/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  */
/* USER CODE END Header */

/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include <stdio.h>

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#define LCD_ADDR (0x27 << 1) // 0x4E
/* USER CODE END PD */

/* Private variables ---------------------------------------------------------*/
I2C_HandleTypeDef hi2c1;

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_I2C1_Init(void);

/* USER CODE BEGIN PFP */
char Keypad_Read(void);

// Prototipuri LCD
void LCD_Send_Cmd(char cmd);
void LCD_Send_Data(char data);
void LCD_Init(void);
void LCD_Send_String(char *str);
void LCD_SetCursor(int row, int col);
void LCD_Clear(void);
/* USER CODE END PFP */

int main(void)
{
  HAL_Init();
  SystemClock_Config();

  MX_GPIO_Init();
  MX_I2C1_Init();

  LCD_Init();
  LCD_SetCursor(0, 0);
  LCD_Send_String("Tasta: ");

  while (1)
  {
      char key = Keypad_Read();
      if (key != 0)
      {
          LCD_SetCursor(0, 7);
          char str[2] = {key, '\0'};
          LCD_Send_String(str);
      }
      HAL_Delay(10);
  }
}

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

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSIDiv = RCC_HSI_DIV1;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  RCC_ClkInitStruct.SYSCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_I2C1_Init(void)
{
  hi2c1.Instance = I2C1;
  hi2c1.Init.Timing = 0x00303D5B;
  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;

  if (HAL_I2C_Init(&hi2c1) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();
  __HAL_RCC_GPIOC_CLK_ENABLE();

  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_5|GPIO_PIN_7, GPIO_PIN_RESET);
  HAL_GPIO_WritePin(GPIOC, GPIO_PIN_7, GPIO_PIN_RESET);
  HAL_GPIO_WritePin(GPIOB, GPIO_PIN_6, GPIO_PIN_RESET);

  GPIO_InitStruct.Pin = GPIO_PIN_5|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(GPIOA, &GPIO_InitStruct);

  GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_4|GPIO_PIN_5;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  GPIO_InitStruct.Pin = GPIO_PIN_8;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  GPIO_InitStruct.Pin = 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(GPIOC, &GPIO_InitStruct);

  GPIO_InitStruct.Pin = GPIO_PIN_6;
  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);
}

// --- Functii LCD1602 I2C ---

void LCD_Send_Cmd(char cmd)
{
    char data_u, data_l;
    uint8_t data_t[4];
    data_u = (cmd & 0xf0);
    data_l = ((cmd << 4) & 0xf0);
    data_t[0] = data_u | 0x0C; // Backlight activat (0x08) + EN=1, RS=0
    data_t[1] = data_u | 0x08; // Backlight activat + EN=0, RS=0
    data_t[2] = data_l | 0x0C; // Backlight activat + EN=1, RS=0
    data_t[3] = data_l | 0x08; // Backlight activat + EN=0, RS=0
    HAL_I2C_Master_Transmit(&hi2c1, LCD_ADDR, (uint8_t *) data_t, 4, 100);
}

void LCD_Send_Data(char data)
{
    char data_u, data_l;
    uint8_t data_t[4];
    data_u = (data & 0xf0);
    data_l = ((data << 4) & 0xf0);
    data_t[0] = data_u | 0x0D; // Backlight activat (0x08) + EN=1, RS=1
    data_t[1] = data_u | 0x09; // Backlight activat + EN=0, RS=1
    data_t[2] = data_l | 0x0D; // Backlight activat + EN=1, RS=1
    data_t[3] = data_l | 0x09; // Backlight activat + EN=0, RS=1
    HAL_I2C_Master_Transmit(&hi2c1, LCD_ADDR, (uint8_t *) data_t, 4, 100);
}
void LCD_Init(void)
{
    HAL_Delay(50);
    LCD_Send_Cmd(0x30);
    HAL_Delay(5);
    LCD_Send_Cmd(0x30);
    HAL_Delay(1);
    LCD_Send_Cmd(0x32);
    HAL_Delay(10);

    LCD_Send_Cmd(0x28);
    HAL_Delay(1);
    LCD_Send_Cmd(0x0C);
    HAL_Delay(1);
    LCD_Send_Cmd(0x01);
    HAL_Delay(2);
}

void LCD_Send_String(char *str)
{
    while (*str) LCD_Send_Data(*str++);
}

void LCD_SetCursor(int row, int col)
{
    uint8_t mask = (row == 0) ? 0x80 : 0xC0;
    LCD_Send_Cmd(mask + col);
}

void LCD_Clear(void)
{
    LCD_Send_Cmd(0x01);
    HAL_Delay(2);
}

// --- Keypad Read ---

char Keypad_Read(void)
{
    char keys[4][4] = {
        {'1', '2', '3', 'A'},
        {'4', '5', '6', 'B'},
        {'7', '8', '9', 'C'},
        {'*', '0', '#', 'D'}
    };

    GPIO_TypeDef* ROW_PORTS[4] = {GPIOA, GPIOC, GPIOB, GPIOA};
    uint16_t ROW_PINS[4] = {GPIO_PIN_5, GPIO_PIN_7, GPIO_PIN_6, GPIO_PIN_7};

    GPIO_TypeDef* COL_PORTS[4] = {GPIOB, GPIOB, GPIOB, GPIOA};
    uint16_t COL_PINS[4] = {GPIO_PIN_5, GPIO_PIN_4, GPIO_PIN_10, GPIO_PIN_8};

    for (int i = 0; i < 4; i++) {
        HAL_GPIO_WritePin(ROW_PORTS[i], ROW_PINS[i], GPIO_PIN_SET);
    }

    for (int r = 0; r < 4; r++) {
        HAL_GPIO_WritePin(ROW_PORTS[r], ROW_PINS[r], GPIO_PIN_RESET);

        for (int c = 0; c < 4; c++) {
            if (HAL_GPIO_ReadPin(COL_PORTS[c], COL_PINS[c]) == GPIO_PIN_RESET) {
                HAL_Delay(20);
                while (HAL_GPIO_ReadPin(COL_PORTS[c], COL_PINS[c]) == GPIO_PIN_RESET);
                HAL_GPIO_WritePin(ROW_PORTS[r], ROW_PINS[r], GPIO_PIN_SET);
                return keys[r][c];
            }
        }
        HAL_GPIO_WritePin(ROW_PORTS[r], ROW_PINS[r], GPIO_PIN_SET);
    }
    return 0;
}

void Error_Handler(void)
{
  __disable_irq();
  while (1) {}
}