/**
 * 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 <stdlib.h>
#include <stdio.h>
#include <memory.h>

#include <windows.h>
#include <mmsystem.h>
#include <dsound.h>

#include "alMain.h"
#include "AL/al.h"
#include "AL/alc.h"


typedef struct {
    // DirectSound Playback Device
    LPDIRECTSOUND          lpDS;
    LPDIRECTSOUNDBUFFER    DSpbuffer;
    LPDIRECTSOUNDBUFFER    DSsbuffer;

    int killNow;
    ALvoid *thread;
} DSoundData;


static ALCchar *DeviceList[16];


static ALuint DSoundProc(ALvoid *ptr)
{
    ALCdevice *pDevice = (ALCdevice*)ptr;
    DSoundData *pData = (DSoundData*)pDevice->ExtraData;
    DWORD LastCursor = 0;
    DWORD PlayCursor;
    VOID *WritePtr;
    DWORD WriteCnt;
    DWORD avail;
    HRESULT err;

    while(!pData->killNow)
    {
        // Get current play and write cursors
        IDirectSoundBuffer_GetCurrentPosition(pData->DSsbuffer, &PlayCursor, NULL);
        avail = (PlayCursor-LastCursor) % (pDevice->UpdateFreq*pDevice->FrameSize);

        if(avail == 0)
        {
            Sleep(1);
            continue;
        }

        // Lock output buffer
        WriteCnt = 0;
        err = IDirectSoundBuffer_Lock(pData->DSsbuffer, LastCursor, avail, &WritePtr, &WriteCnt, NULL, NULL, 0);

        // If the buffer is lost, restore it, play and lock
        if(err == DSERR_BUFFERLOST)
        {
            err = IDirectSoundBuffer_Restore(pData->DSsbuffer);
            if(SUCCEEDED(err))
                err = IDirectSoundBuffer_Play(pData->DSsbuffer, 0, 0, DSBPLAY_LOOPING);
            if(SUCCEEDED(err))
                err = IDirectSoundBuffer_Lock(pData->DSsbuffer, LastCursor, avail, (LPVOID*)&WritePtr, &WriteCnt, NULL, NULL, 0);
        }

        // Successfully locked the output buffer
        if(SUCCEEDED(err))
        {
            // If we have an active context, mix data directly into output buffer otherwise fill with silence
            SuspendContext(NULL);
            aluMixData(pDevice->Context, WritePtr, WriteCnt, pDevice->Format);
            ProcessContext(NULL);

            // Unlock output buffer only when successfully locked
            IDirectSoundBuffer_Unlock(pData->DSsbuffer, WritePtr, WriteCnt, NULL, 0);
        }
        else
            AL_PRINT("Buffer lock error: %#lx\n", err);

        // Update old write cursor location
        LastCursor += WriteCnt;
        LastCursor %= pDevice->UpdateFreq*pDevice->FrameSize;
    }

    return 0;
}

static ALCboolean DSoundOpenPlayback(ALCdevice *device, const ALCchar *deviceName)
{
    DSBUFFERDESC DSBDescription;
    DSoundData *pData = NULL;
    WAVEFORMATEX OutputType;
    HRESULT hr;

    if(deviceName)
    {
        int i;
        for(i = 0;DeviceList[i];i++)
        {
            if(strcmp(deviceName, DeviceList[i]) == 0)
            {
                device->szDeviceName = DeviceList[i];
                break;
            }
        }
        if(!DeviceList[i])
            return ALC_FALSE;
    }
    else
        device->szDeviceName = DeviceList[0];

    //Platform specific
    memset(&OutputType, 0, sizeof(WAVEFORMATEX));
    OutputType.wFormatTag = WAVE_FORMAT_PCM;
    OutputType.nChannels = device->Channels;
    OutputType.wBitsPerSample = aluBytesFromFormat(device->Format) * 8;
    OutputType.nBlockAlign = OutputType.nChannels*OutputType.wBitsPerSample/8;
    OutputType.nSamplesPerSec = device->Frequency;
    OutputType.nAvgBytesPerSec = OutputType.nSamplesPerSec*OutputType.nBlockAlign;
    OutputType.cbSize = 0;

    //Initialise requested device

    pData = calloc(1, sizeof(DSoundData));
    if(!pData)
    {
        SetALCError(ALC_OUT_OF_MEMORY);
        return ALC_FALSE;
    }

    //Init COM
    CoInitialize(NULL);

    //DirectSound Init code
    hr = CoCreateInstance(&CLSID_DirectSound, NULL, CLSCTX_INPROC_SERVER, &IID_IDirectSound, (LPVOID*)&pData->lpDS);
    if(SUCCEEDED(hr))
        hr = IDirectSound_Initialize(pData->lpDS, NULL);
    if(SUCCEEDED(hr))
        hr = IDirectSound_SetCooperativeLevel(pData->lpDS, GetForegroundWindow(), DSSCL_PRIORITY);

    if(SUCCEEDED(hr))
    {
        memset(&DSBDescription,0,sizeof(DSBUFFERDESC));
        DSBDescription.dwSize=sizeof(DSBUFFERDESC);
        DSBDescription.dwFlags=DSBCAPS_PRIMARYBUFFER;
        hr = IDirectSound_CreateSoundBuffer(pData->lpDS, &DSBDescription, &pData->DSpbuffer, NULL);
    }
    if(SUCCEEDED(hr))
        hr = IDirectSoundBuffer_SetFormat(pData->DSpbuffer,&OutputType);

    if(SUCCEEDED(hr))
    {
        memset(&DSBDescription,0,sizeof(DSBUFFERDESC));
        DSBDescription.dwSize=sizeof(DSBUFFERDESC);
        DSBDescription.dwFlags=DSBCAPS_GLOBALFOCUS|DSBCAPS_GETCURRENTPOSITION2;
        DSBDescription.dwBufferBytes=device->UpdateFreq * device->FrameSize;
        DSBDescription.lpwfxFormat=&OutputType;
        hr = IDirectSound_CreateSoundBuffer(pData->lpDS, &DSBDescription, &pData->DSsbuffer, NULL);
    }

    if(SUCCEEDED(hr))
        hr = IDirectSoundBuffer_Play(pData->DSsbuffer, 0, 0, DSBPLAY_LOOPING);

    device->MaxNoOfSources = 256;
    device->ExtraData = pData;

    pData->thread = StartThread(DSoundProc, device);
    if(!pData->thread)
        hr = E_FAIL;

    if(FAILED(hr))
    {
        if (pData->DSsbuffer)
            IDirectSoundBuffer_Release(pData->DSsbuffer);
        if (pData->DSpbuffer)
            IDirectSoundBuffer_Release(pData->DSpbuffer);
        if (pData->lpDS)
            IDirectSound_Release(pData->lpDS);

        free(pData);
        return ALC_FALSE;
    }

    return ALC_TRUE;
}

static void DSoundClosePlayback(ALCdevice *device)
{
    DSoundData *pData = device->ExtraData;

    pData->killNow = 1;
    StopThread(pData->thread);

    IDirectSoundBuffer_Release(pData->DSsbuffer);
    IDirectSoundBuffer_Release(pData->DSpbuffer);
    IDirectSound_Release(pData->lpDS);

    //Deinit COM
    CoUninitialize();

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


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

static void DSoundCloseCapture(ALCdevice *pDevice)
{
    (void)pDevice;
}

static void DSoundStartCapture(ALCdevice *pDevice)
{
    (void)pDevice;
}

static void DSoundStopCapture(ALCdevice *pDevice)
{
    (void)pDevice;
}

static void DSoundCaptureSamples(ALCdevice *pDevice, ALCvoid *pBuffer, ALCuint lSamples)
{
    (void)pDevice;
    (void)pBuffer;
    (void)lSamples;
}

static ALCuint DSoundAvailableSamples(ALCdevice *pDevice)
{
    (void)pDevice;
    return 0;
}


BackendFuncs DSoundFuncs = {
    DSoundOpenPlayback,
    DSoundClosePlayback,
    DSoundOpenCapture,
    DSoundCloseCapture,
    DSoundStartCapture,
    DSoundStopCapture,
    DSoundCaptureSamples,
    DSoundAvailableSamples
};

void alcDSoundInit(BackendFuncs *FuncList)
{
    *FuncList = DSoundFuncs;

    DeviceList[0] = AppendDeviceList("DirectSound Software");
    AppendAllDeviceList(DeviceList[0]);
}