again
        start_scan();
        if (memcmp(p_data->disconnect.remote_bda, gl_profile_tab[PROFILE_A_APP_ID].remote_bda, 6) == 0){
            ESP_LOGI(GATTC_TAG, "device a disconnect");
            conn_device_a = false;
            get_service_a = false;
        }
        break;
    default:
        break;
    }
}

static void gattc_profile_b_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param)
{
    esp_ble_gattc_cb_param_t *p_data = (esp_ble_gattc_cb_param_t *)param;

    switch (event) {
    case ESP_GATTC_REG_EVT:
        ESP_LOGI(GATTC_TAG, "REG_EVT");
        break;
    case ESP_GATTC_CONNECT_EVT:
        break;
    case ESP_GATTC_OPEN_EVT:
        if (p_data->open.status != ESP_GATT_OK){
            //open failed, ignore the second device, connect the third device
            ESP_LOGE(GATTC_TAG, "connect device failed, status %d", p_data->open.status);
            conn_device_b = false;
            start_scan();
            break;
        }
        memcpy(gl_profile_tab[PROFILE_B_APP_ID].remote_bda, p_data->open.remote_bda, 6);
        gl_profile_tab[PROFILE_B_APP_ID].conn_id = p_data->open.conn_id;
        ESP_LOGI(GATTC_TAG, "ESP_GATTC_OPEN_EVT conn_id %d, if %d, status %d, mtu %d", p_data->open.conn_id, gattc_if, p_data->open.status, p_data->open.mtu);
        ESP_LOGI(GATTC_TAG, "REMOTE BDA:");
        esp_log_buffer_hex(GATTC_TAG, p_data->open.remote_bda, sizeof(esp_bd_addr_t));
        esp_err_t mtu_ret = esp_ble_gattc_send_mtu_req (gattc_if, p_data->open.conn_id);
        if (mtu_ret){
            ESP_LOGE(GATTC_TAG, "config MTU error, error code = %x", mtu_ret);
        }
        break;
    case ESP_GATTC_CFG_MTU_EVT:
        if (param->cfg_mtu.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG,"Config mtu failed");
        }
        ESP_LOGI(GATTC_TAG, "Status %d, MTU %d, conn_id %d", param->cfg_mtu.status, param->cfg_mtu.mtu, param->cfg_mtu.conn_id);
        esp_ble_gattc_search_service(gattc_if, param->cfg_mtu.conn_id, &remote_filter_service_uuid);
        break;
    case ESP_GATTC_SEARCH_RES_EVT: {
        esp_gatt_srvc_id_t *srvc_id = &p_data->search_res.srvc_id;
        ESP_LOGI(GATTC_TAG, "SEARCH RES: conn_id = %x", p_data->search_res.conn_id);
        if (srvc_id->id.uuid.len == ESP_UUID_LEN_16 && srvc_id->id.uuid.uuid.uuid16 == REMOTE_SERVICE_UUID) {
            ESP_LOGI(GATTC_TAG, "UUID16: %x", srvc_id->id.uuid.uuid.uuid16);
            get_service_b = true;
        }
        break;
    }
    case ESP_GATTC_SEARCH_CMPL_EVT:
        if (p_data->search_cmpl.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "search service failed, error status = %x", p_data->search_cmpl.status);
            break;
        }
        if (get_service_b){
            esp_ble_gattc_get_characteristic(gattc_if, p_data->search_cmpl.conn_id, &remote_service_id, NULL);
        }
        break;
    case ESP_GATTC_GET_CHAR_EVT:
        if (p_data->get_char.status != ESP_GATT_OK) {
            break;
        }
        ESP_LOGI(GATTC_TAG, "GET CHAR: conn_id = %x, status %d", p_data->get_char.conn_id, p_data->get_char.status);
        ESP_LOGI(GATTC_TAG, "GET CHAR: srvc_id = %04x, char_id = %04x", p_data->get_char.srvc_id.id.uuid.uuid.uuid16, p_data->get_char.char_id.uuid.uuid.uuid16);

        if (p_data->get_char.char_id.uuid.uuid.uuid16 == REMOTE_NOTIFY_CHAR_UUID) {
            ESP_LOGI(GATTC_TAG, "register notify");
            esp_ble_gattc_register_for_notify(gattc_if, gl_profile_tab[PROFILE_B_APP_ID].remote_bda, &remote_service_id, &p_data->get_char.char_id);
        }

        esp_ble_gattc_get_characteristic(gattc_if, p_data->get_char.conn_id, &remote_service_id, &p_data->get_char.char_id);
        break;
    case ESP_GATTC_REG_FOR_NOTIFY_EVT: {

        ESP_LOGI(GATTC_TAG, "REG FOR NOTIFY: status %d, srvc_id = %04x, char_id = %04x",
                p_data->reg_for_notify.status,
                p_data->reg_for_notify.srvc_id.id.uuid.uuid.uuid16,
                p_data->reg_for_notify.char_id.uuid.uuid.uuid16);
        uint16_t notify_en = 1;
        esp_ble_gattc_write_char_descr(gattc_if,
                                       gl_profile_tab[PROFILE_B_APP_ID].conn_id,
                                       &remote_service_id,
                                       &p_data->reg_for_notify.char_id,
                                       &notify_descr_id,
                                       sizeof(notify_en),
                                       (uint8_t *)&notify_en,
                                       ESP_GATT_WRITE_TYPE_RSP,
                                       ESP_GATT_AUTH_REQ_NONE);
        break;
    }
    case ESP_GATTC_NOTIFY_EVT:
        ESP_LOGI(GATTC_TAG, "ESP_GATTC_NOTIFY_EVT, Receive notify value:");
        esp_log_buffer_hex(GATTC_TAG, p_data->notify.value, p_data->notify.value_len);
        //write  back
        esp_ble_gattc_write_char(gattc_if,
                                gl_profile_tab[PROFILE_B_APP_ID].conn_id,
                                &remote_service_id,
                                &p_data->notify.char_id,
                                p_data->notify.value_len,
                                p_data->notify.value,
                                ESP_GATT_WRITE_TYPE_RSP,
                                ESP_GATT_AUTH_REQ_NONE);
        break;
    case ESP_GATTC_WRITE_DESCR_EVT:
        if (p_data->write.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "write descr failed, error status = %x", p_data->write.status);
            break;
        }
        ESP_LOGI(GATTC_TAG, "write descr success");
        break;
    case ESP_GATTC_WRITE_CHAR_EVT:
        if (p_data->write.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "Write char failed, error status = %x", p_data->write.status);
        }else{
            ESP_LOGI(GATTC_TAG, "Write char success");
        }
        start_scan();
        break;
    case ESP_GATTC_SRVC_CHG_EVT: {
        esp_bd_addr_t bda;
        memcpy(bda, p_data->srvc_chg.remote_bda, sizeof(esp_bd_addr_t));
        ESP_LOGI(GATTC_TAG, "ESP_GATTC_SRVC_CHG_EVT, bd_addr:%08x%04x",(bda[0] << 24) + (bda[1] << 16) + (bda[2] << 8) + bda[3],
                 (bda[4] << 8) + bda[5]);
        break;
    }
    case ESP_GATTC_DISCONNECT_EVT:
        ESP_LOGI(GATTC_TAG,"ESP_GATTC_DISCONNECT_EVT");
        ESP_LOGI(GATTC_TAG, "conn_id %d, if %d", p_data->disconnect.conn_id, gattc_if);
        if (memcmp(p_data->disconnect.remote_bda, gl_profile_tab[PROFILE_B_APP_ID].remote_bda, 6) == 0){
            ESP_LOGI(GATTC_TAG, "device b disconnect");
            conn_device_b = false;
            get_service_b = false;
        }
        break;
    default:
        break;
    }
}

static void gattc_profile_c_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param)
{
    esp_ble_gattc_cb_param_t *p_data = (esp_ble_gattc_cb_param_t *)param;

    switch (event) {
    case ESP_GATTC_REG_EVT:
        ESP_LOGI(GATTC_TAG, "REG_EVT");
        break;
    case ESP_GATTC_CONNECT_EVT:
        break;
    case ESP_GATTC_OPEN_EVT:
        if (p_data->open.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "connect device failed, status %d", p_data->open.status);
            conn_device_c = false;
            start_scan();
            break;
        }
        memcpy(gl_profile_tab[PROFILE_C_APP_ID].remote_bda, p_data->open.remote_bda, 6);
        gl_profile_tab[PROFILE_C_APP_ID].conn_id = p_data->open.conn_id;
        ESP_LOGI(GATTC_TAG, "ESP_GATTC_OPEN_EVT conn_id %d, if %d, status %d, mtu %d", p_data->open.conn_id, gattc_if, p_data->open.status, p_data->open.mtu);
        ESP_LOGI(GATTC_TAG, "REMOTE BDA:");
        esp_log_buffer_hex(GATTC_TAG, p_data->open.remote_bda, sizeof(esp_bd_addr_t));
        esp_err_t mtu_ret = esp_ble_gattc_send_mtu_req (gattc_if, p_data->open.conn_id);
        if (mtu_ret){
            ESP_LOGE(GATTC_TAG, "config MTU error, error code = %x", mtu_ret);
        }
        break;
    case ESP_GATTC_CFG_MTU_EVT:
        if (param->cfg_mtu.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG,"Config mtu failed");
        }
        ESP_LOGI(GATTC_TAG, "Status %d, MTU %d, conn_id %d", param->cfg_mtu.status, param->cfg_mtu.mtu, param->cfg_mtu.conn_id);
        esp_ble_gattc_search_service(gattc_if, param->cfg_mtu.conn_id, &remote_filter_service_uuid);
        break;
    case ESP_GATTC_SEARCH_RES_EVT: {
        esp_gatt_srvc_id_t *srvc_id = &p_data->search_res.srvc_id;
        ESP_LOGI(GATTC_TAG, "SEARCH RES: conn_id = %x", p_data->search_res.conn_id);
        if (srvc_id->id.uuid.len == ESP_UUID_LEN_16 && srvc_id->id.uuid.uuid.uuid16 == REMOTE_SERVICE_UUID) {
            ESP_LOGI(GATTC_TAG, "UUID16: %x", srvc_id->id.uuid.uuid.uuid16);
            get_service_c = true;
        }
        break;
    }
    case ESP_GATTC_SEARCH_CMPL_EVT:
        if (p_data->search_cmpl.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "search service failed, error status = %x", p_data->search_cmpl.status);
            break;
        }
        if (get_service_c){
            esp_ble_gattc_get_characteristic(gattc_if, p_data->search_cmpl.conn_id, &remote_service_id, NULL);
        }
        break;
    case ESP_GATTC_GET_CHAR_EVT:
        if (p_data->get_char.status != ESP_GATT_OK) {
            ESP_LOGE(GATTC_TAG, "GET CHAR failed, error status = %x", p_data->get_char.status);
            break;
        }
        ESP_LOGI(GATTC_TAG, "GET CHAR: srvc_id = %04x, char_id = %04x", p_data->get_char.srvc_id.id.uuid.uuid.uuid16, p_data->get_char.char_id.uuid.uuid.uuid16);
        if (p_data->get_char.char_id.uuid.uuid.uuid16 == REMOTE_NOTIFY_CHAR_UUID) {
            ESP_LOGI(GATTC_TAG, "register notify");
            esp_ble_gattc_register_for_notify(gattc_if, gl_profile_tab[PROFILE_C_APP_ID].remote_bda, &remote_service_id, &p_data->get_char.char_id);
        }
        esp_ble_gattc_get_characteristic(gattc_if, p_data->get_char.conn_id, &remote_service_id, &p_data->get_char.char_id);
        break;
    case ESP_GATTC_REG_FOR_NOTIFY_EVT: {
        uint16_t notify_en = 1;
        ESP_LOGI(GATTC_TAG, "REG FOR NOTIFY: status %d, srvc_id = %04x, char_id = %04x",
                p_data->reg_for_notify.status,
                p_data->reg_for_notify.srvc_id.id.uuid.uuid.uuid16,
                p_data->reg_for_notify.char_id.uuid.uuid.uuid16);

        esp_ble_gattc_write_char_descr(gattc_if,
                                       gl_profile_tab[PROFILE_C_APP_ID].conn_id,
                                       &remote_service_id,
                                       &p_data->reg_for_notify.char_id,
                                       &notify_descr_id,
                                       sizeof(notify_en),
                                       (uint8_t *)&notify_en,
                                       ESP_GATT_WRITE_TYPE_RSP,
                                       ESP_GATT_AUTH_REQ_NONE);
        break;
    }
    case ESP_GATTC_NOTIFY_EVT:
        ESP_LOGI(GATTC_TAG, "ESP_GATTC_NOTIFY_EVT, Receive notify value:");
        esp_log_buffer_hex(GATTC_TAG, p_data->notify.value, p_data->notify.value_len);
        //write  back
        esp_ble_gattc_write_char(gattc_if,
                                gl_profile_tab[PROFILE_C_APP_ID].conn_id,
                                &remote_service_id,
                                &p_data->notify.char_id,
                                p_data->notify.value_len,
                                p_data->notify.value,
                                ESP_GATT_WRITE_TYPE_RSP,
                                ESP_GATT_AUTH_REQ_NONE);
        break;
    case ESP_GATTC_WRITE_DESCR_EVT:
        if (p_data->write.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "write descr failed, error status = %x", p_data->write.status);
            break;
        }
        ESP_LOGI(GATTC_TAG, "write descr success");
        break;
    case ESP_GATTC_WRITE_CHAR_EVT:
        if (p_data->write.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "Write char failed, error status = %x", p_data->write.status);
            break;
        }
        ESP_LOGI(GATTC_TAG, "Write char success");
        start_scan();
        break;
    case ESP_GATTC_SRVC_CHG_EVT: {
        esp_bd_addr_t bda;
        memcpy(bda, p_data->srvc_chg.remote_bda, sizeof(esp_bd_addr_t));
        ESP_LOGI(GATTC_TAG, "ESP_GATTC_SRVC_CHG_EVT, bd_addr:%08x%04x",(bda[0] << 24) + (bda[1] << 16) + (bda[2] << 8) + bda[3],
                 (bda[4] << 8) + bda[5]);
        break;
    }
    case ESP_GATTC_DISCONNECT_EVT:
        ESP_LOGI(GATTC_TAG,"ESP_GATTC_DISCONNECT_EVT");
        ESP_LOGI(GATTC_TAG, "conn_id %d, if %d", p_data->disconnect.conn_id, gattc_if);
        if (memcmp(p_data->disconnect.remote_bda, gl_profile_tab[PROFILE_C_APP_ID].remote_bda, 6) == 0){
            ESP_LOGI(GATTC_TAG, "device c disconnect");
            conn_device_c = false;
            get_service_c = false;
        }
        break;
    default:
        break;
    }
}

static void esp_gap_cb(esp_gap_ble_cb_event_t event, esp_ble_gap_cb_param_t *param)
{
    uint8_t *adv_name = NULL;
    uint8_t adv_name_len = 0;
    switch (event) {
    case ESP_GAP_BLE_SCAN_PARAM_SET_COMPLETE_EVT: {
        //the unit of the duration is second
        uint32_t duration = 30;
        esp_ble_gap_start_scanning(duration);
        break;
    }
    case ESP_GAP_BLE_SCAN_START_COMPLETE_EVT:
        //scan start complete event to indicate scan start successfully or failed
        if (param->scan_start_cmpl.status == ESP_BT_STATUS_SUCCESS) {
            ESP_LOGE(GATTC_TAG, "Scan start success");
        }else{
            ESP_LOGE(GATTC_TAG, "Scan start failed");
        }
        break;
    case ESP_GAP_BLE_SCAN_RESULT_EVT: {
        esp_ble_gap_cb_param_t *scan_result = (esp_ble_gap_cb_param_t *)param;
        switch (scan_result->scan_rst.search_evt) {
        case ESP_GAP_SEARCH_INQ_RES_EVT:
            esp_log_buffer_hex(GATTC_TAG, scan_result->scan_rst.bda, 6);
            ESP_LOGI(GATTC_TAG, "Searched Adv Data Len %d, Scan Response Len %d", scan_result->scan_rst.adv_data_len, scan_result->scan_rst.scan_rsp_len);
            adv_name = esp_ble_resolve_adv_data(scan_result->scan_rst.ble_adv,
                                                ESP_BLE_AD_TYPE_NAME_CMPL, &adv_name_len);
            ESP_LOGI(GATTC_TAG, "Searched Device Name Len %d", adv_name_len);
            esp_log_buffer_char(GATTC_TAG, adv_name, adv_name_len);
            ESP_LOGI(GATTC_TAG, "\n");
            if (Isconnecting){
                break;
            }
            if (conn_device_a && conn_device_b && conn_device_c && !stop_scan_done){
                stop_scan_done = true;
                esp_ble_gap_stop_scanning();
                ESP_LOGI(GATTC_TAG, "all devices are connected");
                break;
            }
            if (adv_name != NULL) {

                if (strlen(remote_device_name[0]) == adv_name_len && strncmp((char *)adv_name, remote_device_name[0], adv_name_len) == 0) {
                    if (conn_device_a == false) {
                        conn_device_a = true;
                        ESP_LOGI(GATTC_TAG, "Searched device %s\n", remote_device_name[0]);
                        esp_ble_gap_stop_scanning();
                        esp_ble_gattc_open(gl_profile_tab[PROFILE_A_APP_ID].gattc_if, scan_result->scan_rst.bda, true);
                        Isconnecting = true;
                    }
                    break;
                }
                else if (strlen(remote_device_name[1]) == adv_name_len && strncmp((char *)adv_name, remote_device_name[1], adv_name_len) == 0) {
                    if (conn_device_b == false) {
                        conn_device_b = true;
                        ESP_LOGI(GATTC_TAG, "Searched device %s\n", remote_device_name[1]);
                        esp_ble_gap_stop_scanning();
                        esp_ble_gattc_open(gl_profile_tab[PROFILE_B_APP_ID].gattc_if, scan_result->scan_rst.bda, true);
                        Isconnecting = true;

                    }
                }
                else if (strlen(remote_device_name[2]) == adv_name_len && strncmp((char *)adv_name, remote_device_name[2], adv_name_len) == 0) {
                    if (conn_device_c == false) {
                        conn_device_c = true;
                        ESP_LOGI(GATTC_TAG, "Searched device %s\n", remote_device_name[2]);
                        esp_ble_gap_stop_scanning();
                        esp_ble_gattc_open(gl_profile_tab[PROFILE_C_APP_ID].gattc_if, scan_result->scan_rst.bda, true);
                        Isconnecting = true;
                    }
                    break;
                }

            }
            break;
        case ESP_GAP_SEARCH_INQ_CMPL_EVT:
            break;
        default:
            break;
        }
        break;
    }

    case ESP_GAP_BLE_SCAN_STOP_COMPLETE_EVT:
        if (param->scan_stop_cmpl.status != ESP_BT_STATUS_SUCCESS){
            ESP_LOGE(GATTC_TAG, "Scan stop failed");
            break;
        }
        ESP_LOGI(GATTC_TAG, "Stop scan successfully");

        break;

    case ESP_GAP_BLE_ADV_STOP_COMPLETE_EVT:
        if (param->adv_stop_cmpl.status != ESP_BT_STATUS_SUCCESS){
            ESP_LOGE(GATTC_TAG, "Adv stop failed");
            break;
        }
        ESP_LOGI(GATTC_TAG, "Stop adv successfully");
        break;

    default:
        break;
    }
}

static void esp_gattc_cb(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param)
{
    //ESP_LOGI(GATTC_TAG, "EVT %d, gattc if %d, app_id %d", event, gattc_if, param->reg.app_id);

    /* If event is register event, store the gattc_if for each profile */
    if (event == ESP_GATTC_REG_EVT) {
        if (param->reg.status == ESP_GATT_OK) {
            gl_profile_tab[param->reg.app_id].gattc_if = gattc_if;
        } else {
            ESP_LOGI(GATTC_TAG, "Reg app failed, app_id %04x, status %d",
                    param->reg.app_id,
                    param->reg.status);
            return;
        }
    }

    /* If the gattc_if equal to profile A, call profile A cb handler,
     * so here call each profile's callback */
    do {
        int idx;
        for (idx = 0; idx < PROFILE_NUM; idx++) {
            if (gattc_if == ESP_GATT_IF_NONE || /* ESP_GATT_IF_NONE, not specify a certain gatt_if, need to call every profile cb function */
                    gattc_if == gl_profile_tab[idx].gattc_if) {
                if (gl_profile_tab[idx].gattc_cb) {
                    gl_profile_tab[idx].gattc_cb(event, gattc_if, param);
                }
            }
        }
    } while (0);
}

void app_main()
{
    esp_err_t ret = nvs_flash_init();
    if (ret == ESP_ERR_NVS_NO_FREE_PAGES) {
        ESP_ERROR_CHECK(nvs_flash_erase());
        ret = nvs_flash_init();
    }
    ESP_ERROR_CHECK( ret );

    esp_bt_controller_config_t bt_cfg = BT_CONTROLLER_INIT_CONFIG_DEFAULT();
    ret = esp_bt_controller_init(&bt_cfg);
    if (ret) {
        ESP_LOGE(GATTC_TAG, "%s initialize controller failed\n", __func__);
        return;
    }

    ret = esp_bt_controller_enable(ESP_BT_MODE_BTDM);
    if (ret) {
        ESP_LOGE(GATTC_TAG, "%s enable controller failed\n", __func__);
        return;
    }

    ret = esp_bluedroid_init();
    if (ret) {
        ESP_LOGE(GATTC_TAG, "%s init bluetooth failed\n", __func__);
        return;
    }

    ret = esp_bluedroid_enable();
    if (ret) {
        ESP_LOGE(GATTC_TAG, "%s enable bluetooth failed\n", __func__);
        return;
    }

    //register the  callback function to the gap module
    ret = esp_ble_gap_register_callback(esp_gap_cb);
    if (ret){
        ESP_LOGE(GATTC_TAG, "gap register error, error code = %x", ret);
        return;
    }

    //register the callback function to the gattc module
    ret = esp_ble_gattc_register_callback(esp_gattc_cb);
    if(ret){
        ESP_LOGE(GATTC_TAG, "gattc register error, error code = %x", ret);
        return;
    }

    ret = esp_ble_gattc_app_register(PROFILE_A_APP_ID);
    if (ret){
        ESP_LOGE(GATTC_TAG, "gattc app register error, error code = %x", ret);
        return;
    }

    ret = esp_ble_gattc_app_register(PROFILE_B_APP_ID);
    if (ret){
        ESP_LOGE(GATTC_TAG, "gattc app register error, error code = %x", ret);
        return;
    }

    ret = esp_ble_gattc_app_register(PROFILE_C_APP_ID);
    if (ret){
        ESP_LOGE(GATTC_TAG, "gattc app register error, error code = %x", ret);
        return;
    }
    ret = esp_ble_gatt_set_local_mtu(200);
    if (ret){
        ESP_LOGE(GATTC_TAG, "set local  MTU failed, error code = %x", ret);
    }


}