#include "stm32c0xx_hal.h"

/* SPI Handle */
SPI_HandleTypeDef hspi1;

/* Function prototypes */
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_SPI1_Init(void);

/* 74HC595 — LATCH (ST_CP) pin */
#define LATCH_PIN GPIO_PIN_0
#define LATCH_PORT GPIOA

void LATCH_Init()
{
    GPIO_InitTypeDef GPIO_InitStruct = {0};
    HAL_GPIO_WritePin(LATCH_PORT, LATCH_PIN, GPIO_PIN_SET);

    GPIO_InitStruct.Pin = LATCH_PIN;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    HAL_GPIO_Init(LATCH_PORT, &GPIO_InitStruct);
}

void LATCH_Set(uint8_t val)
{
    HAL_GPIO_WritePin(LATCH_PORT, LATCH_PIN, val ? GPIO_PIN_SET : GPIO_PIN_RESET);
}

/* SPI SEND */
void Send(uint8_t out_value)
{
    LATCH_Set(0);
    HAL_SPI_Transmit(&hspi1, &out_value, 1, 100);
    LATCH_Set(1);
}

/* DIP-switch Read PB0–PB7 */
uint8_t Read_DIP(void)
{
    uint8_t value = 0;
    for(uint8_t i = 0; i < 8; i++)
        value |= (HAL_GPIO_ReadPin(GPIOB, (1 << i)) == GPIO_PIN_RESET ? (1 << i) : 0);
    return value;
}

/* 7-сегментна таблиця (коммон-анод) */
uint8_t digit_table[9] = {
    0b11111111, // All OFF
    0b01101110, // 1
    0b00000101, // 2
    0b00100100, // 3
    0b01101000, // 4
    0b00110000, // 5
    0b00010000, // 6
    0b01100110, // 7
    0b00000000  // 8 (усі сегменти)
};

uint8_t DIP_to_digit(uint8_t dip_val)
{
    for(uint8_t i = 0; i < 8; i++)
        if(dip_val & (1 << i))
            return i + 1;
    return 0;
}

/* MAIN */
int main(void)
{
    HAL_Init();
    SystemClock_Config();
    MX_GPIO_Init();
    MX_SPI1_Init();
    LATCH_Init();

    while (1)
    {
        uint8_t dip_val = Read_DIP();
        uint8_t digit = DIP_to_digit(dip_val);
        Send(digit_table[digit]);
        HAL_Delay(100);
    }
}

/* CLOCK CONFIG */
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();
}

/* SPI INIT */
static void MX_SPI1_Init(void)
{
    __HAL_RCC_SPI1_CLK_ENABLE();
    __HAL_RCC_GPIOA_CLK_ENABLE();

    GPIO_InitTypeDef GPIO_InitStruct = {0};
    GPIO_InitStruct.Pin = GPIO_PIN_1 | GPIO_PIN_7; // SCK, MOSI
    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);

    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_2;
    hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
    hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
    hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
    hspi1.Init.CRCPolynomial = 7;
    hspi1.Init.CRCLength = SPI_CRC_LENGTH_DATASIZE;
    hspi1.Init.NSSPMode = SPI_NSS_PULSE_ENABLE;
    if (HAL_SPI_Init(&hspi1) != HAL_OK) Error_Handler();
}

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

    GPIO_InitTypeDef GPIO_InitStruct = {0};

    /* DIP-switch PB0–PB7 */
    GPIO_InitStruct.Pin = GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_2 | GPIO_PIN_3 |
                          GPIO_PIN_4 | GPIO_PIN_5 | GPIO_PIN_6 | GPIO_PIN_7;
    GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
    GPIO_InitStruct.Pull = GPIO_PULLUP;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

    /* LATCH pin */
    GPIO_InitStruct.Pin = LATCH_PIN;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    HAL_GPIO_Init(LATCH_PORT, &GPIO_InitStruct);
}

/* ERROR HANDLER */
void Error_Handler(void)
{
    __disable_irq();
    while (1) {}
}