//********************************** Banshee Engine (www.banshee3d.com) **************************************************//
//**************** Copyright (c) 2016 Marko Pintera (marko.pintera@gmail.com). All rights reserved. **********************//
#include "Importer/BsImporter.h"
#include "Resources/BsResource.h"
#include "FileSystem/BsFileSystem.h"
#include "Importer/BsSpecificImporter.h"
#include "Importer/BsShaderIncludeImporter.h"
#include "Importer/BsImportOptions.h"
#include "Debug/BsDebug.h"
#include "FileSystem/BsDataStream.h"
#include "Error/BsException.h"
#include "Utility/BsUUID.h"
#include "Resources/BsResources.h"

namespace bs
{
	Importer::Importer()
	{
		_registerAssetImporter(bs_new<ShaderIncludeImporter>());
	}

	Importer::~Importer()
	{
		for(auto i = mAssetImporters.begin(); i != mAssetImporters.end(); ++i)
		{
			if((*i) != nullptr)
				bs_delete(*i);
		}

		mAssetImporters.clear();
	}

	bool Importer::supportsFileType(const WString& extension) const
	{
		for(auto iter = mAssetImporters.begin(); iter != mAssetImporters.end(); ++iter)
		{
			if(*iter != nullptr && (*iter)->isExtensionSupported(extension))
				return true;
		}

		return false;
	}

	bool Importer::supportsFileType(const UINT8* magicNumber, UINT32 magicNumSize) const
	{
		for(auto iter = mAssetImporters.begin(); iter != mAssetImporters.end(); ++iter)
		{
			if(*iter != nullptr && (*iter)->isMagicNumberSupported(magicNumber, magicNumSize))
				return true;
		}

		return false;
	}

	HResource Importer::import(const Path& inputFilePath, SPtr<const ImportOptions> importOptions, const String& UUID)
	{
		if(!FileSystem::isFile(inputFilePath))
		{
			LOGWRN("Trying to import asset that doesn't exists. Asset path: " + inputFilePath.toString());
			return HResource();
		}

		SpecificImporter* importer = getImporterForFile(inputFilePath);
		if(importer == nullptr)
			return HResource();

		if(importOptions == nullptr)
			importOptions = importer->getDefaultImportOptions();
		else
		{
			SPtr<const ImportOptions> defaultImportOptions = importer->getDefaultImportOptions();
			if(importOptions->getTypeId() != defaultImportOptions->getTypeId())
			{
				BS_EXCEPT(InvalidParametersException, "Provided import options is not of valid type. " \
					"Expected: " + defaultImportOptions->getTypeName() + ". Got: " + importOptions->getTypeName() + ".");
			}
		}

		SPtr<Resource> importedResource = importer->import(inputFilePath, importOptions);

		if(UUID.empty())
			return gResources()._createResourceHandle(importedResource);

		return gResources()._createResourceHandle(importedResource, UUID);
	}

	Vector<SubResource> Importer::importAll(const Path& inputFilePath, SPtr<const ImportOptions> importOptions)
	{
		Vector<SubResource> output;

		Vector<SubResourceRaw> importedResource = _importAllRaw(inputFilePath, importOptions);
		for(auto& entry : importedResource)
		{
			HResource handle = gResources()._createResourceHandle(entry.value);

			output.push_back({ entry.name, handle });
		}

		return output;
	}

	Vector<SubResourceRaw> Importer::_importAllRaw(const Path& inputFilePath, SPtr<const ImportOptions> importOptions)
	{
		if (!FileSystem::isFile(inputFilePath))
		{
			LOGWRN("Trying to import asset that doesn't exists. Asset path: " + inputFilePath.toString());
			return Vector<SubResourceRaw>();
		}

		SpecificImporter* importer = getImporterForFile(inputFilePath);
		if (importer == nullptr)
			return Vector<SubResourceRaw>();

		if (importOptions == nullptr)
			importOptions = importer->getDefaultImportOptions();
		else
		{
			SPtr<const ImportOptions> defaultImportOptions = importer->getDefaultImportOptions();
			if (importOptions->getTypeId() != defaultImportOptions->getTypeId())
			{
				BS_EXCEPT(InvalidParametersException, "Provided import options is not of valid type. " \
					"Expected: " + defaultImportOptions->getTypeName() + ". Got: " + importOptions->getTypeName() + ".");
			}
		}

		return importer->importAll(inputFilePath, importOptions);
	}

	void Importer::reimport(HResource& existingResource, const Path& inputFilePath, SPtr<const ImportOptions> importOptions)
	{
		if(!FileSystem::isFile(inputFilePath))
		{
			LOGWRN("Trying to import asset that doesn't exists. Asset path: " + inputFilePath.toString());
			return;
		}

		SpecificImporter* importer = getImporterForFile(inputFilePath);
		if(importer == nullptr)
			return;

		if(importOptions == nullptr)
			importOptions = importer->getDefaultImportOptions();
		else
		{
			SPtr<const ImportOptions> defaultImportOptions = importer->getDefaultImportOptions();
			if(importOptions->getTypeId() != defaultImportOptions->getTypeId())
			{
				BS_EXCEPT(InvalidParametersException, "Provided import options is not of valid type. " \
					"Expected: " + defaultImportOptions->getTypeName() + ". Got: " + importOptions->getTypeName() + ".");
			}
		}

		SPtr<Resource> importedResource = importer->import(inputFilePath, importOptions);
		gResources().update(existingResource, importedResource);
	}

	SPtr<ImportOptions> Importer::createImportOptions(const Path& inputFilePath)
	{
		if(!FileSystem::isFile(inputFilePath))
		{
			LOGWRN("Trying to import asset that doesn't exists. Asset path: " + inputFilePath.toString());
			return nullptr;
		}

		SpecificImporter* importer = getImporterForFile(inputFilePath);
		if(importer == nullptr)
			return nullptr;

		return importer->createImportOptions();
	}

	void Importer::_registerAssetImporter(SpecificImporter* importer)
	{
		if(!importer)
		{
			LOGWRN("Trying to register a null asset importer!");
			return;
		}

		mAssetImporters.push_back(importer);
	}

	SpecificImporter* Importer::getImporterForFile(const Path& inputFilePath) const
	{
		WString ext = inputFilePath.getWExtension();
		if (ext.empty())
			return nullptr;

		ext = ext.substr(1, ext.size() - 1); // Remove the .
		if(!supportsFileType(ext))
		{
			LOGWRN("There is no importer for the provided file type. (" + inputFilePath.toString() + ")");
			return nullptr;
		}

		for(auto iter = mAssetImporters.begin(); iter != mAssetImporters.end(); ++iter)
		{
			if(*iter != nullptr && (*iter)->isExtensionSupported(ext))
			{
				return *iter;
			}
		}

		return nullptr;
	}

	BS_CORE_EXPORT Importer& gImporter()
	{
		return Importer::instance();
	}
}