From 304bf35c08fb76dbb233cc335d0a16cfd5a2c836 Mon Sep 17 00:00:00 2001
From: SirLynix <lynix680@gmail.com>
Date: Thu, 2 Feb 2023 18:30:36 +0100
Subject: [PATCH] Core/AppFilesystemComponent: Add Open method

---
 .../Nazara/Core/AppFilesystemComponent.hpp    |  4 ++
 .../Nazara/Core/AppFilesystemComponent.inl    | 59 +++++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/include/Nazara/Core/AppFilesystemComponent.hpp b/include/Nazara/Core/AppFilesystemComponent.hpp
index 89bb3ae81..dbffb7c86 100644
--- a/include/Nazara/Core/AppFilesystemComponent.hpp
+++ b/include/Nazara/Core/AppFilesystemComponent.hpp
@@ -43,6 +43,9 @@ namespace Nz
 			inline const VirtualDirectoryPtr& Mount(std::string_view name, std::filesystem::path filepath);
 			inline const VirtualDirectoryPtr& Mount(std::string_view name, VirtualDirectoryPtr directory);
 
+			template<typename T> std::shared_ptr<T> Open(std::string_view assetPath);
+			template<typename T> std::shared_ptr<T> Open(std::string_view assetPath, typename T::Params params);
+
 			template<typename T> void SetDefaultResourceParameters(typename T::Params params);
 
 			AppFilesystemComponent& operator=(const AppFilesystemComponent&) = delete;
@@ -52,6 +55,7 @@ namespace Nz
 
 		private:
 			template<typename T> std::shared_ptr<T> LoadImpl(std::string_view assetPath, const typename T::Params& params);
+			template<typename T> std::shared_ptr<T> OpenImpl(std::string_view assetPath, const typename T::Params& params);
 
 			std::vector<std::unique_ptr<ResourceParameters>> m_defaultParameters;
 			VirtualDirectoryPtr m_rootDirectory;
diff --git a/include/Nazara/Core/AppFilesystemComponent.inl b/include/Nazara/Core/AppFilesystemComponent.inl
index 833e2d168..ae310025d 100644
--- a/include/Nazara/Core/AppFilesystemComponent.inl
+++ b/include/Nazara/Core/AppFilesystemComponent.inl
@@ -72,6 +72,24 @@ namespace Nz
 		return m_rootDirectory->StoreDirectory(name, std::move(directory)).directory;
 	}
 
+	template<typename T>
+	std::shared_ptr<T> AppFilesystemComponent::Open(std::string_view assetPath)
+	{
+		return Open<T>(assetPath, typename T::Params{});
+	}
+
+	template<typename T>
+	std::shared_ptr<T> AppFilesystemComponent::Open(std::string_view assetPath, typename T::Params params)
+	{
+		if constexpr (Detail::ResourceParameterHasMerge<typename T::Params>::value)
+		{
+			if (const auto* defaultParams = GetDefaultResourceParameters<T>())
+				params.Merge(*defaultParams);
+		}
+
+		return OpenImpl<T>(assetPath, params);
+	}
+
 	template<typename T>
 	void AppFilesystemComponent::SetDefaultResourceParameters(typename T::Params params)
 	{
@@ -154,6 +172,47 @@ namespace Nz
 		m_rootDirectory->GetEntry(assetPath, callback);
 		return resource;
 	}
+
+	template<typename T>
+	std::shared_ptr<T> AppFilesystemComponent::OpenImpl(std::string_view assetPath, const typename T::Params& params)
+	{
+		std::shared_ptr<T> resource;
+		if (!m_rootDirectory)
+			return resource;
+
+		auto callback = [&](const VirtualDirectory::Entry& entry)
+		{
+			return std::visit([&](auto&& arg)
+			{
+				using Param = std::decay_t<decltype(arg)>;
+				if constexpr (std::is_base_of_v<VirtualDirectory::DirectoryEntry, Param>)
+				{
+					NazaraError(std::string(assetPath) + " is a directory");
+					return false;
+				}
+				else if constexpr (std::is_same_v<Param, VirtualDirectory::DataPointerEntry>)
+				{
+					resource = T::OpenFromMemory(arg.data, arg.size, params);
+					return true;
+				}
+				else if constexpr (std::is_same_v<Param, VirtualDirectory::FileContentEntry>)
+				{
+					resource = T::OpenFromMemory(&arg.data[0], arg.data.size(), params);
+					return true;
+				}
+				else if constexpr (std::is_same_v<Param, VirtualDirectory::PhysicalFileEntry>)
+				{
+					resource = T::OpenFromFile(arg.filePath, params);
+					return true;
+				}
+				else
+					static_assert(AlwaysFalse<Param>(), "unhandled case");
+			}, entry);
+		};
+
+		m_rootDirectory->GetEntry(assetPath, callback);
+		return resource;
+	}
 }
 
 #include <Nazara/Core/DebugOff.hpp>