/**
 * OpenAL cross platform audio library
 * Copyright (C) 1999-2007 by authors.
 * 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 Software Foundation, Inc., 59 Temple Place - Suite 330,
 *  Boston, MA  02111-1307, USA.
 * Or go to http://www.gnu.org/copyleft/lgpl.html
 */

#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "alMain.h"
#include "AL/al.h"
#include "AL/alc.h"
#ifdef HAVE_DLFCN_H
#include <dlfcn.h>
#endif

#include <portaudio.h>

static void *pa_handle;
#define MAKE_FUNC(x) static typeof(x) * p##x
MAKE_FUNC(Pa_Initialize);
MAKE_FUNC(Pa_GetErrorText);
MAKE_FUNC(Pa_StartStream);
MAKE_FUNC(Pa_StopStream);
MAKE_FUNC(Pa_OpenStream);
MAKE_FUNC(Pa_CloseStream);
MAKE_FUNC(Pa_GetDefaultOutputDevice);
#undef MAKE_FUNC


static char *pa_device;

typedef struct {
    PaStream *stream;
} pa_data;


static int pa_callback(const void *inputBuffer, void *outputBuffer,
                       unsigned long framesPerBuffer, const PaStreamCallbackTimeInfo *timeInfo,
                       const PaStreamCallbackFlags statusFlags, void *userData)
{
    ALCdevice *device = (ALCdevice*)userData;
    int frameSize;

    (void)inputBuffer;
    (void)timeInfo;
    (void)statusFlags;

    frameSize  = aluBytesFromFormat(device->Format);
    frameSize *= aluChannelsFromFormat(device->Format);

    SuspendContext(NULL);
    aluMixData(device->Context, outputBuffer, framesPerBuffer*frameSize, device->Format);
    ProcessContext(NULL);

    return 0;
}


static ALCboolean pa_open_playback(ALCdevice *device, const ALCchar *deviceName)
{
    PaStreamParameters outParams;
    pa_data *data;
    int periods;
    PaError err;

    if(pa_handle == NULL)
        return ALC_FALSE;

    if(deviceName)
    {
        if(strcmp(deviceName, pa_device) != 0)
            return ALC_FALSE;
    }

    device->szDeviceName = pa_device;

    data = (pa_data*)calloc(1, sizeof(pa_data));
    device->ExtraData = data;

    outParams.device = GetConfigValueInt("port", "device", -1);
    if(outParams.device < 0)
        outParams.device = pPa_GetDefaultOutputDevice();
    outParams.suggestedLatency = (float)device->UpdateSize /
                                 (float)device->Frequency;
    outParams.hostApiSpecificStreamInfo = NULL;

    switch(aluBytesFromFormat(device->Format))
    {
        case 1:
            outParams.sampleFormat = paUInt8;
            break;
        case 2:
            outParams.sampleFormat = paInt16;
            break;
        default:
            outParams.sampleFormat = -1;
            AL_PRINT("Unknown format?! %x\n", device->Format);
    }

    periods = GetConfigValueInt("port", "periods", 4);
    if((int)periods <= 0)
        periods = 4;
    outParams.channelCount = aluChannelsFromFormat(device->Format);

    err = pPa_OpenStream(&data->stream, NULL, &outParams, device->Frequency,
                        device->UpdateSize/periods, paNoFlag,
                        pa_callback, device);
    if(err != paNoError)
    {
        AL_PRINT("Pa_OpenStream() returned an error: %s\n", pPa_GetErrorText(err));
        device->ExtraData = NULL;
        free(data);
        return ALC_FALSE;
    }

    err = pPa_StartStream(data->stream);
    if(err != paNoError)
    {
        AL_PRINT("Pa_StartStream() returned an error: %s\n", pPa_GetErrorText(err));
        pPa_CloseStream(data->stream);
        device->ExtraData = NULL;
        free(data);
        return ALC_FALSE;
    }

    device->UpdateSize /= periods;
    return ALC_TRUE;
}

static void pa_close_playback(ALCdevice *device)
{
    pa_data *data = (pa_data*)device->ExtraData;
    PaError err;

    err = pPa_StopStream(data->stream);
    if(err != paNoError)
      fprintf(stderr, "Error stopping stream: %s\n", pPa_GetErrorText(err));

    err = pPa_CloseStream(data->stream);
    if(err != paNoError)
        fprintf(stderr, "Error closing stream: %s\n", pPa_GetErrorText(err));

    free(data);
    device->ExtraData = NULL;
}


static ALCboolean pa_open_capture(ALCdevice *device, const ALCchar *deviceName, ALCuint frequency, ALCenum format, ALCsizei SampleSize)
{
    return ALC_FALSE;
    (void)device;
    (void)deviceName;
    (void)frequency;
    (void)format;
    (void)SampleSize;
}



static const BackendFuncs pa_funcs = {
    pa_open_playback,
    pa_close_playback,
    pa_open_capture,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL
};

void alc_pa_init(BackendFuncs *func_list)
{
    const char *str;
    PaError err;

    *func_list = pa_funcs;

#ifdef HAVE_DLFCN_H
#if defined(__APPLE__) && defined(__MACH__)
# define PALIB "libportaudio.2.dylib"
#else
# define PALIB "libportaudio.so.2"
#endif
    pa_handle = dlopen(PALIB, RTLD_NOW);
    if(!pa_handle)
        return;
    dlerror();

#define LOAD_FUNC(f) do { \
    p##f = (typeof(f)*)dlsym(pa_handle, #f); \
    if((str=dlerror()) != NULL) \
    { \
        dlclose(pa_handle); \
        pa_handle = NULL; \
        AL_PRINT("Could not load %s from "PALIB": %s\n", #f, str); \
        return; \
    } \
} while(0)
#else
    str = NULL;
    pa_handle = (void*)0xDEADBEEF;
#define LOAD_FUNC(f) p##f = f
#endif

    LOAD_FUNC(Pa_Initialize);
    LOAD_FUNC(Pa_GetErrorText);
    LOAD_FUNC(Pa_StartStream);
    LOAD_FUNC(Pa_StopStream);
    LOAD_FUNC(Pa_OpenStream);
    LOAD_FUNC(Pa_CloseStream);
    LOAD_FUNC(Pa_GetDefaultOutputDevice);
#undef LOAD_FUNC

    if((err=pPa_Initialize()) != paNoError)
    {
        AL_PRINT("Pa_Initialize() returned an error: %s\n", pPa_GetErrorText(err));
        return;
    }

    pa_device = AppendDeviceList("PortAudio Software");
    AppendAllDeviceList(pa_device);
}