#include "main.h"
#include "stm32c0xx_hal.h"
#include "LiquidCrystal_I2C.h"
#include "Keypad.h"

// Button config
#define BUTTON_PIN GPIO_PIN_0
#define BUTTON_GPIO_PORT GPIOA
#define DEBOUNCE_DELAY 50
#define TRIPLE_PRESS_TIME 3000

// Global variables
I2C_HandleTypeDef hi2c1;

uint8_t buttonState = 0;
uint8_t lastButtonState = 0;
uint32_t lastDebounceTime = 0;
uint32_t firstPressTime = 0;
uint8_t pressCount = 0;
char inputBuffer[20] = {0};
uint8_t inputIndex = 0;
uint8_t displayOn = 1;

// Function declarations
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_I2C1_Init(void);
void toggleDisplay(void);
void clearInputBuffer(void);
void updateLCD(void);

int main(void)
{
    HAL_Init();
    SystemClock_Config();
    MX_GPIO_Init();
    MX_I2C1_Init();

    Keypad_Init();             // <-- Your Keypad driver must have this function
    LCD_Init(&hi2c1);          // Custom LCD driver (I2C-based)
    LCD_Clear(&hi2c1);
    LCD_Backlight(&hi2c1, 1);  // Turn on backlight

    while (1)
    {
        char key = Keypad_GetKey();
        if (key != 0)
        {
            if (inputIndex < 20)
            {
                inputBuffer[inputIndex++] = key;
            }
            else
            {
                // Shift buffer for rolling display
                for (int i = 0; i < 19; i++)
                {
                    inputBuffer[i] = inputBuffer[i + 1];
                }
                inputBuffer[19] = key;
            }

            if (displayOn)
            {
                updateLCD();
            }
        }
    }
}

void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
    if (GPIO_Pin == BUTTON_PIN)
    {
        uint32_t currentTime = HAL_GetTick();
        if ((currentTime - lastDebounceTime) > DEBOUNCE_DELAY)
        {
            if ((currentTime - firstPressTime) <= TRIPLE_PRESS_TIME)
            {
                pressCount++;
            }
            else
            {
                pressCount = 1;
                firstPressTime = currentTime;
            }

            if (pressCount == 3)
            {
                pressCount = 0;
                clearInputBuffer();
                LCD_Clear(&hi2c1);
            }
            else
            {
                toggleDisplay();
            }

            lastDebounceTime = currentTime;
        }
    }
}

void toggleDisplay(void)
{
    displayOn = !displayOn;
    if (displayOn)
    {
        LCD_Backlight(&hi2c1, 1);
        updateLCD();
    }
    else
    {
        LCD_Backlight(&hi2c1, 0);
    }
}

void clearInputBuffer(void)
{
    for (int i = 0; i < 20; i++)
    {
        inputBuffer[i] = 0;
    }
    inputIndex = 0;
}

void updateLCD(void)
{
    LCD_Clear(&hi2c1);
    for (int i = 0; i < inputIndex && i < 16; i++)
    {
        LCD_SetCursor(&hi2c1, 0, i);
        LCD_WriteChar(&hi2c1, inputBuffer[i]);
    }
    if (inputIndex > 16)
    {
        LCD_SetCursor(&hi2c1, 1, 0);
        for (int i = 16; i < inputIndex && i < 32; i++)
        {
            LCD_WriteChar(&hi2c1, inputBuffer[i]);
        }
    }
}