/***
    Copyright (C) 2021 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: FileArbitraryReader.hpp
    Date: 2021-6-10
    Author: Reece
***/
#pragma once

namespace Aurora::IO::FS
{
    class FileArbitraryReader : public IArbitraryStreamer
    {
    public:
        AU_NO_COPY_NO_MOVE(FileArbitraryReader)
        
        FileArbitraryReader() {}
        ~FileArbitraryReader() {}
        
        template<typename... T>
        bool OpenFile(T... args)
        {
            stream_ = OpenReadUnique(args...);
            return stream_ != nullptr;
        }

        virtual EStreamError Open() override
        {
            return stream_ ? EStreamError::eErrorNone : EStreamError::eErrorStreamInterrupted;
        }

        virtual EStreamError ArbitraryRead(AuUInt32 offset, void *buffer, AuUInt32 &len) override
        {
            auto oldLen = std::exchange(len, 0);
            if (!stream_) return EStreamError::eErrorStreamNotOpen;
            stream_->SetOffset(offset);
            len = stream_->Read(buffer, oldLen);
            if (len == 0) return EStreamError::eErrorEndOfStream;
            return EStreamError::eErrorNone;
        }

        virtual void Close() override
        {
            stream_.reset();
        }

    private:
        OpenReadUnique_t stream_{};
    };
}