/*
   Copyright (c) 2017 Red Hat, Inc. <http://www.redhat.com>
   This file is part of GlusterFS.

   This file is licensed to you under your choice of the GNU Lesser
   General Public License, version 3 or any later version (LGPLv3 or
   later), or the GNU General Public License, version 2 (GPLv2), in all
   cases as published by the Free Software Foundation.
   */
#include <stdio.h>
#include <libgen.h>

#include <glusterfs/common-utils.h>
#include <glusterfs/syscall.h>

#define MAX_GFID2PATH_LINK_SUP 500
#define GFID_SIZE 16
#define GFID_XATTR_KEY "trusted.gfid"

int
main(int argc, char **argv)
{
    int ret = 0;
    struct stat st;
    char *dname = NULL;
    char *bname = NULL;
    ssize_t ret_size = 0;
    uuid_t pgfid_raw = {
        0,
    };
    char pgfid[36 + 1] = "";
    char xxh64[GF_XXH64_DIGEST_LENGTH * 2 + 1] = {
        0,
    };
    char pgfid_bname[1024] = {
        0,
    };
    char *key = NULL;
    char *val = NULL;
    size_t key_size = 0;
    size_t val_size = 0;
    const char *file_path = NULL;
    char *file_path1 = NULL;
    char *file_path2 = NULL;

    if (argc != 2) {
        fprintf(stderr, "Usage: setgfid2path <file-path>\n");
        return -1;
    }

    ret = sys_lstat(argv[1], &st);
    if (ret != 0) {
        fprintf(stderr, "Invalid File Path\n");
        return -1;
    }

    if (st.st_nlink >= MAX_GFID2PATH_LINK_SUP) {
        fprintf(stderr,
                "Number of Hardlink support exceeded. "
                "max=%d\n",
                MAX_GFID2PATH_LINK_SUP);
        return -1;
    }

    file_path = argv[1];
    file_path1 = strdup(file_path);
    file_path2 = strdup(file_path);

    dname = dirname(file_path1);
    bname = basename(file_path2);

    /* Get GFID of Parent directory */
    ret_size = sys_lgetxattr(dname, GFID_XATTR_KEY, pgfid_raw, GFID_SIZE);
    if (ret_size != GFID_SIZE) {
        fprintf(stderr, "Failed to get GFID of parent directory. dir=%s\n",
                dname);
        ret = -1;
        goto out;
    }

    /* Convert to UUID format */
    if (uuid_utoa_r(pgfid_raw, pgfid) == NULL) {
        fprintf(stderr,
                "Failed to format GFID of parent directory. "
                "dir=%s GFID=%s\n",
                dname, pgfid_raw);
        ret = -1;
        goto out;
    }

    /* Find xxhash for PGFID/BaseName */
    snprintf(pgfid_bname, sizeof(pgfid_bname), "%s/%s", pgfid, bname);
    gf_xxh64_wrapper((unsigned char *)pgfid_bname, strlen(pgfid_bname),
                     GF_XXHSUM64_DEFAULT_SEED, xxh64);

    key_size = SLEN(GFID2PATH_XATTR_KEY_PREFIX) + GF_XXH64_DIGEST_LENGTH * 2 +
               1;
    key = alloca(key_size);
    snprintf(key, key_size, GFID2PATH_XATTR_KEY_PREFIX "%s", xxh64);

    val_size = UUID_CANONICAL_FORM_LEN + NAME_MAX + 2;
    val = alloca(val_size);
    snprintf(val, val_size, "%s/%s", pgfid, bname);

    /* Set the Xattr, ignore if same key xattr already exists */
    ret = sys_lsetxattr(file_path, key, val, strlen(val), XATTR_CREATE);
    if (ret == -1) {
        if (errno == EEXIST) {
            printf("Xattr already exists, ignoring..\n");
            ret = 0;
            goto out;
        }

        fprintf(stderr, "Failed to set gfid2path xattr. errno=%d\n error=%s",
                errno, strerror(errno));
        ret = -1;
        goto out;
    }

    printf("Success. file=%s key=%s value=%s\n", file_path, key, val);

out:
    if (file_path1 != NULL)
        free(file_path1);

    if (file_path2 != NULL)
        free(file_path2);

    return ret;
}