LibCBOR/LibCBOR/Include/CBOR/Decoder.hpp

#ifndef LIBCBOR_DECODER_HPP
#define LIBCBOR_DECODER_HPP

#include "Core.hpp"

#include <span>
#include <string_view>

namespace CBOR
{
    class DecodeError: public Error
    {
    public:
        using Error::Error;
    };

    // Forward decl
    class Decoder;

    class Item
    {
    private:
        Item(Decoder &decoder);

    public:
        bool Bool();
        Special Special();

        std::int8_t  Int8();
        std::int16_t Int16();
        std::int32_t Int32();
        std::int64_t Int64();

        std::uint8_t  Uint8();
        std::uint16_t Uint16();
        std::uint32_t Uint32();
        std::uint64_t Uint64();

        // Note(3011): float16_t is currently not supported
        float  Float();
        double Double();

        std::span<std::uint8_t> Binary();
        std::string_view        String();
        class Binary            IndefiniteBinary();
        class String            IndefiniteString();
        class Array             Array();
        class Map               Map();

    private:
        friend class Decoder;
        friend class Array;
        friend class KeyValue;

        Decoder *mDecoder;
    };

    class KeyValue
    {
    private:
        KeyValue(Decoder &decoder);

    public:
        Item Key();
        Item Value();
    private:
        friend class Decoder;
        friend class Map;

        enum class State
        {
            Initial, KeyPulled, Done,
        };

        State    mState;
        Decoder *mDecoder;
    };

    class Binary
    {
    private:
        Binary(Decoder &decoder);

    public:
        bool                    Done();
        std::span<std::uint8_t> Next();

    private:
        friend class Decoder;

        bool     mHeaderParsed;
        bool     mDone;
        bool     mCheckedDone;
        Decoder *mDecoder;
    };

    class String
    {
    private:
        String(Decoder &decoder);

    public:
        bool             Done();
        std::string_view Next();

    private:
        friend class Decoder;

        bool     mHeaderParsed;
        bool     mDone;
        bool     mCheckedDone;
        Decoder *mDecoder;
    };

    class Array
    {
    private:
        Array(Decoder &decoder);

    public:
        bool Done();
        Item Next();

    private:
        friend class Decoder;

        bool        mHeaderParsed;
        bool        mDone;
        bool        mCheckedDone;
        std::size_t mCurrent;
        std::size_t mSize;
        Decoder    *mDecoder;
    };

    class Map
    {
    private:
        Map(Decoder &decoder);

    public:
        bool     Done();
        KeyValue Next();

    private:
        friend class Decoder;

        bool        mHeaderParsed;
        bool        mDone;
        bool        mCheckedDone;
        std::size_t mCurrent;
        std::size_t mSize;
        Decoder    *mDecoder;
    };

    class Decoder
    {
    public:
        Decoder(std::span<std::uint8_t> buffer);

        bool Bool();
        Special Special();

        std::int8_t   Int8();
        std::int16_t  Int16();
        std::int32_t  Int32();
        std::int64_t  Int64();

        std::uint8_t  Uint8();
        std::uint16_t Uint16();
        std::uint32_t Uint32();
        std::uint64_t Uint64();

        // Note(3011): float16_t is currently not supported
        float  Float();
        double Double();

        std::span<std::uint8_t> Binary();
        std::string_view        String();
        class Binary            IndefiniteBinary();
        class String            IndefiniteString();
        class Array             Array();
        class Map               Map();

    private:
        friend class Binary;
        friend class String;
        friend class Array;
        friend class Map;

        std::size_t             mCurrent;
        std::span<std::uint8_t> mBuffer;
    };
}

#endif // LIBCBOR_DECODER_HPP