// Copyright (c) 2005, Rodrigo Braz Monteiro
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//   * Redistributions of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//   * Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//   * Neither the name of the Aegisub Group nor the names of its contributors
//     may be used to endorse or promote products derived from this software
//     without specific prior written permission.
//
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// Aegisub Project http://www.aegisub.org/

/// @file avisynth_wrap.cpp
/// @brief Wrapper-layer for Avisynth
/// @ingroup video_input audio_input
///

#ifdef WITH_AVISYNTH
#include "avisynth_wrap.h"

#include "avisynth.h"
#include "options.h"

#include <mutex>

// Allocate storage for and initialise static members
namespace {
	int avs_refcount = 0;
	HINSTANCE hLib = nullptr;
	IScriptEnvironment *env = nullptr;
	std::mutex AviSynthMutex;
}

typedef IScriptEnvironment* __stdcall FUNC(int);

AviSynthWrapper::AviSynthWrapper() {
	if (!avs_refcount++) {
		hLib = LoadLibrary(L"avisynth.dll");

		if (!hLib)
			throw AvisynthError("Could not load avisynth.dll");

		FUNC *CreateScriptEnv = (FUNC*)GetProcAddress(hLib, "CreateScriptEnvironment");
		if (!CreateScriptEnv)
			throw AvisynthError("Failed to get address of CreateScriptEnv from avisynth.dll");

		// Require Avisynth 2.5.6+?
		if (OPT_GET("Provider/Avisynth/Allow Ancient")->GetBool())
			env = CreateScriptEnv(AVISYNTH_INTERFACE_VERSION-1);
		else
			env = CreateScriptEnv(AVISYNTH_INTERFACE_VERSION);

		if (!env)
			throw AvisynthError("Failed to create a new avisynth script environment. Avisynth is too old?");

		// Set memory limit
		const int memoryMax = OPT_GET("Provider/Avisynth/Memory Max")->GetInt();
		if (memoryMax)
			env->SetMemoryMax(memoryMax);
	}
}

AviSynthWrapper::~AviSynthWrapper() {
	if (!--avs_refcount) {
		delete env;
		FreeLibrary(hLib);
	}
}

std::mutex& AviSynthWrapper::GetMutex() const {
	return AviSynthMutex;
}

IScriptEnvironment *AviSynthWrapper::GetEnv() const {
	return env;
}

#endif