/*
 * Copyright (c) Huawei Device Co., Ltd. 2026-2026. All rights reserved.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef ALLOCTABLE_H
#define ALLOCTABLE_H

#include <vector>

#include "utils.h"

namespace OHOS {
namespace ObjectEditor {

class AllocTable {
public:
    static const uint32_t Eof;
    static const uint32_t Avail;
    static const uint32_t Bat;
    static const uint32_t MetaBat;
    static constexpr uint32_t kDefaultBlockSize = 4096;
    static constexpr size_t kGrowStep = 10;

public:
    explicit AllocTable(uint32_t blockSize = kDefaultBlockSize)
    {
        SetBlockSize(blockSize);
    }

public:
    size_t Count() const
    {
        return data_.size();
    }
    uint32_t BlockSize() const
    {
        return blockSize_;
    }
    uint32_t operator[](size_t index) const
    {
        if (data_.empty()) {
            return 0;
        }
        if (index >= data_.size()) {
            return 0;
        }

        return data_[index];
    }

    bool Follow(uint32_t start, std::vector<uint32_t> &chain) const;

public:
    void SetBlockSize(uint32_t size);
    void SetChain(const std::vector<uint32_t> &chain);
    bool Load(const Byte *buffer, size_t len);
    bool Save(Byte *buffer, size_t len);
    void Debug() const;
    void Resize(size_t newSize)
    {
        constexpr size_t MAX_CAPACITY = SIZE_MAX / sizeof(uint32_t);
        if (newSize > MAX_CAPACITY) {
            return;
        }
        data_.resize(newSize, Avail);
    }
    void Set(size_t index, uint32_t val);
    size_t Unused();

private:
    std::vector<uint32_t> data_;
    uint32_t blockSize_ = 0;
    size_t nextUnused_ = 0;

    AllocTable(const AllocTable &);
    AllocTable &operator=(const AllocTable &);
};
} // namespace ObjectEditor
} // namespace OHOS

#endif