#include "main.h"
#include "tm1637.h"
#include "keyboard.h"

volatile uint32_t tickCount;
uint32_t last_display_update;
uint16_t counter;
char lastKey;
uint32_t lastScanTime;
const PIN_TypeDef DEFAULT_PIN = { '1', '1', '1', '1' };
const PIN_TypeDef START_PIN = { '0', '0', '0', '0' };

PIN_TypeDef g_current_pin = DEFAULT_PIN;


void osSystickHandler(void) {
  tickCount++;
}

void initGPIO() {
  // Включаем тактирование GPIOA и GPIOB
  RCC->AHBENR |= RCC_AHBENR_GPIOAEN | RCC_AHBENR_GPIOBEN;

  GPIOA->ODR &= ~((1 << 5) | (1 << 9) | (1 << 15)); 

  // Настраиваем PA5 как выход
  GPIOA->MODER = (GPIOA->MODER & ~(3 << 10)) | (1 << 10);
  GPIOA->OTYPER &= ~(1 << 5);
  GPIOA->OSPEEDR |= (1 << 10);

  // Настраиваем PA9 как выход
  GPIOA->MODER = (GPIOA->MODER & ~(3 << 18)) | (1 << 18); 
  GPIOA->OTYPER &= ~(1 << 9); 
  GPIOA->OSPEEDR |= (1 << 18); 

  // Настраиваем PA15 как выход
  GPIOA->MODER = (GPIOA->MODER & ~(3 << 30)) | (1 << 30); 
  GPIOA->OTYPER &= ~(1 << 15); 
  GPIOA->OSPEEDR |= (1 << 30); 
}

void initUSART2() {
  // Включаем тактирование USART2
  RCC->APB1ENR |= RCC_APB1ENR_USART2EN;

  // Настраиваем PA2 и PA3 в альтернативный режим
  GPIOA->MODER = (GPIOA->MODER & ~(0xF << 4)) | (0xA << 4);
  GPIOA->AFR[0] = (GPIOA->AFR[0] & ~(0xFF << 8)) | (1 << 8) | (1 << 12);

  // Настраиваем USART2
  USART2->BRR = 417; // 48MHz/115200
  USART2->CR1 = USART_CR1_TE | USART_CR1_UE;
}

void initSysTick() {
  SysTick->LOAD = 47999; // 1ms при 48MHz
  SysTick->VAL = 0;
  SysTick->CTRL = (1 << 2) | (1 << 1) | (1 << 0);
}

int _write(int file, uint8_t *ptr, int len) {
  for (int i = 0; i < len; i++) {
    while (!(USART2->ISR & USART_ISR_TXE));
    USART2->TDR = ptr[i];
  }
  return len;
}

void checkTickCount() {
  if ((tickCount % 2000) == 0) {
    GPIOA->ODR ^= (1 << 5); // Toggle LED
  }
}

Step processState(char input_digit, unsigned char *input_count) {
  switch (input_digit) {
    case ENTER_SYMBOL:
      if (*input_count == 4) {
        return LIGHT;
      }
      return SKIP;
    default:
      if (*input_count < 4) {
        *input_count = *input_count + 1;
        return FILL_DIGIT;
      }
      return SKIP;
  }
}

void fillPinDigit(PIN_TypeDef *pin_to_fill, char input_digit, unsigned char *input_count){
  switch(*input_count){
    case 1:
     pin_to_fill->first_digit = input_digit;
     break;
    case 2:
     pin_to_fill->second_digit = input_digit;
     break;
    case 3:
     pin_to_fill->third_digit = input_digit;
     break;
    default:
     pin_to_fill->fourth_digit = input_digit;
     break; 
  }
}

int checkPwd(PIN_TypeDef *input_pin) {
    if (input_pin->first_digit == g_current_pin.first_digit &&
        input_pin->second_digit == g_current_pin.second_digit &&
        input_pin->third_digit == g_current_pin.third_digit &&
        input_pin->fourth_digit == g_current_pin.fourth_digit) {
        return 1; 
    }
    return 0; 
}

int checkClearSymbol(char input_digit){
  if (input_digit == CLEAR_SYMBOL){
    return 1;
  }
  return 0;
}

int checkEnterSymbol(char input_digit){
  if (input_digit == ENTER_SYMBOL){
    return 1;
  }
  return 0;
}

void changePwdLight() {
  GPIOA->ODR |= (1 << 5); 
  uint32_t startTime = tickCount;
  while ((tickCount - startTime) < 1500) { 
    __asm__("nop"); 
  }
  GPIOA->ODR &= ~(1 << 5); 
}

void enterPwdAcceptLight() {
  GPIOA->ODR |= (1 << 9); 
  uint32_t startTime = tickCount;
  while ((tickCount - startTime) < 1500) { 
    __asm__("nop");
  }
  GPIOA->ODR &= ~(1 << 9); 
}

void enterPwdFailLight() {
  GPIOA->ODR |= (1 << 15); 
  uint32_t startTime = tickCount;
  while ((tickCount - startTime) < 1500) { 
    __asm__("nop");
  }
  GPIOA->ODR &= ~(1 << 15); 
}


void handleDigit(Action *action, PIN_TypeDef *input_pin, char input_digit, unsigned char *input_count){
  if (input_digit == SKIP_SYMBOL){
    return;
  }
  if (checkClearSymbol(input_digit) == 1){
    *action = CHANGE_PWD;
    *input_count = 0;
    printf(SET_PIN_MSG);
    tm1637_clear();
    return;
  }  
  Step next_step = processState(input_digit, input_count);
  switch(*action){
    case CHANGE_PWD:
      switch(next_step){
        case LIGHT:
          changePwdLight();
          *input_count = 0;
          *action = ENTER_PWD;
          tm1637_clear();
          printf(PIN_SET_SUCCESS_MSG);
          printf(SEPARATOR_MSG);
          printf(ENTER_PIN_MSG);
          return;
        case FILL_DIGIT:
          fillPinDigit(&g_current_pin, input_digit, input_count);
          tm1637_display_pin_digit(input_digit, *input_count - 1);
          return;
        default:
          return;
      }
    default:
      switch(next_step){
        case LIGHT:
          if(checkPwd(input_pin)){
            printf(ACCESS_ENTER_MSG);
            enterPwdAcceptLight();
          } else {
            printf(FAIL_ENTER_MSG);
            enterPwdFailLight();
          }
          *input_count = 0; 
          *input_pin = START_PIN;
          tm1637_clear();
          printf(ENTER_PIN_MSG);
          return;
        case FILL_DIGIT:
          tm1637_display_pin_digit(input_digit, *input_count - 1);
          fillPinDigit(input_pin, input_digit, input_count);
          return;
        default:
          return;
      }
  }
}

int main(void) {
  initGPIO();
  initUSART2();
  initSysTick();
  initKeyboard();
  tm1637_init();
  tm1637_clear();
  Action action = CHANGE_PWD;
  PIN_TypeDef input_pin = START_PIN;
  volatile unsigned char input_count = 0;
  volatile char input_digit;
  
  while (1) {
    input_digit = scanKeyboard();
    handleDigit(&action, &input_pin, input_digit, &input_count);
  }

  return 0;
}