text: /**********************************************************************
  * - Description:		blue-scanner-driver
  * - File:				blue_gattc.c
  * - Compiler:			xtensa-esp32
  * - Debugger:			USB2USART
  * - Author:				Mohamed El-Sabagh
  * - Target:				ESP32
  * - Created:			2017-12-24
  * - Last changed:		2017-12-24
  *
  **********************************************************************/
  #include "blue_gattc.h"
  
  #define GATTC_TAG "GATTC_DEMO"
  
  #define REMOTE_SERVICE_UUID        0x00FF
  #define REMOTE_NOTIFY_CHAR_UUID    0xFF01
  
  #define PROFILE_NUM             1
  #define INVALID_HANDLE          0
  
  static esp_gattc_char_elem_t *char_elem_result   = NULL;
  static esp_gattc_descr_elem_t *descr_elem_result = NULL;
  
  #define RSSI_THRESHOLD -70
  
  #define MANUFACTURER_BYTE1      0xBE
  #define MANUFACTURER_BYTE2      0xEF
  
  struct gattc_profile_inst {
      esp_gattc_cb_t gattc_cb;
      uint16_t gattc_if;
      uint16_t app_id;
      uint16_t conn_id;
      uint16_t service_start_handle;
      uint16_t service_end_handle;
      uint16_t char_handle;
      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_CLIENT] = {
          .gattc_cb = gattc_profile_event_handler,
          .gattc_if = ESP_GATT_IF_NONE,       /* Not get the gatt_if, so initial is ESP_GATT_IF_NONE */
      },
  };
  
  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
  };
  
  static esp_bt_uuid_t remote_filter_service_uuid = {
      .len = ESP_UUID_LEN_16,
      .uuid = {.uuid16 = REMOTE_SERVICE_UUID,},
  };
  
  static const char remote_device_name[] = "ESP_GATTS_DEMO";
  static bool connect    = false;
  static bool get_server = false;
  
  static esp_bt_uuid_t remote_filter_char_uuid = {
      .len = ESP_UUID_LEN_16,
      .uuid = {.uuid16 = REMOTE_NOTIFY_CHAR_UUID,},
  };
  
  static esp_bt_uuid_t notify_descr_uuid = {
      .len = ESP_UUID_LEN_16,
      .uuid = {.uuid16 = ESP_GATT_UUID_CHAR_CLIENT_CONFIG,},
  };
  
  void gattc_profile_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;
      case ESP_GATTC_CONNECT_EVT:{
          ESP_LOGI(GATTC_TAG, "ESP_GATTC_CONNECT_EVT conn_id %d, if %d", p_data->connect.conn_id, gattc_if);
          gl_profile_tab[PROFILE_A_APP_ID_CLIENT].conn_id = p_data->connect.conn_id;
          memcpy(gl_profile_tab[PROFILE_A_APP_ID_CLIENT].remote_bda, p_data->connect.remote_bda, sizeof(esp_bd_addr_t));
          ESP_LOGI(GATTC_TAG, "REMOTE BDA:");
          esp_log_buffer_hex(GATTC_TAG, gl_profile_tab[PROFILE_A_APP_ID_CLIENT].remote_bda, sizeof(esp_bd_addr_t));
          esp_err_t mtu_ret = esp_ble_gattc_send_mtu_req (gattc_if, p_data->connect.conn_id);
          if (mtu_ret){
              ESP_LOGE(GATTC_TAG, "config MTU error, error code = %x", mtu_ret);
          }
          break;
      }
      case ESP_GATTC_OPEN_EVT:
          if (param->open.status != ESP_GATT_OK){
              ESP_LOGE(GATTC_TAG, "open failed, status %d", p_data->open.status);
              break;
          }
          ESP_LOGI(GATTC_TAG, "open success");
          break;
      case ESP_GATTC_CFG_MTU_EVT:
          if (param->cfg_mtu.status != ESP_GATT_OK){
              ESP_LOGE(GATTC_TAG,"config mtu failed, error status = %x", param->cfg_mtu.status);
          }
          ESP_LOGI(GATTC_TAG, "ESP_GATTC_CFG_MTU_EVT, 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_LOGI(GATTC_TAG, "ESP_GATTC_SEARCH_RES_EVT");
          esp_gatt_srvc_id_t *srvc_id =(esp_gatt_srvc_id_t *)&p_data->search_res.srvc_id;
          if (srvc_id->id.uuid.len == ESP_UUID_LEN_16 && srvc_id->id.uuid.uuid.uuid16 == REMOTE_SERVICE_UUID) {
              ESP_LOGI(GATTC_TAG, "service found");
              get_server = true;
              gl_profile_tab[PROFILE_A_APP_ID_CLIENT].service_start_handle = p_data->search_res.start_handle;
              gl_profile_tab[PROFILE_A_APP_ID_CLIENT].service_end_handle = p_data->search_res.end_handle;
              ESP_LOGI(GATTC_TAG, "UUID16: %x", srvc_id->id.uuid.uuid.uuid16);
          }
          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;
          }
          ESP_LOGI(GATTC_TAG, "ESP_GATTC_SEARCH_CMPL_EVT");
          if (get_server){
              uint16_t count = 0;
              esp_gatt_status_t status = esp_ble_gattc_get_attr_count( gattc_if,
                                                                       p_data->search_cmpl.conn_id,
                                                                       ESP_GATT_DB_CHARACTERISTIC,
                                                                       gl_profile_tab[PROFILE_A_APP_ID_CLIENT].service_start_handle,
                                                                       gl_profile_tab[PROFILE_A_APP_ID_CLIENT].service_end_handle,
                                                                       INVALID_HANDLE,
                                                                       &count);
              if (status != ESP_GATT_OK){
                  ESP_LOGE(GATTC_TAG, "esp_ble_gattc_get_attr_count error");
              }
  
              if (count > 0){
                  char_elem_result = (esp_gattc_char_elem_t *)malloc(sizeof(esp_gattc_char_elem_t) * count);
                  if (!char_elem_result){
                      ESP_LOGE(GATTC_TAG, "gattc no mem");
                  }else{
                      status = esp_ble_gattc_get_char_by_uuid( gattc_if,
                                                               p_data->search_cmpl.conn_id,
                                                               gl_profile_tab[PROFILE_A_APP_ID_CLIENT].service_start_handle,
                                                               gl_profile_tab[PROFILE_A_APP_ID_CLIENT].service_end_handle,
                                                               remote_filter_char_uuid,
                                                               char_elem_result,
                                                               &count);
                      if (status != ESP_GATT_OK){
                          ESP_LOGE(GATTC_TAG, "esp_ble_gattc_get_char_by_uuid error");
                      }
  
                      /*  Every service have only one char in our 'ESP_GATTS_DEMO' demo, so we used first 'char_elem_result' */
                      if (count > 0 && (char_elem_result[0].properties & ESP_GATT_CHAR_PROP_BIT_NOTIFY)){
                          gl_profile_tab[PROFILE_A_APP_ID_CLIENT].char_handle = char_elem_result[0].char_handle;
                          esp_ble_gattc_register_for_notify (gattc_if, gl_profile_tab[PROFILE_A_APP_ID_CLIENT].remote_bda, char_elem_result[0].char_handle);
                      }
                  }
                  /* free char_elem_result */
                  free(char_elem_result);
              }else{
                  ESP_LOGE(GATTC_TAG, "no char found");
              }
          }
           break;
      case ESP_GATTC_REG_FOR_NOTIFY_EVT: {
          ESP_LOGI(GATTC_TAG, "ESP_GATTC_REG_FOR_NOTIFY_EVT");
          if (p_data->reg_for_notify.status != ESP_GATT_OK){
              ESP_LOGE(GATTC_TAG, "REG FOR NOTIFY failed: error status = %d", p_data->reg_for_notify.status);
          }else{
              uint16_t count = 0;
              uint16_t notify_en = 1;
              esp_gatt_status_t ret_status = esp_ble_gattc_get_attr_count( gattc_if,
                                                                           gl_profile_tab[PROFILE_A_APP_ID_CLIENT].conn_id,
                                                                           ESP_GATT_DB_DESCRIPTOR,
                                                                           gl_profile_tab[PROFILE_A_APP_ID_CLIENT].service_start_handle,
                                                                           gl_profile_tab[PROFILE_A_APP_ID_CLIENT].service_end_handle,
                                                                           gl_profile_tab[PROFILE_A_APP_ID_CLIENT].char_handle,
                                                                           &count);
              if (ret_status != ESP_GATT_OK){
                  ESP_LOGE(GATTC_TAG, "esp_ble_gattc_get_attr_count error");
              }
              if (count > 0){
                  descr_elem_result = malloc(sizeof(esp_gattc_descr_elem_t) * count);
                  if (!descr_elem_result){
                      ESP_LOGE(GATTC_TAG, "malloc error, gattc no mem");
                  }else{
                      ret_status = esp_ble_gattc_get_descr_by_char_handle( gattc_if,
                                                                           gl_profile_tab[PROFILE_A_APP_ID_CLIENT].conn_id,
                                                                           p_data->reg_for_notify.handle,
                                                                           notify_descr_uuid,
                                                                           descr_elem_result,
                                                                           &count);
                      if (ret_status != ESP_GATT_OK){
                          ESP_LOGE(GATTC_TAG, "esp_ble_gattc_get_descr_by_char_handle error");
                      }
  
                      /* Erery char have only one descriptor in our 'ESP_GATTS_DEMO' demo, so we used first 'descr_elem_result' */
                      if (count > 0 && descr_elem_result[0].uuid.len == ESP_UUID_LEN_16 && descr_elem_result[0].uuid.uuid.uuid16 == ESP_GATT_UUID_CHAR_CLIENT_CONFIG){
                          ret_status = esp_ble_gattc_write_char_descr( gattc_if,
                                                                       gl_profile_tab[PROFILE_A_APP_ID_CLIENT].conn_id,
                                                                       descr_elem_result[0].handle,
                                                                       sizeof(notify_en),
                                                                       (uint8_t *)&notify_en,
                                                                       ESP_GATT_WRITE_TYPE_RSP,
                                                                       ESP_GATT_AUTH_REQ_NONE);
                      }
  
                      if (ret_status != ESP_GATT_OK){
                          ESP_LOGE(GATTC_TAG, "esp_ble_gattc_write_char_descr error");
                      }
  
                      /* free descr_elem_result */
                      free(descr_elem_result);
                  }
              }
              else{
                  ESP_LOGE(GATTC_TAG, "decsr not found");
              }
  
          }
          break;
      }
      case ESP_GATTC_NOTIFY_EVT:
          if (p_data->notify.is_notify){
              ESP_LOGI(GATTC_TAG, "ESP_GATTC_NOTIFY_EVT, receive notify value:");
          }else{
              ESP_LOGI(GATTC_TAG, "ESP_GATTC_NOTIFY_EVT, receive indicate value:");
          }
          esp_log_buffer_hex(GATTC_TAG, p_data->notify.value, p_data->notify.value_len);
          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 ");
          uint8_t write_char_data[35];
          for (int i = 0; i < sizeof(write_char_data); ++i)
          {
              write_char_data[i] = i % 256;
          }
          esp_ble_gattc_write_char( gattc_if,
                                    gl_profile_tab[PROFILE_A_APP_ID_CLIENT].conn_id,
                                    gl_profile_tab[PROFILE_A_APP_ID_CLIENT].char_handle,
                                    sizeof(write_char_data),
                                    write_char_data,
                                    ESP_GATT_WRITE_TYPE_RSP,
                                    ESP_GATT_AUTH_REQ_NONE);
          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:");
          esp_log_buffer_hex(GATTC_TAG, bda, sizeof(esp_bd_addr_t));
          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 ");
          break;
      case ESP_GATTC_DISCONNECT_EVT:
          connect = false;
          get_server = false;
          ESP_LOGI(GATTC_TAG, "ESP_GATTC_DISCONNECT_EVT, reason = %d", p_data->disconnect.reason);
          break;
      default:
          break;
      }
  }
  
  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;
      int16_t rssi = 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 failed, error status = %x", param->scan_start_cmpl.status);
              break;
          }
          ESP_LOGI(GATTC_TAG, "scan start success");
  
          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:
              rssi = scan_result->scan_rst.rssi;
              if (rssi > RSSI_THRESHOLD)
              {
                  uint8_t i = 0;
                  uint8_t id_found = 0;
                  ESP_LOGI(GATTC_TAG, "printing raw data\n");
                  for (i = 0 ; i < scan_result->scan_rst.adv_data_len; i++) {
                      // ESP_LOGI(GATTC_TAG, "%02X", scan_result->scan_rst.ble_adv[i]);
                      if (scan_result->scan_rst.ble_adv[i] == MANUFACTURER_BYTE2 &&
                           scan_result->scan_rst.ble_adv[i + 1] == MANUFACTURER_BYTE1) {
                               id_found = 1;
                      }
                  }
  
                  if (id_found) {
                      ESP_LOGI(GATTC_TAG, "RSSI = %d", rssi);
                      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");
  
                      esp_log_buffer_char(GATTC_TAG, adv_name, adv_name_len);
                      ESP_LOGI(GATTC_TAG, "\n");
  
                      /****************************************************/
                      ESP_LOGI(GATTC_TAG, "============ NEAREST TAG ============");
                      esp_log_buffer_hex(GATTC_TAG, scan_result->scan_rst.bda, 6);
                      ESP_LOGI(GATTC_TAG, "RSSI : %d", rssi);
                      ESP_LOGI(GATTC_TAG, " ");
                      /****************************************************/
  
                      if (adv_name != NULL) {
                          if (strlen(remote_device_name) == adv_name_len && strncmp((char *)adv_name, remote_device_name, adv_name_len) == 0) {
                              ESP_LOGI(GATTC_TAG, "searched device %s\n", remote_device_name);
                              if (connect == false) {
                                  connect = true;
                                  ESP_LOGI(GATTC_TAG, "connect to the remote device.");
                                  esp_ble_gap_stop_scanning();
                                  esp_ble_gattc_open(gl_profile_tab[PROFILE_A_APP_ID_CLIENT].gattc_if, scan_result->scan_rst.bda, true);
                              }
                          }
                      }
                  } else {
                      ESP_LOGI(GATTC_TAG, "The scanned beacons manufacturer id doesn't match the preassigned ID");
                  }
              }
              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, error status = %x", param->scan_stop_cmpl.status);
              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, error status = %x", param->adv_stop_cmpl.status);
              break;
          }
          ESP_LOGI(GATTC_TAG, "stop adv successfully");
          break;
      case ESP_GAP_BLE_UPDATE_CONN_PARAMS_EVT:
           ESP_LOGI(GATTC_TAG, "update connetion params status = %d, min_int = %d, max_int = %d,conn_int = %d,latency = %d, timeout = %d",
                    param->update_conn_params.status,
                    param->update_conn_params.min_int,
                    param->update_conn_params.max_int,
                    param->update_conn_params.conn_int,
                    param->update_conn_params.latency,
                    param->update_conn_params.timeout);
          break;
      default:
          break;
      }
  }
  
  void esp_gattc_cb(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param)
  {
      /* 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);
  }
  