#include "stm32c0xx_hal.h"
#include "spi_ili9341.h"
#include <stdlib.h>

/* Private define */
#define TFT_WIDTH  240
#define TFT_HEIGHT 320

/* Private variables */
SPI_HandleTypeDef hspi1;  // SPI handle for TFT

/* Private function prototypes */
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_SPI1_Init(void);

/* USER CODE BEGIN 0 */
// Initialize control pins (CS, DC, RESET) for TFT
void ControlPin_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStruct = {0};

    // Set all pins low initially
    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_6 | GPIO_PIN_8 | GPIO_PIN_9, GPIO_PIN_RESET);

    // Configure pins as output push-pull
    GPIO_InitStruct.Pin = GPIO_PIN_6 | GPIO_PIN_8 | GPIO_PIN_9;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}

// Convert 24-bit RGB888 color to 16-bit RGB565
uint16_t ToRGB565(uint32_t clr)
{
    uint8_t *rgb888Pixel = (uint8_t*)&clr;

    uint8_t red   = rgb888Pixel[2];
    uint8_t green = rgb888Pixel[1];
    uint8_t blue  = rgb888Pixel[0];

    uint16_t b = (blue >> 3) & 0x1F;
    uint16_t g = ((green >> 2) & 0x3F) << 5;
    uint16_t r = ((red >> 3) & 0x1F) << 11;
    return (uint16_t)(r | g | b);
}

// Fill the TFT screen with vertical gradient
void TFT9341_FillGradient(uint32_t colorTop, uint32_t colorBottom)
{
    uint8_t rTop = (colorTop >> 16) & 0xFF;
    uint8_t gTop = (colorTop >> 8) & 0xFF;
    uint8_t bTop = colorTop & 0xFF;

    uint8_t rBottom = (colorBottom >> 16) & 0xFF;
    uint8_t gBottom = (colorBottom >> 8) & 0xFF;
    uint8_t bBottom = colorBottom & 0xFF;

    for (uint16_t y = 0; y < TFT_HEIGHT; y++)
    {
        uint8_t r = (uint8_t)((rTop * (TFT_HEIGHT - y) + rBottom * y) / TFT_HEIGHT);
        uint8_t g = (uint8_t)((gTop * (TFT_HEIGHT - y) + gBottom * y) / TFT_HEIGHT);
        uint8_t b = (uint8_t)((bTop * (TFT_HEIGHT - y) + bBottom * y) / TFT_HEIGHT);

        uint16_t colorLine = ToRGB565((r << 16) | (g << 8) | b);

        for (uint16_t x = 0; x < TFT_WIDTH; x++)
        {
            TFT9341_DrawPixel(x, y, colorLine);
        }
    }
}
/* USER CODE END 0 */

/* Main function */
int main(void)
{
    HAL_Init();
    SystemClock_Config();
    MX_GPIO_Init();
    MX_SPI1_Init();  // Initialize SPI for TFT

    ControlPin_Init();  // Initialize TFT control pins

    // Initialize TFT display
    TFT9341_ini(TFT_WIDTH, TFT_HEIGHT);
    HAL_Delay(500);

    // Fill screen with gradient
    TFT9341_FillGradient(0x00FFFF, 0xFFFF00);
    HAL_Delay(1500);

    // Draw some characters
    TFT9341_SetTextColor(TFT9341_YELLOW);
    TFT9341_SetBackColor(TFT9341_BLUE);
    TFT9341_SetFont(&Font24);
    TFT9341_DrawChar(10,10,'S');
    TFT9341_DrawChar(27,10,'t');
    TFT9341_DrawChar(44,10,'m');
    TFT9341_DrawChar(61,10,'3');
    TFT9341_DrawChar(78,10,'2');

    while (1) { }  // Infinite loop
}

/* System Clock Configuration */
void SystemClock_Config(void)
{
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

    __HAL_FLASH_SET_LATENCY(FLASH_LATENCY_1);

    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.AHBCLKDivider = RCC_SYSCLK_DIV1;
    RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV1;
    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK) { Error_Handler(); }
}

/* SPI1 Initialization */
static void MX_SPI1_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStruct = {0};
    __HAL_RCC_SPI1_CLK_ENABLE();
    __HAL_RCC_GPIOA_CLK_ENABLE();

    // Configure SPI pins (SCK, MOSI)
    GPIO_InitStruct.Pin = GPIO_PIN_1 | GPIO_PIN_7;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF0_SPI1;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    // SPI configuration
    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_4;
    hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
    hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
    hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
    hspi1.Init.CRCPolynomial = 10;
    hspi1.Init.CRCLength = SPI_CRC_LENGTH_DATASIZE;
    hspi1.Init.NSSPMode = SPI_NSS_PULSE_ENABLE;
    if (HAL_SPI_Init(&hspi1) != HAL_OK) { Error_Handler(); }
}

/* GPIO Initialization */
static void MX_GPIO_Init(void)
{
    __HAL_RCC_GPIOA_CLK_ENABLE();
    __HAL_RCC_GPIOB_CLK_ENABLE();
}

/* Error Handler */
void Error_Handler(void)
{
    __disable_irq();
    while (1) { }
}