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

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

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


typedef struct {
    // MMSYSTEM Capture Device
    ALboolean        bWaveInShutdown;
    HANDLE           hWaveInHdrEvent;
    HANDLE           hWaveInThreadEvent;
    HANDLE           hWaveInThread;
    DWORD            ulWaveInThreadID;
    ALint            lWaveInBuffersCommitted;
    HWAVEIN          hWaveInHandle;
    WAVEHDR          WaveInBuffer[4];
    ALCchar          *pCapturedSampleData;
    ALuint           ulCapturedDataSize;
    ALuint           ulReadCapturedDataPos;
    ALuint           ulWriteCapturedDataPos;
} WinMMData;


static ALCchar *CaptureDeviceList[16];

/*
    WaveInProc

    Posts a message to 'CaptureThreadProc' everytime a WaveIn Buffer is completed and
    returns to the application (with more data)
*/
static void CALLBACK WaveInProc(HWAVEIN hDevice,UINT uMsg,DWORD_PTR dwInstance,DWORD_PTR dwParam1,DWORD_PTR dwParam2)
{
    ALCdevice *pDevice = (ALCdevice *)dwInstance;
    WinMMData *pData = pDevice->ExtraData;

    (void)hDevice;
    (void)dwParam2;

    if ((uMsg==WIM_DATA) && (pDevice))
    {
        // Decrement number of buffers in use
        pData->lWaveInBuffersCommitted--;

        if (pData->bWaveInShutdown == AL_FALSE)
        {
            // Notify Wave Processor Thread that a Wave Header has returned
            PostThreadMessage(pData->ulWaveInThreadID,uMsg,0,dwParam1);
        }
        else
        {
            if (pData->lWaveInBuffersCommitted == 0)
            {
                // Signal Wave Buffers Returned event
                if (pData->hWaveInHdrEvent)
                    SetEvent(pData->hWaveInHdrEvent);

                // Post 'Quit' Message to WaveIn Processor Thread
                PostThreadMessage(pData->ulWaveInThreadID,WM_QUIT,0,0);
            }
        }
    }
}

/*
    CaptureThreadProc

    Used by "MMSYSTEM" Device.  Called when a WaveIn buffer had been filled with new
    audio data.
*/
DWORD WINAPI CaptureThreadProc(LPVOID lpParameter)
{
    ALCdevice *pDevice = (ALCdevice*)lpParameter;
    WinMMData *pData = pDevice->ExtraData;
    ALuint ulOffset, ulMaxSize, ulSection;
    LPWAVEHDR pWaveHdr;
    MSG msg;

    while (GetMessage(&msg, NULL, 0, 0))
    {
        if ((msg.message==WIM_DATA)&&(!pData->bWaveInShutdown))
        {
            SuspendContext(NULL);

            pWaveHdr = ((LPWAVEHDR)msg.lParam);

            // Calculate offset in local buffer to write data to
            ulOffset = pData->ulWriteCapturedDataPos % pData->ulCapturedDataSize;

            if ((ulOffset + pWaveHdr->dwBytesRecorded) > pData->ulCapturedDataSize)
            {
                ulSection = pData->ulCapturedDataSize - ulOffset;
                memcpy(pData->pCapturedSampleData + ulOffset, pWaveHdr->lpData, ulSection);
                memcpy(pData->pCapturedSampleData, pWaveHdr->lpData + ulSection, pWaveHdr->dwBytesRecorded - ulSection);
            }
            else
            {
                memcpy(pData->pCapturedSampleData + ulOffset, pWaveHdr->lpData, pWaveHdr->dwBytesRecorded);
            }

            pData->ulWriteCapturedDataPos += pWaveHdr->dwBytesRecorded;

            if (pData->ulWriteCapturedDataPos > (pData->ulReadCapturedDataPos + pData->ulCapturedDataSize))
            {
                // Application has not read enough audio data from the capture buffer so data has been
                // overwritten.  Reset ReadPosition.
                pData->ulReadCapturedDataPos = pData->ulWriteCapturedDataPos - pData->ulCapturedDataSize;
            }

            // To prevent an over-flow prevent the offset values from getting too large
            ulMaxSize = pData->ulCapturedDataSize << 4;
            if ((pData->ulReadCapturedDataPos > ulMaxSize) && (pData->ulWriteCapturedDataPos > ulMaxSize))
            {
                pData->ulReadCapturedDataPos -= ulMaxSize;
                pData->ulWriteCapturedDataPos -= ulMaxSize;
            }

            // Send buffer back to capture more data
            waveInAddBuffer(pData->hWaveInHandle,pWaveHdr,sizeof(WAVEHDR));
            pData->lWaveInBuffersCommitted++;

            ProcessContext(NULL);
        }
    }

    // Signal Wave Thread completed event
    if (pData->hWaveInThreadEvent)
        SetEvent(pData->hWaveInThreadEvent);

    ExitThread(0);

    return 0;
}


static ALCboolean WinMMOpenPlayback(ALCdevice *device, const ALCchar *deviceName)
{
    (void)device;
    (void)deviceName;
    return ALC_FALSE;
}

static void WinMMClosePlayback(ALCdevice *device)
{
    (void)device;
}


static ALCboolean WinMMOpenCapture(ALCdevice *pDevice, const ALCchar *deviceName, ALCuint frequency, ALCenum format, ALCsizei SampleSize)
{
    WAVEFORMATEX wfexCaptureFormat;
    WinMMData *pData = NULL;
    ALint lDeviceID = 0;
    ALint lBufferSize;
    ALint i;

    (void)format;

    // Find the Device ID matching the deviceName if valid
    if (deviceName)
    {
        for(i = 0;CaptureDeviceList[i];i++)
        {
            if (!strcmp(deviceName, CaptureDeviceList[i]))
            {
                lDeviceID = i;
                break;
            }
        }
        if(!CaptureDeviceList[i])
            return ALC_FALSE;
    }
    pDevice->szDeviceName = CaptureDeviceList[lDeviceID];

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

    memset(&wfexCaptureFormat, 0, sizeof(WAVEFORMATEX));
    wfexCaptureFormat.wFormatTag = WAVE_FORMAT_PCM;
    wfexCaptureFormat.nChannels = pDevice->Channels;
    wfexCaptureFormat.wBitsPerSample = pDevice->FrameSize / pDevice->Channels * 8;
    wfexCaptureFormat.nBlockAlign = pDevice->FrameSize;
    wfexCaptureFormat.nSamplesPerSec = frequency;
    wfexCaptureFormat.nAvgBytesPerSec = wfexCaptureFormat.nSamplesPerSec *
                                        pDevice->FrameSize;
    wfexCaptureFormat.cbSize = 0;

    if (waveInOpen(&pData->hWaveInHandle, lDeviceID, &wfexCaptureFormat, (DWORD_PTR)&WaveInProc, (DWORD_PTR)pDevice, CALLBACK_FUNCTION) != MMSYSERR_NOERROR)
        goto failure;

    pData->hWaveInHdrEvent = CreateEvent(NULL, AL_TRUE, AL_FALSE, "WaveInAllHeadersReturned");
    if (pData->hWaveInHdrEvent == NULL)
        goto failure;

    pData->hWaveInThreadEvent = CreateEvent(NULL, AL_TRUE, AL_FALSE, "WaveInThreadDestroyed");
    if (pData->hWaveInThreadEvent == NULL)
        goto failure;

    pData->hWaveInThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)CaptureThreadProc, (LPVOID)pDevice, 0, &pData->ulWaveInThreadID);
    if (pData->hWaveInThread == NULL)
        goto failure;

    // Allocate circular memory buffer for the captured audio
    pData->ulCapturedDataSize = SampleSize * wfexCaptureFormat.nBlockAlign;

    // Make sure circular buffer is at least 100ms in size (and an exact multiple of
    // the block alignment
    if (pData->ulCapturedDataSize < (wfexCaptureFormat.nAvgBytesPerSec / 10))
    {
        pData->ulCapturedDataSize = wfexCaptureFormat.nAvgBytesPerSec / 10;
        pData->ulCapturedDataSize -= (pData->ulCapturedDataSize % wfexCaptureFormat.nBlockAlign);
    }

    pData->pCapturedSampleData = (ALCchar*)malloc(pData->ulCapturedDataSize);
    pData->lWaveInBuffersCommitted=0;

    // Create 4 Buffers of 50ms each
    lBufferSize = wfexCaptureFormat.nAvgBytesPerSec / 20;
    lBufferSize -= (lBufferSize % wfexCaptureFormat.nBlockAlign);

    for (i=0;i<4;i++)
    {
        memset(&pData->WaveInBuffer[i], 0, sizeof(WAVEHDR));
        pData->WaveInBuffer[i].dwBufferLength = lBufferSize;
        pData->WaveInBuffer[i].lpData = calloc(1,pData->WaveInBuffer[i].dwBufferLength);
        pData->WaveInBuffer[i].dwFlags = 0;
        pData->WaveInBuffer[i].dwLoops = 0;
        waveInPrepareHeader(pData->hWaveInHandle, &pData->WaveInBuffer[i], sizeof(WAVEHDR));
        waveInAddBuffer(pData->hWaveInHandle, &pData->WaveInBuffer[i], sizeof(WAVEHDR));
        pData->lWaveInBuffersCommitted++;
    }

    pData->ulReadCapturedDataPos = 0;
    pData->ulWriteCapturedDataPos = 0;

    pDevice->ExtraData = pData;
    return ALC_TRUE;

failure:
    if (pData->hWaveInThreadEvent)
        CloseHandle(pData->hWaveInThreadEvent);
    if (pData->hWaveInHdrEvent)
        CloseHandle(pData->hWaveInHdrEvent);
    if (pData->hWaveInHandle)
        waveInClose(pData->hWaveInHandle);

    free(pData);
    return ALC_FALSE;
}

static void WinMMCloseCapture(ALCdevice *pDevice)
{
    WinMMData *pData = (WinMMData*)pDevice->ExtraData;
    int i;

    // Call waveOutReset to shutdown wave device
    pData->bWaveInShutdown = AL_TRUE;
    waveInReset(pData->hWaveInHandle);

    // Wait for signal that all Wave Buffers have returned
    WaitForSingleObjectEx(pData->hWaveInHdrEvent, 5000, FALSE);

    // Wait for signal that Wave Thread has been destroyed
    WaitForSingleObjectEx(pData->hWaveInThreadEvent, 5000, FALSE);

    // Release the wave buffers
    for (i=0;i<4;i++)
    {
        waveInUnprepareHeader(pData->hWaveInHandle, &pData->WaveInBuffer[i], sizeof(WAVEHDR));
        free(pData->WaveInBuffer[i].lpData);
    }

    // Free Audio Buffer data
    free(pData->pCapturedSampleData);
    pData->pCapturedSampleData = NULL;

    // Close the Wave device
    waveInClose(pData->hWaveInHandle);
    pData->hWaveInHandle = 0;

    CloseHandle(pData->hWaveInThread);
    pData->hWaveInThread = 0;

    if (pData->hWaveInHdrEvent)
    {
        CloseHandle(pData->hWaveInHdrEvent);
        pData->hWaveInHdrEvent = 0;
    }

    if (pData->hWaveInThreadEvent)
    {
        CloseHandle(pData->hWaveInThreadEvent);
        pData->hWaveInThreadEvent = 0;
    }

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

static void WinMMStartCapture(ALCdevice *pDevice)
{
    WinMMData *pData = (WinMMData*)pDevice->ExtraData;
    waveInStart(pData->hWaveInHandle);
}

static void WinMMStopCapture(ALCdevice *pDevice)
{
    WinMMData *pData = (WinMMData*)pDevice->ExtraData;
    waveInStop(pData->hWaveInHandle);
}

static void WinMMCaptureSamples(ALCdevice *pDevice, ALCvoid *pBuffer, ALCuint lSamples)
{
    WinMMData *pData = (WinMMData*)pDevice->ExtraData;
    ALuint ulSamples = (unsigned long)lSamples;
    ALuint ulBytes, ulBytesToCopy;
    ALuint ulCapturedSamples;
    ALuint ulReadOffset;

    // Check that we have the requested numbers of Samples
    ulCapturedSamples = (pData->ulWriteCapturedDataPos - pData->ulReadCapturedDataPos) / pDevice->FrameSize;
    if(ulSamples > ulCapturedSamples)
    {
        SetALCError(ALC_INVALID_VALUE);
        return;
    }

    ulBytes = ulSamples * pDevice->FrameSize;

    // Get Read Offset
    ulReadOffset = (pData->ulReadCapturedDataPos % pData->ulCapturedDataSize);

    // Check for wrap-around condition
    if ((ulReadOffset + ulBytes) > pData->ulCapturedDataSize)
    {
        // Copy data from last Read position to end of data
        ulBytesToCopy = pData->ulCapturedDataSize - ulReadOffset;
        memcpy(pBuffer, pData->pCapturedSampleData + ulReadOffset, ulBytesToCopy);

        // Copy rest of the data from the start of the captured data
        memcpy(((char *)pBuffer) + ulBytesToCopy, pData->pCapturedSampleData, ulBytes - ulBytesToCopy);
    }
    else
    {
        // Copy data from the read position in the captured data
        memcpy(pBuffer, pData->pCapturedSampleData + ulReadOffset, ulBytes);
    }

    // Update Read Position
    pData->ulReadCapturedDataPos += ulBytes;
}

static ALCuint WinMMAvailableSamples(ALCdevice *pDevice)
{
    WinMMData *pData = (WinMMData*)pDevice->ExtraData;
    ALCuint lCapturedBytes = (pData->ulWriteCapturedDataPos - pData->ulReadCapturedDataPos);
    return lCapturedBytes / pDevice->FrameSize;
}


BackendFuncs WinMMFuncs = {
    WinMMOpenPlayback,
    WinMMClosePlayback,
    WinMMOpenCapture,
    WinMMCloseCapture,
    WinMMStartCapture,
    WinMMStopCapture,
    WinMMCaptureSamples,
    WinMMAvailableSamples
};

void alcWinMMInit(BackendFuncs *FuncList)
{
    ALint lNumDevs;
    ALint lLoop;

    *FuncList = WinMMFuncs;

    lNumDevs = waveInGetNumDevs();
    for (lLoop = 0; lLoop < lNumDevs; lLoop++)
    {
        WAVEINCAPS WaveInCaps;
        if(waveInGetDevCaps(lLoop, &WaveInCaps, sizeof(WAVEINCAPS)) == MMSYSERR_NOERROR)
        {
            char name[128];
            snprintf(name, sizeof(name), "WaveIn on %s", WaveInCaps.szPname);
            CaptureDeviceList[lLoop] = AppendCaptureDeviceList(name);
        }
    }
}