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

    File: LSMutex.Linux.cpp
    Date: 2021-10-1
    Date: 2022-4-4
    Author: Reece
***/
#include <Source/RuntimeInternal.hpp>
#include "LSMutex.hpp"
#include "LSFromFdNonblocking.hpp"

namespace Aurora::Loop
{
    LSMutex::LSMutex()
    {
    }

    bool LSMutex::OnTrigger(AuUInt handle)
    {
        AuUInt64 oldSemaphoreValue {};
        auto ok = read(this->handle, &oldSemaphoreValue, sizeof(oldSemaphoreValue)) == 8;
        SysAssertDbg(oldSemaphoreValue == 1, "Double unlock caught");
        return ok;
    }

    void LSMutex::Init()
    {
        handle = eventfd(1, EFD_NONBLOCK);
    }

    bool LSMutex::Unlock()
    {
        AuUInt64 plsNoOverflow {1};
        return write(this->handle, &plsNoOverflow, sizeof(plsNoOverflow)) == 8;
    }

    bool LSMutex::IsSignaled()
    {
        return IsSignaledFromNonblockingImpl(this, this, &LSMutex::IsSignaledNonblocking);
    }

    bool LSMutex::IsSignaledNonblocking()
    {
        AuUInt64 oldSemaphoreValue {};
        auto ok = read(this->handle, &oldSemaphoreValue, sizeof(oldSemaphoreValue)) == 8;
        SysAssertDbg(!ok || oldSemaphoreValue == 1, "Double unlock caught");
        return ok;
    }

    ELoopSource LSMutex::GetType()
    {
        return ELoopSource::eSourceMutex;
    }

    AUKN_SYM AuSPtr<ILSMutex> NewLSMutex()
    {
        auto mutex = AuMakeShared<LSMutex>();
        if (!mutex)
        {
            return {};
        }

        if (!mutex->HasValidHandle())
        {
            return {};
        }

        return mutex;
    }
}