#include <stdio.h>
#include <string.h>
#include <stdint.h>

typedef uint32_t nfs_fh_t;

static const char file_data[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
static const size_t file_len = 26;

int nfs_read(nfs_fh_t fh, uint64_t offset, uint32_t count, char *buf, uint32_t *nread) {
    printf("NFS-REQ READ fh=%u off=%llu cnt=%u\n", (unsigned)fh, (unsigned long long)offset, count);
    if (fh != 7) {
        printf("NFS-ERR stale handle\n");
        return -1;
    }
    if (offset >= file_len) {
        *nread = 0;
        printf("NFS-REP 0 bytes (EOF)\n");
        return 0;
    }
    size_t remain = file_len - (size_t)offset;
    uint32_t copy = count < remain ? count : (uint32_t)remain;
    memcpy(buf, file_data + (size_t)offset, copy);
    *nread = copy;
    printf("NFS-REP %u bytes\n", copy);
    return 0;
}

int main(void) {
    char buf[32];
    uint32_t got;
    nfs_fh_t fh = 7;
    printf("Client starts using NFS file handle 7\n");
    if (nfs_read(fh, 0, 5, buf, &got) == 0) {
        buf[got] = '\0';
        printf("DATA: %s\n", buf);
    }
    if (nfs_read(fh, 10, 5, buf, &got) == 0) {
        buf[got] = '\0';
        printf("DATA: %s\n", buf);
    }
    printf(">>> simulated server crash and restart <<<\n");
    if (nfs_read(fh, 20, 10, buf, &got) == 0) {
        buf[got] = '\0';
        printf("DATA: %s\n", buf);
    }
    nfs_read(fh, 30, 4, buf, &got);
    printf("EOF reached as expected\n");
    return 0;
}