/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */

/***************************************************************************
 opl2.c Copyright (C) 2002/04 Solomon Peachy, Christoph Reichenbach

 This program may be modified and copied freely according to the terms of
 the GNU general public license (GPL), as long as the above copyright
 notice and the licensing information contained herein are preserved.

 Please refer to www.gnu.org for licensing details.

 This work is provided AS IS, without warranty of any kind, expressed or
 implied, including but not limited to the warranties of merchantibility,
 noninfringement, and fitness for a specific purpose. The author will not
 be held liable for any damage caused by this work or derivatives of it.

 By using this source code, you agree to the licensing terms as stated
 above.

***************************************************************************/

#include "sci/include/resource.h"
#include "sci/include/sfx_iterator.h"
#include "../softseq.h"
#include "../adlib.h"
#include <math.h>

#include "sound/fmopl.h"

#ifdef __DC__
#define SAMPLE_RATE 22050
#define CHANNELS SFX_PCM_MONO
#define STEREO 0
#else
#define SAMPLE_RATE 44100
#define CHANNELS SFX_PCM_STEREO_LR
#define STEREO 1
#endif


/* local function declarations */

static void opl2_allstop(sfx_softseq_t *self);

//#define DEBUG_ADLIB

/* portions shamelessly lifted from claudio's XMP */
/* other portions lifted from sound/opl3.c in the Linux kernel */

#define ADLIB_LEFT 0
#define ADLIB_RIGHT 1

/* #define OPL_INTERNAL_FREQ     3600000 */
#define OPL_INTERNAL_FREQ    3579545

static int ready = 0;
static int pcmout_stereo = STEREO;

static int register_base[11] = {
	0x20, 0x23, 0x40, 0x43,
	0x60, 0x63, 0x80, 0x83,
	0xe0, 0xe3, 0xc0
};

static int register_offset[12] = {
	/* Channel           1     2     3     4     5     6     7     8     9  */
	/* Operator 1 */   0x00, 0x01, 0x02, 0x08, 0x09, 0x0A, 0x10, 0x11, 0x12, 0x18, 0x19, 0x1A

};

static int ym3812_note[13] = {
	0x157, 0x16b, 0x181, 0x198, 0x1b0, 0x1ca,
	0x1e5, 0x202, 0x220, 0x241, 0x263, 0x287,
	0x2ae
};

static guint8 sci_adlib_vol_base[16] = {
	0x00, 0x11, 0x15, 0x19, 0x1D, 0x22, 0x26, 0x2A,
	0x2E, 0x23, 0x37, 0x3B, 0x3F, 0x3F, 0x3F, 0x3F
};
static guint8 sci_adlib_vol_tables[16][64];

/* back to your regularly scheduled definitions */

static guint8 instr[MIDI_CHANNELS];
static guint16 pitch[MIDI_CHANNELS];
static guint8 vol[MIDI_CHANNELS];
static guint8 pan[MIDI_CHANNELS];
static int free_voices = ADLIB_VOICES;
static guint8 oper_note[ADLIB_VOICES];
static guint8 oper_chn[ADLIB_VOICES];

static FM_OPL *ym3812_L = NULL;
static FM_OPL *ym3812_R = NULL;

static guint8 adlib_reg_L[256];
static guint8 adlib_reg_R[256];
static guint8 adlib_master;


/* initialise note/operator lists, etc. */
void adlibemu_init_lists(void) {
	int i;

	int j;

	for (i = 0 ; i < 16 ; i++) {
		for (j = 0; j < 64 ; j++) {
			sci_adlib_vol_tables[i][j] = ((guint16)sci_adlib_vol_base[i]) * j / 63;
		}
	}

	for (i = 0; i < MIDI_CHANNELS ; i++) {
		pitch[i] = 8192;  /* center the pitch wheel */
	}

	free_voices = ADLIB_VOICES;

	memset(instr, 0, sizeof(instr));
	memset(vol, 0x7f, sizeof(vol));
	memset(pan, 0x3f, sizeof(pan));
	memset(adlib_reg_L, 0, sizeof(adlib_reg_L));
	memset(adlib_reg_R, 0, sizeof(adlib_reg_R));
	memset(oper_chn, 0xff, sizeof(oper_chn));
	memset(oper_note, 0xff, sizeof(oper_note));
	adlib_master = 12;
}

/* more shamelessly lifted from xmp and adplug.  And altered.  :) */

static inline int opl_write_L(int a, int v) {
	adlib_reg_L[a] = v;
	OPLWrite(ym3812_L, 0x388, a);
	return OPLWrite(ym3812_L, 0x389, v);
}

static inline int opl_write_R(int a, int v) {
	adlib_reg_R[a] = v;
	OPLWrite(ym3812_R, 0x388, a);
	return OPLWrite(ym3812_R, 0x389, v);
}

static inline int opl_write(int a, int v) {
	opl_write_L(a, v);
	return opl_write_R(a, v);
}

/*
static inline guint8 opl_read (int a)
{
  OPLWrite (ym3812_L, 0x388, a);
  return OPLRead (ym3812_L, 0x389);
}
*/

void synth_setpatch(int voice, guint8 *data) {
	int i;

	opl_write(0xBD, 0);

	for (i = 0; i < 10; i++)
		opl_write(register_base[i] + register_offset[voice], data[i]);

	opl_write(register_base[10] + voice, data[10]);

	/* mute voice after patch change */
	opl_write_L(0xb0 + voice, adlib_reg_L[0xb0+voice] & 0xdf);
	opl_write_R(0xb0 + voice, adlib_reg_R[0xb0+voice] & 0xdf);

#ifdef DEBUG_ADLIB
	for (i = 0; i < 10; i++)
		printf("%02x ", adlib_reg_L[register_base[i] + register_offset[voice]]);
	printf("%02x ", adlib_reg_L[register_base[10] + voice]);
#endif

}

void synth_setvolume_L(int voice, int volume) {
	gint8 level1, level2;

	level1 = ~adlib_reg_L[register_base[2] + register_offset[voice]] & 0x3f;
	level2 = ~adlib_reg_L[register_base[3] + register_offset[voice]] & 0x3f;

	if (level1) {
		level1 += sci_adlib_vol_tables[adlib_master][volume>>1];
	}

	if (level2) {
		level2 += sci_adlib_vol_tables[adlib_master][volume>>1];
	}

	if (level1 > 0x3f)
		level1 = 0x3f;
	if (level1 < 0)
		level1 = 0;

	if (level2 > 0x3f)
		level2 = 0x3f;
	if (level2 < 0)
		level2 = 0;

	/* algorithm-dependent; we may need to set both operators. */
	if (adlib_reg_L[register_base[10] + voice] & 1)
		opl_write_L(register_base[2] + register_offset[voice],
		            (guint8)((~level1 &0x3f) |
		                     (adlib_reg_L[register_base[2] + register_offset[voice]]&0xc0)));

	opl_write_L(register_base[3] + register_offset[voice],
	            (guint8)((~level2 &0x3f) |
	                     (adlib_reg_L[register_base[3] + register_offset[voice]]&0xc0)));

}

void synth_setvolume_R(int voice, int volume) {
	gint8 level1, level2;

	level1 = ~adlib_reg_R[register_base[2] + register_offset[voice]] & 0x3f;
	level2 = ~adlib_reg_R[register_base[3] + register_offset[voice]] & 0x3f;

	if (level1) {
		level1 += sci_adlib_vol_tables[adlib_master][volume>>1];
	}

	if (level2) {
		level2 += sci_adlib_vol_tables[adlib_master][volume>>1];
	}

	if (level1 > 0x3f)
		level1 = 0x3f;
	if (level1 < 0)
		level1 = 0;

	if (level2 > 0x3f)
		level2 = 0x3f;
	if (level2 < 0)
		level2 = 0;

	/* now for the other side. */
	if (adlib_reg_R[register_base[10] + voice] & 1)
		opl_write_R(register_base[2] + register_offset[voice],
		            (guint8)((~level1 &0x3f) |
		                     (adlib_reg_R[register_base[2] + register_offset[voice]]&0xc0)));

	opl_write_R(register_base[3] + register_offset[voice],
	            (guint8)((~level2 &0x3f) |
	                     (adlib_reg_R[register_base[3] + register_offset[voice]]&0xc0)));

}

void synth_setnote(int voice, int note, int bend) {
	int n, fre, oct;
	float delta;

	delta = 0;

	n = note % 12;

	if (bend < 8192)
		bend = 8192 - bend;
	delta = pow(2, (float)(bend % 8192) / 8192.0);

	if (bend > 8192)
		fre = (int)(ym3812_note[n] * delta);
	else
		fre = (int)(ym3812_note[n] / delta);

	oct = note / 12 - 1;

	if (oct < 0)
		oct = 0;

	opl_write(0xa0 + voice, fre & 0xff);
	opl_write(0xb0 + voice,
	          0x20 | ((oct << 2) & 0x1c) | ((fre >> 8) & 0x03));
#ifdef DEBUG_ADLIB
	printf("-- %02x %02x\n", adlib_reg_L[0xa0+voice], adlib_reg_L[0xb0+voice]);
#endif

}


/* back to your regularly scheduled driver */

int adlibemu_stop_note(int chn, int note, int velocity) {
	int i, op = 255;

	//  sciprintf("Note off %d %d %d\n", chn, note, velocity);

	for (i = 0;i < ADLIB_VOICES && op == 255;i++) {
		if (oper_chn[i] == chn)
			if (oper_note[i] == note)
				op = i;
	}

	if (op == 255) {
#ifdef DEBUG_ADLIB
		printf("ADLIB: can't stop note: C%02x N%02x V%02x\n", chn, note, velocity);
		printf("C ");
		for (i = 0; i < ADLIB_VOICES ; i++) {
			printf("%02x ", oper_chn[i]);
		}
		printf("\n");
		printf("N ");
		for (i = 0; i < ADLIB_VOICES ; i++) {
			printf("%02x ", oper_note[i]);
		}
		printf("\n");
#endif
		return -1; /* that note isn't playing.. */
	}

	opl_write_L(0xb0 + op, (adlib_reg_L[0xb0+op] & 0xdf));
	opl_write_R(0xb0 + op, (adlib_reg_R[0xb0+op] & 0xdf));

	oper_chn[op] = 255;
	oper_note[op] = 255;

	free_voices++;

#ifdef DEBUG_ADLIB
	printf("stop voice %d (%d rem):  C%02x N%02x V%02x\n", op, free_voices, chn, note, velocity);
#endif

	return 0;
}

int adlibemu_start_note(int chn, int note, int velocity) {
	int op, volume_L, volume_R, inst = 0;

	//  sciprintf("Note on %d %d %d\n", chn, note, velocity);

	if (velocity == 0) {
		return adlibemu_stop_note(chn, note, velocity);
	}

	if (free_voices <= 0) {
		printf("ADLIB: All voices full\n");  /* XXX implement overflow code */
		return -1;
	}

	for (op = 0; op < ADLIB_VOICES ; op++)
		if (oper_chn[op] == 255)
			break;

	if (op == ADLIB_VOICES) {
		printf("ADLIB:  WTF?  We couldn't find a voice yet it we have %d left.\n", free_voices);
		return -1;
	}

	/* Scale channel volume */
	volume_L = velocity * vol[chn] / 127;
	volume_R = velocity * vol[chn] / 127;

	/* Apply a pan */
	if (pcmout_stereo) {
		if (pan[chn] > 0x3f)  /* pan right; so we scale the left down. */
			volume_L = volume_L / 0x3f * (0x3f - (pan[chn] - 0x3f));
		else if (pan[chn] < 0x3f) /* pan left; so we scale the right down.*/
			volume_R = volume_R / 0x3f * (0x3f - (0x3f - pan[chn]));
	}
	inst = instr[chn];

	synth_setpatch(op, adlib_sbi[inst]);
	synth_setvolume_L(op, volume_L);
	synth_setvolume_R(op, volume_R);
	synth_setnote(op, note, pitch[chn]);

	oper_chn[op] = chn;
	oper_note[op] = note;
	free_voices--;

#ifdef DEBUG_ADLIB
	printf("play voice %d (%d rem):  C%02x N%02x V%02x/%02x-%02x P%02x (%02x/%02x)\n", op, free_voices, chn, note, velocity, volume_L, volume_R, inst,
	       adlib_reg_L[register_base[2] + register_offset[op]] & 0x3f,
	       adlib_reg_L[register_base[3] + register_offset[op]] & 0x3f);
#endif

	return 0;
}

static
void adlibemu_update_pitch(int chn, int note, int newpitch) {
	int i;
	int matched = 0;

	pitch[chn] = newpitch;

	for (i = 0;i < ADLIB_VOICES;i++) {
		if (oper_chn[i] == chn) {
			matched++;
			synth_setnote(i, oper_note[i], newpitch);
		}
	}

//  printf("Matched %d notes on channel %d.\n", matched, chn);
}

void test_adlib(void) {

	int voice = 0;
#if 0
	guint8 data[] = { 0x25, 0x21, 0x48, 0x48, 0xf0, 0xf2, 0xf0, 0xa5, 0x00, 0x00, 0x06 };
#else
	guint8 *data = adlib_sbi[0x0a];
#endif

#if 1
	opl_write(register_base[0] + register_offset[voice], data[0]);
	opl_write(register_base[1] + register_offset[voice], data[1]);
	opl_write(register_base[2] + register_offset[voice], data[2]);
	opl_write(register_base[3] + register_offset[voice], data[3]);
	opl_write(register_base[4] + register_offset[voice], data[4]);
	opl_write(register_base[5] + register_offset[voice], data[5]);
	opl_write(register_base[6] + register_offset[voice], data[6]);
	opl_write(register_base[7] + register_offset[voice], data[7]);
	opl_write(register_base[8] + register_offset[voice], data[8]);
	opl_write(register_base[9] + register_offset[voice], data[9]);
	opl_write(register_base[10] + register_offset[voice], data[10]);
#else
	synth_setpatch(voice, data);
#endif

#if 0
	opl_write(0xA0 + voice, 0x57);
	opl_write(0xB0 + voice, 0x2d);
#else
	synth_setvolume_L(voice, 0x50);
	synth_setvolume_R(voice, 0x50);
	synth_setnote(voice, 0x30, 0);
#endif

	/*
	instr[0x0e] = 0x0a;
	instr[0x03] = 0x26;

	adlibemu_start_note(0x0e, 0x30, 0x40);
	sleep(1);
	adlibemu_start_note(0x03, 0x48, 0x40);
	sleep(1);
	*/
}


/* count is # of FRAMES, not bytes.
   We assume 16-bit stereo frames (ie 4 bytes)
*/
static void
opl2_poll(sfx_softseq_t *self, byte *dest, int count) {
	gint16 *buffer = (gint16 *) dest;
	gint16 *ptr = buffer;

	if (!ready) {
		fprintf(stderr, "synth_mixer(): !ready \n");
		exit(1);
	}

	if (!buffer) {
		fprintf(stderr, "synth_mixer(): !buffer \n");
		exit(1);
	}

#if 0
	{
		static unsigned long remaining_delta = 0;
		int samples;
		int remaining = count;

		while (remaining > 0) {
			samples = remaining_delta * pcmout_sample_rate / 1000000;
			samples = sci_min(samples, remaining);
			if (samples) {
				YM3812UpdateOne(ADLIB_LEFT, ptr, samples, 1);
				YM3812UpdateOne(ADLIB_RIGHT, ptr + 1, samples, 1);
			}
			if (remaining > samples) {
				remaining_delta = (remaining - samples) * 1000000 / pcmout_sample_rate;
			} else {
				song->play_next_note();
				remaining_delta = song->get_next_delta();
				song->advance();
			}
			remaining -= samples;
		}
	}
#endif

	if (pcmout_stereo) {
		YM3812UpdateOne(ym3812_L, ptr, count, 1);
		YM3812UpdateOne(ym3812_R, ptr + 1, count, 1);
	} else {
		YM3812UpdateOne(ym3812_L, ptr, count, 0);
	}
}

static int
opl2_init(sfx_softseq_t *self, byte *data_ptr, int data_length, byte *data2_ptr,
          int data2_length) {
	int i;

	/* load up the patch.003 file, parse out the instruments */
	if (data_length < 1344) {
		sciprintf("[sfx:seq:opl2] Invalid patch.003: Expected %d, got %d\n", 1344, data_length);
		return -1;
	}

	for (i = 0; i < 48; i++)
		make_sbi((adlib_def *)(data_ptr + (28 * i)), adlib_sbi[i]);

	if (data_length > 1344)
		for (i = 48; i < 96; i++)
			make_sbi((adlib_def *)(data_ptr + 2 + (28 * i)), adlib_sbi[i]);

	OPLBuildTables(FMOPL_ENV_BITS_HQ, FMOPL_EG_ENT_HQ);

	if (!(ym3812_L = OPLCreate(OPL_TYPE_YM3812, OPL_INTERNAL_FREQ, SAMPLE_RATE)) ||
	        !(ym3812_R = OPLCreate(OPL_TYPE_YM3812, OPL_INTERNAL_FREQ, SAMPLE_RATE))) {
		sciprintf("[sfx:seq:opl2] Failure: Emulator init failed!\n");
		return SFX_ERROR;
	}

	ready = 1;

	opl2_allstop(self);
	return SFX_OK;
}


static void
opl2_exit(sfx_softseq_t *self) {
	FM_OPL *opl = ym3812_L;
	ym3812_L = NULL;
	OPLDestroy(opl);
	opl = ym3812_R;
	ym3812_R = NULL;
	OPLDestroy(opl);

	// XXX deregister with pcm layer.
}

static void
opl2_allstop(sfx_softseq_t *self) {
	//  printf("AdlibEmu:  Reset\n");
	if (! ready)
		return;

	adlibemu_init_lists();

	OPLResetChip(ym3812_L);
	OPLResetChip(ym3812_R);

	opl_write(0x01, 0x20);
	opl_write(0xBD, 0xc0);

#ifdef DEBUG_ADLIB
	printf("ADLIB: reset complete\n");
#endif
	//  test_adlib();
}

int midi_adlibemu_reverb(short param) {
	printf("ADLIB: reverb NYI %04x \n", param);
	return 0;
}

int midi_adlibemu_event(guint8 command, guint8 note, guint8 velocity, guint32 delta) {
	guint8 channel, oper;

	channel = command & 0x0f;
	oper = command & 0xf0;

	switch (oper) {
	case 0x80:
		return adlibemu_stop_note(channel, note, velocity);
	case 0x90:  /* noteon and noteoff */
		return adlibemu_start_note(channel, note, velocity);
	case 0xe0: { /* Pitch bend */
		int bend = (note & 0x7f) | ((velocity & 0x7f) << 7);
//      printf("Bend to %d\n", bend);
		adlibemu_update_pitch(channel, note, bend);
	}
	case 0xb0:    /* CC changes. */
		switch (note) {
		case 0x07:
			vol[channel] = velocity;
			break;
		case 0x0a:
			pan[channel] = velocity;
			break;
		case 0x4b:
			break;
		case 0x7b:  { /* all notes off */
			int i = 0;
			for (i = 0;i < ADLIB_VOICES;i++)
				if (oper_chn[i] == channel)
					adlibemu_stop_note(channel, oper_note[i], 0);
			break;
		}
		default:
			; /* XXXX ignore everything else for now */
		}
		return 0;
	case 0xd0:    /* aftertouch */
		/* XXX Aftertouch in the OPL thing? */
		return 0;
	default:
		printf("ADLIB: Unknown event %02x\n", command);
		return 0;
	}

	return 0;
}

int midi_adlibemu_event2(guint8 command, guint8 param, guint32 delta) {
	guint8 channel;
	guint8 oper;

	channel = command & 0x0f;
	oper = command & 0xf0;
	switch (oper) {
	case 0xc0:   /* change instrument */
#ifdef DEBUG_ADLIB
		printf("ADLIB: Selecting instrument %d on channel %d\n", param, channel);
#endif
		instr[channel] = param;
		return 0;
	default:
		printf("ADLIB: Unknown event %02x\n", command);
	}

	return 0;
}

static void
opl2_volume(sfx_softseq_t *self, int volume) {
	guint8 i;

	i = (guint8)volume * 15 / 100;

	adlib_master = i;

#ifdef DEBUG_ADLIB
	printf("ADLIB: master volume set to %d\n", adlib_master);
#endif
}

int
opl2_set_option(sfx_softseq_t *self, const char *name, const char *value) {
	return SFX_ERROR;
}

void
opl2_event(sfx_softseq_t *self, byte cmd, int argc, byte *argv) {
	if (argc == 1)
		midi_adlibemu_event2(cmd, argv[0], 0);
	else if (argc == 2)
		midi_adlibemu_event(cmd, argv[0], argv[1], 0);
}

/* the driver struct */

sfx_softseq_t sfx_softseq_opl2 = {
	"adlibemu",
	"0.1",
	opl2_set_option,
	opl2_init,
	opl2_exit,
	opl2_volume,
	opl2_event,
	opl2_poll,
	opl2_allstop,
	NULL,
	3,	/* use patch.003 */
	SFX_SEQ_PATCHFILE_NONE,
	0x4,	/* Play flags */
	0,	/* No rhythm channel (9) */
	ADLIB_VOICES, /* # of voices */
	{SAMPLE_RATE, CHANNELS, SFX_PCM_FORMAT_S16_NATIVE}
};