#pragma once

#include <xrpl/basics/Blob.h>
#include <xrpl/basics/CountedObject.h>
#include <xrpl/basics/base_uint.h>

#include <cstddef>
#include <cstdint>
#include <memory>

// VFALCO NOTE Intentionally not in the NodeStore namespace

namespace xrpl {

/**
 * The types of node objects.
 */
enum class NodeObjectType : std::uint32_t {
    Unknown = 0,
    Ledger = 1,
    AccountNode = 3,
    TransactionNode = 4,
    Dummy = 512  // an invalid or missing object
};

/**
 * A simple object that the Ledger uses to store entries.
 * NodeObjects are comprised of a type, a hash, and a blob.
 * They can be uniquely identified by the hash, which is a half-SHA512 of
 * the blob. The blob is a variable length block of serialized data. The
 * type identifies what the blob contains.
 *
 * @note No checking is performed to make sure the hash matches the data.
 * @see SHAMap
 */
class NodeObject : public CountedObject<NodeObject>
{
public:
    static constexpr std::size_t kKeyBytes = 32;

private:
    // This hack is used to make the constructor effectively private
    // except for when we use it in the call to make_shared.
    // There's no portable way to make make_shared<> a friend work.
    struct PrivateAccess
    {
        explicit PrivateAccess() = default;
    };

public:
    // This constructor is private, use createObject instead.
    NodeObject(NodeObjectType type, Blob&& data, uint256 const& hash, PrivateAccess);

    /**
     * Create an object from fields.
     *
     * The caller's variable is modified during this call. The
     * underlying storage for the Blob is taken over by the NodeObject.
     *
     * @param type The type of object.
     * @param ledgerIndex The ledger in which this object appears.
     * @param data A buffer containing the payload. The caller's variable
     *             is overwritten.
     * @param hash The 256-bit hash of the payload data.
     */
    static std::shared_ptr<NodeObject>
    createObject(NodeObjectType type, Blob&& data, uint256 const& hash);

    /**
     * Returns the type of this object.
     */
    [[nodiscard]] NodeObjectType
    getType() const;

    /**
     * Returns the hash of the data.
     */
    [[nodiscard]] uint256 const&
    getHash() const;

    /**
     * Returns the underlying data.
     */
    [[nodiscard]] Blob const&
    getData() const;

private:
    NodeObjectType const type_;
    uint256 const hash_;
    Blob const data_;
};

}  // namespace xrpl