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

    File: IPCPrimitives.Linux.cpp
    Date: 2022-4-13
    Author: Reece
***/
#include <Source/RuntimeInternal.hpp>
#include "IPC.hpp"
#include "IPCHandle.hpp"
#include "IPCPrimitives.Linux.hpp"

#include <Source/IO/Loop/LSEvent.hpp>
#include <Source/IO/Loop/LSSemaphore.hpp>
#include <Source/IO/Loop/LSMutex.hpp>

#include <Source/IO/IPC/IPC.hpp>
#include <Source/IO/IPC/IPCHandle.hpp>

#include <Source/IO/UNIX/FDIpcServer.hpp>

namespace Aurora::IO::IPC
{
    #define IMPLEMENT_HANDLE \
        IPC::IPCHandle handle_; \
        AuString ExportToString() override \
        { \
            return handle_.ToString(); \
        }


    //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    // Events
    //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

    struct IPCEventProxy : IPCEvent, Loop::ILoopSourceEx
    {
        IPCEventProxy(bool triggered, bool atomicRelease);
        IPCEventProxy(int handle, bool triggered, bool atomicRelease);
        ~IPCEventProxy();

        PROXY_INTERNAL_INTERFACE(event_)
        IMPLEMENT_HANDLE

        bool Set() override;
        bool Reset() override;

        bool IsSignaled() override;
        bool WaitOn(AuUInt32 timeout) override;
        Loop::ELoopSource GetType() override;

    private:
        Loop::LSEvent event_;
    };

    IPCEventProxy::IPCEventProxy(bool triggered, bool atomicRelease) : event_(triggered, atomicRelease, true)
    {
        if (this->event_.HasValidHandle())
        {
            if (!IO::UNIX::FDServe(triggered, atomicRelease, false, true, this->GetHandle(), this->handle_))
            {
                this->event_.~LSEvent();
            }
        }
    }

    IPCEventProxy::IPCEventProxy(int handle, bool triggered, bool atomicRelease) : event_(handle, triggered, atomicRelease)
    {
        if (this->event_.HasValidHandle())
        {
            if (!IO::UNIX::FDServe(triggered, atomicRelease, false, true, this->GetHandle(), this->handle_))
            {
                this->event_.~LSEvent();
            }
        }  
    }

    IPCEventProxy::~IPCEventProxy()
    {
        IO::UNIX::FDServeEnd(this->handle_);
    }

    bool IPCEventProxy::Set()
    {
        return this->event_.Set();
    }

    bool IPCEventProxy::Reset()
    {
        return this->event_.Reset();
    }

    bool IPCEventProxy::IsSignaled()
    {
        return this->event_.IsSignaled();
    }

    bool IPCEventProxy::WaitOn(AuUInt32 timeout)
    {
        return this->event_.WaitOn(timeout);
    }

    Loop::ELoopSource IPCEventProxy::GetType()
    {
        return this->event_.GetType();
    }

    AUKN_SYM AuSPtr<IPCEvent>     NewEvent(bool triggered, bool atomicRelease)
    {
        auto object = AuMakeShared<IPCEventProxy>(triggered, atomicRelease);
        if (!object)
        {
            SysPushErrorMem();
            return {};
        }

        if (!object->HasValidHandle())
        {
            SysPushErrorIO();
            return {};
        }

        return object;
    }

    AUKN_SYM AuSPtr<IPCEvent>     ImportEvent(const AuString &handle)
    {
        IPC::IPCHandle decodedHandle;

        if (!decodedHandle.FromString(handle))
        {
            SysPushErrorParseError("Invalid handle: {}", handle);
            return {};
        }

        int fd {-1};
        if (!IO::UNIX::FDAccept(decodedHandle, fd))
        {
            SysPushErrorNested();
            return {};
        }

        auto object = AuMakeShared<IPCEventProxy>(fd, decodedHandle.flags[0], decodedHandle.flags[1]);
        if (!object)
        {
            SysPushErrorMem();
            ::close(fd);
            return {};
        }

        if (!object->HasValidHandle())
        {
            SysPushErrorIO();
            return {};
        }

        return object;
    }

    //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    // Semaphores
    //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

    struct IPCSemaphoreProxy : IPCSemaphore, Loop::ILoopSourceEx
    {
        IPCSemaphoreProxy(AuUInt32 initialCount);
        IPCSemaphoreProxy(int handle, int tag);
        ~IPCSemaphoreProxy();

        PROXY_INTERNAL_INTERFACE(semaphore_)
        IMPLEMENT_HANDLE

        bool AddOne() override;

        bool IsSignaled() override;
        bool WaitOn(AuUInt32 timeout) override;
        Loop::ELoopSource GetType() override;
        
    private:
        Loop::LSSemaphore semaphore_;
    };

    IPCSemaphoreProxy::IPCSemaphoreProxy(AuUInt32 initialCount) : semaphore_(initialCount)
    {
        if (this->semaphore_.HasValidHandle())
        {
            if (!IO::UNIX::FDServe(true, true, true, true, this->GetHandle(), this->handle_))
            {
                this->semaphore_.~LSSemaphore();
            }
        }
    }

    IPCSemaphoreProxy::IPCSemaphoreProxy(int handle, int tag) : semaphore_(handle, tag)
    {
        if (this->semaphore_.HasValidHandle())
        {
            if (!IO::UNIX::FDServe(true, true, true, true, this->GetHandle(), this->handle_))
            {
                this->semaphore_.~LSSemaphore();
            }
        }  
    }

    IPCSemaphoreProxy::~IPCSemaphoreProxy()
    {
        IO::UNIX::FDServeEnd(this->handle_);
    }

    bool IPCSemaphoreProxy::AddOne()
    {
        return this->semaphore_.AddOne();
    }

    bool IPCSemaphoreProxy::IsSignaled()
    {
        return this->semaphore_.IsSignaled();
    }

    bool IPCSemaphoreProxy::WaitOn(AuUInt32 timeout)
    {
        return this->semaphore_.WaitOn(timeout);
    }

    Loop::ELoopSource IPCSemaphoreProxy::GetType()
    {
        return this->semaphore_.GetType();
    }

    AUKN_SYM AuSPtr<IPCSemaphore> NewSemaphore(int startingValue)
    {
        auto object = AuMakeShared<IPCSemaphoreProxy>(startingValue);
        if (!object)
        {
            SysPushErrorMem();
            return {};
        }

        if (!object->HasValidHandle())
        {
            SysPushErrorIO();
            return {};
        }

        return object;
    }

    AUKN_SYM AuSPtr<IPCSemaphore> ImportSemaphore(const AuString &handle)
    {
        IPC::IPCHandle decodedHandle;

        if (!decodedHandle.FromString(handle))
        {
            SysPushErrorParseError("Invalid handle: {}", handle);
            return {};
        }

        int fd {-1};
        if (!IO::UNIX::FDAccept(decodedHandle, fd))
        {
            SysPushErrorNested();
            return {};
        }

        auto object = AuMakeShared<IPCSemaphoreProxy>(fd, 0xC001C0DE);
        if (!object)
        {
            SysPushErrorMem();
            ::close(fd);
            return {};
        }

        if (!object->HasValidHandle())
        {
            SysPushErrorIO();
            return {};
        }

        return object;
    }

    //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    // Mutexes
    //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

    struct IPCMutexProxy : IPCMutex, Loop::ILoopSourceEx
    {
        IPCMutexProxy();
        IPCMutexProxy(int handle);
        ~IPCMutexProxy();

        PROXY_INTERNAL_INTERFACE(mutex_)
        IMPLEMENT_HANDLE

        bool Unlock() override;

        bool IsSignaled() override;
        bool WaitOn(AuUInt32 timeout) override;
        Loop::ELoopSource GetType() override;

    private:
        Loop::LSMutex mutex_;
    };

    IPCMutexProxy::IPCMutexProxy() : mutex_()
    {
        if (this->mutex_.HasValidHandle())
        {
            if (!IO::UNIX::FDServe(false, false, true, true, this->GetHandle(), this->handle_))
            {
                this->mutex_.~LSMutex();
            }
        }
    }

    IPCMutexProxy::IPCMutexProxy(int handle) : mutex_(handle)
    {
        if (this->mutex_.HasValidHandle())
        {
            if (!IO::UNIX::FDServe(false, false, true, true, this->GetHandle(), this->handle_))
            {
                this->mutex_.~LSMutex();
            }
        }
    }

    IPCMutexProxy::~IPCMutexProxy()
    {
        IO::UNIX::FDServeEnd(this->handle_);
    }

    bool IPCMutexProxy::Unlock()
    {
        return this->mutex_.Unlock();
    }

    bool IPCMutexProxy::IsSignaled()
    {
        return this->mutex_.IsSignaled();
    }

    bool IPCMutexProxy::WaitOn(AuUInt32 timeout)
    {
        return this->mutex_.WaitOn(timeout);
    }

    Loop::ELoopSource IPCMutexProxy::GetType()
    {
        return this->mutex_.GetType();
    }

    AUKN_SYM AuSPtr<IPCMutex>     NewMutex()
    {
        auto object = AuMakeShared<IPCMutexProxy>();
        if (!object)
        {
            SysPushErrorMem();
            return {};
        }

        if (!object->HasValidHandle())
        {
            SysPushErrorIO();
            return {};
        }

        return object;
    }

    AUKN_SYM AuSPtr<IPCMutex>     ImportMutex(const AuString &handle)
    {
        IPC::IPCHandle decodedHandle;

        if (!decodedHandle.FromString(handle))
        {
            SysPushErrorParseError("Invalid handle: {}", handle);
            return {};
        }

        int fd {-1};
        if (!IO::UNIX::FDAccept(decodedHandle, fd))
        {
            SysPushErrorNested();
            return {};
        }

        auto object = AuMakeShared<IPCMutexProxy>(fd);
        if (!object)
        {
            SysPushErrorMem();
            ::close(fd);
            return {};
        }

        if (!object->HasValidHandle())
        {
            SysPushErrorIO();
            return {};
        }

        return object;
    }
}