/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2025 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

// Define an enumeration for the motion level states
typedef enum {
    MOTION_LEVEL_NONE = 0,
    MOTION_LEVEL_LOW,
    MOTION_LEVEL_MEDIUM,
    MOTION_LEVEL_HIGH
} MotionLevel_t;

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */

// Define pin names for clarity (already present via CubeMX in main.h, but helpful)
#define PIR_PIN          GPIO_PIN_1
#define GREEN_LED_PIN    GPIO_PIN_5
#define YELLOW_LED_PIN   GPIO_PIN_6
#define RED_LED_PIN      GPIO_PIN_7

// Motion detection constants (Tweak these values for desired sensitivity)
#define MAX_MOTION_COUNT    20  // Max number of "hits" to track in the window
#define MOTION_WINDOW_MS    800 // 0.8s-second window for counting motion events
#define DEBOUNCE_DELAY_MS   100  // Time to wait after a rising edge to avoid re-triggering immediately
#define LEVEL_LOW_THRESHOLD   5  // 1+ hits in MOTION_WINDOW_MS is Low
#define LEVEL_MEDIUM_THRESHOLD 13  // 3+ hits in MOTION_WINDOW_MS is Medium
#define LEVEL_HIGH_THRESHOLD   18 // 5+ hits in MOTION_WINDOW_MS is High

// LED Flash timings (ON/OFF in milliseconds)
#define FLASH_DELAY_NONE      0    // No Flash, LEDs off
#define FLASH_DELAY_LOW      100  // 1 Hz, Low motion warning
#define FLASH_DELAY_MEDIUM   100  // 2 Hz, Medium motion warning
#define FLASH_DELAY_HIGH     100  // 5 Hz, High motion warning

/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER END PM */

/* Private variables ---------------------------------------------------------*/
UART_HandleTypeDef huart2;

/* USER CODE BEGIN PV */

MotionLevel_t currentMotionLevel = MOTION_LEVEL_NONE;
uint32_t motionCount = 0;             // Counter for motion events in the window
uint32_t motionWindowStartTime = 0;   // Timestamp for the start of the counting window
uint32_t lastPIRTriggerTime = 0;      // Timestamp of the last time the PIR pin went HIGH

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);
/* USER CODE BEGIN PFP */
void Update_Motion_Level(void);
void Handle_LED_Alert(void);
/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/**
  * @brief Updates the current motion level based on motionCount.
  * @retval None
  */
void Update_Motion_Level(void)
{
    if (motionCount >= LEVEL_HIGH_THRESHOLD) {
        currentMotionLevel = MOTION_LEVEL_HIGH;
    } else if (motionCount >= LEVEL_MEDIUM_THRESHOLD) {
        currentMotionLevel = MOTION_LEVEL_MEDIUM;
    } else if (motionCount >= LEVEL_LOW_THRESHOLD) {
        currentMotionLevel = MOTION_LEVEL_LOW;
    } else {
        currentMotionLevel = MOTION_LEVEL_NONE;
    }
}

/**
  * @brief Manages the state and flashing of the alert LEDs.
  * @retval None
  */
void Handle_LED_Alert(void)
{
    // Static variables to track LED state and time for non-blocking flash
    static uint32_t lastFlashTime = 0;
    static GPIO_PinState ledState = GPIO_PIN_RESET;

    uint32_t flashDelay;
    GPIO_TypeDef *ledPort;
    uint16_t ledPin;

    // Reset all LEDs first
    HAL_GPIO_WritePin(GPIOA, GREEN_LED_PIN | YELLOW_LED_PIN | RED_LED_PIN, GPIO_PIN_RESET);

    // Determine the active LED and flash delay based on the current motion level
    switch (currentMotionLevel) {
        case MOTION_LEVEL_LOW:
            ledPort = GPIOA;
            ledPin = GREEN_LED_PIN;
            flashDelay = FLASH_DELAY_LOW;
            break;
        case MOTION_LEVEL_MEDIUM:
            ledPort = GPIOA;
            ledPin = YELLOW_LED_PIN;
            flashDelay = FLASH_DELAY_MEDIUM;
            break;
        case MOTION_LEVEL_HIGH:
            ledPort = GPIOA;
            ledPin = RED_LED_PIN;
            flashDelay = FLASH_DELAY_HIGH;
            break;
        case MOTION_LEVEL_NONE:
        default:
            return; // No motion, all LEDs are already off
    }

    // Non-blocking flash logic
    if ((HAL_GetTick() - lastFlashTime) >= flashDelay) {
        ledState = (ledState == GPIO_PIN_RESET) ? GPIO_PIN_SET : GPIO_PIN_RESET;
        HAL_GPIO_WritePin(ledPort, ledPin, ledState);
        lastFlashTime = HAL_GetTick();
    } else {
        // Ensure the LED is in the correct state until the next toggle
        HAL_GPIO_WritePin(ledPort, ledPin, ledState);
    }
}

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{

  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_USART2_UART_Init();
  /* USER CODE BEGIN 2 */

  // Initialize the motion window start time
  motionWindowStartTime = HAL_GetTick();

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
      // 1. CHECK PIR TRIGGER AND COUNT EVENTS
      if (HAL_GPIO_ReadPin(GPIOA, PIR_PIN) == GPIO_PIN_SET)
      {
          if ((HAL_GetTick() - lastPIRTriggerTime) > DEBOUNCE_DELAY_MS)
          {
              lastPIRTriggerTime = HAL_GetTick();

              if ((lastPIRTriggerTime - motionWindowStartTime) < MOTION_WINDOW_MS)
              {
                  motionCount++;
                  if (motionCount > MAX_MOTION_COUNT)
                  {
                      motionCount = MAX_MOTION_COUNT;
                  }
              }
              else
              {
                  motionCount = 1;
                  motionWindowStartTime = lastPIRTriggerTime;
              }
          }
      } // <-- Correct closing brace for 'if (HAL_GPIO_ReadPin(...))'


      // 2. UPDATE MOTION LEVEL AND HANDLE WINDOW EXPIRATION (Decay)
      // This logic MUST run outside the motion detection 'if' block.
      if ((HAL_GetTick() - motionWindowStartTime) >= MOTION_WINDOW_MS)
      {
          // Decay motion level gradually
          if (motionCount > 0)
          {
              motionCount--;
          }
          motionWindowStartTime = HAL_GetTick(); // Start a new decay window
      }

      // Update the motion level based on the current count
      Update_Motion_Level();

      // 3. HANDLE VISUAL ALERT (Non-blocking LED flashing)
      Handle_LED_Alert();

    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
}
/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
// ... (SystemClock_Config remains unchanged) ...
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure the main internal regulator output voltage
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLM = 16;
  RCC_OscInitStruct.PLL.PLLN = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
  RCC_OscInitStruct.PLL.PLLQ = 4;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
}

/**
  * @brief USART2 Initialization Function
  * @param None
  * @retval None
  */
static void MX_USART2_UART_Init(void)
{
// ... (MX_USART2_UART_Init remains unchanged) ...

  /* USER CODE BEGIN USART2_Init 0 */

  /* USER CODE END USART2_Init 0 */

  /* USER CODE BEGIN USART2_Init 1 */

  /* USER CODE END USART2_Init 1 */
  huart2.Instance = USART2;
  huart2.Init.BaudRate = 115200;
  huart2.Init.WordLength = UART_WORDLENGTH_8B;
  huart2.Init.StopBits = UART_STOPBITS_1;
  huart2.Init.Parity = UART_PARITY_NONE;
  huart2.Init.Mode = UART_MODE_TX_RX;
  huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart2.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart2) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USART2_Init 2 */

  /* USER CODE END USART2_Init 2 */

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
// ... (MX_GPIO_Init remains unchanged, ensuring the correct pins are defined in main.h) ...
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  /* USER CODE BEGIN MX_GPIO_Init_1 */

  /* USER CODE END MX_GPIO_Init_1 */

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOH_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOA, Green_LED_Pin|Yellow_LED_Pin|Red_LED_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pin : B1_Pin */
  GPIO_InitStruct.Pin = B1_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_IT_FALLING;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(B1_GPIO_Port, &GPIO_InitStruct);

  /*Configure GPIO pin : PIR_Pin */
  GPIO_InitStruct.Pin = PIR_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(PIR_GPIO_Port, &GPIO_InitStruct);

  /*Configure GPIO pins : Green_LED_Pin Yellow_LED_Pin Red_LED_Pin */
  GPIO_InitStruct.Pin = Green_LED_Pin|Yellow_LED_Pin|Red_LED_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /* USER CODE BEGIN MX_GPIO_Init_2 */

  /* USER CODE END MX_GPIO_Init_2 */
}

/* USER CODE BEGIN 4 */

void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
    if (GPIO_Pin == PIR_Pin)
    {
        // This code executes ONLY once when the PIR pin goes from LOW to HIGH.
        uint32_t currentTime = HAL_GetTick();

        if ((currentTime - motionWindowStartTime) < MOTION_WINDOW_MS)
        {
            motionCount++;
            if (motionCount > MAX_MOTION_COUNT)
            {
                motionCount = MAX_MOTION_COUNT;
            }
        }
        else // Start a new window
        {
            motionCount = 1;
            motionWindowStartTime = currentTime;
        }
    }
}

/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
// ... (Error_Handler remains unchanged) ...
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */
  __disable_irq();
  while (1)
  {
  }
  /* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  * where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
// ... (assert_failed remains unchanged) ...
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
