/* Copyright (c) 1997-1999 Guenter Geiger, Miller Puckette, Larry Troxler,
* Winfried Ritsch, Karl MacMillan, and others.
* For information on usage and redistribution, and for a DISCLAIMER OF ALL
* WARRANTIES, see the file, "LICENSE.txt," in this distribution.  */

/* MIDI I/O for Linux using OSS */

#include <stdio.h>
#ifdef UNISTD
#include <unistd.h>
#endif
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include "m_pd.h"
#include "s_stuff.h"

static int oss_nmidiin;
static int oss_midiinfd[MAXMIDIINDEV];
static int oss_nmidiout;
static int oss_midioutfd[MAXMIDIOUTDEV];

static void oss_midiout(int fd, int n) {
    char b = n;
    if ((write(fd, (char *) &b, 1)) != 1) perror("midi write");
}

#define O_MIDIFLAG O_NDELAY

void sys_do_open_midi(int nmidiin, int *midiinvec, int nmidiout, int *midioutvec) {
    int i;
    for (i = 0; i < nmidiout; i++) oss_midioutfd[i] = -1;
    for (i = 0, oss_nmidiin = 0; i < nmidiin; i++) {
        int fd = -1, j, outdevindex = -1;
        char namebuf[80];
        int devno = midiinvec[i];
        for (j = 0; j < nmidiout; j++) if (midioutvec[j] == midiinvec[i]) outdevindex = j;
        /* try to open the device for read/write. */
        if (devno == 0 && fd < 0 && outdevindex >= 0) {
            sys_setalarm(1000000); fd = open("/dev/midi", O_RDWR | O_MIDIFLAG);
            if (sys_verbose) error("device 1: tried /dev/midi READ/WRITE; returned %d", fd);
            if (outdevindex >= 0 && fd >= 0) oss_midioutfd[outdevindex] = fd;
        }
        if (fd < 0 && outdevindex >= 0) {
            sprintf(namebuf, "/dev/midi%2.2d", devno);
            sys_setalarm(1000000); fd = open(namebuf, O_RDWR | O_MIDIFLAG);
            if (sys_verbose) error("device %d: tried %s READ/WRITE; returned %d", devno, namebuf, fd);
            if (outdevindex >= 0 && fd >= 0) oss_midioutfd[outdevindex] = fd;
        }
        if (fd < 0 && outdevindex >= 0) {
            sprintf(namebuf, "/dev/midi%d", devno);
            sys_setalarm(1000000); fd = open(namebuf, O_RDWR | O_MIDIFLAG);
            if (sys_verbose) error("device %d: tried %s READ/WRITE; returned %d", devno, namebuf, fd);
            if (outdevindex >= 0 && fd >= 0) oss_midioutfd[outdevindex] = fd;
        }
        if (devno == 1 && fd < 0) {
            sys_setalarm(1000000); fd = open("/dev/midi", O_RDONLY | O_MIDIFLAG);
            if (sys_verbose) error("device 1: tried /dev/midi READONLY; returned %d", fd);
        }
        if (fd < 0) {
            sprintf(namebuf, "/dev/midi%2.2d", devno);
            sys_setalarm(1000000); fd = open(namebuf, O_RDONLY | O_MIDIFLAG);
            if (sys_verbose) error("device %d: tried %s READONLY; returned %d", devno, namebuf, fd);
        }
        if (fd < 0) {
            sprintf(namebuf, "/dev/midi%d", devno);
            sys_setalarm(1000000); fd = open(namebuf, O_RDONLY | O_MIDIFLAG);
            if (sys_verbose) error("device %d: tried %s READONLY; returned %d", devno, namebuf, fd);
        }
        if (fd >= 0) oss_midiinfd[oss_nmidiin++] = fd;
        else post("couldn't open MIDI input device %d", devno);
    }
    for (i = 0, oss_nmidiout = 0; i < nmidiout; i++) {
        int fd = oss_midioutfd[i];
        char namebuf[80];
        int devno = midioutvec[i];
        if (devno == 1 && fd < 0) {
            sys_setalarm(1000000); fd = open("/dev/midi", O_WRONLY | O_MIDIFLAG);
            if (sys_verbose) error("device 1: tried /dev/midi WRITEONLY; returned %d", fd);
        }
        if (fd < 0) {
            sprintf(namebuf, "/dev/midi%2.2d", devno);
            sys_setalarm(1000000); fd = open(namebuf, O_WRONLY | O_MIDIFLAG);
            if (sys_verbose) error("device %d: tried %s WRITEONLY; returned %d", devno, namebuf, fd);
        }
        if (fd < 0) {
            sprintf(namebuf, "/dev/midi%d", devno);
            sys_setalarm(1000000); fd = open(namebuf, O_WRONLY | O_MIDIFLAG);
            if (sys_verbose) error("device %d: tried %s WRITEONLY; returned %d", devno, namebuf, fd);
        }
        if (fd >= 0) oss_midioutfd[oss_nmidiout++] = fd;
        else post("couldn't open MIDI output device %d", devno);
    }
    if (oss_nmidiin < nmidiin || oss_nmidiout < nmidiout || sys_verbose)
        post("opened %d MIDI input device(s) and %d MIDI output device(s).", oss_nmidiin, oss_nmidiout);
    sys_setalarm(0);
}

#define md_msglen(x) (((x)<0xC0)?2:((x)<0xE0)?1:((x)<0xF0)?2:((x)==0xF2)?2:((x)<0xF4)?1:0)

void sys_putmidimess(int portno, int a, int b, int c) {
    if (portno >= 0 && portno < oss_nmidiout) {
       switch (md_msglen(a)) {
       case 2:
            oss_midiout(oss_midioutfd[portno],a);
            oss_midiout(oss_midioutfd[portno],b);
            oss_midiout(oss_midioutfd[portno],c);
            return;
       case 1:
            oss_midiout(oss_midioutfd[portno],a);
            oss_midiout(oss_midioutfd[portno],b);
            return;
       case 0:
            oss_midiout(oss_midioutfd[portno],a);
            return;
       }
    }
}

void sys_putmidibyte(int portno, int byte) {
    if (portno >= 0 && portno < oss_nmidiout) oss_midiout(oss_midioutfd[portno], byte);
}

#if 0 /* this is the "select" version which doesn't work with OSS driver for emu10k1 (it doesn't implement select.) */
void sys_poll_midi() {
    int throttle = 100;
    struct timeval timout;
    int did = 1, maxfd = 0;
    while (did) {
        fd_set readset, writeset, exceptset;
        did = 0;
        if (throttle-- < 0) break;
        timout.tv_sec = 0;
        timout.tv_usec = 0;
        FD_ZERO(&writeset);
        FD_ZERO(&readset);
        FD_ZERO(&exceptset);
        for (int i=0; i<oss_nmidiin; i++) {
            if (oss_midiinfd[i] > maxfd) maxfd = oss_midiinfd[i];
            FD_SET(oss_midiinfd[i], &readset);
        }
        select(maxfd+1, &readset, &writeset, &exceptset, &timout);
        for (int i=0; i<oss_nmidiin; i++) if (FD_ISSET(oss_midiinfd[i], &readset)) {
            char c;
            int ret = read(oss_midiinfd[i], &c, 1);
            if (ret <= 0) error("Midi read error");
            else sys_midibytein(i, (c & 0xff));
            did = 1;
        }
    }
}
#else
/* this version uses the asynchronous "read()" ... */
void sys_poll_midi() {
    int throttle = 100;
    struct timeval timout;
    int did = 1, maxfd = 0;
    while (did) {
        fd_set readset, writeset, exceptset;
        did = 0;
        if (throttle-- < 0) break;
        for (int i=0; i<oss_nmidiin; i++) {
            char c;
            int ret = read(oss_midiinfd[i], &c, 1);
            if (ret < 0) {
                if (errno != EAGAIN) perror("MIDI");
            } else if (ret != 0) {
                sys_midibytein(i, (c & 0xff));
                did = 1;
            }
        }
    }
}
#endif

void sys_close_midi() {
    for (int i=0; i<oss_nmidiin ; i++) close(oss_midiinfd [i]);
    for (int i=0; i<oss_nmidiout; i++) close(oss_midioutfd[i]);
    oss_nmidiin = oss_nmidiout = 0;
}

#define NSEARCH 10
static int oss_nmidiindevs, oss_nmidioutdevs, oss_initted;

void midi_oss_init() {
    if (oss_initted) return;
    oss_initted = 1;
    for (int i=0; i<NSEARCH; i++) {
        int fd;
        char namebuf[80];
        oss_nmidiindevs = i;
        /* try to open the device for reading */
        if (i == 0) {
            fd = open("/dev/midi", O_RDONLY | O_NDELAY);
            if (fd >= 0) {close(fd); continue;}
        }
        sprintf(namebuf, "/dev/midi%2.2d", i);
        fd = open(namebuf, O_RDONLY | O_NDELAY);
        if (fd >= 0) {close(fd); continue;}
        sprintf(namebuf, "/dev/midi%d", i);
        fd = open(namebuf, O_RDONLY | O_NDELAY);
        if (fd >= 0) {close(fd); continue;}
        break;
    }
    for (int i=0; i<NSEARCH; i++) {
        int fd;
        char namebuf[80];
        oss_nmidioutdevs = i;
        /* try to open the device for writing */
        if (i == 0) {
            fd = open("/dev/midi", O_WRONLY | O_NDELAY);
            if (fd >= 0) {close(fd); continue;}
        }
        sprintf(namebuf, "/dev/midi%2.2d", i);
        fd = open(namebuf, O_WRONLY | O_NDELAY);
        if (fd >= 0) {close(fd); continue;}
        sprintf(namebuf, "/dev/midi%d", i);
        fd = open(namebuf, O_WRONLY | O_NDELAY);
        if (fd >= 0) {close(fd); continue;}
        break;
    }
}

void midi_getdevs(char *indevlist, int *nindevs, char *outdevlist, int *noutdevs, int maxndev, int devdescsize) {
    int i, ndev;
    if ((ndev = oss_nmidiindevs) > maxndev) ndev = maxndev;
    for (i = 0; i < ndev; i++) sprintf(indevlist + i * devdescsize, "OSS MIDI device #%d", i+1);
    *nindevs = ndev;
    if ((ndev = oss_nmidioutdevs) > maxndev) ndev = maxndev;
    for (i = 0; i < ndev; i++) sprintf(outdevlist + i * devdescsize, "OSS MIDI device #%d", i+1);
    *noutdevs = ndev;
}