From 9a223098f658cebd2a7abc173e2392d6d3a4a991 Mon Sep 17 00:00:00 2001
From: Xiao Qi <xiaoqi.loh@digipen.edu>
Date: Thu, 8 Sep 2022 11:17:25 +0800
Subject: [PATCH] Initial Commit

---
 SHADE_Engine/SHADE_Engine.vcxproj            |  2 +
 SHADE_Engine/SHADE_Engine.vcxproj.filters    |  2 +
 SHADE_Engine/src/Filesystem/SHFileSystem.cpp | 75 ++++++++++++++++++++
 SHADE_Engine/src/Filesystem/SHFileSystem.h   | 44 ++++++++++++
 4 files changed, 123 insertions(+)
 create mode 100644 SHADE_Engine/src/Filesystem/SHFileSystem.cpp
 create mode 100644 SHADE_Engine/src/Filesystem/SHFileSystem.h

diff --git a/SHADE_Engine/SHADE_Engine.vcxproj b/SHADE_Engine/SHADE_Engine.vcxproj
index d89ec12a..ba1be338 100644
--- a/SHADE_Engine/SHADE_Engine.vcxproj
+++ b/SHADE_Engine/SHADE_Engine.vcxproj
@@ -103,10 +103,12 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClInclude Include="src\Engine\SHEngine.h" />
+    <ClInclude Include="src\Filesystem\SHFileSystem.h" />
     <ClInclude Include="src\SHpch.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="src\Engine\SHEngine.cpp" />
+    <ClCompile Include="src\Filesystem\SHFileSystem.cpp" />
     <ClCompile Include="src\SHpch.cpp">
       <PrecompiledHeader>Create</PrecompiledHeader>
     </ClCompile>
diff --git a/SHADE_Engine/SHADE_Engine.vcxproj.filters b/SHADE_Engine/SHADE_Engine.vcxproj.filters
index b16c713b..6ca01248 100644
--- a/SHADE_Engine/SHADE_Engine.vcxproj.filters
+++ b/SHADE_Engine/SHADE_Engine.vcxproj.filters
@@ -10,11 +10,13 @@
       <Filter>Engine</Filter>
     </ClInclude>
     <ClInclude Include="src\SHpch.h" />
+    <ClInclude Include="src\Filesystem\SHFileSystem.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="src\Engine\SHEngine.cpp">
       <Filter>Engine</Filter>
     </ClCompile>
     <ClCompile Include="src\SHpch.cpp" />
+    <ClCompile Include="src\Filesystem\SHFileSystem.cpp" />
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/SHADE_Engine/src/Filesystem/SHFileSystem.cpp b/SHADE_Engine/src/Filesystem/SHFileSystem.cpp
new file mode 100644
index 00000000..81ff6a8b
--- /dev/null
+++ b/SHADE_Engine/src/Filesystem/SHFileSystem.cpp
@@ -0,0 +1,75 @@
+#include "SHFileSystem.h"
+#include "fileapi.h"
+#include <cassert>
+
+namespace SHADE
+{
+	char const FOLDER_MAX_COUNT {15};
+
+	std::unordered_map<FolderLocation, std::unique_ptr<SHFolder>> SHFileSystem::folders;
+
+	SHFolder::SHFolder(FolderHandle id, FolderName name)
+		:id{id}, name{name}, subFolders(0)
+	{
+	}
+
+	FolderLocation SHFileSystem::CreateNewFolderHere(FolderName name, FolderLocation here) noexcept
+	{
+		if (here == 0)
+		{
+			if (!folders.contains(0))
+			{
+				folders[0] = std::make_unique<SHFolder>(0, "root");
+			}
+
+			FolderCounter const count = static_cast<FolderCounter>(folders[here]->subFolders.size());
+
+			assert(count < FOLDER_MAX_COUNT, "Max subfolders reached\n");
+
+			FolderHandle const location = static_cast<FolderLocation>(count);
+
+			CreateFolderHelper(folders[0]->path, here, location, name);
+
+			return location;
+		}
+
+		assert(folders.contains(here), "Folder creation location does not exist/invalid\n");
+
+		FolderCounter const count = static_cast<FolderCounter>(folders[here]->subFolders.size());
+
+		FolderHandle location = here;
+		location <<= 4;
+		location |= count;
+
+		assert(count < FOLDER_MAX_COUNT, "Max subfolders reached\n");
+		CreateFolderHelper(folders[0]->path, here, location, name);
+
+		return location;
+	}
+
+	bool SHFileSystem::DeleteFolder(FolderLocation location) noexcept
+	{
+		assert(folders.contains(location), "Delete target does not exist/invalid.\n");
+
+		for (auto const& subFolder : folders[location]->subFolders)
+		{
+			DeleteFolder(subFolder);
+		}
+
+		RemoveDirectoryA(folders[location]->path.string().c_str());
+		return true;
+	}
+
+	bool SHFileSystem::CreateFolderHelper(FolderPath path, FolderLocation parent, FolderHandle location, FolderName name) noexcept
+	{
+		assert(
+			CreateDirectoryA(path.string().c_str(), nullptr),
+			"Failed to create folder\n"
+		);
+
+		folders[location] = std::make_unique<SHFolder>(location, name);
+		folders[parent]->subFolders.push_back(location);
+
+		return true;
+	}
+}
diff --git a/SHADE_Engine/src/Filesystem/SHFileSystem.h b/SHADE_Engine/src/Filesystem/SHFileSystem.h
new file mode 100644
index 00000000..c58eb81e
--- /dev/null
+++ b/SHADE_Engine/src/Filesystem/SHFileSystem.h
@@ -0,0 +1,44 @@
+#pragma once
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <filesystem>
+#include <unordered_map>
+
+namespace SHADE
+{
+	typedef unsigned char FolderCounter;
+	typedef unsigned char FileCounter;
+	typedef uint32_t FolderLocation;
+	typedef uint32_t FolderHandle;
+	typedef std::string FolderName;
+	typedef std::filesystem::path FolderPath;
+
+	class SHFolder
+	{
+	public:
+		SHFolder(FolderHandle id, FolderName name);
+
+		FolderHandle id;
+		FolderName name;
+		std::vector<FolderHandle> subFolders;
+
+	private:
+		FolderPath path;
+		friend class SHFileSystem;
+	};
+
+	class SHFileSystem
+	{
+	public:
+		static FolderLocation CreateNewFolderHere(FolderName name, FolderLocation here = 0) noexcept;
+
+		static bool DeleteFolder(FolderLocation location) noexcept;
+
+	private:
+		static std::unordered_map<FolderLocation, std::unique_ptr<SHFolder>> folders;
+
+		static bool CreateFolderHelper(FolderPath path, FolderLocation parent, FolderHandle location, FolderName name) noexcept;
+	};
+}
\ No newline at end of file