// Copyright Epic Games, Inc. All Rights Reserved.

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using EpicGames.Core;
using Microsoft.Extensions.Logging;
using OpenTracing.Util;
using UnrealBuildBase;

namespace UnrealBuildTool
{
	/// <summary>
	/// Class which compiles (and caches) rules assemblies for different folders.
	/// </summary>
	public class RulesCompiler
	{
		/// <summary>
		/// 
		/// </summary>
		const string FrameworkAssemblyExtension = ".dll";

		/// <summary>
		/// 
		/// </summary>
		const BuildSettingsVersion DefaultEngineBuildSettingsVersion = BuildSettingsVersion.Latest;

		/// <summary>
		/// Find all the module rules files under a given directory
		/// </summary>
		/// <param name="BaseDirectory">The directory to search under</param>
		/// <param name="ModuleContext">The module context for each found rules instance</param>
		/// <param name="ModuleFileToContext">Map of module files to their context</param>
		private static void AddModuleRulesWithContext(DirectoryReference BaseDirectory, ModuleRulesContext ModuleContext, Dictionary<FileReference, ModuleRulesContext> ModuleFileToContext)
		{
			IReadOnlyList<FileReference> RulesFiles = Rules.FindAllRulesFiles(BaseDirectory, Rules.RulesFileType.Module);
			foreach (FileReference RulesFile in RulesFiles)
			{
				ModuleFileToContext[RulesFile] = ModuleContext;
			}
		}

		/// <summary>
		/// Find all the module rules files under a given directory
		/// </summary>
		/// <param name="BaseDirectory">The directory to search under</param>
		/// <param name="SubDirectoryName">Name of the subdirectory to look under</param>
		/// <param name="BaseModuleContext">The module context for each found rules instance</param>
		/// <param name="DefaultUHTModuleType">The UHT module type</param>
		/// <param name="ModuleFileToContext">Map of module files to their context</param>
		private static void AddEngineModuleRulesWithContext(DirectoryReference BaseDirectory, string SubDirectoryName, ModuleRulesContext BaseModuleContext, UHTModuleType? DefaultUHTModuleType, Dictionary<FileReference, ModuleRulesContext> ModuleFileToContext)
		{
			DirectoryReference Directory = DirectoryReference.Combine(BaseDirectory, SubDirectoryName);
			if (DirectoryLookupCache.DirectoryExists(Directory))
			{
				ModuleRulesContext ModuleContext = new ModuleRulesContext(BaseModuleContext) { DefaultUHTModuleType = DefaultUHTModuleType, bCanHotReload = true };
				AddModuleRulesWithContext(Directory, ModuleContext, ModuleFileToContext);
			}
		}

		/// <summary>
		/// The cached rules assembly for engine modules and targets.
		/// </summary>
		private static RulesAssembly? EngineRulesAssembly;

		/// <summary>
		/// Map of assembly names we've already compiled and loaded to their Assembly and list of game folders.  This is used to prevent
		/// trying to recompile the same assembly when ping-ponging between different types of targets
		/// </summary>
		private static ConcurrentDictionary<FileReference, RulesAssembly> LoadedAssemblyMap = new ConcurrentDictionary<FileReference, RulesAssembly>();

		/// <summary>
		/// Creates the engine rules assembly
		/// </summary>
		/// <param name="bUsePrecompiled">Whether to use a precompiled engine</param>
		/// <param name="bSkipCompile">Whether to skip compilation for this assembly</param>
		/// <param name="bForceCompile">Whether to always compile this assembly</param>
		/// <param name="Logger">Logger for output</param>
		/// <returns>New rules assembly</returns>
		public static RulesAssembly CreateEngineRulesAssembly(bool bUsePrecompiled, bool bSkipCompile, bool bForceCompile, ILogger Logger)
		{
			// Prevent multiple conflicting processes building rules assembly at the same time
			string MutexName = GlobalSingleInstanceMutex.GetUniqueMutexForPath("UnrealBuildTool_CreateTargetRulesAssembly", Unreal.EngineDirectory);
			using (new GlobalSingleInstanceMutex(MutexName, true))
			{
				if (EngineRulesAssembly == null)
				{
					List<PluginInfo> EnginePlugins = new List<PluginInfo>();
					List<PluginInfo> MarketplacePlugins = new List<PluginInfo>();

					DirectoryReference MarketplaceDirectory = DirectoryReference.Combine(Unreal.EngineDirectory, "Plugins", "Marketplace");
					foreach (PluginInfo PluginInfo in Plugins.ReadEnginePlugins(Unreal.EngineDirectory))
					{
						if (PluginInfo.File.IsUnderDirectory(MarketplaceDirectory))
						{
							MarketplacePlugins.Add(PluginInfo);
						}
						else
						{
							EnginePlugins.Add(PluginInfo);
						}
					}

					EngineRulesAssembly = CreateEngineRulesAssemblyInternal(Unreal.GetExtensionDirs(Unreal.EngineDirectory), ProjectFileGenerator.EngineRulesAssemblyName, EnginePlugins, Unreal.IsEngineInstalled() || bUsePrecompiled, bSkipCompile, bForceCompile, null, Logger);

					if (MarketplacePlugins.Count > 0)
					{
						EngineRulesAssembly = CreateMarketplaceRulesAssembly(MarketplacePlugins, Unreal.IsEngineInstalled() || bUsePrecompiled, bSkipCompile, bForceCompile, EngineRulesAssembly, Logger);
					}
				}
				return EngineRulesAssembly;
			}
		}

		/// <summary>
		/// Creates a rules assembly
		/// </summary>
		/// <param name="RootDirectories">The root directories to create rules for</param>
		/// <param name="AssemblyPrefix">A prefix for the assembly file name</param>
		/// <param name="Plugins">List of plugins to include in this assembly</param>
		/// <param name="bReadOnly">Whether the assembly should be marked as installed</param>
		/// <param name="bSkipCompile">Whether to skip compilation for this assembly</param>
		/// <param name="bForceCompile">Whether to always compile this assembly</param>
		/// <param name="Parent">The parent rules assembly</param>
		/// <param name="Logger">Logger for output</param>
		/// <returns>New rules assembly</returns>
		private static RulesAssembly CreateEngineRulesAssemblyInternal(List<DirectoryReference> RootDirectories, string AssemblyPrefix, IReadOnlyList<PluginInfo> Plugins, bool bReadOnly, bool bSkipCompile, bool bForceCompile, RulesAssembly? Parent, ILogger Logger)
		{
			// Scope hierarchy
			RulesScope Scope = new RulesScope("Engine", null);
			RulesScope PluginsScope = new RulesScope("Engine Plugins", Scope);
			RulesScope ProgramsScope = new RulesScope("Engine Programs", PluginsScope);

			// Find the shared modules, excluding the programs directory. These are used to create an assembly with the bContainsEngineModules flag set to true.
			Dictionary<FileReference, ModuleRulesContext> ModuleFileToContext = new Dictionary<FileReference, ModuleRulesContext>();
			ModuleRulesContext DefaultModuleContext = new ModuleRulesContext(Scope, RootDirectories[0]);
			List<FileReference> ProgramTargetFiles = new List<FileReference>();

			foreach (DirectoryReference RootDirectory in RootDirectories)
			{
				using (GlobalTracer.Instance.BuildSpan("Finding engine modules").StartActive())
				{
					DirectoryReference SourceDirectory = DirectoryReference.Combine(RootDirectory, "Source");

					AddEngineModuleRulesWithContext(SourceDirectory, "Runtime", DefaultModuleContext, UHTModuleType.EngineRuntime, ModuleFileToContext);
					AddEngineModuleRulesWithContext(SourceDirectory, "Developer", DefaultModuleContext, UHTModuleType.EngineDeveloper, ModuleFileToContext);
					AddEngineModuleRulesWithContext(SourceDirectory, "Editor", DefaultModuleContext, UHTModuleType.EngineEditor, ModuleFileToContext);
					AddEngineModuleRulesWithContext(SourceDirectory, "ThirdParty", DefaultModuleContext, UHTModuleType.EngineThirdParty, ModuleFileToContext);
					AddEngineModuleRulesWithContext(RootDirectory, "Shaders", DefaultModuleContext, UHTModuleType.EngineThirdParty, ModuleFileToContext);
				}
			}

			// Add all the plugin modules too (don't need to loop over RootDirectories since the plugins come in already found
			using (GlobalTracer.Instance.BuildSpan("Finding plugin modules").StartActive())
			{
				ModuleRulesContext PluginsModuleContext = new ModuleRulesContext(PluginsScope, RootDirectories[0]);
				PluginsModuleContext.bCanHotReload = true;
				FindModuleRulesForPlugins(Plugins, PluginsModuleContext, ModuleFileToContext);
				// Plugin test target rules only
				FindTestRulesForPlugins(Plugins, PluginsModuleContext, ModuleFileToContext, ProgramTargetFiles);
			}

			// Create the assembly
			DirectoryReference AssemblyDir = RootDirectories[0];
			FileReference EngineAssemblyFileName = FileReference.Combine(AssemblyDir, "Intermediate", "Build", "BuildRules", AssemblyPrefix + "Rules" + FrameworkAssemblyExtension);
			RulesAssembly EngineAssembly = new RulesAssembly(Scope, RootDirectories, Plugins, ModuleFileToContext, new List<FileReference>(), EngineAssemblyFileName, bContainsEngineModules: true, DefaultBuildSettings: DefaultEngineBuildSettingsVersion, bReadOnly: bReadOnly, bSkipCompile: bSkipCompile, bForceCompile: bForceCompile, Parent: Parent, Logger: Logger);

			Dictionary<FileReference, ModuleRulesContext> ProgramModuleFiles = new Dictionary<FileReference, ModuleRulesContext>();
			foreach (DirectoryReference RootDirectory in RootDirectories)
			{
				DirectoryReference SourceDirectory = DirectoryReference.Combine(RootDirectory, "Source");
				DirectoryReference ProgramsDirectory = DirectoryReference.Combine(SourceDirectory, "Programs");

				// Also create a scope for them, and update the UHT module type
				ModuleRulesContext ProgramsModuleContext = new ModuleRulesContext(ProgramsScope, RootDirectory);
				ProgramsModuleContext.DefaultUHTModuleType = UHTModuleType.Program;

				using (GlobalTracer.Instance.BuildSpan("Finding program modules").StartActive())
				{
					// Find all the rules files
					AddModuleRulesWithContext(ProgramsDirectory, ProgramsModuleContext, ProgramModuleFiles);
				}

				using (GlobalTracer.Instance.BuildSpan("Finding program targets").StartActive())
				{
					ProgramTargetFiles.AddRange(Rules.FindAllRulesFiles(SourceDirectory, Rules.RulesFileType.Target));
				}
			}

			// Create a path to the assembly that we'll either load or compile
			FileReference ProgramAssemblyFileName = FileReference.Combine(AssemblyDir, "Intermediate", "Build", "BuildRules", AssemblyPrefix + "ProgramRules" + FrameworkAssemblyExtension);
			RulesAssembly ProgramAssembly = new RulesAssembly(ProgramsScope, RootDirectories, new List<PluginInfo>().AsReadOnly(), ProgramModuleFiles, ProgramTargetFiles, ProgramAssemblyFileName, bContainsEngineModules: false, DefaultBuildSettings: DefaultEngineBuildSettingsVersion, bReadOnly: bReadOnly, bSkipCompile: bSkipCompile, bForceCompile: bForceCompile, Parent: EngineAssembly, Logger: Logger);

			// Return the combined assembly
			return ProgramAssembly;
		}

		/// <summary>
		/// Creates a rules assembly
		/// </summary>
		/// <param name="Plugins">List of plugins to include in this assembly</param>
		/// <param name="bReadOnly">Whether the assembly should be marked as installed</param>
		/// <param name="bSkipCompile">Whether to skip compilation for this assembly</param>
		/// <param name="bForceCompile">Whether to always compile this assembly</param>
		/// <param name="Parent">The parent rules assembly</param>
		/// <param name="Logger"></param>
		/// <returns>New rules assembly</returns>
		private static RulesAssembly CreateMarketplaceRulesAssembly(IReadOnlyList<PluginInfo> Plugins, bool bReadOnly, bool bSkipCompile, bool bForceCompile, RulesAssembly Parent, ILogger Logger)
		{
			RulesScope MarketplaceScope = new RulesScope("Marketplace", Parent.Scope);

			// Add all the plugin modules too (don't need to loop over RootDirectories since the plugins come in already found
			Dictionary<FileReference, ModuleRulesContext> ModuleFileToContext = new Dictionary<FileReference, ModuleRulesContext>();
			using (GlobalTracer.Instance.BuildSpan("Finding marketplace plugin modules").StartActive())
			{
				ModuleRulesContext PluginsModuleContext = new ModuleRulesContext(MarketplaceScope, Unreal.EngineDirectory);
				FindModuleRulesForPlugins(Plugins, PluginsModuleContext, ModuleFileToContext);
			}

			// Create the assembly
			RulesAssembly Result = Parent;
			if (ModuleFileToContext.Count > 0)
			{
				FileReference AssemblyFileName = FileReference.Combine(Unreal.WritableEngineDirectory, "Intermediate", "Build", "BuildRules", "MarketplaceRules.dll");
				Result = new RulesAssembly(MarketplaceScope, new List<DirectoryReference> { DirectoryReference.Combine(Unreal.EngineDirectory, "Plugins", "Marketplace") }, Plugins, ModuleFileToContext, new List<FileReference>(), AssemblyFileName, bContainsEngineModules: true, DefaultBuildSettings: null, bReadOnly: bReadOnly, bSkipCompile: bSkipCompile, bForceCompile: bForceCompile, Parent: Parent, Logger: Logger);
			}
			return Result;
		}

		/// <summary>
		/// Creates a rules assembly with the given parameters.
		/// </summary>
		/// <param name="ProjectFileName">The project file to create rules for. Null for the engine.</param>
		/// <param name="bUsePrecompiled">Whether to use a precompiled engine</param>
		/// <param name="bSkipCompile">Whether to skip compilation for this assembly</param>
		/// <param name="bForceCompile">Whether to always compile this assembly</param>
		/// <param name="Logger">Logger for output</param>
		/// <returns>New rules assembly</returns>
		public static RulesAssembly CreateProjectRulesAssembly(FileReference ProjectFileName, bool bUsePrecompiled, bool bSkipCompile, bool bForceCompile, ILogger Logger)
		{
			// Prevent multiple conflicting processes building rules assembly at the same time
			string MutexName = GlobalSingleInstanceMutex.GetUniqueMutexForPath("UnrealBuildTool_CreateTargetRulesAssembly", ProjectFileName);
			using (new GlobalSingleInstanceMutex(MutexName, true))
			{
				// Check if there's an existing assembly for this project
				return LoadedAssemblyMap.GetOrAdd(ProjectFileName, _ =>
				{
					Logger.LogTrace("Creating project rules assembly for {Project}...", ProjectFileName);

					ProjectDescriptor Project = ProjectDescriptor.FromFile(ProjectFileName);

					// Create the parent assembly
					RulesAssembly Parent = CreateEngineRulesAssembly(bUsePrecompiled, bSkipCompile, bForceCompile, Logger);

					DirectoryReference MainProjectDirectory = ProjectFileName.Directory;
					//DirectoryReference MainProjectSourceDirectory = DirectoryReference.Combine(MainProjectDirectory, "Source");

					// Create a scope for things in this assembly
					RulesScope Scope = new RulesScope("Project", Parent.Scope);

					// Create a new context for modules created by this assembly
					ModuleRulesContext DefaultModuleContext = new ModuleRulesContext(Scope, MainProjectDirectory);
					DefaultModuleContext.bCanBuildDebugGame = true;
					DefaultModuleContext.bCanHotReload = true;
					DefaultModuleContext.bClassifyAsGameModuleForUHT = true;
					DefaultModuleContext.bCanUseForSharedPCH = false;

					// gather modules from project and platforms
					Dictionary<FileReference, ModuleRulesContext> ModuleFiles = new Dictionary<FileReference, ModuleRulesContext>();
					List<FileReference> TargetFiles = new List<FileReference>();

					// Find all the project directories
					List<DirectoryReference> ProjectDirectories = Unreal.GetExtensionDirs(ProjectFileName.Directory);
					if (Project.AdditionalRootDirectories != null)
					{
						ProjectDirectories.AddRange(Project.AdditionalRootDirectories);
					}

					// Find all the rules/plugins under the project source directories
					foreach (DirectoryReference ProjectDirectory in ProjectDirectories)
					{
						DirectoryReference ProjectSourceDirectory = DirectoryReference.Combine(ProjectDirectory, "Source");

						AddModuleRulesWithContext(ProjectSourceDirectory, DefaultModuleContext, ModuleFiles);
						TargetFiles.AddRange(Rules.FindAllRulesFiles(ProjectSourceDirectory, Rules.RulesFileType.Target));
					}

					// Find all the project plugins
					List<PluginInfo> ProjectPlugins = new List<PluginInfo>();
					ProjectPlugins.AddRange(Plugins.ReadProjectPlugins(MainProjectDirectory));

					// Add the project's additional plugin directories plugins too
					if (Project.AdditionalPluginDirectories != null)
					{
						foreach (DirectoryReference AdditionalPluginDirectory in Project.AdditionalPluginDirectories)
						{
							ProjectPlugins.AddRange(Plugins.ReadAdditionalPlugins(AdditionalPluginDirectory, Logger));
						}
					}

					Logger.LogTrace(" Found {Count} Plugins:", ProjectPlugins.Count);
					ProjectPlugins.ForEach(x => { Logger.LogTrace("  {Plugin}", x.File); });

					// Find all the plugin module rules as well as plugin test target and module rules
					FindModuleRulesForPlugins(ProjectPlugins, DefaultModuleContext, ModuleFiles);
					FindTestRulesForPlugins(ProjectPlugins, DefaultModuleContext, ModuleFiles, TargetFiles);

					Logger.LogTrace(" Found {Count} Modules:", ModuleFiles.Count);
					foreach (KeyValuePair<FileReference, ModuleRulesContext> Item in ModuleFiles)
					{
						Logger.LogTrace("  {Module}", Item.Key);
					}

					// Add the games project's intermediate source folder
					DirectoryReference ProjectIntermediateSourceDirectory = DirectoryReference.Combine(MainProjectDirectory, "Intermediate", "Source");
					if (DirectoryReference.Exists(ProjectIntermediateSourceDirectory))
					{
						AddModuleRulesWithContext(ProjectIntermediateSourceDirectory, DefaultModuleContext, ModuleFiles);
						TargetFiles.AddRange(Rules.FindAllRulesFiles(ProjectIntermediateSourceDirectory, Rules.RulesFileType.Target));
					}

					RulesAssembly ProjectRulesAssembly;
					// Compile the assembly. If there are no module or target files, just use the parent assembly.
					FileReference AssemblyFileName = FileReference.Combine(MainProjectDirectory, "Intermediate", "Build", "BuildRules", ProjectFileName.GetFileNameWithoutExtension() + "ModuleRules" + FrameworkAssemblyExtension);
					if (ModuleFiles.Count == 0 && TargetFiles.Count == 0 && ProjectPlugins.Count == 0)
					{
						ProjectRulesAssembly = Parent;
					}
					else
					{
						ProjectRulesAssembly = new RulesAssembly(Scope, new List<DirectoryReference> { MainProjectDirectory }, ProjectPlugins, ModuleFiles, TargetFiles, AssemblyFileName, bContainsEngineModules: false, DefaultBuildSettings: null, bReadOnly: Unreal.IsProjectInstalled(), bSkipCompile: bSkipCompile, bForceCompile: bForceCompile, Parent: Parent, Logger: Logger);
					}
					return ProjectRulesAssembly;
				});
			}
		}

		/// <summary>
		/// Creates a rules assembly with the given parameters.
		/// </summary>
		/// <param name="PluginFileName">The plugin file to create rules for</param>
		/// <param name="bSkipCompile">Whether to skip compilation for this assembly</param>
		/// <param name="bForceCompile">Whether to always compile this assembly</param>
		/// <param name="Parent">The parent rules assembly</param>
		/// <param name="bBuildPluginAsLocal">Whether the plugin should be built as though it is a local plugin.</param>
		/// <param name="bContainsEngineModules">Whether the plugin contains engine modules. Used to initialize the default value for ModuleRules.bTreatAsEngineModule.</param>
		/// <param name="Logger">Logger for ouptut</param>
		/// <returns>The new rules assembly</returns>
		public static RulesAssembly CreatePluginRulesAssembly(FileReference PluginFileName, bool bSkipCompile, bool bForceCompile, RulesAssembly Parent, bool bBuildPluginAsLocal, bool bContainsEngineModules, ILogger Logger)
		{
			// Prevent multiple conflicting processes building rules assembly at the same time
			string MutexName = GlobalSingleInstanceMutex.GetUniqueMutexForPath("UnrealBuildTool_CreateTargetRulesAssembly", PluginFileName);
			using (new GlobalSingleInstanceMutex(MutexName, true))
			{
				// Check if there's an existing assembly for this project
				return LoadedAssemblyMap.GetOrAdd(PluginFileName, _ =>
				{
					Logger.LogTrace("Creating plugin rules assembly for {Plugin}...", PluginFileName);

					// Find all the rules source files
					Dictionary<FileReference, ModuleRulesContext> ModuleFiles = new Dictionary<FileReference, ModuleRulesContext>();
					List<FileReference> TargetFiles = new List<FileReference>();

					// Create a list of plugins for this assembly. We need to override the parent plugin, if it exists, due to overriding the
					// setting for bClassifyAsGameModuleForUHT below.
					List<PluginInfo> ForeignPlugins = new List<PluginInfo>();
					if (!Parent.EnumeratePlugins().Any(x => x.ChoiceVersion != null && x.ChoiceVersion.File == PluginFileName && x.ChoiceVersion.Type == PluginType.Engine))
					{
						PluginInfo ForeignPluginInfo = new PluginInfo(PluginFileName, PluginType.External)
						{
							bExplicitPluginTarget = true
						};
						ForeignPlugins.Add(ForeignPluginInfo);
					}

					Logger.LogTrace(" Found {Count} ForeignPlugins:", ForeignPlugins.Count);
					ForeignPlugins.ForEach(x => { Logger.LogTrace("  {ForeignPlugin}", x.File); });

					// Create a new scope for the plugin. It should not reference anything else.
					RulesScope Scope = new RulesScope("Plugin", Parent.Scope);

					// Find all the modules
					ModuleRulesContext PluginModuleContext = new ModuleRulesContext(Scope, PluginFileName.Directory);
					PluginModuleContext.bClassifyAsGameModuleForUHT = !bContainsEngineModules;
					if (bBuildPluginAsLocal)
					{
						PluginModuleContext.bCanBuildDebugGame = true;
						PluginModuleContext.bCanHotReload = true;
						PluginModuleContext.bClassifyAsGameModuleForUHT = true;
						PluginModuleContext.bCanUseForSharedPCH = false;
					}
					FindModuleRulesForPlugins(ForeignPlugins, PluginModuleContext, ModuleFiles);

					Logger.LogTrace(" Found {Count} Modules:", ModuleFiles.Count);
					foreach (KeyValuePair<FileReference, ModuleRulesContext> Item in ModuleFiles)
					{
						Logger.LogTrace("  {Module}", Item.Key);
					}

					// Compile the assembly
					FileReference AssemblyFileName = FileReference.Combine(PluginFileName.Directory, "Intermediate", "Build", "BuildRules", Path.GetFileNameWithoutExtension(PluginFileName.FullName) + "ModuleRules" + FrameworkAssemblyExtension);
					return new RulesAssembly(Scope, new List<DirectoryReference> { PluginFileName.Directory }, ForeignPlugins, ModuleFiles, TargetFiles, AssemblyFileName, bContainsEngineModules, DefaultBuildSettings: null, bReadOnly: false, bSkipCompile: bSkipCompile, bForceCompile: bForceCompile, Parent: Parent, Logger: Logger);
				});
			}
		}

		/// <summary>
		/// Compile a rules assembly for the current target
		/// </summary>
		/// <param name="ProjectFile">The project file being compiled</param>
		/// <param name="TargetName">The target being built</param>
		/// <param name="bSkipRulesCompile">Whether to skip compiling any rules assemblies</param>
		/// <param name="bForceRulesCompile">Whether to always compile all rules assemblies</param>
		/// <param name="bUsePrecompiled">Whether to use a precompiled engine build</param>
		/// <param name="ForeignPlugin">Foreign plugin to be compiled</param>
		/// <param name="bBuildPluginAsLocal">Whether the plugin should be built as though it is a local plugin</param>
		/// <param name="Logger">Logger for output</param>
		/// <returns>The compiled rules assembly</returns>
		public static RulesAssembly CreateTargetRulesAssembly(FileReference? ProjectFile, string TargetName, bool bSkipRulesCompile, bool bForceRulesCompile, bool bUsePrecompiled, FileReference? ForeignPlugin, bool bBuildPluginAsLocal, ILogger Logger)
		{
			RulesAssembly RulesAssembly;
			if (ProjectFile != null)
			{
				RulesAssembly = CreateProjectRulesAssembly(ProjectFile, bUsePrecompiled, bSkipRulesCompile, bForceRulesCompile, Logger);
			}
			else
			{
				RulesAssembly = CreateEngineRulesAssembly(bUsePrecompiled, bSkipRulesCompile, bForceRulesCompile, Logger);
			}
			if (ForeignPlugin != null)
			{
				RulesAssembly = CreatePluginRulesAssembly(ForeignPlugin, bSkipRulesCompile, bForceRulesCompile, RulesAssembly, bBuildPluginAsLocal, true, Logger);
			}
			return RulesAssembly;
		}

		/// <summary>
		/// Finds all the module rules for plugins under the given directory.
		/// </summary>
		/// <param name="Plugins">The list of plugins to search modules for</param>
		/// <param name="DefaultContext">The default context for any files that are enumerated</param>
		/// <param name="ModuleFileToContext">Dictionary which is filled with mappings from the module file to its corresponding context</param>
		private static void FindModuleRulesForPlugins(IReadOnlyList<PluginInfo> Plugins, ModuleRulesContext DefaultContext, Dictionary<FileReference, ModuleRulesContext> ModuleFileToContext)
		{
			Rules.PrefetchRulesFiles(Plugins.Select(x => DirectoryReference.Combine(x.Directory, "Source")));

			foreach (PluginInfo Plugin in Plugins)
			{
				FindModuleRulesForPluginInFolder(Plugin, "Source", DefaultContext, ModuleFileToContext);
			}
		}

		/// <summary>
		/// Finds all the module and target rules for plugins' tests.
		/// </summary>
		/// <param name="Plugins">The list of plugins to search test rules for</param>
		/// <param name="DefaultContext">The default context for any files that are enumerated</param>
		/// <param name="ModuleFileToContext">Dictionary which is filled with mappings from the module file to its corresponding context</param>
		/// <param name="TargetFiles">List of target files to add test target rules to</param>
		private static void FindTestRulesForPlugins(IReadOnlyList<PluginInfo> Plugins, ModuleRulesContext DefaultContext, Dictionary<FileReference, ModuleRulesContext> ModuleFileToContext, List<FileReference> TargetFiles)
		{
			Rules.PrefetchRulesFiles(Plugins.Select(x => DirectoryReference.Combine(x.Directory, "Tests")));

			foreach (PluginInfo Plugin in Plugins)
			{
				FindModuleRulesForPluginInFolder(Plugin, "Tests", DefaultContext, ModuleFileToContext);
				TargetFiles.AddRange(Rules.FindAllRulesFiles(DirectoryReference.Combine(Plugin.Directory, "Tests"), Rules.RulesFileType.Target));
			}
		}

		/// <summary>
		/// Finds all the module rules for a given plugin in a specified folder.
		/// </summary>
		/// <param name="Plugin">The plugin to search module rules for</param>
		/// <param name="Folder">The folder relative to the plugin root to look into, usually "Source" or "Tests"</param>
		/// <param name="DefaultContext">The default context for any files that are enumerated</param>
		/// <param name="ModuleFileToContext">Dictionary which is filled with mappings from the module file to its corresponding context</param>
		private static void FindModuleRulesForPluginInFolder(PluginInfo Plugin, string Folder, ModuleRulesContext DefaultContext, Dictionary<FileReference, ModuleRulesContext> ModuleFileToContext)
		{
			List<FileReference> PluginModuleFiles = Rules.FindAllRulesFiles(DirectoryReference.Combine(Plugin.Directory, Folder), Rules.RulesFileType.Module).ToList();
			foreach (FileReference ChildFile in Plugin.ChildFiles)
			{
				PluginModuleFiles.AddRange(Rules.FindAllRulesFiles(DirectoryReference.Combine(ChildFile.Directory, Folder), Rules.RulesFileType.Module));
			}
			foreach (FileReference ModuleFile in PluginModuleFiles)
			{
				ModuleRulesContext PluginContext = new ModuleRulesContext(DefaultContext);
				PluginContext.DefaultOutputBaseDir = Plugin.Directory;
				PluginContext.Plugin = Plugin;
				ModuleFileToContext[ModuleFile] = PluginContext;
			}
		}

		/// <summary>
		/// Gets the filename that declares the given type.
		/// </summary>
		/// <param name="ExistingType">The type to search for.</param>
		/// <returns>The filename that declared the given type, or null</returns>
		public static string? GetFileNameFromType(Type ExistingType)
		{
			FileReference? FileName;
			if (EngineRulesAssembly != null && EngineRulesAssembly.TryGetFileNameFromType(ExistingType, out FileName))
			{
				return FileName.FullName;
			}

			foreach (RulesAssembly RulesAssembly in LoadedAssemblyMap.Values)
			{
				if (RulesAssembly.TryGetFileNameFromType(ExistingType, out FileName))
				{
					return FileName.FullName;
				}
			}
			return null;
		}
	}
}