/*
Copyright (C) 1996-1997 Id Software, Inc.
Copyright (C) 2015 Marco "eukara" Hladik

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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

#include "globaldef.h"
#include "dumb.h"
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/shm.h>
#include <sys/wait.h>
#include <linux/soundcard.h>
#include <stdio.h>
#include <errno.h>

// eukara - added in tracker playback using DUMB - UNIX ONLY!
char name[256];
DUH *trackmod; 		// The music file ~eukara
DUH_SIGRENDERER *sr; 	// The DUMB renderer
int oss_device;	// output device (by default /dev/dsp for OSS)
static qboolean	bTracker_Initialized = false;

// Set up the renderer options
static int 	depth 		= 16;	// by default 16bit, only affects output not internal 32bit processing
static int 	unsign 		= 0;			
static int 	freq 		= 22050;// 22050 is enough for most music
static int 	n_channels 	= 2;	// stereo action
static float 	trackervolume 	= 1.0f; // default volume...?
static float 	delay 		= 0.0f; // You shouldn't need to touch this.
static float 	delta;			// For the speed, combination of frequency
static int 	bufsize;
static qboolean	playing 	= false;// Is the music playing or not?
extern cvar_t	*midivolume;

union {
	short s16[2048];	// was 8192
	char s8[4096]; 		// was twice as the thing above
} tracker_buffer;

void Tracker_Play(byte track, qboolean looping)
{
	if(bTracker_Initialized == false)
		return;

	dumb_register_stdfiles(); // Initialize loading files
	
	// Attempt to load every format imaginable, TODO: better method?
	sprintf (name, "%s/music/track%d.it", com_gamedir, track);
	trackmod = dumb_load_it(name);
	if (!trackmod) {
		sprintf (name, "%s/music/track%d.xm", com_gamedir, track);
		trackmod = dumb_load_xm(name);
		if (!trackmod) {
			sprintf (name, "%s/music/track%d.s3m", com_gamedir, track);
			trackmod = dumb_load_s3m(name);
			if (!trackmod) {
				sprintf (name, "%s/music/track%d.mod", com_gamedir, track);
				trackmod = dumb_load_mod(name);
				if (!trackmod) {
					fprintf(stderr, "Unable to open %s!\n", name);
					return;
				}
			}
		}
	}
	
	// Let us know which track you are playing
	Con_Printf("Playing %s\n", name);
	sr = duh_start_sigrenderer(trackmod, 0, n_channels, 0); // start rendering, action happens in Tracker_Update
	if (!sr) { // If it doesn't want to render, stop it before it's too late
		unload_duh(trackmod); // Unload the track safely
		fprintf(stderr, "Unable to play file!\n");
		return;
	}

	delta = 61536.0f / freq; 		// This affects the speed
	bufsize = depth == 16 ? 2048 : 4096;	// Buffer size, small buffer = laggy music; big buff = laggy game
	bufsize /= n_channels;			// Tell him we are hopefully stereo
	playing = true;				// Announce that we have a track playing
}

void Tracker_Stop(void)
{
	if(bTracker_Initialized == false || playing == false)
		return;
	if(!trackmod || !sr)
		return;

	playing = false;			// Not playing the song anymore to prevent Tracker_Update
	Con_Printf("Stopping %s\n", name);	// Just print that we are stopping whatever track
	duh_end_sigrenderer(sr);		// Stop the renderer safely
	unload_duh(trackmod);			// Unload the song!
}

void Tracker_Pause(void)
{
	if(bTracker_Initialized == false)
		return;

	playing = false;			// Prevent from Tracker_Update from happening
	Con_Printf("Paused %s\n", name);
}

void Tracker_Resume(void)
{
	if(bTracker_Initialized == false)
		return;

	// Just making sure we aren't calling Tracker_Update with no song...
	if(!trackmod || !sr)
		return;

	playing = true;				// Tracker_Update should now be triggered again
	Con_Printf("Resuming %s\n", name);
}

static void Tracker_f (void)
{
	char	*command;
	int		ret;
	int		n;

	if (Cmd_Argc() < 2)
		return;

	command = Cmd_Argv (1);

	if (Q_strcasecmp(command, "play") == 0)
	{
		Tracker_Play((byte)Q_atoi(Cmd_Argv (2)), false);
		return;
	}

	if (Q_strcasecmp(command, "stop") == 0)
	{
		Tracker_Stop();
		return;
	}

	if (Q_strcasecmp(command, "frequency") == 0)
	{
		freq = (int)Q_atoi(Cmd_Argv (2));
		return;
	}

	if (Q_strcasecmp(command, "pause") == 0)
	{
		Tracker_Pause();
		return;
	}

	if (Q_strcasecmp(command, "resume") == 0)
	{
		Tracker_Resume();
		return;
	}
}

void Tracker_Update(void)
{
	int i;

	// Only update when a song is playing and the renderer works...
	if (!sr)
		return;
	if(playing == false)
		return;

	if (midivolume->value != trackervolume)
		trackervolume = midivolume->value;

	// Render the song
	int l = duh_render(sr, depth, unsign, trackervolume, delta, bufsize, &tracker_buffer);
	if (depth == 16) {	// On 16 bit, fill the buffer accordingly
		for (i = 0; i < l * n_channels; i++) {
			short val = tracker_buffer.s16[i];
			tracker_buffer.s8[i*2] = (char)val;
			tracker_buffer.s8[i*2+1] = (char)(val >> 8);
		}
	}

	// TODO: Write this into the engine's soundbuffer instead for speed!
	write (oss_device, &tracker_buffer, 4096);
}

int Tracker_Init(void)
{
	if (COM_CheckParm("-notracker"))
		return -1;

	if((oss_device = open ("/dev/dsp", O_RDWR)) == -1){ // /dev/dsp is the standard OSS output
		perror("/dev/dsp");
		return 0;				    // just get out if there's none
	}

	Cmd_AddCommand ("dumb", Tracker_f);	// link DUMB
	bTracker_Initialized = true;
	Con_Printf("DUMB Initialized\n");	// Tell them we are ready
	return 1;				// return that we have successfully initialised
}

void Tracker_Shutdown(void)
{
	Tracker_Stop();				// First stop the track	
	dumb_exit();				// Kill DUMB
	close(oss_device);			// Close the device
}