/*  PCSX2 - PS2 Emulator for PCs
 *  Copyright (C) 2002-2010  PCSX2 Dev Team
 *
 *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU Lesser General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with PCSX2.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include "PrecompiledHeader.h"
#include "wxAppWithHelpers.h"

#include "ThreadingInternal.h"
#include "PersistentThread.h"

wxDEFINE_EVENT(pxEvt_StartIdleEventTimer, wxCommandEvent);
wxDEFINE_EVENT(pxEvt_DeleteObject, wxCommandEvent);
wxDEFINE_EVENT(pxEvt_DeleteThread, wxCommandEvent);
wxDEFINE_EVENT(pxEvt_InvokeAction, pxActionEvent);
wxDEFINE_EVENT(pxEvt_SynchronousCommand, pxSynchronousCommandEvent);

wxIMPLEMENT_DYNAMIC_CLASS(pxSimpleEvent, wxEvent);

ConsoleLogSource_App::ConsoleLogSource_App()
{
    static const TraceLogDescriptor myDesc =
        {
            L"AppEvents", L"App Events",
            pxLt("Includes idle event processing and some other uncommon event usages.")};

    m_Descriptor = &myDesc;
}

ConsoleLogSource_App pxConLog_App;

void BaseDeletableObject::DoDeletion()
{
    wxAppWithHelpers *app = wxDynamicCast(wxApp::GetInstance(), wxAppWithHelpers);
    pxAssert(app != NULL);
    app->DeleteObject(*this);
}


// --------------------------------------------------------------------------------------
//  SynchronousActionState Implementations
// --------------------------------------------------------------------------------------

void SynchronousActionState::SetException(const BaseException &ex)
{
    m_exception = ScopedExcept(ex.Clone());
}

void SynchronousActionState::SetException(BaseException *ex)
{
    if (!m_posted) {
        m_exception = ScopedExcept(ex);
    } else if (wxTheApp) {
        // transport the exception to the main thread, since the message is fully
        // asynchronous, or has already entered an asynchronous state.  Message is sent
        // as a non-blocking action since proper handling of user errors on async messages
        // is *usually* to log/ignore it (hah), or to suspend emulation and issue a dialog
        // box to the user.

        pxExceptionEvent ev(ex);
        wxTheApp->AddPendingEvent(ev);
    }
}

void SynchronousActionState::RethrowException() const
{
    if (m_exception)
        m_exception->Rethrow();
}

int SynchronousActionState::WaitForResult()
{
    m_sema.WaitNoCancel();
    RethrowException();
    return return_value;
}

int SynchronousActionState::WaitForResult_NoExceptions()
{
    m_sema.WaitNoCancel();
    return return_value;
}

void SynchronousActionState::PostResult(int res)
{
    return_value = res;
    PostResult();
}

void SynchronousActionState::ClearResult()
{
    m_posted = false;
    m_exception = NULL;
}

void SynchronousActionState::PostResult()
{
    if (m_posted)
        return;
    m_posted = true;
    m_sema.Post();
}

// --------------------------------------------------------------------------------------
//  pxActionEvent Implementations
// --------------------------------------------------------------------------------------

wxIMPLEMENT_DYNAMIC_CLASS(pxActionEvent, wxEvent);

pxActionEvent::pxActionEvent(SynchronousActionState *sema, int msgtype)
    : wxEvent(0, msgtype)
{
    m_state = sema;
}

pxActionEvent::pxActionEvent(SynchronousActionState &sema, int msgtype)
    : wxEvent(0, msgtype)
{
    m_state = &sema;
}

pxActionEvent::pxActionEvent(const pxActionEvent &src)
    : wxEvent(src)
{
    m_state = src.m_state;
}

void pxActionEvent::SetException(const BaseException &ex)
{
    SetException(ex.Clone());
}

void pxActionEvent::SetException(BaseException *ex)
{
    const wxString &prefix(pxsFmt(L"(%s) ", GetClassInfo()->GetClassName()));
    ex->DiagMsg() = prefix + ex->DiagMsg();

    if (!m_state) {
        ScopedExcept exptr(ex); // auto-delete it after handling.
        ex->Rethrow();
    }

    m_state->SetException(ex);
}

// --------------------------------------------------------------------------------------
//  pxSynchronousCommandEvent
// --------------------------------------------------------------------------------------
wxIMPLEMENT_DYNAMIC_CLASS(pxSynchronousCommandEvent, wxCommandEvent);

pxSynchronousCommandEvent::pxSynchronousCommandEvent(SynchronousActionState *sema, wxEventType commandType, int winid)
    : wxCommandEvent(pxEvt_SynchronousCommand, winid)
{
    m_sync = sema;
    m_realEvent = commandType;
}

pxSynchronousCommandEvent::pxSynchronousCommandEvent(SynchronousActionState &sema, wxEventType commandType, int winid)
    : wxCommandEvent(pxEvt_SynchronousCommand)
{
    m_sync = &sema;
    m_realEvent = commandType;
}

pxSynchronousCommandEvent::pxSynchronousCommandEvent(SynchronousActionState *sema, const wxCommandEvent &evt)
    : wxCommandEvent(evt)
{
    m_sync = sema;
    m_realEvent = evt.GetEventType();
    SetEventType(pxEvt_SynchronousCommand);
}

pxSynchronousCommandEvent::pxSynchronousCommandEvent(SynchronousActionState &sema, const wxCommandEvent &evt)
    : wxCommandEvent(evt)
{
    m_sync = &sema;
    m_realEvent = evt.GetEventType();
    SetEventType(pxEvt_SynchronousCommand);
}

pxSynchronousCommandEvent::pxSynchronousCommandEvent(const pxSynchronousCommandEvent &src)
    : wxCommandEvent(src)
{
    m_sync = src.m_sync;
    m_realEvent = src.m_realEvent;
}

void pxSynchronousCommandEvent::SetException(const BaseException &ex)
{
    if (!m_sync)
        ex.Rethrow();
    m_sync->SetException(ex);
}

void pxSynchronousCommandEvent::SetException(BaseException *ex)
{
    if (!m_sync) {
        ScopedExcept exptr(ex); // auto-delete it after handling.
        ex->Rethrow();
    }

    m_sync->SetException(ex);
}

// --------------------------------------------------------------------------------------
//  pxRpcEvent
// --------------------------------------------------------------------------------------
// Unlike pxPingEvent, the Semaphore belonging to this event is typically posted when the
// invoked method is completed.  If the method can be executed in non-blocking fashion then
// it should leave the semaphore postback NULL.
//
class pxRpcEvent : public pxActionEvent
{
    wxDECLARE_DYNAMIC_CLASS_NO_ASSIGN(pxRpcEvent);

    typedef pxActionEvent _parent;

protected:
    void (*m_Method)();

public:
    virtual ~pxRpcEvent() = default;
    virtual pxRpcEvent *Clone() const { return new pxRpcEvent(*this); }

    explicit pxRpcEvent(void (*method)() = NULL, SynchronousActionState *sema = NULL)
        : pxActionEvent(sema)
    {
        m_Method = method;
    }

    explicit pxRpcEvent(void (*method)(), SynchronousActionState &sema)
        : pxActionEvent(sema)
    {
        m_Method = method;
    }

    pxRpcEvent(const pxRpcEvent &src)
        : pxActionEvent(src)
    {
        m_Method = src.m_Method;
    }

    void SetMethod(void (*method)())
    {
        m_Method = method;
    }

protected:
    void InvokeEvent()
    {
        if (m_Method)
            m_Method();
    }
};

wxIMPLEMENT_DYNAMIC_CLASS(pxRpcEvent, pxActionEvent);

// --------------------------------------------------------------------------------------
//  pxExceptionEvent implementations
// --------------------------------------------------------------------------------------
pxExceptionEvent::pxExceptionEvent(const BaseException &ex)
{
    m_except = ex.Clone();
}

void pxExceptionEvent::InvokeEvent()
{
    ScopedExcept deleteMe(m_except);
    if (deleteMe)
        deleteMe->Rethrow();
}

// --------------------------------------------------------------------------------------
//  wxAppWithHelpers Implementation
// --------------------------------------------------------------------------------------
//
// TODO : Ping dispatch and IdleEvent dispatch can be unified into a single dispatch, which
// would mean checking only one list of events per idle event, instead of two.  (ie, ping
// events can be appended to the idle event list, instead of into their own custom list).
//
wxIMPLEMENT_DYNAMIC_CLASS(wxAppWithHelpers, wxApp);


// Posts a method to the main thread; non-blocking.  Post occurs even when called from the
// main thread.
void wxAppWithHelpers::PostMethod(FnType_Void *method)
{
    PostEvent(pxRpcEvent(method));
}

// Posts a method to the main thread; non-blocking.  Post occurs even when called from the
// main thread.
void wxAppWithHelpers::PostIdleMethod(FnType_Void *method)
{
    pxRpcEvent evt(method);
    AddIdleEvent(evt);
}

// Invokes the specified void method, or posts the method to the main thread if the calling
// thread is not Main.  Action is blocking.  For non-blocking method execution, use
// AppRpc_TryInvokeAsync.
//
// This function works something like setjmp/longjmp, in that the return value indicates if the
// function actually executed the specified method or not.
//
// Returns:
//   FALSE if the method was not invoked (meaning this IS the main thread!)
//   TRUE if the method was invoked.
//

bool wxAppWithHelpers::Rpc_TryInvoke(FnType_Void *method)
{
    if (wxThread::IsMain())
        return false;

    SynchronousActionState sync;
    PostEvent(pxRpcEvent(method, sync));
    sync.WaitForResult();

    return true;
}

// Invokes the specified void method, or posts the method to the main thread if the calling
// thread is not Main.  Action is non-blocking (asynchronous).  For blocking method execution,
// use AppRpc_TryInvoke.
//
// This function works something like setjmp/longjmp, in that the return value indicates if the
// function actually executed the specified method or not.
//
// Returns:
//   FALSE if the method was not posted to the main thread (meaning this IS the main thread!)
//   TRUE if the method was posted.
//
bool wxAppWithHelpers::Rpc_TryInvokeAsync(FnType_Void *method)
{
    if (wxThread::IsMain())
        return false;
    PostEvent(pxRpcEvent(method));
    return true;
}

void wxAppWithHelpers::ProcessMethod(FnType_Void *method)
{
    if (wxThread::IsMain()) {
        method();
        return;
    }

    SynchronousActionState sync;
    PostEvent(pxRpcEvent(method, sync));
    sync.WaitForResult();
}

void wxAppWithHelpers::PostEvent(const wxEvent &evt)
{
    // Const Cast is OK!
    // Truth is, AddPendingEvent should be a const-qualified parameter, as
    // it makes an immediate clone copy of the event -- but wxWidgets
    // fails again in structured C/C++ design design.  So I'm forcing it as such
    // here. -- air

    _parent::AddPendingEvent(const_cast<wxEvent &>(evt));
}

bool wxAppWithHelpers::ProcessEvent(wxEvent &evt)
{
    // Note: We can't do an automatic blocking post of the message here, because wxWidgets
    // isn't really designed for it (some events return data to the caller via the event
    // struct, and posting the event would require a temporary clone, where changes would
    // be lost).

    AffinityAssert_AllowFrom_MainUI();
    return _parent::ProcessEvent(evt);
}

bool wxAppWithHelpers::ProcessEvent(wxEvent *evt)
{
    AffinityAssert_AllowFrom_MainUI();
    std::unique_ptr<wxEvent> deleteMe(evt);
    return _parent::ProcessEvent(*deleteMe);
}

bool wxAppWithHelpers::ProcessEvent(pxActionEvent &evt)
{
    if (wxThread::IsMain())
        return _parent::ProcessEvent(evt);
    else {
        SynchronousActionState sync;
        evt.SetSyncState(sync);
        AddPendingEvent(evt);
        sync.WaitForResult();
        return true;
    }
}

bool wxAppWithHelpers::ProcessEvent(pxActionEvent *evt)
{
    if (wxThread::IsMain()) {
        std::unique_ptr<wxEvent> deleteMe(evt);
        return _parent::ProcessEvent(*deleteMe);
    } else {
        SynchronousActionState sync;
        evt->SetSyncState(sync);
        AddPendingEvent(*evt);
        sync.WaitForResult();
        return true;
    }
}


void wxAppWithHelpers::CleanUp()
{
    // I'm pretty sure the message pump is dead by now, which means we need to run through
    // idle event list by hand and process the pending Deletion messages (all others can be
    // ignored -- it's only deletions we want handled, and really we *could* ignore those too
    // but I like to be tidy. -- air

    //IdleEventDispatcher( "CleanUp" );
    //DeletionDispatcher();
    _parent::CleanUp();
}

// Executes the event with exception handling.  If the event throws an exception, the exception
// will be neatly packaged and transported back to the thread that posted the event.
// This function is virtual, however overloading it is not recommended.  Derrived classes
// should overload InvokeEvent() instead.
void pxActionEvent::_DoInvokeEvent()
{
    AffinityAssert_AllowFrom_MainUI();

    try {
        InvokeEvent();
    } catch (BaseException &ex) {
        SetException(ex);
    } catch (std::runtime_error &ex) {
        SetException(new Exception::RuntimeError(ex));
    }

    if (m_state)
        m_state->PostResult();
}

void wxAppWithHelpers::OnSynchronousCommand(pxSynchronousCommandEvent &evt)
{
    AffinityAssert_AllowFrom_MainUI();

    pxAppLog.Write(L"(App) Executing command event synchronously...");
    evt.SetEventType(evt.GetRealEventType());

    try {
        ProcessEvent(evt);
    } catch (BaseException &ex) {
        evt.SetException(ex);
    } catch (std::runtime_error &ex) {
        evt.SetException(new Exception::RuntimeError(ex, evt.GetClassInfo()->GetClassName()));
    }

    if (Semaphore *sema = evt.GetSemaphore())
        sema->Post();
}

void wxAppWithHelpers::AddIdleEvent(const wxEvent &evt)
{
    ScopedLock lock(m_IdleEventMutex);
    if (m_IdleEventQueue.empty())
        PostEvent(wxCommandEvent(pxEvt_StartIdleEventTimer));

    m_IdleEventQueue.push_back(evt.Clone());
}

void wxAppWithHelpers::OnStartIdleEventTimer(wxCommandEvent &evt)
{
    ScopedLock lock(m_IdleEventMutex);
    if (!m_IdleEventQueue.empty())
        m_IdleEventTimer.Start(100, true);
}

void wxAppWithHelpers::IdleEventDispatcher(const wxChar *action)
{
    // Recursion is possible thanks to modal dialogs being issued from the idle event handler.
    // (recursion shouldn't hurt anything anyway, since the node system re-creates the iterator
    // on each pass)

    //static int __guard=0;
    //RecursionGuard guard(__guard);
    //if( !pxAssertDev(!guard.IsReentrant(), "Re-entrant call to IdleEventdispatcher caught on camera!") ) return;

    wxEventList postponed;
    wxEventList::iterator node;

    ScopedLock lock(m_IdleEventMutex);

    while (node = m_IdleEventQueue.begin(), node != m_IdleEventQueue.end()) {
        std::unique_ptr<wxEvent> deleteMe(*node);
        m_IdleEventQueue.erase(node);

        lock.Release();
        if (!Threading::AllowDeletions() && (deleteMe->GetEventType() == pxEvt_DeleteThread)) {
            // Threads that have active semaphores or mutexes (other threads are waiting on them) cannot
            // be deleted because those mutex/sema objects will become invalid and cause the pending
            // thread to crash.  So we disallow deletions when those waits are in action, and continue
            // to postpone the deletion of the thread until such time that it is safe.

            pxThreadLog.Write(((pxThread *)((wxCommandEvent *)deleteMe.get())->GetClientData())->GetName(), L"Deletion postponed due to mutex or semaphore dependency.");
            postponed.push_back(deleteMe.release());
        } else {
            pxAppLog.Write(L"(AppIdleQueue%s) Dispatching event '%s'", action, deleteMe->GetClassInfo()->GetClassName());
            ProcessEvent(*deleteMe); // dereference to prevent auto-deletion by ProcessEvent
        }
        lock.Acquire();
    }

    m_IdleEventQueue = postponed;
    if (!m_IdleEventQueue.empty())
        pxAppLog.Write(L"(AppIdleQueue%s) %d events postponed due to dependencies.", action, m_IdleEventQueue.size());
}

void wxAppWithHelpers::OnIdleEvent(wxIdleEvent &evt)
{
    m_IdleEventTimer.Stop();
    IdleEventDispatcher();
}

void wxAppWithHelpers::OnIdleEventTimeout(wxTimerEvent &evt)
{
    IdleEventDispatcher(L"[Timeout]");
}

void wxAppWithHelpers::Ping()
{
    pxThreadLog.Write(pxGetCurrentThreadName().c_str(), L"App Event Ping Requested.");

    SynchronousActionState sync;
    pxActionEvent evt(sync);
    AddIdleEvent(evt);
    sync.WaitForResult();
}

void wxAppWithHelpers::PostCommand(void *clientData, int evtType, int intParam, long longParam, const wxString &stringParam)
{
    wxCommandEvent evt(evtType);
    evt.SetClientData(clientData);
    evt.SetInt(intParam);
    evt.SetExtraLong(longParam);
    evt.SetString(stringParam);
    AddPendingEvent(evt);
}

void wxAppWithHelpers::PostCommand(int evtType, int intParam, long longParam, const wxString &stringParam)
{
    PostCommand(NULL, evtType, intParam, longParam, stringParam);
}

sptr wxAppWithHelpers::ProcessCommand(void *clientData, int evtType, int intParam, long longParam, const wxString &stringParam)
{
    SynchronousActionState sync;
    pxSynchronousCommandEvent evt(sync, evtType);

    evt.SetClientData(clientData);
    evt.SetInt(intParam);
    evt.SetExtraLong(longParam);
    evt.SetString(stringParam);
    AddPendingEvent(evt);
    sync.WaitForResult();

    return sync.return_value;
}

sptr wxAppWithHelpers::ProcessCommand(int evtType, int intParam, long longParam, const wxString &stringParam)
{
    return ProcessCommand(NULL, evtType, intParam, longParam, stringParam);
}

void wxAppWithHelpers::PostAction(const pxActionEvent &evt)
{
    PostEvent(evt);
}

void wxAppWithHelpers::ProcessAction(pxActionEvent &evt)
{
    if (!wxThread::IsMain()) {
        SynchronousActionState sync;
        evt.SetSyncState(sync);
        AddPendingEvent(evt);
        sync.WaitForResult();
    } else
        evt._DoInvokeEvent();
}


void wxAppWithHelpers::DeleteObject(BaseDeletableObject &obj)
{
    pxAssert(!obj.IsBeingDeleted());
    wxCommandEvent evt(pxEvt_DeleteObject);
    evt.SetClientData((void *)&obj);
    AddIdleEvent(evt);
}

void wxAppWithHelpers::DeleteThread(pxThread &obj)
{
    pxThreadLog.Write(obj.GetName(), L"Scheduling for deletion...");
    wxCommandEvent evt(pxEvt_DeleteThread);
    evt.SetClientData((void *)&obj);
    AddIdleEvent(evt);
}

bool wxAppWithHelpers::OnInit()
{
    Bind(pxEvt_SynchronousCommand, &wxAppWithHelpers::OnSynchronousCommand, this);
    Bind(pxEvt_InvokeAction, &wxAppWithHelpers::OnInvokeAction, this);

    Bind(pxEvt_StartIdleEventTimer, &wxAppWithHelpers::OnStartIdleEventTimer, this);

    Bind(pxEvt_DeleteObject, &wxAppWithHelpers::OnDeleteObject, this);
    Bind(pxEvt_DeleteThread, &wxAppWithHelpers::OnDeleteThread, this);

    Bind(wxEVT_IDLE, &wxAppWithHelpers::OnIdleEvent, this);

    Bind(wxEVT_TIMER, &wxAppWithHelpers::OnIdleEventTimeout, this, m_IdleEventTimer.GetId());

    return _parent::OnInit();
}

void wxAppWithHelpers::OnInvokeAction(pxActionEvent &evt)
{
    evt._DoInvokeEvent(); // wow this is easy!
}

void wxAppWithHelpers::OnDeleteObject(wxCommandEvent &evt)
{
    if (evt.GetClientData() == NULL)
        return;
    delete (BaseDeletableObject *)evt.GetClientData();
}

// In theory we create a Pcsx2App object which inherit from wxAppWithHelpers,
// so Pcsx2App::CreateTraits must be used instead.
//
// However it doesn't work this way because wxAppWithHelpers constructor will
// be called first. This constructor will build some wx objects (here wxTimer)
// that require a trait. In others word, wxAppWithHelpers::CreateTraits will be
// called instead
wxAppTraits *wxAppWithHelpers::CreateTraits()
{
    return new Pcsx2AppTraits;
}

// Threads have their own deletion handler that propagates exceptions thrown by the thread to the UI.
// (thus we have a fairly automatic threaded exception system!)
void wxAppWithHelpers::OnDeleteThread(wxCommandEvent &evt)
{
    std::unique_ptr<pxThread> thr((pxThread *)evt.GetClientData());
    if (!thr) {
        pxThreadLog.Write(L"null", L"OnDeleteThread: NULL thread object received (and ignored).");
        return;
    }

    pxThreadLog.Write(thr->GetName(), wxString(wxString(L"Thread object deleted successfully") + (thr->HasPendingException() ? L" [exception pending!]" : L"")).wc_str());
    thr->RethrowException();
}

wxAppWithHelpers::wxAppWithHelpers()
    : m_IdleEventTimer(this)
{
#ifdef __WXMSW__
    // This variable assignment ensures that MSVC links in the TLS setup stubs even in
    // full optimization builds.  Without it, DLLs that use TLS won't work because the
    // FS segment register won't have been initialized by the main exe, due to tls_insurance
    // being optimized away >_<  --air

    static thread_local int tls_insurance = 0;
    tls_insurance = 1;
#endif
}