// Emacs style mode select   -*- C++ -*- 
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// 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.
//
// $Log:$
//
// DESCRIPTION:  none
//
//-----------------------------------------------------------------------------


#include <stdio.h>
#include <stdlib.h>

#include "i_system.h"
#include "i_sound.h"
#include "sounds.h"
#include "s_sound.h"

#include "z_zone.h"
#include "m_random.h"
#include "w_wad.h"

#include "doomdef.h"
#include "p_local.h"

#include "doomstat.h"


// Purpose?
//const char snd_prefixen[]
//= { 'P', 'P', 'A', 'S', 'S', 'S', 'M', 'M', 'M', 'S', 'S', 'S' };

//#define S_MAX_VOLUME		127

// when to clip out sounds
// Does not fit the large outdoor areas.
#define S_CLIPPING_DIST		(1200*0x10000)

// Distance tp origin when sounds should be maxed out.
// This should relate to movement clipping resolution
// (see BLOCKMAP handling).
// Originally: (200*0x10000).
#define S_CLOSE_DIST		(160*0x10000)


#define S_ATTENUATOR		((S_CLIPPING_DIST-S_CLOSE_DIST)>>FRACBITS)

// Adjustable by menu.
//#define NORM_VOLUME    		snd_MaxVolume

#define NORM_PITCH     		128
#define NORM_SEP		128

//#define S_PITCH_PERTURB		1
#define S_STEREO_SWING		(96*0x10000)

// percent attenuation from front to back
//#define S_IFRACVOL		30

//#define NA			0
//#define S_NUMCHANNELS		2


// Current music/sfx card - index useless
//  w/o a reference LUT in a sound module.
//extern int snd_MusicDevice;
//extern int snd_SfxDevice;
// Config file? Same disclaimer as above.
//extern int snd_DesiredMusicDevice;
//extern int snd_DesiredSfxDevice;



typedef struct
{
    // sound information (if null, channel avail.)
    sfxinfo_t*	sfxinfo;

    // origin of sound
    const mobj_t*	origin;

    // handle of the sound being played
    int		handle;
    
} channel_t;


// the set of channels available
static channel_t*	channels;

// Maximum volume of a sound effect.
// Internal default is max out of 0-127.
static int 		snd_SfxVolume;



// whether songs are mus_paused
static boolean		mus_paused;	

// music currently being played
static musicinfo_t*	mus_playing=0;

// following is set
//  by the defaults code in M_misc:
// number of channels available
int			numChannels;	

//static int		nextcleanup;



//
// Internals.
//
static int
S_getChannel
( const mobj_t*	origin,
  sfxinfo_t*	sfxinfo );


static int
S_AdjustSoundParams
( const mobj_t*	listener,
  const mobj_t*	source,
  int*		vol,
  int*		sep );

static void S_StopChannel(int cnum);



//
// Initializes sound stuff, including volume
// Sets channels, SFX and music volume,
//  allocates channel buffer, sets S_sfx lookup.
//
void S_Init
( int		sfxVolume,
  int		musicVolume )
{  
  int		i;

  fprintf( stderr, "S_Init: default sfx volume %d\n", sfxVolume);

  I_SetChannels(numChannels);
  
  S_SetSfxVolume(sfxVolume);
  S_SetMusicVolume(musicVolume);

  // Allocating the internal channels for mixing
  // (the maximum numer of sounds rendered
  // simultaneously) within zone memory.
  channels =
    (channel_t *) Z_Malloc(numChannels*sizeof(channel_t), PU_STATIC, 0);
  
  // Free all channels for use
  for (i=0 ; i<numChannels ; i++)
    channels[i].sfxinfo = 0;
  
  // no sounds are playing, and they are not mus_paused
  mus_paused = 0;

  // Note that sounds have not been cached (yet).
  for (i=1 ; i<NUMSFX ; i++)
    S_sfx[i].lumpnum = S_sfx[i].usefulness = -1;
}




//
// Per level startup code.
// Kills playing sounds at start of level,
//  determines music if any, changes music.
//
void S_Start(void)
{
  int cnum;
  int mnum;

  // kill all playing sounds at start of level
  //  (trust me - a good idea)
  for (cnum=0 ; cnum<numChannels ; cnum++)
    if (channels[cnum].sfxinfo)
      S_StopChannel(cnum);
  
  // start new music for the level
  mus_paused = 0;
  
  if (gamemode == commercial)
    mnum = mus_runnin + gamemap - 1;
  else
  {
    int spmus[]=
    {
      // Song - Who? - Where?
      
      mus_e3m4,	// American	e4m1
      mus_e3m2,	// Romero	e4m2
      mus_e3m3,	// Shawn	e4m3
      mus_e1m5,	// American	e4m4
      mus_e2m7,	// Tim 	e4m5
      mus_e2m4,	// Romero	e4m6
      mus_e2m6,	// J.Anderson	e4m7 CHIRON.WAD
      mus_e2m5,	// Shawn	e4m8
      mus_e1m9	// Tim		e4m9
    };
    
    if (gameepisode < 4)
      mnum = mus_e1m1 + (gameepisode-1)*9 + gamemap-1;
    else
      mnum = spmus[gamemap-1];
    }	
  
  // HACK FOR COMMERCIAL
  //  if (commercial && mnum > mus_e3m9)	
  //      mnum -= mus_e3m9;
  
  S_ChangeMusic(mnum, true);
  
  //nextcleanup = 15;
}	





void
S_StartSoundAtVolume
( const mobj_t*	origin,
  int		sfx_id,
  int		volume )
{

  int		rc;
  int		sep;
  int		pitch;
  sfxinfo_t*	sfx;
  int		cnum;
  
  
  // Debug.
  /*fprintf( stderr,
  	   "S_StartSoundAtVolume: playing sound %d (%s)\n",
  	   sfx_id, S_sfx[sfx_id].name );*/

#ifdef RANGECHECK
  // check for bogus sound #
  if (sfx_id < 1 || sfx_id > NUMSFX)
    I_Error("Bad sfx #: %d", sfx_id);
#endif

  sfx = &S_sfx[sfx_id];
  
  // Initialize sound parameters
  if (sfx->link)
  {
    pitch = sfx->pitch;
    volume += sfx->volume;
    
    if (volume < 1)
      return;
    
    if (volume > snd_SfxVolume)
      volume = snd_SfxVolume;
  }	
  else
  {
    pitch = NORM_PITCH;
  }


  // Check to see if it is audible,
  //  and if not, modify the params
  if (origin && origin != players[consoleplayer].mo)
  {
    rc = S_AdjustSoundParams(players[consoleplayer].mo,
			     origin,
			     &volume,
			     &sep);
	
    if ( origin->x == players[consoleplayer].mo->x
	 && origin->y == players[consoleplayer].mo->y)
    {	
      sep 	= NORM_SEP;
    }
    
    if (!rc)
      return;
  }	
  else
  {
    sep = NORM_SEP;
  }
  
  // hacks to vary the sfx pitches
  if (sfx_id >= sfx_sawup
      && sfx_id <= sfx_sawhit)
  {	
    pitch += 8 - (M_Random()&15);
    
    if (pitch<0)
      pitch = 0;
    else if (pitch>255)
      pitch = 255;
  }
  else if (sfx_id != sfx_itemup
	   && sfx_id != sfx_tink)
  {
    pitch += 16 - (M_Random()&31);
    
    if (pitch<0)
      pitch = 0;
    else if (pitch>255)
      pitch = 255;
  }

  // kill old sound
  S_StopSound(origin);

  // try to find a channel
  cnum = S_getChannel(origin, sfx);
  
  if (cnum<0)
    return;

  //
  // This is supposed to handle the loading/caching.
  // For some odd reason, the caching is done nearly
  //  each time the sound is needed?
  //
  
  // get lumpnum if necessary
  if (sfx->lumpnum < 0)
    sfx->lumpnum = I_GetSfxLumpNum(sfx);

#ifndef SNDSRV
  // cache data if necessary
  if (!sfx->data)
  {
    fprintf( stderr,
	     "S_StartSoundAtVolume: 16bit and not pre-cached - wtf?\n");

    // DOS remains, 8bit handling
    //sfx->data = (void *) W_CacheLumpNum(sfx->lumpnum, PU_MUSIC);
    // fprintf( stderr,
    //	     "S_StartSoundAtVolume: loading %d (lump %d) : 0x%x\n",
    //       sfx_id, sfx->lumpnum, (int)sfx->data );
    
  }
#endif
  
  // increase the usefulness
  if (sfx->usefulness++ < 0)
    sfx->usefulness = 1;
  
  // Assigns the handle to one of the channels in the
  //  mix/output buffer.
  channels[cnum].handle = I_StartSound(sfx_id,
				       /*sfx->data,*/
				       volume,
				       sep,
				       pitch);
}	

void
S_StartSound
( const mobj_t*	origin,
  int		sfx_id )
{
#ifdef SAWDEBUG
    // if (sfx_id == sfx_sawful)
    // sfx_id = sfx_itemup;
#endif
  
    S_StartSoundAtVolume(origin, sfx_id, snd_SfxVolume);


    // UNUSED. We had problems, had we not?
#ifdef SAWDEBUG
{
    int i;
    int n;
	
    static mobj_t*      last_saw_origins[10] = {1,1,1,1,1,1,1,1,1,1};
    static int		first_saw=0;
    static int		next_saw=0;
	
    if (sfx_id == sfx_sawidl
	|| sfx_id == sfx_sawful
	|| sfx_id == sfx_sawhit)
    {
	for (i=first_saw;i!=next_saw;i=(i+1)%10)
	    if (last_saw_origins[i] != origin)
		fprintf(stderr, "old origin 0x%lx != "
			"origin 0x%lx for sfx %d\n",
			last_saw_origins[i],
			origin,
			sfx_id);
	    
	last_saw_origins[next_saw] = origin;
	next_saw = (next_saw + 1) % 10;
	if (next_saw == first_saw)
	    first_saw = (first_saw + 1) % 10;
	    
	for (n=i=0; i<numChannels ; i++)
	{
	    if (channels[i].sfxinfo == &S_sfx[sfx_sawidl]
		|| channels[i].sfxinfo == &S_sfx[sfx_sawful]
		|| channels[i].sfxinfo == &S_sfx[sfx_sawhit]) n++;
	}
	    
	if (n>1)
	{
	    for (i=0; i<numChannels ; i++)
	    {
		if (channels[i].sfxinfo == &S_sfx[sfx_sawidl]
		    || channels[i].sfxinfo == &S_sfx[sfx_sawful]
		    || channels[i].sfxinfo == &S_sfx[sfx_sawhit])
		{
		    fprintf(stderr,
			    "chn: sfxinfo=0x%lx, origin=0x%lx, "
			    "handle=%d\n",
			    channels[i].sfxinfo,
			    channels[i].origin,
			    channels[i].handle);
		}
	    }
	    fprintf(stderr, "\n");
	}
    }
}
#endif
 
}




void S_StopSound(const mobj_t *origin)
{

    int cnum;

    for (cnum=0 ; cnum<numChannels ; cnum++)
    {
	if (channels[cnum].sfxinfo && channels[cnum].origin == origin)
	{
	    S_StopChannel(cnum);
	    break;
	}
    }
}









//
// Stop and resume music, during game PAUSE.
//
void S_PauseSound(void)
{
    if (mus_playing && !mus_paused)
    {
	I_PauseSong(mus_playing->handle);
	mus_paused = true;
    }
}

void S_ResumeSound(void)
{
    if (mus_playing && mus_paused)
    {
	I_ResumeSong(mus_playing->handle);
	mus_paused = false;
    }
}


//
// Updates music & sounds
//
void S_UpdateSounds(const mobj_t* listener)
{
    int		audible;
    int		cnum;
    int		volume;
    int		sep;
    int		pitch;
    const sfxinfo_t*	sfx;
    const channel_t*	c;


    
    // Clean up unused data.
    // This is currently not done for 16bit (sounds cached static).
    // DOS 8bit remains. 
    /*if (gametic > nextcleanup)
    {
	for (i=1 ; i<NUMSFX ; i++)
	{
	    if (S_sfx[i].usefulness < 1
		&& S_sfx[i].usefulness > -1)
	    {
		if (--S_sfx[i].usefulness == -1)
		{
		    Z_ChangeTag(S_sfx[i].data, PU_CACHE);
		    S_sfx[i].data = 0;
		}
	    }
	}
	nextcleanup = gametic + 15;
    }*/
    
    for (cnum=0 ; cnum<numChannels ; cnum++)
    {
	c = &channels[cnum];
	sfx = c->sfxinfo;

	if (c->sfxinfo)
	{
	    if (I_SoundIsPlaying(c->handle))
	    {
		// initialize parameters
		volume = snd_SfxVolume;
		pitch = NORM_PITCH;
		sep = NORM_SEP;

		if (sfx->link)
		{
		    pitch = sfx->pitch;
		    volume += sfx->volume;
		    if (volume < 1)
		    {
			S_StopChannel(cnum);
			continue;
		    }
		    else if (volume > snd_SfxVolume)
		    {
			volume = snd_SfxVolume;
		    }
		}

		// check non-local sounds for distance clipping
		//  or modify their params
		if (c->origin && listener != c->origin)
		{
		    audible = S_AdjustSoundParams(listener,
						  c->origin,
						  &volume,
						  &sep);
		    
		    if (!audible)
		    {
			S_StopChannel(cnum);
		    }
		    else
			I_UpdateSoundParams(c->handle, volume, sep, pitch);
		}
	    }
	    else
	    {
		// if channel is allocated but sound has stopped,
		//  free it
		S_StopChannel(cnum);
	    }
	}
    }
    // kill music if it is a single-play && finished
    // if (	mus_playing
    //      && !I_QrySongPlaying(mus_playing->handle)
    //      && !mus_paused )
    // S_StopMusic();
}


void S_SetMusicVolume(int volume)
{
#ifdef RANGECHECK
    if (volume < 0 || volume > 127)
	I_Error("Attempt to set music volume at %d", volume);
#endif

    I_SetMusicVolume(volume);
}



void S_SetSfxVolume(int volume)
{
#ifdef RANGECHECK
    if (volume < 0 || volume > 127)
	I_Error("Attempt to set sfx volume at %d", volume);
#endif

    snd_SfxVolume = volume;
}

//
// Starts some music with the music id found in sounds.h.
//
void S_StartMusic(int m_id)
{
    S_ChangeMusic(m_id, false);
}

void
S_ChangeMusic
( int			musicnum,
  boolean		looping )
{
    musicinfo_t*	music;
    char		namebuf[9];

#ifdef RANGECHECK
    if ( (musicnum <= mus_None)
	 || (musicnum >= NUMMUSIC) )
	I_Error("Bad music number %d", musicnum);
#endif

    music = &S_music[musicnum];

    if (mus_playing == music)
	return;

    // shutdown old music
    S_StopMusic();

    // get lumpnum if neccessary
    if (!music->lumpnum)
    {
	sprintf(namebuf, "d_%s", music->name);
	music->lumpnum = W_GetNumForName(namebuf);
    }

    // load & register it
    music->data = W_CacheLumpNum(music->lumpnum, PU_MUSIC);
    size_t size = W_LumpLength(music->lumpnum);
    music->handle = I_RegisterSong(music->data, size);

    // play it
    I_PlaySong(music->handle, looping);

    mus_playing = music;
}


void S_StopMusic(void)
{
    if (mus_playing)
    {
	if (mus_paused)
	    I_ResumeSong(mus_playing->handle);

	I_StopSong(mus_playing->handle);
	I_UnRegisterSong(mus_playing->handle);
	Z_ChangeTag(mus_playing->data, PU_CACHE);
	
	mus_playing->data = 0;
	mus_playing = 0;
    }
}




static void S_StopChannel(int cnum)
{

    int		i;
    channel_t*	c = &channels[cnum];

    if (c->sfxinfo)
    {
	// stop the sound playing
	if (I_SoundIsPlaying(c->handle))
	{
#ifdef SAWDEBUG
	    if (c->sfxinfo == &S_sfx[sfx_sawful])
		fprintf(stderr, "stopped\n");
#endif
	    I_StopSound(c->handle);
	}

	// check to see
	//  if other channels are playing the sound
	for (i=0 ; i<numChannels ; i++)
	{
	    if (cnum != i
		&& c->sfxinfo == channels[i].sfxinfo)
	    {
		break;
	    }
	}
	
	// degrade usefulness of sound data
	c->sfxinfo->usefulness--;

	c->sfxinfo = 0;
    }
}



//
// Changes volume, stereo-separation, and pitch variables
//  from the norm of a sound effect to be played.
// If the sound is not audible, returns a 0.
// Otherwise, modifies parameters and returns 1.
//
static int
S_AdjustSoundParams
( const mobj_t*	listener,
  const mobj_t*	source,
  int*		vol,
  int*		sep )
{
    fixed_t	approx_dist;
    fixed_t	adx;
    fixed_t	ady;
    angle_t	angle;

    // calculate the distance to sound origin
    //  and clip it if necessary
    adx = abs(listener->x - source->x);
    ady = abs(listener->y - source->y);

    // From _GG1_ p.428. Appox. eucledian distance fast.
    approx_dist = adx + ady - ((adx < ady ? adx : ady)>>1);
    
    if ((gamemode == commercial || gamemap != 8)
	&& approx_dist > S_CLIPPING_DIST)
    {
	return 0;
    }
    
    // angle of source to listener
    angle = R_PointToAngle2(listener->x,
			    listener->y,
			    source->x,
			    source->y);

    if (angle > listener->angle)
	angle = angle - listener->angle;
    else
	angle = angle + (0xffffffff - listener->angle);

    angle >>= ANGLETOFINESHIFT;

    // stereo separation
    *sep = 128 - (FixedMul(S_STEREO_SWING,finesine[angle])>>FRACBITS);

    // volume calculation
    if (approx_dist < S_CLOSE_DIST)
    {
	*vol = snd_SfxVolume;
    }
    else if (gamemode != commercial && gamemap == 8)
    {
	// See https://doomwiki.org/wiki/Sound_effects_behave_differently_on_level_8
	if (snd_SfxVolume <= 15)
	{
	    *vol = snd_SfxVolume;
	}
	else
	{
	    if (approx_dist > S_CLIPPING_DIST)
		approx_dist = S_CLIPPING_DIST;

	    *vol = 15+ ((snd_SfxVolume-15)
			*((S_CLIPPING_DIST - approx_dist)>>FRACBITS))
		/ S_ATTENUATOR;
	}
    }
    else
    {
	// distance effect
	*vol = (snd_SfxVolume
		* ((S_CLIPPING_DIST - approx_dist)>>FRACBITS))
	    / S_ATTENUATOR; 
    }
    
    return (*vol > 0);
}




//
// S_getChannel :
//   If none available, return -1.  Otherwise channel #.
//
static int
S_getChannel
( const mobj_t*	origin,
  sfxinfo_t*	sfxinfo )
{
    // channel number to use
    int		cnum;
    
    channel_t*	c;

    // Find an open channel
    for (cnum=0 ; cnum<numChannels ; cnum++)
    {
	if (!channels[cnum].sfxinfo)
	    break;
	else if (origin &&  channels[cnum].origin ==  origin)
	{
	    S_StopChannel(cnum);
	    break;
	}
    }

    // None available
    if (cnum == numChannels)
    {
	// Look for lower priority
	for (cnum=0 ; cnum<numChannels ; cnum++)
	    if (channels[cnum].sfxinfo->priority >= sfxinfo->priority) break;

	if (cnum == numChannels)
	{
	    // FUCK!  No lower priority.  Sorry, Charlie.    
	    return -1;
	}
	else
	{
	    // Otherwise, kick out lower priority.
	    S_StopChannel(cnum);
	}
    }

    c = &channels[cnum];

    // channel is decided to be cnum.
    c->sfxinfo = sfxinfo;
    c->origin = origin;

    return cnum;
}