//
// Copyright (c) Microsoft Corporation.  All rights reserved.
//
//
// Use of this sample source code is subject to the terms of the Microsoft
// license agreement under which you licensed this sample source code. If
// you did not accept the terms of the license agreement, you are not
// authorized to use this sample source code. For the terms of the license,
// please see the license agreement between you and Microsoft or, if applicable,
// see the LICENSE.RTF on your install media or the root of your tools installation.
// THE SAMPLE SOURCE CODE IS PROVIDED "AS IS", WITH NO WARRANTIES.
//
/* 
** Copyright 2000-2003 Intel Corporation All Rights Reserved.
**
** Portions of the source code contained or described herein and all documents
** related to such source code (Material) are owned by Intel Corporation
** or its suppliers or licensors and is licensed by Microsoft Corporation for distribution.  
** Title to the Material remains with Intel Corporation or its suppliers and licensors. 
** Use of the Materials is subject to the terms of the Microsoft license agreement which accompanied the Materials.  
** No other license under any patent, copyright, trade secret or other intellectual
** property right is granted to or conferred upon you by disclosure or
** delivery of the Materials, either expressly, by implication, inducement,
** estoppel or otherwise 
** Some portion of the Materials may be copyrighted by Microsoft Corporation.
*/
#include "wavemain.h"

HRESULT StreamContext::Open(DeviceContext *pDeviceContext, LPWAVEOPENDESC lpWOD, DWORD dwFlags)
{
    m_RefCount = 1;
    m_pDeviceContext = pDeviceContext;
    m_pfnCallback = (DRVCALLBACK *)lpWOD->dwCallback;
    m_dwInstance  = lpWOD->dwInstance;
    m_hWave       = lpWOD->hWave;
    m_dwFlags     = dwFlags;
    m_bRunning    = FALSE;
    m_bForceSpeaker = FALSE;

    // If it's a PCMWAVEFORMAT struct, it's smaller than a WAVEFORMATEX struct (it doesn't have the cbSize field),
    // so don't copy too much or we risk a fault if the structure is located on the end of a page.
    // All other non-PCM wave formats share the WAVEFORMATEX base structure
    // Note: I don't keep around anything after the cbSize of the WAVEFORMATEX struct so that I don't need to
    // worry about allocating additional space. If we need to keep this info around in the future, we can either
    // allocate it dynamically here, or keep the information in any derived format-specific classes.
    DWORD dwSize;
    WAVEFORMATEX *pwfx = lpWOD->lpFormat;
    if (pwfx->wFormatTag == WAVE_FORMAT_PCM)
    {
        dwSize = sizeof(PCMWAVEFORMAT);
        m_WaveFormat.cbSize = 0;
    }
    else
    {
        dwSize = sizeof(WAVEFORMATEX);
    }

    memcpy(&m_WaveFormat,pwfx,dwSize);

    m_lpWaveHdrHead    = NULL;
    m_lpWaveHdrTail    = NULL;
    m_lpWaveHdrCurrent = NULL;
    m_lpCurrData       = NULL;
    m_lpCurrDataEnd    = NULL;
    m_dwByteCount      = 0;
    m_dwLoopCount = 0;

    m_SecondaryGainClass=0;
    SetGain(pDeviceContext->GetDefaultStreamGain()); // Set gain to default value

    // DEBUGMSG(1, (TEXT("Opening stream 0x%x\r\n"),this));

    // Add stream to list. This will start playback.
    pDeviceContext->NewStream(this);

    DoCallbackStreamOpened();

    return S_OK;
}

DWORD StreamContext::Close()
{
    if (StillPlaying())
    {
        return WAVERR_STILLPLAYING;
    }

    // Be sure to turn off speaker if we turned it on.
    ForceSpeaker(FALSE);

    // DEBUGMSG(1, (TEXT("Closing stream 0x%x\r\n"),this));
    DoCallbackStreamClosed();

    return MMSYSERR_NOERROR;
}

// Assumes lock is taken
LONG StreamContext::AddRef()
{
    LONG RefCount = ++m_RefCount;
//    DEBUGMSG(1, (TEXT("AddRef stream 0x%x, RefCount=%d\r\n"),this,RefCount));
    return RefCount;
}

// Assumes lock is taken
LONG StreamContext::Release()
{
    LONG RefCount = --m_RefCount;

//    DEBUGMSG(1, (TEXT("Releasing stream 0x%x, RefCount=%d\r\n"),this,RefCount));
    if (RefCount==0)
    {
        // DEBUGMSG(1, (TEXT("Deleting stream 0x%x\r\n"),this));
        // Only remove stream from list when all refcounts are gone.
        m_pDeviceContext->DeleteStream(this);
        delete this;
    }
    return RefCount;
}

DWORD StreamContext::QueueBuffer(LPWAVEHDR lpWaveHdr)
{
    if (!(lpWaveHdr->dwFlags & WHDR_PREPARED))
    {
        return WAVERR_UNPREPARED;
    }

    lpWaveHdr->dwFlags |= WHDR_INQUEUE;
    lpWaveHdr->dwFlags &= ~WHDR_DONE;
    lpWaveHdr->lpNext=NULL;
    lpWaveHdr->dwBytesRecorded=0;

    if (!m_lpWaveHdrHead)
    {
        m_lpWaveHdrHead = lpWaveHdr;
    }
    else
    {
        m_lpWaveHdrTail->lpNext=lpWaveHdr;
    }

    m_lpWaveHdrTail=lpWaveHdr;

    // Note: Even if head & tail are valid, current may be NULL if we're in the middle of
    // a loop and ran out of data. So, we need to check specifically against current to
    // decide if we need to initialize it.
    if (!m_lpWaveHdrCurrent)
    {
        m_lpWaveHdrCurrent = lpWaveHdr;
        m_lpCurrData    = (PBYTE)lpWaveHdr->lpData;
        m_lpCurrDataEnd = (PBYTE)lpWaveHdr->lpData + lpWaveHdr->dwBufferLength;
        if (lpWaveHdr->dwFlags & WHDR_BEGINLOOP)    // if this is the start of a loop block
        {
            m_dwLoopCount = lpWaveHdr->dwLoops;     // save # of loops
        }
    }

    if (m_bRunning)
    {
        m_pDeviceContext->StreamReadyToRender(this);
    }

    return MMSYSERR_NOERROR;
}

// Note: I've found that when we return used buffers, the wave manager may
// call back into the wave driver in the same thread context to close the stream when
// we return the last buffer.
// If it wasn't the last buffer, the close call will return MMSYSERR_STILLPLAYING.
// However, if it was the last buffer, the close will proceed, and the
// stream may be deleted out from under us. Note that a Lock won't help us here,
// since we're in the same thread which already owns the lock.
// The solution to this is the AddRef/Release use on the stream context, which keeps it
// around if we're acessing it, even if it's closed.

// Assumes lock is taken
PBYTE StreamContext::GetNextBuffer()
{
    LPWAVEHDR lpOldHdr;
    LPWAVEHDR lpNewHdr;
    LPSTR pNewBuf=NULL;

    // Get a pointer to the current buffer which is now done being processed
    lpOldHdr=m_lpWaveHdrCurrent;

    if (!lpOldHdr)
    {
        return NULL;
    }

    // Are we in a loop
    // Note: a loopcount of 1 means we're not really in a loop
    if (m_dwLoopCount>1)
    {
        // We're in a loop!
        if (lpOldHdr->dwFlags & WHDR_ENDLOOP)
        {
           // In loop, last buffer
            // If dwLoopCount was set to INFINITE, loop forever
            // (Note: this is not explicitly in the wave driver API spec)
            if (m_dwLoopCount!=INFINITE)
            {
           m_dwLoopCount--;                    // decrement loop count
            }
           lpNewHdr=m_lpWaveHdrHead;           // go back to start of loop
        }
        else
        {
           // In loop, intermediate buffer
           lpNewHdr=lpOldHdr->lpNext;          // just go to next buffer in loop block
        }

        lpOldHdr=NULL;
    }
    else
    {
        // Not in a loop; return old buffer and get new buffer
        lpNewHdr=lpOldHdr->lpNext;

        m_lpWaveHdrHead = lpNewHdr;           // reset list head
        if (!lpNewHdr)
        {
            m_lpWaveHdrTail=NULL;             // no new buffer, reset tail to NULL
        }
        else if (lpNewHdr->dwFlags & WHDR_BEGINLOOP)    // if new buffer is start of a loop block
        {
            m_dwLoopCount=lpNewHdr->dwLoops;  // save # of loops
        }
    }

    m_lpWaveHdrCurrent=lpNewHdr;              // save current buffer pointer

    if (lpNewHdr)
    {
        m_lpCurrData    = (PBYTE)lpNewHdr->lpData;  // reinitialize data pointer
        m_lpCurrDataEnd = m_lpCurrData + lpNewHdr->dwBufferLength;
    }
    else
    {
        m_lpCurrData  = NULL;
        m_lpCurrDataEnd = NULL;
    }

    // Return the old buffer
    // This may cause the stream to be destroyed, so make sure that any calls to this function
    // are within an AddRef/Release block
    if (lpOldHdr)
    {
        ReturnBuffer(lpOldHdr);
    }

    return m_lpCurrData;
}

DWORD StreamContext::BreakLoop()
{
    AddRef();

    if (m_dwLoopCount>0)
    {
        m_dwLoopCount = 0;

        LPWAVEHDR lpHdr;
        while (m_lpWaveHdrHead!=m_lpWaveHdrCurrent)
        {
            lpHdr = m_lpWaveHdrHead;
            m_lpWaveHdrHead = lpHdr->lpNext;
            if (m_lpWaveHdrHead==NULL)
            {
                m_lpWaveHdrTail=NULL;
            }
            ReturnBuffer(lpHdr);
        }
    }