/* $Id$ */

/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD 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 General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file win32_s.cpp Handling of sound for Windows. */

#include "../stdafx.h"
#include "../openttd.h"
#include "../driver.h"
#include "../mixer.h"
#include "../core/alloc_func.hpp"
#include "../core/bitmath_func.hpp"
#include "win32_s.h"
#include <windows.h>
#include <mmsystem.h>

static FSoundDriver_Win32 iFSoundDriver_Win32;

static HWAVEOUT _waveout;
static WAVEHDR _wave_hdr[2];
static int _bufsize;
static HANDLE _thread;
static DWORD _threadId;

static void PrepareHeader(WAVEHDR *hdr)
{
	hdr->dwBufferLength = _bufsize * 4;
	hdr->dwFlags = 0;
	hdr->lpData = MallocT<char>(_bufsize * 4);
	if (waveOutPrepareHeader(_waveout, hdr, sizeof(WAVEHDR)) != MMSYSERR_NOERROR) usererror("waveOutPrepareHeader failed");
}

static DWORD WINAPI SoundThread(LPVOID arg)
{
	MSG msg;

	while (_waveout != NULL) {
		for (WAVEHDR *hdr = _wave_hdr; hdr != endof(_wave_hdr); hdr++) {
			if ((hdr->dwFlags & WHDR_INQUEUE) != 0) continue;
			MxMixSamples(hdr->lpData, hdr->dwBufferLength / 4);
			if (waveOutWrite(_waveout, hdr, sizeof(WAVEHDR)) != MMSYSERR_NOERROR) usererror("waveOutWrite failed");
		}

		/* Wait for the device to be closed or ready to play new data. */
		GetMessage(&msg, NULL, MM_WOM_CLOSE, MM_WOM_DONE);
	}

	return 0;
}

const char *SoundDriver_Win32::Start(const char * const *parm)
{
	WAVEFORMATEX wfex;
	wfex.wFormatTag = WAVE_FORMAT_PCM;
	wfex.nChannels = 2;
	wfex.wBitsPerSample = 16;
	wfex.nSamplesPerSec = GetDriverParamInt(parm, "hz", 44100);
	wfex.nBlockAlign = (wfex.nChannels * wfex.wBitsPerSample) / 8;
	wfex.nAvgBytesPerSec = wfex.nSamplesPerSec * wfex.nBlockAlign;

	_bufsize = GetDriverParamInt(parm, "bufsize", (GB(GetVersion(), 0, 8) > 5) ? 8192 : 4096);

	/* Create the sound thread in suspended state because we are not ready to play anything. */
	if (NULL == (_thread = CreateThread(NULL, 8192, SoundThread, 0, CREATE_SUSPENDED, &_threadId))) return "Failed to create thread";

	/* Open the sound device, it will send messages to sound thread. */
	if (waveOutOpen(&_waveout, WAVE_MAPPER, &wfex, (DWORD_PTR)_threadId, 0, CALLBACK_THREAD) != MMSYSERR_NOERROR) return "waveOutOpen failed";

	MxInitialize(wfex.nSamplesPerSec);

	PrepareHeader(&_wave_hdr[0]);
	PrepareHeader(&_wave_hdr[1]);

	/* We are now ready to play sound, so resume the sound thread. */
	ResumeThread(_thread);

	return NULL;
}

void SoundDriver_Win32::Stop()
{
	HWAVEOUT waveout = _waveout;

	/* Break the sound thread loop, but the thread can still be waiting for a message. */
	_waveout = NULL;

	/* Stop the playback (if any) and close the device. This will unlock the thread if it's waiting for a message. */
	waveOutReset(waveout); // Triggers MM_WOM_DONE message if there were pending playbacks.
	waveOutUnprepareHeader(waveout, &_wave_hdr[0], sizeof(WAVEHDR));
	waveOutUnprepareHeader(waveout, &_wave_hdr[1], sizeof(WAVEHDR));
	waveOutClose(waveout); // Triggers MM_WOM_CLOSE message.

	/* Now we can wait for the sound thread to finish because we know it will. */
	WaitForMultipleObjects(1, &_thread, true, INFINITE);
	CloseHandle(_thread);
}