#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <openssl/sha.h>

int main() {
    FILE *f = fopen("romfs/dragonfly.bin", "r");
    if (!f) {
        perror("Failed to open file");
        return 1;
    }

    // Get file size
    fseek(f, 0, SEEK_END);
    long file_size = ftell(f);
    fseek(f, 0, SEEK_SET);

    uint8_t *dragonfly = malloc(file_size);
    if (!dragonfly) {
        perror("malloc failed");
        fclose(f);
        return 1;
    }

    fread(dragonfly, 1, file_size, f);
    fclose(f);

    uint8_t flag[0x1d] = {0};  // 29 bytes

    for (int i = 7; i >= 0; i--) {
        uint8_t *target_hash = dragonfly + SHA256_DIGEST_LENGTH * (7 - i);
        int found = 0;

        uint64_t max_n = 1ULL << sizeof(flag);
        for (uint64_t n = 0; n < max_n; n++) {
            uint64_t tmp = n;
            for (int j = 0; j < sizeof(flag); j++) {
                uint8_t bit = tmp & 1;
                tmp >>= 1;
                flag[j] = (flag[j] & 0xFE) | bit;
            }

            // Compute SHA-256
            uint8_t hash[SHA256_DIGEST_LENGTH];
            SHA256(flag, sizeof(flag), hash);

            if (memcmp(hash, target_hash, SHA256_DIGEST_LENGTH) == 0) {
                found = 1;
                break;
            }

            if (n % 1000000 == 0) {
                printf("\r%09lu", n);
                fflush(stdout);
            }
        }

        printf("\n");
        if (!found) {
            printf("Could not find it on level: %d\n", i);
            break;
        }

        // Print flag in hex
        for (int j = 0; j < sizeof(flag); j++) {
            printf("%02x", flag[j]);
        }
        printf("\n");

        // Shift left by 1
        for (int j = 0; j < sizeof(flag); j++) {
            flag[j] = (flag[j] << 1) & 0xFF;
        }
    }

    // Print final flag
    for (int j = 0; j < sizeof(flag); j++) {
        printf("%02x", flag[j]);
    }
    printf("\n");

    // Bitwise NOT
    for (int j = 0; j < sizeof(flag); j++) {
        flag[j] = (~flag[j]) & 0xFF;
    }

    for (int j = 0; j < sizeof(flag); j++) {
        printf("%02x", flag[j]);
    }
    printf("\n");

    printf("%s\n", flag);

    free(dragonfly);
    return 0;
}