#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>
#include <linux/fs.h> 

class RawDisk{

    int fd;
    const char* dir;
    u_int64_t numSectors;
    u_int64_t diskSize;

public:
    RawDisk(const char *directory) : fd(-1), dir(nullptr), numSectors(0), diskSize(0) {
        dir = directory;
        /*dir = strdup("/dev/vdc");
        numSectors = 62914560;
        diskSize = 32212254720;*/
        
        // Open the block device (replace /dev/sdX with the actual device)
        fd = open(dir, O_RDWR); // Allow read and write
        if (fd == -1) {
            perror("Error opening device");
            exit(1);
        }

        // Use ioctl with BLKGETSIZE to get the number of sectors
        if (ioctl(fd, BLKGETSIZE64, &diskSize) == -1) {
            perror("Error getting disk size");
            close(fd);
            exit(1);
        }

        // Calculate the size in bytes
        numSectors = diskSize / 512; // Assuming a sector size of 512 bytes

        printf("====Initializing RawDisk====\n");
        printf("Number of sectors: %llu\n", numSectors);
        printf("Disk size (in bytes): %llu\n", diskSize);
    }

    ~RawDisk() {
        if (fd != -1) {
            close(fd);
        }
    }

    int rawdisk_read(u_int64_t offset, char *buffer, size_t length) {
        if (lseek(fd, offset, SEEK_SET) == (u_int64_t)-1) {
            perror("Error seeking to offset");
            return -1;
        }

        ssize_t bytesRead = read(fd, buffer, length);
        if (bytesRead == -1) {
            perror("Error reading from device");
            return -1;
        }

        return 0;
    }

    // Write a specified number of bytes at a given byte offset
    int rawdisk_write(u_int64_t offset, char *buffer, size_t length) {
        if (lseek(fd, offset, SEEK_SET) == (u_int64_t)-1) {
            perror("Error seeking to offset");
            return -1;
        }

        ssize_t bytesWritten = write(fd, buffer, length);
        if (bytesWritten == -1) {
            perror("Error writing to device");
            return -1;
        }

        return 0;
    }

};