/***
    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: IAsyncTransaction.hpp
    Date: 2022-2-14
    Author: Reece
***/
#pragma once

namespace Aurora::IO::Loop
{
    struct ILoopSource;
}

namespace Aurora::IO
{
    /**
     * @brief Cross-platform reusable overlapped-based IO transaction
     * 
     * @warning this object is bound by the current thread at time of creation.
     * Do not access this object across threads as there is no MT guarantee on this particular object
     * Using the synchronization primitives, loop or authreading, is fine. 

    */
    struct IAsyncTransaction
    {
        virtual bool StartRead(AuUInt64 uOffset, const AuSPtr<Memory::MemoryViewWrite> &memoryView) = 0;
        virtual bool StartWrite(AuUInt64 uOffset, const AuSPtr<Memory::MemoryViewRead> &memoryView) = 0;
        
        /**
         * @brief Non-blocking is-signaled and call callback poll routine
        */ 
        virtual bool     Complete() = 0;

        /**
         * @brief 
         * @return 
        */
        virtual bool     Failed() = 0;
        
        /**
         * @brief 
         * @return 
        */
        virtual AuUInt   GetOSErrorCode() = 0;

        /**
         * @brief Returns the last packets length assuming ::Complete() is true or you are within the registered callback 
        */
        virtual AuUInt32 GetLastPacketLength() = 0;
        
        /**
         * @brief Registers an NT-like APC callback for the IO transaction.
         *        Can be executed under any Aurora loop subsystem sleep
        */
        virtual void SetCallback(const AuSPtr<IAsyncFinishedSubscriber> &pSubscriber) = 0;

        /**
         * @brief Block for completion
        */ 
        virtual bool Wait(AuUInt32 uTimeout) = 0;

        /**
         * @brief Provides a loop source that becomes signaled once the transaction is complete.
         *        Polling the transaction may result in the execution of the callback.
        */ 
        virtual AuSPtr<IO::Loop::ILoopSource> NewLoopSource() = 0;

        /**
         * @brief Resets ::Complete() and NewLoopSource()->IsSignaled() to false
        */
        virtual void Reset() = 0;

        AURT_ADD_USR_DATA;
    };
}