/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2004 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Library General Public

    License as published by the Free Software Foundation; either

    version 2 of the License, or (at your option) any later version.

    This library 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

    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public

    License along with this library; if not, write to the Free

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

    Sam Lantinga

    slouken@libsdl.org

*/

#include "SDL_config.h"

#include <errno.h>

#include <unistd.h>

#include <fcntl.h>

#include <signal.h>

#include <sys/types.h>

#include <sys/time.h>

#include <sched.h>

#include <sys/select.h>

#include <sys/neutrino.h>

#include <sys/asoundlib.h>

#include "SDL_timer.h"

#include "SDL_audio.h"

#include "../SDL_audiomem.h"

#include "../SDL_audio_c.h"

#include "SDL_nto_audio.h"

/* The tag name used by NTO audio */

#define DRIVER_NAME "qsa-nto"

/* default channel communication parameters */

#define DEFAULT_CPARAMS_RATE 22050

#define DEFAULT_CPARAMS_VOICES 1

/* FIXME: need to add in the near future flexible logic with frag_size and frags count */

#define DEFAULT_CPARAMS_FRAG_SIZE 4096

#define DEFAULT_CPARAMS_FRAGS_MIN 1

#define DEFAULT_CPARAMS_FRAGS_MAX 1

/* Open the audio device for playback, and don't block if busy */

#define OPEN_FLAGS SND_PCM_OPEN_PLAYBACK

#define QSA_NO_WORKAROUNDS  0x00000000

#define QSA_MMAP_WORKAROUND 0x00000001

struct BuggyCards

{

   char* cardname;

   unsigned long bugtype;

};

#define QSA_WA_CARDS 3

struct BuggyCards buggycards[QSA_WA_CARDS]=

{

   {"Sound Blaster Live!", QSA_MMAP_WORKAROUND},

   {"Vortex 8820",         QSA_MMAP_WORKAROUND},

   {"Vortex 8830",         QSA_MMAP_WORKAROUND},

};

/* Audio driver functions */

static void NTO_ThreadInit(_THIS);

static int NTO_OpenAudio(_THIS, SDL_AudioSpec* spec);

static void NTO_WaitAudio(_THIS);

static void NTO_PlayAudio(_THIS);

static Uint8* NTO_GetAudioBuf(_THIS);

static void NTO_CloseAudio(_THIS);

/* card names check to apply the workarounds */

static int NTO_CheckBuggyCards(_THIS, unsigned long checkfor)

{

    char scardname[33];

    int it;

    if (snd_card_get_name(cardno, scardname, 32)<0)

    {

        return 0;

    }

    for (it=0; it<QSA_WA_CARDS; it++)

    {

       if (SDL_strcmp(buggycards[it].cardname, scardname)==0)

       {

          if (buggycards[it].bugtype==checkfor)

          {

              return 1;

          }

       }

    }

    return 0;

}

static void NTO_ThreadInit(_THIS)

{

   int status;

   struct sched_param param;

   /* increasing default 10 priority to 25 to avoid jerky sound */

   status=SchedGet(0, 0, &param);

   param.sched_priority=param.sched_curpriority+15;

   status=SchedSet(0, 0, SCHED_NOCHANGE, &param);

}

/* PCM transfer channel parameters initialize function */

static void NTO_InitAudioParams(snd_pcm_channel_params_t* cpars)

{

    SDL_memset(cpars, 0, sizeof(snd_pcm_channel_params_t));

    cpars->channel = SND_PCM_CHANNEL_PLAYBACK;

    cpars->mode = SND_PCM_MODE_BLOCK;

    cpars->start_mode = SND_PCM_START_DATA;

    cpars->stop_mode  = SND_PCM_STOP_STOP;

    cpars->format.format = SND_PCM_SFMT_S16_LE;

    cpars->format.interleave = 1;

    cpars->format.rate = DEFAULT_CPARAMS_RATE;

    cpars->format.voices = DEFAULT_CPARAMS_VOICES;

    cpars->buf.block.frag_size = DEFAULT_CPARAMS_FRAG_SIZE;

    cpars->buf.block.frags_min = DEFAULT_CPARAMS_FRAGS_MIN;

    cpars->buf.block.frags_max = DEFAULT_CPARAMS_FRAGS_MAX;

}

static int NTO_AudioAvailable(void)

{

    /*  See if we can open a nonblocking channel.

        Return value '1' means we can.

        Return value '0' means we cannot. */

    int available;

    int rval;

    snd_pcm_t* handle;

    available = 0;

    handle = NULL;

    rval = snd_pcm_open_preferred(&handle, NULL, NULL, OPEN_FLAGS);

    if (rval >= 0)

    {

        available = 1;

        if ((rval = snd_pcm_close(handle)) < 0)

        {

            SDL_SetError("NTO_AudioAvailable(): snd_pcm_close failed: %s\n", snd_strerror(rval));

            available = 0;

        }

    }

    else

    {

        SDL_SetError("NTO_AudioAvailable(): there are no available audio devices.\n");

    }

    return (available);

}

static void NTO_DeleteAudioDevice(SDL_AudioDevice *device)

{

    if ((device)&&(device->hidden))

    {

        SDL_free(device->hidden);

    }

    if (device)

    {

        SDL_free(device);

    }

}

static SDL_AudioDevice* NTO_CreateAudioDevice(int devindex)

{

    SDL_AudioDevice *this;

    /* Initialize all variables that we clean on shutdown */

    this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));

    if (this)

    {

        SDL_memset(this, 0, sizeof(SDL_AudioDevice));

        this->hidden = (struct SDL_PrivateAudioData *)SDL_malloc(sizeof(struct SDL_PrivateAudioData));

    }

    if ((this == NULL) || (this->hidden == NULL))

    {

        SDL_OutOfMemory();

        if (this)

        {

            SDL_free(this);

	}

        return (0);

    }

    SDL_memset(this->hidden, 0, sizeof(struct SDL_PrivateAudioData));

    audio_handle = NULL;

    /* Set the function pointers */

    this->ThreadInit = NTO_ThreadInit;

    this->OpenAudio = NTO_OpenAudio;

    this->WaitAudio = NTO_WaitAudio;

    this->PlayAudio = NTO_PlayAudio;

    this->GetAudioBuf = NTO_GetAudioBuf;

    this->CloseAudio = NTO_CloseAudio;

    this->free = NTO_DeleteAudioDevice;

    return this;

}

AudioBootStrap QNXNTOAUDIO_bootstrap =

{

    DRIVER_NAME, "QNX6 QSA-NTO Audio",

    NTO_AudioAvailable,

    NTO_CreateAudioDevice

};

/* This function waits until it is possible to write a full sound buffer */

static void NTO_WaitAudio(_THIS)

{

    fd_set wfds;

    int selectret;

    FD_ZERO(&wfds);

    FD_SET(audio_fd, &wfds);

    do {

        selectret=select(audio_fd + 1, NULL, &wfds, NULL, NULL);

        switch (selectret)

        {

            case -1:

            case  0: SDL_SetError("NTO_WaitAudio(): select() failed: %s\n", strerror(errno));

                     return;

            default: if (FD_ISSET(audio_fd, &wfds))

                     {

                         return;

                     }

                     break;

        }

    } while(1);

}

static void NTO_PlayAudio(_THIS)

{

    int written, rval;

    int towrite;

    void* pcmbuffer;

    if (!this->enabled)

    {

        return;

    }

    towrite = this->spec.size;

    pcmbuffer = pcm_buf;

    /* Write the audio data, checking for EAGAIN (buffer full) and underrun */

    do {

        written = snd_pcm_plugin_write(audio_handle, pcm_buf, towrite);

        if (written != towrite)

        {

            if ((errno == EAGAIN) || (errno == EWOULDBLOCK))

            {

                /* Let a little CPU time go by and try to write again */

                SDL_Delay(1);

                /* if we wrote some data */

                towrite -= written;

                pcmbuffer += written * this->spec.channels;

                continue;

            }		

            else

            {

                if ((errno == EINVAL) || (errno == EIO))

                {

                    SDL_memset(&cstatus, 0, sizeof(cstatus));

                    cstatus.channel = SND_PCM_CHANNEL_PLAYBACK;

                    if ((rval = snd_pcm_plugin_status(audio_handle, &cstatus)) < 0)

                    {

                        SDL_SetError("NTO_PlayAudio(): snd_pcm_plugin_status failed: %s\n", snd_strerror(rval));

                        return;

                    }	

                    if ((cstatus.status == SND_PCM_STATUS_UNDERRUN) || (cstatus.status == SND_PCM_STATUS_READY))

                    {

                        if ((rval = snd_pcm_plugin_prepare(audio_handle, SND_PCM_CHANNEL_PLAYBACK)) < 0)

                        {

                            SDL_SetError("NTO_PlayAudio(): snd_pcm_plugin_prepare failed: %s\n", snd_strerror(rval));

                            return;

                        }

                    }		        		

                    continue;

                }

                else

                {

                    return;

                }

            }

        }

        else

        {

            /* we wrote all remaining data */

            towrite -= written;

            pcmbuffer += written * this->spec.channels;

        }

    } while ((towrite > 0)  && (this->enabled));

    /* If we couldn't write, assume fatal error for now */

    if (towrite != 0)

    {

        this->enabled = 0;

    }

    return;

}

static Uint8* NTO_GetAudioBuf(_THIS)

{

    return pcm_buf;

}

static void NTO_CloseAudio(_THIS)

{

    int rval;

    this->enabled = 0;

    if (audio_handle != NULL)

    {

        if ((rval = snd_pcm_plugin_flush(audio_handle, SND_PCM_CHANNEL_PLAYBACK)) < 0)

        {

            SDL_SetError("NTO_CloseAudio(): snd_pcm_plugin_flush failed: %s\n", snd_strerror(rval));

            return;

        }

        if ((rval = snd_pcm_close(audio_handle)) < 0)

        {

            SDL_SetError("NTO_CloseAudio(): snd_pcm_close failed: %s\n",snd_strerror(rval));

            return;

        }

        audio_handle = NULL;

    }

}

static int NTO_OpenAudio(_THIS, SDL_AudioSpec* spec)

{

    int rval;

    int format;

    Uint16 test_format;

    int found;

    audio_handle = NULL;

    this->enabled = 0;

    if (pcm_buf != NULL)

    {

        SDL_FreeAudioMem(pcm_buf); 

        pcm_buf = NULL;

    }

    /* initialize channel transfer parameters to default */

    NTO_InitAudioParams(&cparams);

    /* Open the audio device */

    rval = snd_pcm_open_preferred(&audio_handle, &cardno, &deviceno, OPEN_FLAGS);

    if (rval < 0)

    {

        SDL_SetError("NTO_OpenAudio(): snd_pcm_open failed: %s\n", snd_strerror(rval));

        return (-1);

    }

    if (!NTO_CheckBuggyCards(this, QSA_MMAP_WORKAROUND))

    {

        /* enable count status parameter */

        if ((rval = snd_pcm_plugin_set_disable(audio_handle, PLUGIN_DISABLE_MMAP)) < 0)

        {

            SDL_SetError("snd_pcm_plugin_set_disable failed: %s\n", snd_strerror(rval));

            return (-1);

        }

    }

    /* Try for a closest match on audio format */

    format = 0;

    /* can't use format as SND_PCM_SFMT_U8 = 0 in nto */

    found = 0;

    for (test_format=SDL_FirstAudioFormat(spec->format); !found ;)

    {

        /* if match found set format to equivalent ALSA format */

        switch (test_format)

        {

            case AUDIO_U8:

                           format = SND_PCM_SFMT_U8;

                           found = 1;

                           break;

            case AUDIO_S8:

                           format = SND_PCM_SFMT_S8;

                           found = 1;

                           break;

            case AUDIO_S16LSB:

                           format = SND_PCM_SFMT_S16_LE;

                           found = 1;

                           break;

            case AUDIO_S16MSB:

                           format = SND_PCM_SFMT_S16_BE;

                           found = 1;

                           break;

            case AUDIO_U16LSB:

                           format = SND_PCM_SFMT_U16_LE;

                           found = 1;

                           break;

            case AUDIO_U16MSB:

                           format = SND_PCM_SFMT_U16_BE;

                           found = 1;

                           break;

            default:

                           break;

        }

        if (!found)

        {

            test_format = SDL_NextAudioFormat();

        }

    }

    /* assumes test_format not 0 on success */

    if (test_format == 0)

    {

        SDL_SetError("NTO_OpenAudio(): Couldn't find any hardware audio formats");

        return (-1);

    }

    spec->format = test_format;

    /* Set the audio format */

    cparams.format.format = format;

    /* Set mono or stereo audio (currently only two channels supported) */

    cparams.format.voices = spec->channels;

    /* Set rate */

    cparams.format.rate = spec->freq;

    /* Setup the transfer parameters according to cparams */

    rval = snd_pcm_plugin_params(audio_handle, &cparams);

    if (rval < 0)

    {

        SDL_SetError("NTO_OpenAudio(): snd_pcm_channel_params failed: %s\n", snd_strerror(rval));

        return (-1);

    }

    /* Make sure channel is setup right one last time */

    SDL_memset(&csetup, 0x00, sizeof(csetup));

    csetup.channel = SND_PCM_CHANNEL_PLAYBACK;

    if (snd_pcm_plugin_setup(audio_handle, &csetup) < 0)

    {

        SDL_SetError("NTO_OpenAudio(): Unable to setup playback channel\n");

        return -1;

    }

    /* Calculate the final parameters for this audio specification */

    SDL_CalculateAudioSpec(spec);

    pcm_len = spec->size;

    if (pcm_len==0)

    {

        pcm_len = csetup.buf.block.frag_size * spec->channels * (snd_pcm_format_width(format)/8);

    }

    /* Allocate memory to the audio buffer and initialize with silence (Note that

       buffer size must be a multiple of fragment size, so find closest multiple)

    */

    pcm_buf = (Uint8*)SDL_AllocAudioMem(pcm_len);

    if (pcm_buf == NULL)

    {

        SDL_SetError("NTO_OpenAudio(): pcm buffer allocation failed\n");

        return (-1);

    }

    SDL_memset(pcm_buf, spec->silence, pcm_len);

    /* get the file descriptor */

    if ((audio_fd = snd_pcm_file_descriptor(audio_handle, SND_PCM_CHANNEL_PLAYBACK)) < 0)

    {

        SDL_SetError("NTO_OpenAudio(): snd_pcm_file_descriptor failed with error code: %s\n", snd_strerror(rval));

        return (-1);

    }

    /* Trigger audio playback */

    rval = snd_pcm_plugin_prepare(audio_handle, SND_PCM_CHANNEL_PLAYBACK);

    if (rval < 0)

    {

        SDL_SetError("snd_pcm_plugin_prepare failed: %s\n", snd_strerror(rval));

        return (-1);

    }

    this->enabled = 1;

    /* Get the parent process id (we're the parent of the audio thread) */

    parent = getpid();

    /* We're really ready to rock and roll. :-) */

    return (0);

}