//
//  apfs_util.c
//  electra
//
//  Created by CoolStar on 2/26/18.
//  Copyright © 2018 Electra Team. All rights reserved.
//

#include "apfs_util.h"

#include <fcntl.h>
#include <sys/syscall.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/attr.h>
#include <sys/snapshot.h>

int list_snapshots(const char *vol)
{
    int dirfd = open(vol, O_RDONLY, 0);
    if (dirfd < 0) {
        perror("open");
        return -1;
    }
    
    struct attrlist alist = { 0 };
    char abuf[2048];
    
    alist.commonattr = ATTR_BULK_REQUIRED;
    
    int count = fs_snapshot_list(dirfd, &alist, &abuf[0], sizeof (abuf), 0);
    if (count < 0) {
        perror("fs_snapshot_list");
        return -1;
    }
    
    char *p = &abuf[0];
    for (int i = 0; i < count; i++) {
        char *field = p;
        uint32_t len = *(uint32_t *)field;
        field += sizeof (uint32_t);
        attribute_set_t attrs = *(attribute_set_t *)field;
        field += sizeof (attribute_set_t);
        
        if (attrs.commonattr & ATTR_CMN_NAME) {
            attrreference_t ar = *(attrreference_t *)field;
            char *name = field + ar.attr_dataoffset;
            field += sizeof (attrreference_t);
            (void) printf("%s\n", name);
        }
        
        p += len;
    }
    
    return (0);
}

int check_snapshot(const char *vol, const char *snap)
{
    int dirfd = open(vol, O_RDONLY, 0);
    if (dirfd < 0) {
        perror("open");
        return -1;
    }
    
    struct attrlist alist = { 0 };
    char abuf[2048];
    
    alist.commonattr = ATTR_BULK_REQUIRED;
    
    int count = fs_snapshot_list(dirfd, &alist, &abuf[0], sizeof (abuf), 0);
    if (count < 0) {
        perror("fs_snapshot_list");
        return -1;
    }
    
    char *p = &abuf[0];
    for (int i = 0; i < count; i++) {
        char *field = p;
        uint32_t len = *(uint32_t *)field;
        field += sizeof (uint32_t);
        attribute_set_t attrs = *(attribute_set_t *)field;
        field += sizeof (attribute_set_t);
        
        if (attrs.commonattr & ATTR_CMN_NAME) {
            attrreference_t ar = *(attrreference_t *)field;
            const char *name = field + ar.attr_dataoffset;
            field += sizeof (attrreference_t);
            
            if (strcmp(name, snap) == 0){
                return 1;
            }
        }
        
        p += len;
    }
    
    return (0);
}