---

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#include <linux/i2c.h>

unsigned char mirror_byte(unsigned char b) {
    b = ((b & 0xF0) >> 4) | ((b & 0x0F) << 4);
    b = ((b & 0xCC) >> 2) | ((b & 0x33) << 2);
    b = ((b & 0xAA) >> 1) | ((b & 0x55) << 1);
    return b;
}

/* Функция для принудительного чтения статуса 0x3C прямо внутри процесса */
void read_embedded_status(int fd, const char *label) {
    unsigned char cmd[] = { mirror_byte(0x3C), 0x00, 0x00, 0x00 };
    unsigned char buf[8] = {0};
    
    // Записываем команду чтения статуса
    write(fd, cmd, 4);
    usleep(1000);
    // Читаем 8 байт ответа
    if (read(fd, buf, 8) == 8) {
        printf("[STATUS %s]: 0x%02X%02X%02X%02X%02X%02X%02X%02X\n", label,
               buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
    } else {
        printf("[STATUS %s]: Failed to read status bytes\n", label);
    }
}

int main(int argc, char *argv[]) {
    if (argc < 3) {
        printf("Usage: %s <i2c-dev-path> <bitstream.bit>\n", argv);
        return 1;
    }

    int fd = open(argv[1], O_RDWR);
    if (fd < 0) { perror("Failed to open I2C bus"); return 1; }
    if (ioctl(fd, I2C_SLAVE_FORCE, 0x40) < 0) { perror("Failed to set slave address"); return 1; }

    FILE *f_bit = fopen(argv[2], "rb");
    if (!f_bit) { perror("Failed to open bit file"); return 1; }

    printf("[DEBUG_FLASH] Connected to 0x40. Absolute mirroring mode...\n");

    /* 1. Ключ активации */
    unsigned char act_key[] = { 0xA4, 0xC6, 0xF4, 0x8A };
    write(fd, act_key, 4); usleep(5000);

    /* 2. ISC_ENABLE */
    unsigned char isc_enable[] = { mirror_byte(0xC6), 0x00, 0x00, 0x00 };
    write(fd, isc_enable, 4); usleep(10000);

    /* 3. ISC_ERASE */
    unsigned char isc_erase[] = { mirror_byte(0x0E), mirror_byte(0x01), 0x00, 0x00 };
    write(fd, isc_erase, 4); usleep(100000);
    
    // Смотрим статус сразу после очистки памяти ПЛИС
    read_embedded_status(fd, "AFTER_ERASE");

    /* 4. LSC_BITSTREAM_BURST */
    unsigned char burst_cmd[] = { mirror_byte(0x7A), 0x00, 0x00, 0x00 };
    write(fd, burst_cmd, 4); usleep(2000);

    /* 5. Потоковая передача всего файла с полным отзеркалированием */
    unsigned char block;
    size_t read_bytes, total_sent = 0;
    while ((read_bytes = fread(block, 1, sizeof(block), f_bit)) > 0) {
        for (size_t i = 0; i < read_bytes; i++) {
            block[i] = mirror_byte(block[i]);
        }
        write(fd, block, read_bytes);
        total_sent += read_bytes;
    }
    printf("[DEBUG_FLASH] Sent %zu bytes of bitstream payload.\n", total_sent);
    usleep(5000);

    /* ================================================================== */
    /* КРИТИЧЕСКАЯ ТОЧКА: Читаем статус ДО закрытия режима прошивки        */
    /* ================================================================== */
    read_embedded_status(fd, "BEFORE_ISC_DISABLE");
    /* ================================================================== */

    /* 6. Добивка FIFO */
    unsigned char padding[1024];
    for(int i=0; i<1024; i++) padding[i] = 0xFF;
    write(fd, padding, 1024); usleep(5000);

    /* 7. ISC_DISABLE */
    unsigned char isc_disable[] = { mirror_byte(0x26), 0x00, 0x00, 0x00 };
    write(fd, isc_disable, 4); usleep(5000);

    /* 8. LSC_REFRESH */
    unsigned char refresh[] = { mirror_byte(0x79), 0x00, 0x00, 0x00 };
    write(fd, refresh, 4); usleep(5000);
    
    read_embedded_status(fd, "FINAL_STAGE");

    fclose(f_bit); close(fd);
    return 0;
}