#include "stm32l0xx_hal.h"

// SPI and GPIO initialization
SPI_HandleTypeDef hspi1;
GPIO_InitTypeDef GPIO_InitStruct = {0};

// Function to initialize SPI
void SPI1_Init(void)
{
    hspi1.Instance = SPI1;
    hspi1.Init.Mode = SPI_MODE_MASTER;
    hspi1.Init.Direction = SPI_DIRECTION_2LINES;
    hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
    hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
    hspi1.Init.CLKPhase = SPI_PHASE_1EDGE;
    hspi1.Init.NSS = SPI_NSS_SOFT;
    hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_16;
    hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
    HAL_SPI_Init(&hspi1);
}

// Function to initialize GPIO pins for CS, DC, and RESET
void GPIO_Init(void)
{
    __HAL_RCC_GPIOA_CLK_ENABLE();  // Enable clock for GPIOA

    GPIO_InitStruct.Pin = GPIO_PIN_2 | GPIO_PIN_3 | GPIO_PIN_4;  // RESET, DC, CS pins
    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);
}

// Function to reset the display
void ST7735_Reset(void)
{
    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_2, GPIO_PIN_RESET); // RESET low
    HAL_Delay(100);
    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_2, GPIO_PIN_SET);   // RESET high
    HAL_Delay(100);
}

// Function to send command to the display
void ST7735_SendCommand(uint8_t cmd)
{
    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_3, GPIO_PIN_RESET); // DC low for command mode
    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_RESET); // CS low
    HAL_SPI_Transmit(&hspi1, &cmd, 1, HAL_MAX_DELAY);
    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_SET);   // CS high
}

// Function to send data to the display
void ST7735_SendData(uint8_t data)
{
    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_3, GPIO_PIN_SET);   // DC high for data mode
    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_RESET); // CS low
    HAL_SPI_Transmit(&hspi1, &data, 1, HAL_MAX_DELAY);
    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_SET);   // CS high
}

// ST7735 Initialization sequence
void ST7735_Init(void)
{
    ST7735_Reset();

    // Start initialization with some common ST7735 commands
    ST7735_SendCommand(0x01);  // Software Reset
    HAL_Delay(150);

    ST7735_SendCommand(0x11);  // Sleep Out
    HAL_Delay(500);

    ST7735_SendCommand(0x29);  // Display On
}

// Function to draw a pixel (simplified)
void ST7735_DrawPixel(uint16_t x, uint16_t y, uint16_t color)
{
    // Set the column address
    ST7735_SendCommand(0x2A);  // Column address set
    ST7735_SendData(x >> 8);   // MSB of X
    ST7735_SendData(x & 0xFF); // LSB of X

    // Set the row address
    ST7735_SendCommand(0x2B);  // Row address set
    ST7735_SendData(y >> 8);   // MSB of Y
    ST7735_SendData(y & 0xFF); // LSB of Y

    ST7735_SendCommand(0x2C);  // Memory Write
    ST7735_SendData(color >> 8);  // MSB of color
    ST7735_SendData(color & 0xFF);  // LSB of color
}

// Main function to initialize and test display
int main(void)
{
    HAL_Init();
    SystemClock_Config();
    
    // Initialize SPI and GPIO
    SPI1_Init();
    GPIO_Init();
    
    // Initialize the ST7735 display
    ST7735_Init();

    // Draw a pixel (example: red at position (10, 10))
    ST7735_DrawPixel(10, 10, 0xF800); // Red color
    
    while (1)
    {
    }
}