text: /*
   *
   *    Copyright (c) 2020 Project CHIP Authors
   *    Copyright (c) 2018 Nest Labs, Inc.
   *    All rights reserved.
   *
   *    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.
   */
  
  /**
   * @file Button.cpp
   *
   * Implements a Button tied to a GPIO and provides debouncing and polling
   *
   **/
  
  #include "driver/gpio.h"
  #include "esp_log.h"
  #include "esp_system.h"
  
  #include "Button.h"
  #include <platform/CHIPDeviceLayer.h>
  #include <support/CodeUtils.h>
  
  extern const char * TAG;
  
  esp_err_t Button::Init(gpio_num_t gpioNum, uint16_t debouncePeriod)
  {
      mGPIONum         = gpioNum;
      mDebouncePeriod  = debouncePeriod / portTICK_PERIOD_MS;
      mState           = false;
      mLastPolledState = false;
  
      esp_err_t err = gpio_set_direction(gpioNum, GPIO_MODE_INPUT);
      if (err == ESP_OK)
      {
          Poll();
      }
      return err;
  }
  
  bool Button::Poll()
  {
      uint32_t now = xTaskGetTickCount();
  
      bool newState = gpio_get_level(mGPIONum) == 0;
  
      if (newState != mLastPolledState)
      {
          mLastPolledState = newState;
          mLastReadTime    = now;
      }
  
      else if (newState != mState && (now - mLastReadTime) >= mDebouncePeriod)
      {
          mState          = newState;
          mPrevStateDur   = now - mStateStartTime;
          mStateStartTime = now;
          return true;
      }
  
      return false;
  }
  
  uint32_t Button::GetStateDuration()
  {
      return (xTaskGetTickCount() - mStateStartTime) * portTICK_PERIOD_MS;
  }
  