/*
 * Copyright 2017, Chế Vũ Gia Hy, cvghy116@gmail.com.
 * Copyright 2011, Jérôme Duval, korli@users.berlios.de.
 * This file may be used under the terms of the MIT License.
 */


#include "AttributeIterator.h"


//#define TRACE_BTRFS
#ifdef TRACE_BTRFS
#       define TRACE(x...) dprintf("\33[34mbtrfs:\33[0m " x)
#else
#       define TRACE(x...) ;
#endif
#       define ERROR(x...) dprintf("\33[34mbtrfs:\33[0m " x)


AttributeIterator::AttributeIterator(Inode* inode)
        :
        fOffset(-1ULL),
        fInode(inode),
        fIterator(NULL)
{
        btrfs_key key;
        key.SetType(BTRFS_KEY_TYPE_XATTR_ITEM);
        key.SetObjectID(inode->ID());
        key.SetOffset(BTREE_BEGIN);
        fIterator = new(std::nothrow) TreeIterator(inode->GetVolume()->FSTree(),
                key);
}


AttributeIterator::~AttributeIterator()
{
        delete fIterator;
        fIterator = NULL;
}


status_t
AttributeIterator::InitCheck()
{
        return fIterator != NULL ? B_OK : B_NO_MEMORY;
}


status_t
AttributeIterator::GetNext(char* name, size_t* _nameLength)
{
        btrfs_dir_entry* entries;
        uint32 entries_length;
        status_t status = fIterator->GetPreviousEntry((void**)&entries,
                &entries_length);
        if (status != B_OK)
                return status;

        btrfs_dir_entry* entry = entries;
        uint16 current = 0;
        while (current < entries_length) {
                current += entry->Length();
                break;
                // TODO there could be several entries with the same name hash
                entry = (btrfs_dir_entry*)((uint8*)entry + entry->Length());
        }

        TRACE("DirectoryIterator::GetNext() entries_length %ld name_length %d\n",
                entries_length, entry->NameLength());

        memcpy(name, entry->name, entry->NameLength());
        name[entry->NameLength()] = '\0';
        *_nameLength = entry->NameLength();
        free(entries);

        return B_OK;
}


status_t
AttributeIterator::Rewind()
{
        fIterator->Rewind();
        fOffset = -1ULL;
        return B_OK;
}