/* 

flext - C++ layer for Max/MSP and pd (pure data) externals

Copyright (c) 2001-2005 Thomas Grill (gr@grrrr.org)
For information on usage and redistribution, and for a DISCLAIMER OF ALL
WARRANTIES, see the file, "license.txt," in this distribution.  

*/

/*! \file flqueue.cpp
    \brief Implementation of the flext message queuing functionality.

    \todo Let's see if queuing can be implemented for Max/MSP with defer_low

    if FLEXT_PDLOCK is defined, the new PD thread lock functions are used
*/

#include "flext.h"
#include "flinternal.h"
#include "flcontainers.h"
#include <string.h> // for memcpy

#ifdef FLEXT_THREADS
//! Thread id of message queue thread
flext::thrid_t flext::thrmsgid;
#endif

static bool qustarted = false;

#ifdef FLEXT_SHARED
/*
    For the shared version it _should_ be possible to have only one queue for all externals.
    Yet I don't know how to do this cross-platform
*/
#define PERMANENTIDLE
#endif

static void Trigger();


class flext::MsgBundle;

typedef PooledFifo<flext::MsgBundle> QueueFifo;

class Queue:
    public flext,
    public QueueFifo
{
public:
    inline bool Empty() const { return Size() == 0; }
    
    inline void Push(MsgBundle *m); // defined after MsgBundle (gcc 3.3. won't take it otherwise...)
};

static Queue queue;


#define STATSIZE 8

class flext::MsgBundle:
    public flext,
    public Fifo::Cell
{
public:
    static MsgBundle *New()
    {
        MsgBundle *m = queue.New();
        m->msg.Init();
        return m;
    }

    static void Free(MsgBundle *m)
    {       
        for(Msg *mi = m->msg.nxt; mi; ) {
            Msg *mn = mi->nxt;
            mi->Free();
            delete mi;
            mi = mn;
        }
        m->msg.Free();
        queue.Free(m);
    }

    inline MsgBundle &Add(flext_base *t,int o,const t_symbol *s,int ac,const t_atom *av)
    {
        Get()->Set(t,o,s,ac,av);
        return *this;
    }

    inline MsgBundle &Add(const t_symbol *r,const t_symbol *s,int ac,const t_atom *av)
    {
        Get()->Set(r,s,ac,av);
        return *this;
    }

    inline MsgBundle &Add(flext_base *th,int o) // bang
    { 
        return Add(th,o,sym_bang,0,NULL);
    }

    inline MsgBundle &Add(flext_base *th,int o,float dt) 
    { 
        t_atom at; 
        SetFloat(at,dt);
        return Add(th,o,sym_float,1,&at);
    }

    inline MsgBundle &Add(flext_base *th,int o,int dt) 
    { 
        t_atom at; 
        SetInt(at,dt);
        const t_symbol *sym;
#if FLEXT_SYS == FLEXT_SYS_PD
        sym = sym_float;
#elif FLEXT_SYS == FLEXT_SYS_MAX
        sym = sym_int;
#else
#error Not implemented!
#endif
        return Add(th,o,sym,1,&at);
    }

    inline MsgBundle &Add(flext_base *th,int o,const t_symbol *dt) 
    { 
        t_atom at; 
        SetSymbol(at,dt);
        return Add(th,o,sym_symbol,1,&at);
    }

    inline MsgBundle &Add(flext_base *th,int o,const t_atom &a) 
    { 
        const t_symbol *sym;
        if(IsSymbol(a))
            sym = sym_symbol;
        else if(IsFloat(a))
            sym = sym_float;
#if FLEXT_SYS == FLEXT_SYS_MAX
        else if(IsInt(a))
            sym = sym_int;
#endif
#if FLEXT_SYS == FLEXT_SYS_PD
        else if(IsPointer(a))
            sym = sym_pointer;
#endif
        else {
            error("atom type not supported");
            return *this;
        }
        return Add(th,o,sym,1,&a);
    }

    inline MsgBundle &Add(flext_base *th,int o,int argc,const t_atom *argv) 
    {
        return Add(th,o,sym_list,argc,argv);
    }

    // \note PD sys lock must already be held by caller
    inline void Send() const
    {
        if(!msg.Ok()) return; // Empty!

        const Msg *m = &msg;
        do {
            m->Send();
            m = m->nxt;
        } while(m);
    }

private:

    class Msg {
    public:
        inline bool Ok() const { return th || recv; }

        void Init()
        {
            th = NULL;
            recv = NULL;
            nxt = NULL;
            argc = 0;
        }

        void Free()
        {
            if(argc > STATSIZE) {
                FLEXT_ASSERT(argv);
                delete[] argv;
            }
        }

        void Set(flext_base *t,int o,const t_symbol *s,int ac,const t_atom *av)
        {
            FLEXT_ASSERT(t);
            th = t;
            out = o;
            SetMsg(s,ac,av);
}

        void Set(const t_symbol *r,const t_symbol *s,int ac,const t_atom *av)
        {
            FLEXT_ASSERT(r);
            th = NULL;
            recv = r;
            SetMsg(s,ac,av);
        }

        void Send() const
        {
            if(th) {
                if(out < 0)
                    // message to self
                    th->CbMethodHandler(-1-out,sym,argc,argc > STATSIZE?argv:argl); 
                else
                    // message to outlet
                    th->ToSysAnything(out,sym,argc,argc > STATSIZE?argv:argl);
            }
            else
                flext::SysForward(recv,sym,argc,argc > STATSIZE?argv:argl);
        }

        Msg *nxt;

    protected:
        flext_base *th;
        union {
            int out;
            const t_symbol *recv;
        };
        const t_symbol *sym;
        int argc;
        union {
            t_atom *argv;
            t_atom argl[STATSIZE];
        };

        void SetMsg(const t_symbol *s,int cnt,const t_atom *lst)
        {
            sym = s;
            argc = cnt;
            if(cnt > STATSIZE) {
                argv = new t_atom[cnt];
                flext::CopyAtoms(cnt,argv,lst);
            }
            else
                flext::CopyAtoms(cnt,argl,lst);
        }

    } msg;

    Msg *Get()
    {
        Msg *m = &msg;
        if(m->Ok()) {
            for(; m->nxt; m = m->nxt) {}
            m = m->nxt = new Msg;
            m->Init();
        }
        return m;
    }
};

inline void Queue::Push(MsgBundle *m)
{
    if(m) {
        Put(m);
        Trigger();
    }
}

#if FLEXT_QMODE == 2
static flext::ThrCond qthrcond;
#elif FLEXT_QMODE == 0
//static t_qelem *qclk = NULL;
static t_clock *qclk = NULL;
#endif


#define CHUNK 10

static void QWork(bool syslock)
{
    for(;;) {
        // Since qcnt can only be increased from any other function than QWork
        // qc will be a minimum guaranteed number of present queue elements.
        // On the other hand, if new queue elements are added by the methods called
        // in the loop, these will be sent in the next tick to avoid recursion overflow.
        size_t qc = queue.Size();
        if(!qc) break;

    #if FLEXT_QMODE == 2
        if(syslock) flext::Lock();
    #endif

        flext::MsgBundle *q;
        while((q = queue.Get()) != NULL) {
            q->Send();
            flext::MsgBundle::Free(q);
        }

    #if FLEXT_QMODE == 2
        if(syslock) flext::Unlock();
    #endif

    }
}

#if FLEXT_QMODE == 0
#if FLEXT_SYS == FLEXT_SYS_JMAX
static void QTick(fts_object_t *c,int winlet, fts_symbol_t s, int ac, const fts_atom_t *at)
{
#else
static void QTick(flext_base *c)
{
#endif
#ifdef FLEXT_THREADS
    FLEXT_ASSERT(flext::IsSystemThread());
#endif
    QWork(false);
}

#elif FLEXT_QMODE == 1
#ifndef PERMANENTIDLE
static bool qtickactive = false;
#endif
static t_int QTick(t_int *)
{
#ifndef PERMANENTIDLE
    qtickactive = false;
#endif

    QWork(false);

#ifdef PERMANENTIDLE
    // will be run in the next idle cycle
    return 2;
#else
    // won't be run again
    // for non-shared externals assume that there's rarely a message waiting
    // so it's better to delete the callback meanwhile
    return 0; 
#endif
}
#endif

/*
It would be sufficient to only flush messages belonging to object th
But then the order of sent messages is not as intended
*/
void flext_base::QFlush(flext_base *th)
{
#ifdef FLEXT_THREADS
    if(!IsSystemThread()) {
        error("flext - Queue flush called by wrong thread!");
        return;
    }
#endif

    while(!queue.Empty()) QWork(false);
}

static void Trigger()
{
#if FLEXT_SYS == FLEXT_SYS_PD
    #if FLEXT_QMODE == 2
        // wake up worker thread
        qthrcond.Signal();
    #elif FLEXT_QMODE == 1 && !defined(PERMANENTIDLE)
        if(!qtickactive) {
            sys_callback(QTick,NULL,0);
            qtickactive = true;
        }
    #elif FLEXT_QMODE == 0
        clock_delay(qclk,0);
    #endif
#elif FLEXT_SYS == FLEXT_SYS_MAX
    #if FLEXT_QMODE == 0
//        qelem_front(qclk);
        clock_delay(qclk,0);
    #endif
#else
#error Not implemented
#endif
}

#if FLEXT_QMODE == 2
void flext_base::QWorker(thr_params *)
{
    thrmsgid = GetThreadId();
    qustarted = true;
    for(;;) {
        qthrcond.Wait();
        QWork(true);
    }
}
#endif

void flext_base::StartQueue()
{
    if(qustarted) return;
#if FLEXT_QMODE == 1
#ifdef PERMANENTIDLE
    sys_callback(QTick,NULL,0);
    qustarted = true;
#endif
#elif FLEXT_QMODE == 2
    LaunchThread(QWorker,NULL);
    // very unelegant... but waiting should be ok, since happens only on loading
    while(!qustarted) Sleep(0.001);
#elif FLEXT_QMODE == 0 && (FLEXT_SYS == FLEXT_SYS_PD || FLEXT_SYS == FLEXT_SYS_MAX)
//    qclk = (t_qelem *)(qelem_new(NULL,(t_method)QTick));
    qclk = (t_clock *)(clock_new(NULL,(t_method)QTick));
    qustarted = true;
#else
#error Not implemented!
#endif
}


flext::MsgBundle *flext::MsgNew() 
{ 
    return MsgBundle::New(); 
}

void flext::MsgFree(MsgBundle *m) 
{ 
    MsgBundle::Free(m); 
}

void flext::ToSysMsg(MsgBundle *m)
{
    m->Send();
    queue.Free(m);
}

void flext::ToQueueMsg(MsgBundle *m)
{
    queue.Push(m);
}



void flext_base::ToQueueBang(int o) const 
{
    MsgBundle *m = MsgBundle::New();
    m->Add(const_cast<flext_base *>(this),o);
    queue.Push(m);
}

void flext_base::ToQueueFloat(int o,float f) const
{
    MsgBundle *m = MsgBundle::New();
    m->Add(const_cast<flext_base *>(this),o,f);
    queue.Push(m);
}

void flext_base::ToQueueInt(int o,int f) const
{
    MsgBundle *m = MsgBundle::New();
    m->Add(const_cast<flext_base *>(this),o,f);
    queue.Push(m);
}

void flext_base::ToQueueSymbol(int o,const t_symbol *s) const
{
    MsgBundle *m = MsgBundle::New();
    m->Add(const_cast<flext_base *>(this),o,s);
    queue.Push(m);
}

void flext_base::ToQueueAtom(int o,const t_atom &at) const
{
    MsgBundle *m = MsgBundle::New();
    m->Add(const_cast<flext_base *>(this),o,at);
    queue.Push(m);
}

void flext_base::ToQueueList(int o,int argc,const t_atom *argv) const
{
    MsgBundle *m = MsgBundle::New();
    m->Add(const_cast<flext_base *>(this),o,argc,argv);
    queue.Push(m);
}

void flext_base::ToQueueAnything(int o,const t_symbol *s,int argc,const t_atom *argv) const
{
    MsgBundle *m = MsgBundle::New();
    m->Add(const_cast<flext_base *>(this),o,s,argc,argv);
    queue.Push(m);
}


void flext_base::MsgAddBang(MsgBundle *m,int n) const 
{ 
    m->Add(const_cast<flext_base *>(this),n);
}

void flext_base::MsgAddFloat(MsgBundle *m,int n,float f) const
{
    m->Add(const_cast<flext_base *>(this),n,f);
}

void flext_base::MsgAddInt(MsgBundle *m,int n,int f) const
{
    m->Add(const_cast<flext_base *>(this),n,f);
}

void flext_base::MsgAddSymbol(MsgBundle *m,int n,const t_symbol *s) const
{
    m->Add(const_cast<flext_base *>(this),n,s);
}

void flext_base::MsgAddAtom(MsgBundle *m,int n,const t_atom &at) const
{
    m->Add(const_cast<flext_base *>(this),n,at);
}

void flext_base::MsgAddList(MsgBundle *m,int n,int argc,const t_atom *argv) const
{
    m->Add(const_cast<flext_base *>(this),n,argc,argv);
}

void flext_base::MsgAddAnything(MsgBundle *m,int n,const t_symbol *s,int argc,const t_atom *argv) const
{
    m->Add(const_cast<flext_base *>(this),n,s,argc,argv);
}




bool flext::SysForward(const t_symbol *recv,const t_symbol *s,int argc,const t_atom *argv)
{
    void *cl = recv->s_thing;
    if(!cl) return false;
    
#if FLEXT_SYS == FLEXT_SYS_PD
    pd_typedmess((t_class **)cl,(t_symbol *)s,argc,(t_atom *)argv);
#elif FLEXT_SYS == FLEXT_SYS_MAX
    typedmess(recv->s_thing,(t_symbol *)s,argc,(t_atom *)argv);
#else
#error Not implemented
#endif
    return true;
}

bool flext::QueueForward(const t_symbol *recv,const t_symbol *s,int argc,const t_atom *argv)
{
    MsgBundle *m = MsgBundle::New();
    m->Add(recv,s,argc,argv);
    // send over queue
    queue.Push(m);
    return true;
}

bool flext::MsgForward(MsgBundle *m,const t_symbol *recv,const t_symbol *s,int argc,const t_atom *argv)
{
    m->Add(recv,s,argc,argv);
    return true;
}