/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2024 The FreeBSD Foundation
 *
 * This software was developed by Christos Margiolis <christos@FreeBSD.org>
 * under sponsorship from the FreeBSD Foundation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/soundcard.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define NOTE2OCTAVE(n)  (n / 12 - 1)
#define NOTE2FREQ(n)    (440 * pow(2.0f, ((float)n - 69) / 12))
#define CHAN_MASK       0x0f

static struct note {
        const char *name;
        const char *alt;
} notes[] = {
        { "C",  NULL },
        { "C#", "Db" },
        { "D",  NULL },
        { "D#", "Eb" },
        { "E",  NULL },
        { "F",  NULL },
        { "F#", "Gb" },
        { "G",  NULL },
        { "G#", "Ab" },
        { "A",  NULL },
        { "A#", "Bb" },
        { "B",  NULL },
};

/* Hardcoded values are not defined in sys/soundcard.h. */
static const char *ctls[] = {
        [CTL_BANK_SELECT]               = "Bank Select",
        [CTL_MODWHEEL]                  = "Modulation Wheel",
        [CTL_BREATH]                    = "Breath Controller",
        [0x03]                          = "Undefined",
        [CTL_FOOT]                      = "Foot Pedal",
        [CTL_PORTAMENTO_TIME]           = "Portamento Time",
        [CTL_DATA_ENTRY]                = "Data Entry",
        [CTL_MAIN_VOLUME]               = "Volume",
        [CTL_BALANCE]                   = "Balance",
        [0x09]                          = "Undefined",
        [CTL_PAN]                       = "Pan",
        [CTL_EXPRESSION]                = "Expression",
        [0x0c]                          = "Effect Controller 1",
        [0x0d]                          = "Effect Controller 2",
        [0x0e]                          = "Undefined",
        [0x0f]                          = "Undefined",
        [CTL_GENERAL_PURPOSE1]          = "General Purpose 1",
        [CTL_GENERAL_PURPOSE2]          = "General Purpose 2",
        [CTL_GENERAL_PURPOSE3]          = "General Purpose 3",
        [CTL_GENERAL_PURPOSE4]          = "General Purpose 4",
        [0x14 ... 0x1f]                 = "Undefined",
        [0x20 ... 0x3f]                 = "LSB Controller",
        [CTL_DAMPER_PEDAL]              = "Damper Pedal (Sustain)",
        [CTL_PORTAMENTO]                = "Portamento",
        [CTL_SOSTENUTO]                 = "Sostenuto Pedal",
        [CTL_SOFT_PEDAL]                = "Soft Pedal",
        [0x44]                          = "Legato Foot-Switch",
        [CTL_HOLD2]                     = "Hold 2",
        [0x46]                          = "Sound Controller 1",
        [0x47]                          = "Sound Controller 2",
        [0x48]                          = "Sound Controller 3",
        [0x49]                          = "Sound Controller 4",
        [0x4a]                          = "Sound Controller 5",
        [0x4b]                          = "Sound Controller 6",
        [0x4c]                          = "Sound Controller 7",
        [0x4d]                          = "Sound Controller 8",
        [0x4e]                          = "Sound Controller 9",
        [0x4f]                          = "Sound Controller 10",
        [CTL_GENERAL_PURPOSE5]          = "General Purpose 5",
        [CTL_GENERAL_PURPOSE6]          = "General Purpose 6",
        [CTL_GENERAL_PURPOSE7]          = "General Purpose 7",
        [CTL_GENERAL_PURPOSE8]          = "General Purpose 8",
        [0x54]                          = "Portamento CC",
        [0x55 ... 0x57]                 = "Undefined",
        [0x58]                          = "Hi-Res Velocity Prefix",
        [0x59 ... 0x5a]                 = "Undefined",
        [CTL_EXT_EFF_DEPTH]             = "Effect 1 Depth",
        [CTL_TREMOLO_DEPTH]             = "Effect 2 Depth",
        [CTL_CHORUS_DEPTH]              = "Effect 3 Depth",
        [CTL_DETUNE_DEPTH]              = "Effect 4 Depth",
        [CTL_PHASER_DEPTH]              = "Effect 5 Depth",
        [CTL_DATA_INCREMENT]            = "Data Increment",
        [CTL_DATA_DECREMENT]            = "Data Decrement",
        [CTL_NONREG_PARM_NUM_LSB]       = "NRPN (LSB)",
        [CTL_NONREG_PARM_NUM_MSB]       = "NRPN (MSB)",
        [CTL_REGIST_PARM_NUM_LSB]       = "RPN (LSB)",
        [CTL_REGIST_PARM_NUM_MSB]       = "RPN (MSB)",
        [0x66 ... 0x77]                 = "Undefined",
        /* Channel mode messages */
        [0x78]                          = "All Sound Off",
        [0x79]                          = "Reset All Controllers",
        [0x7a]                          = "Local On/Off Switch",
        [0x7b]                          = "All Notes Off",
        [0x7c]                          = "Omni Mode Off",
        [0x7d]                          = "Omni Mode On",
        [0x7e]                          = "Mono Mode",
        [0x7f]                          = "Poly Mode",
};

static void __dead2
usage(void)
{
        fprintf(stderr, "usage: %s [-t] device\n", getprogname());
        exit(1);
}

static uint8_t
read_byte(int fd)
{
        uint8_t byte;

        if (read(fd, &byte, sizeof(byte)) < (ssize_t)sizeof(byte))
                err(1, "read");

        return (byte);
}

int
main(int argc, char *argv[])
{
        struct note *pn;
        char buf[16];
        int fd, ch, tflag = 0;
        uint8_t event, chan, b1, b2;

        while ((ch = getopt(argc, argv, "t")) != -1) {
                switch (ch) {
                case 't':
                        tflag = 1;
                        break;
                case '?':       /* FALLTHROUGH */
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

        if (argc < 1)
                usage();

        if ((fd = open(*argv, O_RDONLY)) < 0)
                err(1, "open(%s)", *argv);

        for (;;) {
                event = read_byte(fd);
                if (!(event & 0x80))
                        continue;
                chan = (event & CHAN_MASK) + 1;

                switch (event) {
                case 0x80 ... 0x8f:     /* FALLTHROUGH */
                case 0x90 ... 0x9f:
                        b1 = read_byte(fd);
                        b2 = read_byte(fd);
                        pn = &notes[b1 % nitems(notes)];
                        snprintf(buf, sizeof(buf), "%s%d", pn->name,
                            NOTE2OCTAVE(b1));
                        if (pn->alt != NULL) {
                                snprintf(buf + strlen(buf), sizeof(buf),
                                    "/%s%d", pn->alt, NOTE2OCTAVE(b1));
                        }
                        printf("Note %-3s               channel=%d, "
                            "note=%d (%s, %.2fHz), velocity=%d\n",
                            (event >= 0x80 && event <= 0x8f) ? "off" : "on",
                            chan, b1, buf, NOTE2FREQ(b1), b2);
                        break;
                case 0xa0 ... 0xaf:
                        b1 = read_byte(fd);
                        b2 = read_byte(fd);
                        printf("Polyphonic aftertouch   channel=%d, note=%d, "
                            "pressure=%d\n",
                            chan, b1, b2);
                        break;
                case 0xb0 ... 0xbf:
                        b1 = read_byte(fd);
                        b2 = read_byte(fd);
                        if (b1 > nitems(ctls) - 1)
                                break;
                        printf("Control/Mode change     channel=%d, "
                            "control=%d (%s), value=%d",
                            chan, b1, ctls[b1], b2);
                        if (b1 >= 0x40 && b1 <= 0x45) {
                                if (b2 <= 63)
                                        printf(" (off)");
                                else
                                        printf(" (on)");
                        }
                        if (b1 == 0x7a) {
                                if (b2 == 0)
                                        printf(" (off)");
                                else if (b2 == 127)
                                        printf(" (on");
                        }
                        putchar('\n');
                        break;
                case 0xc0 ... 0xcf:
                        b1 = read_byte(fd);
                        printf("Program change          channel=%d, "
                            "program=%d\n",
                            chan, b1);
                        break;
                case 0xd0 ... 0xdf:
                        b1 = read_byte(fd);
                        printf("Channel aftertouch      channel=%d, "
                            "pressure=%d\n",
                            chan, b1);
                        break;
                case 0xe0 ... 0xef:
                        /* TODO Improve */
                        b1 = read_byte(fd);
                        b2 = read_byte(fd);
                        printf("Pitch bend              channel=%d, change=%d\n",
                            chan, b1 | b2 << 7);
                        break;
                case 0xf0:
                        printf("SysEx                   vendorid=");
                        b1 = read_byte(fd);
                        printf("0x%02x", b1);
                        if (b1 == 0) {
                                printf(" 0x%02x 0x%02x",
                                    read_byte(fd), read_byte(fd));
                        }
                        printf(" data=");
                        for (;;) {
                                b1 = read_byte(fd);
                                printf("0x%02x ", b1);
                                /* End of SysEx (EOX) */
                                if (b1 == 0xf7)
                                        break;
                        }
                        putchar('\n');
                        break;
                case 0xf2:
                        b1 = read_byte(fd);
                        b2 = read_byte(fd);
                        printf("Song position pointer   ptr=%d\n",
                            b1 | b2 << 7);
                        break;
                case 0xf3:
                        b1 = read_byte(fd);
                        printf("Song select             song=%d\n", b1);
                        break;
                case 0xf6:
                        printf("Tune request\n");
                        break;
                case 0xf7:
                        printf("End of SysEx (EOX)\n");
                        break;
                case 0xf8:
                        if (tflag)
                                printf("Timing clock\n");
                        break;
                case 0xfa:
                        printf("Start\n");
                        break;
                case 0xfb:
                        printf("Continue\n");
                        break;
                case 0xfc:
                        printf("Stop\n");
                        break;
                case 0xfe:
                        printf("Active sensing\n");
                        break;
                case 0xff:
                        printf("System reset\n");
                        break;
                case 0xf1:              /* TODO? MIDI time code qtr. frame */
                case 0xf4:              /* Undefined (reserved) */
                case 0xf5:
                case 0xf9:
                case 0xfd:
                        break;
                default:
                        printf("Unknown event type: 0x%02x\n", event);
                        break;
                }
        }

        close(fd);

        return (0);
}