/* 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.
  *
  ******************************************************************************
  */
// Feeling sneaky.
extern "C" {
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
}

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
#include <stdbool.h>

enum class TrafficState { GREEN, YELLOW, RED };
void SetTrafficLights(TrafficState s);

TrafficState currentState = TrafficState::GREEN;
uint32_t stateStartTime = 0; //HAL_GetTick() at the start of this state
bool buttonPressedThisCycle = false;
bool pedestrianNextCycle = false;
bool pedestrianThisCycle = false;

const uint32_t DURATION_GREEN = 5000;
const uint32_t DURATION_YELLOW = 3000;
const uint32_t DURATION_RED_NOPED = 5000;
const uint32_t DURATION_RED_PED = 7000;

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */

void SetTrafficLights(TrafficState s)
{
	// reset all
	HAL_GPIO_WritePin(GPIOD, Green_Pin, GPIO_PIN_RESET);
	HAL_GPIO_WritePin(GPIOD, Yellow_Pin, GPIO_PIN_RESET);
	HAL_GPIO_WritePin(GPIOD, Red_Pin, GPIO_PIN_SET);

	switch (s)
	{
	case TrafficState::GREEN :
		HAL_GPIO_WritePin(GPIOD, Green_Pin, GPIO_PIN_SET);
		break;
	case TrafficState::YELLOW :
		HAL_GPIO_WritePin(GPIOD, Yellow_Pin, GPIO_PIN_SET);
		break;
	case TrafficState::RED:
		HAL_GPIO_WritePin(GPIOD, Red_Pin, GPIO_PIN_SET);
		break;
	}
}

int main(void)
{

  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();
  MX_GPIO_Init();
  
  stateStartTime = HAL_GetTick();
  SetTrafficLights(currentState);
  
  while (1)
  {
    /* USER CODE END WHILE */
	  uint32_t now = HAL_GetTick();
	  uint32_t elapsed = now - stateStartTime;

	  switch(currentState)
	  {
	  case TrafficState::GREEN:
		  if (buttonPressedThisCycle)
			  pedestrianThisCycle = true;

		  else if (elapsed >= DURATION_GREEN)
		  {
			  currentState = TrafficState::YELLOW;
			  stateStartTime = now;
			  SetTrafficLights(currentState);
		  }
		  break;
	  case TrafficState::YELLOW:
		  if (buttonPressedThisCycle || pedestrianNextCycle)
			  pedestrianThisCycle = true;

		  if (elapsed >= DURATION_YELLOW)
		  {
			  currentState = TrafficState::RED;
			  stateStartTime = now;
			  buttonPressedThisCycle = false; //TODO add pressed pedestrian button in yellow
			  SetTrafficLights(currentState);
			  // If Ped Button was pressed during GREEN or YELLOW, we need to enable WHITE this cycle
		  }
		  break;
	  case TrafficState::RED:
		  if (buttonPressedThisCycle)
			  pedestrianNextCycle = true;

		  if (pedestrianThisCycle) {
			  HAL_GPIO_WritePin(White_GPIO_Port, White_Pin, GPIO_PIN_RESET);
			  pedestrianThisCycle = false;
			  pedestrianNextCycle = false;
			  currentState = TrafficState::GREEN;
			  stateStartTime = now;
			  SetTrafficLights(currentState);
			  buttonPressedThisCycle = false;
		  } else {
			  HAL_GPIO_WritePin(White_GPIO_Port, White_Pin, GPIO_PIN_RESET);
			  if (elapsed >= DURATION_RED_NOPED)
			  {
				  currentState = TrafficState::GREEN;
				  stateStartTime = now;
				  SetTrafficLights(currentState);
				  buttonPressedThisCycle = false;
			  }
		  }
		  break;
	  }
    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */

void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure the main internal regulator output voltage
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE3);

  /** 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 = 8;
  RCC_OscInitStruct.PLL.PLLN = 50;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  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_DIV8;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV4;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
  {
    Error_Handler();
  }
}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  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_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOD_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOD, White_Pin|Red_Pin|Yellow_Pin|Green_Pin, GPIO_PIN_RESET);

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

  /*Configure GPIO pins : White_Pin Red_Pin Yellow_Pin Green_Pin */
  GPIO_InitStruct.Pin = White_Pin|Red_Pin|Yellow_Pin|Green_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);

  /* EXTI interrupt init*/
  HAL_NVIC_SetPriority(EXTI15_10_IRQn, 15, 0);
  HAL_NVIC_EnableIRQ(EXTI15_10_IRQn);

  /* USER CODE BEGIN MX_GPIO_Init_2 */

  /* USER CODE END MX_GPIO_Init_2 */
}

/* USER CODE BEGIN 4 */

/*
extern "C" void EXTI15_10_IRQHandler()
{
	HAL_GPIO_EXTI_IRQHandler(PedButton_Pin);
}
*/

extern "C" void HAL_GPIO_EXTI_CallBack(uint16_t GPIO_Pin)
{
	static uint32_t lastInterruptTime = 0;
	uint32_t now = HAL_GetTick();

	// software debounce
	if (now - lastInterruptTime < 100)
		return;

	lastInterruptTime = now;

	if (GPIO_Pin == PedButton_Pin)
		buttonPressedThisCycle = true;

}

/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* 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)
{
  /* 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 */