/* Copyright (c) 1997-1999 Miller Puckette.
* For information on usage and redistribution, and for a DISCLAIMER OF ALL
* WARRANTIES, see the file, "LICENSE.txt," in this distribution.  */

#include "m_pd.h"
#include "s_stuff.h"
#include <stdio.h>
#include <windows.h>
#include <MMSYSTEM.H>

/* ------------- MIDI time stamping from audio clock ------------ */
#ifdef MIDI_TIMESTAMP

static double msw_hibuftime;
static double initsystime = -1;

/* call this whenever we reset audio */
static void msw_resetmidisync() {
    initsystime = clock_getsystime();
    msw_hibuftime = sys_getrealtime();
}

/* call this whenever we're idled waiting for audio to be ready. The routine maintains a high and low water point
   for the difference between real and DAC time. */
static void msw_midisync() {
    if (initsystime == -1) msw_resetmidisync();
    double jittersec = max(msw_dacjitterbufsallowed,msw_adcjitterbufsallowed) * REALDACBLKSIZE / sys_getsr();
    double diff = sys_getrealtime() - 0.001 * clock_gettimesince(initsystime);
    if (diff > msw_hibuftime) msw_hibuftime = diff;
    if (diff < msw_hibuftime - jittersec) {
        post("jitter excess %d %f", dac, diff);
        msw_resetmidisync();
    }
}

static double msw_midigettimefor(LARGE_INTEGER timestamp) {
    /* this is broken now... used to work when "timestamp" was derived from QueryPerformanceCounter() instead of
       the MS-approved timeGetSystemTime() call in the MIDI callback routine below. */
    return msw_tixtotime(timestamp) - msw_hibuftime;
}
#endif /* MIDI_TIMESTAMP */

/* ------------------------- MIDI output -------------------------- */
static void msw_midiouterror(char *s, int err) {
    char t[256];
    midiOutGetErrorText(err, t, 256);
    error(s,t);
}

static HMIDIOUT hMidiOut[MAXMIDIOUTDEV];    /* output device */
static int msw_nmidiout;                            /* number of devices */

static void msw_open_midiout(int nmidiout, int *midioutvec) {
    UINT result, wRtn;
    MIDIOUTCAPS midioutcaps;
    if (nmidiout > MAXMIDIOUTDEV) nmidiout = MAXMIDIOUTDEV;
    int dev = 0;
    for (int i=0; i<nmidiout; i++) {
        MIDIOUTCAPS mocap;
        int devno =  midioutvec[i];
        result = midiOutOpen(&hMidiOut[dev], devno, 0, 0, CALLBACK_NULL);
        wRtn = midiOutGetDevCaps(i, (LPMIDIOUTCAPS) &mocap, sizeof(mocap));
        if (result != MMSYSERR_NOERROR) {
            error("midiOutOpen: %s",midioutcaps.szPname);
            msw_midiouterror("midiOutOpen: %s", result);
        } else {
            if (sys_verbose) error("midiOutOpen: Open %s as Port %d", midioutcaps.szPname, dev);
            dev++;
        }
    }
    msw_nmidiout = dev;
}

static void msw_close_midiout() {
    for (int i=0; i<msw_nmidiout; i++) {
        midiOutReset(hMidiOut[i]);
        midiOutClose(hMidiOut[i]);
    }
    msw_nmidiout = 0;
}

/* -------------------------- MIDI input ---------------------------- */

#define INPUT_BUFFER_SIZE 1000     // size of input buffer in events

static void msw_midiinerror(char *s, int err) {
    char t[256];
    midiInGetErrorText(err, t, 256);
    error(s,t);
}

/* Structure to represent a single MIDI event. */
#define EVNT_F_ERROR    0x00000001L
typedef struct evemsw_tag {
    DWORD fdwEvent;
    DWORD dwDevice;
    LARGE_INTEGER timestamp;
    DWORD data;
} EVENT;
typedef EVENT FAR *LPEVENT;

/* Structure to manage the circular input buffer. */
typedef struct circularBuffer_tag {
    HANDLE  hSelf;          /* handle to this structure */
    HANDLE  hBuffer;        /* buffer handle */
    WORD    wError;         /* error flags */
    DWORD   dwSize;         /* buffer size (in EVENTS) */
    DWORD   dwCount;        /* byte count (in EVENTS) */
    LPEVENT lpStart;        /* ptr to start of buffer */
    LPEVENT lpEnd;          /* ptr to end of buffer (last byte + 1) */
    LPEVENT lpHead;         /* ptr to head (next location to fill) */
    LPEVENT lpTail;         /* ptr to tail (next location to empty) */
} CIRCULARBUFFER;
typedef CIRCULARBUFFER FAR *LPCIRCULARBUFFER;

/* Structure to pass instance data from the application to the low-level callback function. */
typedef struct callbackInstance_tag {
    HANDLE              hSelf;
    DWORD               dwDevice;
    LPCIRCULARBUFFER    lpBuf;
} CALLBACKINSTANCEDATA;
typedef CALLBACKINSTANCEDATA FAR *LPCALLBACKINSTANCEDATA;

/* Function prototypes */
LPCALLBACKINSTANCEDATA FAR PASCAL AllocCallbackInstanceData();
void FAR PASCAL FreeCallbackInstanceData(LPCALLBACKINSTANCEDATA lpBuf);
LPCIRCULARBUFFER AllocCircularBuffer(DWORD dwSize);
void FreeCircularBuffer(LPCIRCULARBUFFER lpBuf);
WORD FAR PASCAL GetEvent(LPCIRCULARBUFFER lpBuf, LPEVENT lpEvent);

// Callback instance data pointers
LPCALLBACKINSTANCEDATA lpCallbackInstanceData[MAXMIDIINDEV];

UINT wNumDevices = 0;                    // Number of MIDI input devices opened
BOOL bRecordingEnabled = 1;             // Enable/disable recording flag
int  nNumBufferLines = 0;                // Number of lines in display buffer
RECT rectScrollClip;                    // Clipping rectangle for scrolling
LPCIRCULARBUFFER lpInputBuffer;         // Input buffer structure
EVENT incomingEvent;                    // Incoming MIDI event structure
MIDIINCAPS midiInCaps[MAXMIDIINDEV]; // Device capabilities structures
HMIDIIN hMidiIn[MAXMIDIINDEV];       // MIDI input device handles

/* AllocCallbackInstanceData - Allocates a CALLBACKINSTANCEDATA structure.  This structure is used to pass information
   to the low-level callback function, each time it receives a message. Because this structure is accessed by the
   low-level callback function, it must be allocated using GlobalAlloc() with the GMEM_SHARE and GMEM_MOVEABLE flags
   and page-locked with GlobalPageLock().
   Return:  A pointer to the allocated CALLBACKINSTANCE data structure. */
LPCALLBACKINSTANCEDATA FAR PASCAL AllocCallbackInstanceData() {
    HANDLE hMem;
    LPCALLBACKINSTANCEDATA lpBuf;
    /* Allocate and lock global memory. */
    hMem = GlobalAlloc(GMEM_SHARE | GMEM_MOVEABLE, (DWORD)sizeof(CALLBACKINSTANCEDATA));
    if(!hMem) return 0;
    lpBuf = (LPCALLBACKINSTANCEDATA)GlobalLock(hMem);
    if(!lpBuf) {GlobalFree(hMem); return 0;}
    /* Page lock the memory. */
    //GlobalPageLock((HGLOBAL)HIWORD(lpBuf));
    /* Save the handle. */
    lpBuf->hSelf = hMem;
    return lpBuf;
}

/* FreeCallbackInstanceData - Frees the given CALLBACKINSTANCEDATA structure.
 * Params:  lpBuf - Points to the CALLBACKINSTANCEDATA structure to be freed. */
void FAR PASCAL FreeCallbackInstanceData(LPCALLBACKINSTANCEDATA lpBuf) {
    HANDLE hMem;
    /* Save the handle until we're through here. */
    hMem = lpBuf->hSelf;
    /* Free the structure. */
    //GlobalPageUnlock((HGLOBAL)HIWORD(lpBuf));
    GlobalUnlock(hMem);
    GlobalFree(hMem);
}

/* AllocCircularBuffer -    Allocates memory for a CIRCULARBUFFER structure
 * and a buffer of the specified size.  Each memory block is allocated 
 * with GlobalAlloc() using GMEM_SHARE and GMEM_MOVEABLE flags, locked 
 * with GlobalLock(), and page-locked with GlobalPageLock().
 * Params:  dwSize - The size of the buffer, in events.
 * Return:  A pointer to a CIRCULARBUFFER structure identifying the allocated display buffer.  NULL if the buffer could not be allocated. */
 
LPCIRCULARBUFFER AllocCircularBuffer(DWORD dwSize) {
    HANDLE hMem;
    LPCIRCULARBUFFER lpBuf;
    LPEVENT lpMem;
    /* Allocate and lock a CIRCULARBUFFER structure. */
    hMem = GlobalAlloc(GMEM_SHARE | GMEM_MOVEABLE, (DWORD)sizeof(CIRCULARBUFFER));
    if(!hMem) return 0;
    lpBuf = (LPCIRCULARBUFFER)GlobalLock(hMem);
    if(!lpBuf) {GlobalFree(hMem); return 0;}
    /* Page lock the memory.  Global memory blocks accessed by low-level callback functions must be page locked. */
#ifndef _WIN32
    GlobalSmartPageLock((HGLOBAL)HIWORD(lpBuf));
#endif
    /* Save the memory handle. */
    lpBuf->hSelf = hMem;
    /* Allocate and lock memory for the actual buffer. */
    hMem = GlobalAlloc(GMEM_SHARE | GMEM_MOVEABLE, dwSize * sizeof(EVENT));
    if(!hMem) {
#ifndef _WIN32
        GlobalSmartPageUnlock((HGLOBAL)HIWORD(lpBuf));
#endif
        GlobalUnlock(lpBuf->hSelf);
        GlobalFree(lpBuf->hSelf);
        return 0;
    }
    lpMem = (LPEVENT)GlobalLock(hMem);
    if(!lpMem) {
        GlobalFree(hMem);
#ifndef _WIN32
        GlobalSmartPageUnlock((HGLOBAL)HIWORD(lpBuf));
#endif
        GlobalUnlock(lpBuf->hSelf);
        GlobalFree(lpBuf->hSelf);
        return NULL;
    }
    /* Page lock the memory.  Global memory blocks accessed by low-level callback functions must be page locked. */
#ifndef _WIN32
    GlobalSmartPageLock((HGLOBAL)HIWORD(lpMem));
#endif
    /* Set up the CIRCULARBUFFER structure. */
    lpBuf->hBuffer = hMem;
    lpBuf->wError = 0;
    lpBuf->dwSize = dwSize;
    lpBuf->dwCount = 0L;
    lpBuf->lpStart = lpMem;
    lpBuf->lpEnd = lpMem + dwSize;
    lpBuf->lpTail = lpMem;
    lpBuf->lpHead = lpMem;
    return lpBuf;
}

/* FreeCircularBuffer - Frees the memory for the given CIRCULARBUFFER structure and the memory for the buffer it references.
 * Params:  lpBuf - Points to the CIRCULARBUFFER to be freed. */
void FreeCircularBuffer(LPCIRCULARBUFFER lpBuf) {
    HANDLE hMem;
    /* Free the buffer itself. */
#ifndef _WIN32
    GlobalSmartPageUnlock((HGLOBAL)HIWORD(lpBuf->lpStart));
#endif
    GlobalUnlock(lpBuf->hBuffer);
    GlobalFree(lpBuf->hBuffer);
    /* Free the CIRCULARBUFFER structure. */
    hMem = lpBuf->hSelf;
#ifndef _WIN32
    GlobalSmartPageUnlock((HGLOBAL)HIWORD(lpBuf));
#endif
    GlobalUnlock(hMem);
    GlobalFree(hMem);
}

/* GetEvent - Gets a MIDI event from the circular input buffer.  Events
 *  are removed from the buffer.  The corresponding PutEvent() function
 *  is called by the low-level callback function, so it must reside in
 *  the callback DLL.  PutEvent() is defined in the CALLBACK.C module.
 *
 * Params:  lpBuf - Points to the circular buffer.
 *          lpEvent - Points to an EVENT structure that is filled with the retrieved event.
 * Return:  Returns non-zero if successful, zero if there are no events to get. */
WORD FAR PASCAL GetEvent(LPCIRCULARBUFFER lpBuf, LPEVENT lpEvent) {
    /* If no event available, return */
    if (!wNumDevices || lpBuf->dwCount <= 0) return 0;
    /* Get the event. */
    *lpEvent = *lpBuf->lpTail;
    /* Decrement the byte count, bump the tail pointer. */
    --lpBuf->dwCount;
    ++lpBuf->lpTail;
    /* Wrap the tail pointer, if necessary. */
    if (lpBuf->lpTail >= lpBuf->lpEnd) lpBuf->lpTail = lpBuf->lpStart;
    return 1;
}

/* PutEvent - Puts an EVENT in a CIRCULARBUFFER.  If the buffer is full, 
 *      it sets the wError element of the CIRCULARBUFFER structure 
 *      to be non-zero.
 *
 * Params:  lpBuf - Points to the CIRCULARBUFFER.
 *          lpEvent - Points to the EVENT. */

void FAR PASCAL PutEvent(LPCIRCULARBUFFER lpBuf, LPEVENT lpEvent) {
    /* If the buffer is full, set an error and return. */
    if(lpBuf->dwCount >= lpBuf->dwSize){
        lpBuf->wError = 1;
        return;
    }
    /* Put the event in the buffer, bump the head pointer and the byte count.  */
    *lpBuf->lpHead = *lpEvent;
    ++lpBuf->lpHead;
    ++lpBuf->dwCount;
    /* Wrap the head pointer, if necessary. */
    if(lpBuf->lpHead >= lpBuf->lpEnd) lpBuf->lpHead = lpBuf->lpStart;
}

/* midiInputHandler - Low-level callback function to handle MIDI input.
 *      Installed by midiInOpen().  The input handler takes incoming
 *      MIDI events and places them in the circular input buffer.  It then
 *      notifies the application by posting a MM_MIDIINPUT message.
 *
 *      This function is accessed at interrupt time, so it should be as 
 *      fast and efficient as possible.  You can't make any
 *      Windows calls here, except PostMessage().  The only Multimedia
 *      Windows call you can make are timeGetSystemTime(), midiOutShortMsg().
 *
 * Param:   hMidiIn - Handle for the associated input device.
 *          wMsg - One of the MIM_***** messages.
 *          dwInstance - Points to CALLBACKINSTANCEDATA structure.
 *          dwParam1 - MIDI data.
 *          dwParam2 - Timestamp (in milliseconds) */
void FAR PASCAL midiInputHandler(HMIDIIN hMidiIn, WORD wMsg, DWORD dwInstance, DWORD dwParam1, DWORD dwParam2) {
    EVENT event;
    switch(wMsg) {
        case MIM_OPEN: break;
        /* The only error possible is invalid MIDI data, so just pass the invalid data on so we'll see it. */
        case MIM_ERROR:
        case MIM_DATA:
            event.fdwEvent = (wMsg == MIM_ERROR) ? EVNT_F_ERROR : 0;
            event.dwDevice = ((LPCALLBACKINSTANCEDATA)dwInstance)->dwDevice;
            event.data = dwParam1;
#ifdef MIDI_TIMESTAMP
            event.timestamp = timeGetSystemTime();
#endif
            /* Put the MIDI event in the circular input buffer. */
            PutEvent(((LPCALLBACKINSTANCEDATA)dwInstance)->lpBuf, (LPEVENT)&event);
            break;
        default: break;
    }
}

void msw_open_midiin(int nmidiin, int *midiinvec) {
    UINT  wRtn;
    char szErrorText[256];
    unsigned int i;
    unsigned int ndev = 0;
    /* Allocate a circular buffer for low-level MIDI input.  This buffer is filled by the low-level callback function
       and emptied by the application. */
    lpInputBuffer = AllocCircularBuffer((DWORD)(INPUT_BUFFER_SIZE));
    if (!lpInputBuffer) {
        printf("Not enough memory available for input buffer.\n");
        return;
    }
    /* Open all MIDI input devices after allocating and setting up instance data for each device.  The instance data is
       used to pass buffer management information between the application and the low-level callback function.  It also
       includes a device ID, a handle to the MIDI Mapper, and a handle to the application's display window, so the callback
       can notify the window when input data is available.  A single callback function is used to service all opened input devices. */
    for (i=0; (i<(unsigned)nmidiin) && (i<MAXMIDIINDEV); i++) {
        if ((lpCallbackInstanceData[ndev] = AllocCallbackInstanceData()) == NULL) {
            printf("Not enough memory available.\n");
            FreeCircularBuffer(lpInputBuffer);
            return;
        }
        lpCallbackInstanceData[i]->dwDevice = i;
        lpCallbackInstanceData[i]->lpBuf = lpInputBuffer;
        wRtn = midiInOpen((LPHMIDIIN)&hMidiIn[ndev], midiinvec[i], (DWORD)midiInputHandler,
            (DWORD)lpCallbackInstanceData[ndev], CALLBACK_FUNCTION);
        if (wRtn) {
            FreeCallbackInstanceData(lpCallbackInstanceData[ndev]);
            msw_midiinerror("midiInOpen: %s", wRtn);
        } else ndev++;
    }
    /* Start MIDI input. */
    for (i=0; i<ndev; i++) {
        if (hMidiIn[i]) midiInStart(hMidiIn[i]);
    }
    wNumDevices = ndev;
}

static void msw_close_midiin() {
    unsigned int i;
    /* Stop, reset, close MIDI input.  Free callback instance data. */
    for (i=0; (i<wNumDevices) && (i<MAXMIDIINDEV); i++) {
        if (hMidiIn[i]) {
            if (sys_verbose) post("closing MIDI input %d...", i);
            midiInStop(hMidiIn[i]);
            midiInReset(hMidiIn[i]);
            midiInClose(hMidiIn[i]);
            FreeCallbackInstanceData(lpCallbackInstanceData[i]);
        }
    }
    /* Free input buffer. */
    if (lpInputBuffer) FreeCircularBuffer(lpInputBuffer);
    if (sys_verbose) post("...done");
    wNumDevices = 0;
}

/* ------------------- public routines -------------------------- */

void sys_putmidimess(int portno, int a, int b, int c) {
    DWORD foo;
    MMRESULT res;
    if (portno >= 0 && portno < msw_nmidiout) {
        foo = (a & 0xff) | ((b & 0xff) << 8) | ((c & 0xff) << 16);
        res = midiOutShortMsg(hMidiOut[portno], foo);
        if (res != MMSYSERR_NOERROR) post("MIDI out error %d", res);
    }
}

void sys_putmidibyte(int portno, int byte) {
    MMRESULT res;
    if (portno >= 0 && portno < msw_nmidiout) {
        res = midiOutShortMsg(hMidiOut[portno], byte);
        if (res != MMSYSERR_NOERROR) post("MIDI out error %d", res);
    }
}

void sys_poll_midi() {
    static EVENT msw_nextevent;
    static int msw_isnextevent;
    static double msw_nexteventtime;
    while (1) {
        if (!msw_isnextevent) {
            if (!GetEvent(lpInputBuffer, &msw_nextevent)) break;
            msw_isnextevent = 1;
#ifdef MIDI_TIMESTAMP
            msw_nexteventtime = msw_midigettimefor(&foo.timestamp);
#endif
        }
#ifdef MIDI_TIMESTAMP
        if (0.001 * clock_gettimesince(initsystime) >= msw_nexteventtime)
#endif
        {
            int msgtype = ((msw_nextevent.data & 0xf0) >> 4) - 8;
            int commandbyte = msw_nextevent.data & 0xff;
            int byte1 = (msw_nextevent.data >> 8) & 0xff;
            int byte2 = (msw_nextevent.data >> 16) & 0xff;
            int portno = msw_nextevent.dwDevice;
            switch (msgtype) {
            case 0:
            case 1:
            case 2:
            case 3:
            case 6:
                sys_midibytein(portno, commandbyte);
                sys_midibytein(portno, byte1);
                sys_midibytein(portno, byte2);
                break; 
            case 4:
            case 5:
                sys_midibytein(portno, commandbyte);
                sys_midibytein(portno, byte1);
                break;
            case 7:
                sys_midibytein(portno, commandbyte);
                break;
            }
            msw_isnextevent = 0;
        }
    }
}

void sys_do_open_midi(int nmidiin, int *midiinvec, int nmidiout, int *midioutvec) {
    if (nmidiout) msw_open_midiout(nmidiout, midioutvec);
    if (nmidiin) {
        post("Warning: midi input is dangerous in Microsoft Windows; see Pd manual)");
        msw_open_midiin(nmidiin, midiinvec);
    }
}

void sys_close_midi() {
    msw_close_midiin();
    msw_close_midiout();
}

#if 0
/* list the audio and MIDI device names */
void sys_listmididevs() {
    UINT  wRtn, ndevices;
    unsigned int i;
    /* for MIDI and audio in and out, get the number of devices. Then get the capabilities of each device and print its description. */
    ndevices = midiInGetNumDevs();
    for (i = 0; i < ndevices; i++) {
        MIDIINCAPS micap;
        wRtn = midiInGetDevCaps(i, (LPMIDIINCAPS) &micap, sizeof(micap));
        if (wRtn) msw_midiinerror("midiInGetDevCaps: %s", wRtn);
        else error("MIDI input device #%d: %s", i+1, micap.szPname);
    }
    ndevices = midiOutGetNumDevs();
    for (i = 0; i < ndevices; i++) {
        MIDIOUTCAPS mocap;
        wRtn = midiOutGetDevCaps(i, (LPMIDIOUTCAPS) &mocap, sizeof(mocap));
        if (wRtn) msw_midiouterror("midiOutGetDevCaps: %s", wRtn);
        else error("MIDI output device #%d: %s", i+1, mocap.szPname);
    }
}
#endif

void midi_getdevs(char *indevlist, int *nindevs, char *outdevlist, int *noutdevs, int maxndev, int devdescsize) {
    int i, nin = midiInGetNumDevs(), nout = midiOutGetNumDevs();
    UINT  wRtn;
    if (nin > maxndev) nin = maxndev;
    for (i = 0; i < nin; i++) {
        MIDIINCAPS micap;
        wRtn = midiInGetDevCaps(i, (LPMIDIINCAPS) &micap, sizeof(micap));
        strncpy(indevlist + i * devdescsize, (wRtn ? "???" : micap.szPname), devdescsize);
        indevlist[(i+1) * devdescsize - 1] = 0;
    }
    if (nout > maxndev) nout = maxndev;
    for (i = 0; i < nout; i++) {
        MIDIOUTCAPS mocap;
        wRtn = midiOutGetDevCaps(i, (LPMIDIOUTCAPS) &mocap, sizeof(mocap));
        strncpy(outdevlist + i * devdescsize, (wRtn ? "???" : mocap.szPname), devdescsize);
        outdevlist[(i+1) * devdescsize - 1] = 0;
    }
    *nindevs = nin;
    *noutdevs = nout;
}