#include "main.h"
#include "usb_device.h"
#include <stdbool.h>

#define MODE_INACTIVE 0
#define MODE_MASTER 1
#define MODE_MODULE 2
#define DMA_BUFFER_SIZE 16

#define MODULE_HANDSHAKE_REQUEST 0x000F0000

typedef struct{
  uint8_t data[4];
} Packet;

typedef struct {
  Packet buffer[DMA_BUFFER_SIZE];
  volatile uint16_t head;
  volatile uint16_t tail;
} DMA_QUEUE;

DMA_QUEUE RxQueue;
uint8_t DMA_RX_BUFFER[4];

I2C_HandleTypeDef hi2c1;
TIM_HandleTypeDef htim3;

UART_HandleTypeDef huart4;
UART_HandleTypeDef huart5;
UART_HandleTypeDef huart1;
UART_HandleTypeDef huart2;
UART_HandleTypeDef* UART_PORTS[] = { &huart4, &huart5, &huart1, &huart2 };
UART_HandleTypeDef* PARENT;
DMA_HandleTypeDef hdma_uart4_rx;
DMA_HandleTypeDef hdma_uart5_rx;
DMA_HandleTypeDef hdma_usart1_rx;
DMA_HandleTypeDef hdma_usart2_rx;

uint8_t CURRENT_MODE;

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_I2C1_Init(void);
static void MX_TIM3_Init(void);
static void MX_UART4_Init(void);
static void MX_UART5_Init(void);
static void MX_USART1_UART_Init(void);
static void MX_USART2_UART_Init(void);
void DMA_Queue_Init(DMA_QUEUE* q);


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

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

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_I2C1_Init();
  MX_TIM3_Init();
  MX_UART4_Init();
  MX_UART5_Init();
  MX_USART1_UART_Init();
  MX_USART2_UART_Init();
  MX_USB_DEVICE_Init();

  CURRENT_MODE = MODE_INACTIVE;

  while (1)
  {
    switch(CURRENT_MODE){

      case MODE_INACTIVE:
        //TODO: Check if connected VIA USB, If so switch to master mode 
        uint8_t candidates_depth[] = {0xFF, 0xFF, 0xFF, 0xFF};

        //Poll all UART Ports
        for(uint8_t i = 0; i<4; i++){
          uint8_t rxBuffer[4] = {0};
          uint8_t msg[4] = {0x00, 0x0F, 0x00, 0x00};
          HAL_UART_Transmit(UART_PORTS[i], msg, 4, HAL_MAX_DELAY);
          if (HAL_UART_Receive(UART_PORTS[i], rxBuffer, 4, 500) == HAL_OK) {
            //Is a type of confirmation message
            if(rxBuffer[1] == 0xFF){
              candidates_depth[i] = rxBuffer[0];
            }else{
              candidates_depth[i] = 0xFF;
            }
          } else {
            // Timeout or error
            candidates_depth[i] = 0xFF; 
          } 
        }

        // Arbitration: 0xFF means invalid
        uint8_t min = 0xFF;           // start with invalid value
        uint8_t best_parent = 0xFF;   // invalid index by default

        for(uint8_t i = 0; i < 4; i++){
          if(candidates_depth[i] != 0xFF && candidates_depth[i] < min){
            min = candidates_depth[i];
            best_parent = i;
          }
        }
        if(best_parent != 0xFF){      // found a valid parent
          PARENT = UART_PORTS[best_parent];  // assign UART handle pointer
          CURRENT_MODE = MODE_MODULE;
        }
        break;

      case MODE_MODULE:
        DMA_Queue_Init(&RxQueue);
        break;
      
      case MODE_MASTER:
        
        

      break;  
    }
  }
}

void DMA_Queue_Init(DMA_QUEUE* q){
  q->head = 0;
  q->tail = 0;
  //Activate DMA to all ports
  for(uint8_t i = 0; i<4; i++){
    HAL_UART_Receive_DMA(UART_PORTS[i], DMA_RX_BUFFER, 4);
  }
}

bool DMA_Queue_IsFull(DMA_QUEUE* q){
  return ((q->head + 1)%DMA_BUFFER_SIZE) == q->tail;
}

bool DMA_Queue_IsEmpty(DMA_QUEUE* q){
  return (q->head == q->tail);
}

bool DMA_Queue_Push(DMA_QUEUE* q, Packet* data) {
    if (DMA_Queue_IsFull(q)) {
      return false;
    }
    q->buffer[q->head] = *data;
    q->head = (q->head + 1) % DMA_BUFFER_SIZE;
    return true;
}

bool PacketQueue_Pop(DMA_QUEUE* q, Packet* pkt) {
    if (DMA_Queue_IsEmpty(q)) {
        return false; 
    }
    *pkt = q->buffer[q->tail];  
    q->tail = (q->tail + 1) % DMA_BUFFER_SIZE;
    return true;
}

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_HSE;
  RCC_OscInitStruct.PLL.PLLM = 4;
  RCC_OscInitStruct.PLL.PLLN = 72;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 3;
  RCC_OscInitStruct.PLL.PLLR = 2;
  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_HSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

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

//For I2C Devices
static void MX_I2C1_Init(void)
{

  /* USER CODE BEGIN I2C1_Init 0 */

  /* USER CODE END I2C1_Init 0 */

  /* USER CODE BEGIN I2C1_Init 1 */

  /* USER CODE END I2C1_Init 1 */
  hi2c1.Instance = I2C1;
  hi2c1.Init.ClockSpeed = 100000;
  hi2c1.Init.DutyCycle = I2C_DUTYCYCLE_2;
  hi2c1.Init.OwnAddress1 = 0;
  hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
  hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
  hi2c1.Init.OwnAddress2 = 0;
  hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
  hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
  if (HAL_I2C_Init(&hi2c1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN I2C1_Init 2 */

  /* USER CODE END I2C1_Init 2 */

}

//Rotary Encoder
static void MX_TIM3_Init(void)
{

  /* USER CODE BEGIN TIM3_Init 0 */

  /* USER CODE END TIM3_Init 0 */

  TIM_Encoder_InitTypeDef sConfig = {0};
  TIM_MasterConfigTypeDef sMasterConfig = {0};

  /* USER CODE BEGIN TIM3_Init 1 */

  /* USER CODE END TIM3_Init 1 */
  htim3.Instance = TIM3;
  htim3.Init.Prescaler = 0;
  htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim3.Init.Period = 65535;
  htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim3.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  sConfig.EncoderMode = TIM_ENCODERMODE_TI1;
  sConfig.IC1Polarity = TIM_ICPOLARITY_RISING;
  sConfig.IC1Selection = TIM_ICSELECTION_DIRECTTI;
  sConfig.IC1Prescaler = TIM_ICPSC_DIV1;
  sConfig.IC1Filter = 0;
  sConfig.IC2Polarity = TIM_ICPOLARITY_RISING;
  sConfig.IC2Selection = TIM_ICSELECTION_DIRECTTI;
  sConfig.IC2Prescaler = TIM_ICPSC_DIV1;
  sConfig.IC2Filter = 0;
  if (HAL_TIM_Encoder_Init(&htim3, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN TIM3_Init 2 */

  /* USER CODE END TIM3_Init 2 */

}

static void MX_UART4_Init(void)
{

  /* USER CODE BEGIN UART4_Init 0 */

  /* USER CODE END UART4_Init 0 */

  /* USER CODE BEGIN UART4_Init 1 */

  /* USER CODE END UART4_Init 1 */
  huart4.Instance = UART4;
  huart4.Init.BaudRate = 115200;
  huart4.Init.WordLength = UART_WORDLENGTH_8B;
  huart4.Init.StopBits = UART_STOPBITS_1;
  huart4.Init.Parity = UART_PARITY_NONE;
  huart4.Init.Mode = UART_MODE_TX_RX;
  huart4.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart4.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart4) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN UART4_Init 2 */

  /* USER CODE END UART4_Init 2 */

}

static void MX_UART5_Init(void)
{

  /* USER CODE BEGIN UART5_Init 0 */

  /* USER CODE END UART5_Init 0 */

  /* USER CODE BEGIN UART5_Init 1 */

  /* USER CODE END UART5_Init 1 */
  huart5.Instance = UART5;
  huart5.Init.BaudRate = 115200;
  huart5.Init.WordLength = UART_WORDLENGTH_8B;
  huart5.Init.StopBits = UART_STOPBITS_1;
  huart5.Init.Parity = UART_PARITY_NONE;
  huart5.Init.Mode = UART_MODE_TX_RX;
  huart5.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart5.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart5) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN UART5_Init 2 */

  /* USER CODE END UART5_Init 2 */

}

static void MX_USART1_UART_Init(void)
{

  /* USER CODE BEGIN USART1_Init 0 */

  /* USER CODE END USART1_Init 0 */

  /* USER CODE BEGIN USART1_Init 1 */

  /* USER CODE END USART1_Init 1 */
  huart1.Instance = USART1;
  huart1.Init.BaudRate = 115200;
  huart1.Init.WordLength = UART_WORDLENGTH_8B;
  huart1.Init.StopBits = UART_STOPBITS_1;
  huart1.Init.Parity = UART_PARITY_NONE;
  huart1.Init.Mode = UART_MODE_TX_RX;
  huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart1.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USART1_Init 2 */

  /* USER CODE END USART1_Init 2 */

}

static void MX_USART2_UART_Init(void)
{

  /* 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 */

}

static void MX_DMA_Init(void)
{

  /* DMA controller clock enable */
  __HAL_RCC_DMA1_CLK_ENABLE();
  __HAL_RCC_DMA2_CLK_ENABLE();

  /* DMA interrupt init */
  /* DMA1_Stream0_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA1_Stream0_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream0_IRQn);
  /* DMA1_Stream2_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA1_Stream2_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream2_IRQn);
  /* DMA1_Stream5_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA1_Stream5_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream5_IRQn);
  /* DMA2_Stream2_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA2_Stream2_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA2_Stream2_IRQn);

}

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_GPIOH_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();
  __HAL_RCC_GPIOD_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOC, GPIO_PIN_7|GPIO_PIN_8|GPIO_PIN_9, GPIO_PIN_RESET);

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_8, GPIO_PIN_RESET);

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOB, GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7, GPIO_PIN_RESET);

  /*Configure GPIO pins : PC4 PC5 */
  GPIO_InitStruct.Pin = GPIO_PIN_4|GPIO_PIN_5;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_PULLDOWN;
  HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

  /*Configure GPIO pins : PB0 PB1 PB2 PB10 */
  GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_10;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_PULLDOWN;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  /*Configure GPIO pins : PC7 PC8 PC9 */
  GPIO_InitStruct.Pin = GPIO_PIN_7|GPIO_PIN_8|GPIO_PIN_9;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

  /*Configure GPIO pin : PA8 */
  GPIO_InitStruct.Pin = GPIO_PIN_8;
  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);

  /*Configure GPIO pins : PB4 PB5 PB6 PB7 */
  GPIO_InitStruct.Pin = GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  /* USER CODE BEGIN MX_GPIO_Init_2 */

  /* USER CODE END MX_GPIO_Init_2 */
}

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 */