/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Unity Technologies.
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/
using System;
using System.Collections.Generic;
using System.Linq;
using UnityEditor;
using UnityEditor.Compilation;
using UnityEditor.PackageManager;

namespace Microsoft.Unity.VisualStudio.Editor
{
	public interface IAssemblyNameProvider
	{
		string[] ProjectSupportedExtensions { get; }
		string ProjectGenerationRootNamespace { get; }
		ProjectGenerationFlag ProjectGenerationFlag { get; }

		string GetAssemblyNameFromScriptPath(string path);
		string GetAssemblyName(string assemblyOutputPath, string assemblyName);
		bool IsInternalizedPackagePath(string path);
		IEnumerable<Assembly> GetAssemblies(Func<string, bool> shouldFileBePartOfSolution);
		IEnumerable<string> GetAllAssetPaths();
		UnityEditor.PackageManager.PackageInfo FindForAssetPath(string assetPath);
		ResponseFileData ParseResponseFile(string responseFilePath, string projectDirectory, string[] systemReferenceDirectories);
		void ToggleProjectGeneration(ProjectGenerationFlag preference);
	}

	public class AssemblyNameProvider : IAssemblyNameProvider
	{
		private readonly Dictionary<string, UnityEditor.PackageManager.PackageInfo> m_PackageInfoCache = new Dictionary<string, UnityEditor.PackageManager.PackageInfo>();

		ProjectGenerationFlag m_ProjectGenerationFlag = (ProjectGenerationFlag)EditorPrefs.GetInt(
			"unity_project_generation_flag",
			(int)(ProjectGenerationFlag.Local | ProjectGenerationFlag.Embedded));

		public string[] ProjectSupportedExtensions => EditorSettings.projectGenerationUserExtensions;

		public string ProjectGenerationRootNamespace => EditorSettings.projectGenerationRootNamespace;

		public ProjectGenerationFlag ProjectGenerationFlag
		{
			get { return ProjectGenerationFlagImpl; }
			private set { ProjectGenerationFlagImpl = value;}
		}

		internal virtual ProjectGenerationFlag ProjectGenerationFlagImpl
		{
			get => m_ProjectGenerationFlag;
			private set
			{
				EditorPrefs.SetInt("unity_project_generation_flag", (int)value);
				m_ProjectGenerationFlag = value;
			}
		}

		public string GetAssemblyNameFromScriptPath(string path)
		{
			return CompilationPipeline.GetAssemblyNameFromScriptPath(path);
		}

		internal static readonly string AssemblyOutput = @"Temp\bin\Debug\".NormalizePathSeparators();
		internal static readonly string PlayerAssemblyOutput = @"Temp\bin\Debug\Player\".NormalizePathSeparators();

		public IEnumerable<Assembly> GetAssemblies(Func<string, bool> shouldFileBePartOfSolution)
		{
			IEnumerable<Assembly> assemblies = GetAssembliesByType(AssembliesType.Editor, shouldFileBePartOfSolution, AssemblyOutput);

			if (!ProjectGenerationFlag.HasFlag(ProjectGenerationFlag.PlayerAssemblies))
			{
				return assemblies;
			}
			var playerAssemblies = GetAssembliesByType(AssembliesType.Player, shouldFileBePartOfSolution, PlayerAssemblyOutput);
			return assemblies.Concat(playerAssemblies);
		}

		private static IEnumerable<Assembly> GetAssembliesByType(AssembliesType type, Func<string, bool> shouldFileBePartOfSolution, string outputPath)
		{
			foreach (var assembly in CompilationPipeline.GetAssemblies(type))
			{
				if (assembly.sourceFiles.Any(shouldFileBePartOfSolution))
				{
					yield return new Assembly(
						assembly.name,
						outputPath,
						assembly.sourceFiles,
						assembly.defines,
						assembly.assemblyReferences,
						assembly.compiledAssemblyReferences,
						assembly.flags,
						assembly.compilerOptions
#if UNITY_2020_2_OR_NEWER
						, assembly.rootNamespace
#endif
					);
				}
			}
		}

		public string GetCompileOutputPath(string assemblyName)
		{
			// We need to keep this one for API surface check (AssemblyNameProvider is public), but not used anymore
			throw new NotImplementedException();
		}

		public IEnumerable<string> GetAllAssetPaths()
		{
			return AssetDatabase.GetAllAssetPaths();
		}

		private static string ResolvePotentialParentPackageAssetPath(string assetPath)
		{
			const string packagesPrefix = "packages/";
			if (!assetPath.StartsWith(packagesPrefix, StringComparison.OrdinalIgnoreCase))
			{
				return null;
			}

			var followupSeparator = assetPath.IndexOf('/', packagesPrefix.Length);
			if (followupSeparator == -1)
			{
				return assetPath.ToLowerInvariant();
			}

			return assetPath.Substring(0, followupSeparator).ToLowerInvariant();
		}

		public UnityEditor.PackageManager.PackageInfo FindForAssetPath(string assetPath)
		{
			var parentPackageAssetPath = ResolvePotentialParentPackageAssetPath(assetPath);
			if (parentPackageAssetPath == null)
			{
				return null;
			}

			if (m_PackageInfoCache.TryGetValue(parentPackageAssetPath, out var cachedPackageInfo))
			{
				return cachedPackageInfo;
			}

			var result = UnityEditor.PackageManager.PackageInfo.FindForAssetPath(parentPackageAssetPath);
			m_PackageInfoCache[parentPackageAssetPath] = result;
			return result;
		}

		public bool IsInternalizedPackagePath(string path)
		{
			if (string.IsNullOrEmpty(path.Trim()))
			{
				return false;
			}
			var packageInfo = FindForAssetPath(path);
			if (packageInfo == null)
			{
				return false;
			}
			var packageSource = packageInfo.source;
			switch (packageSource)
			{
				case PackageSource.Embedded:
					return !ProjectGenerationFlag.HasFlag(ProjectGenerationFlag.Embedded);
				case PackageSource.Registry:
					return !ProjectGenerationFlag.HasFlag(ProjectGenerationFlag.Registry);
				case PackageSource.BuiltIn:
					return !ProjectGenerationFlag.HasFlag(ProjectGenerationFlag.BuiltIn);
				case PackageSource.Unknown:
					return !ProjectGenerationFlag.HasFlag(ProjectGenerationFlag.Unknown);
				case PackageSource.Local:
					return !ProjectGenerationFlag.HasFlag(ProjectGenerationFlag.Local);
				case PackageSource.Git:
					return !ProjectGenerationFlag.HasFlag(ProjectGenerationFlag.Git);
				case PackageSource.LocalTarball:
					return !ProjectGenerationFlag.HasFlag(ProjectGenerationFlag.LocalTarBall);
			}

			return false;
		}

		public ResponseFileData ParseResponseFile(string responseFilePath, string projectDirectory, string[] systemReferenceDirectories)
		{
			return CompilationPipeline.ParseResponseFile(
			  responseFilePath,
			  projectDirectory,
			  systemReferenceDirectories
			);
		}

		public void ToggleProjectGeneration(ProjectGenerationFlag preference)
		{
			if (ProjectGenerationFlag.HasFlag(preference))
			{
				ProjectGenerationFlag ^= preference;
			}
			else
			{
				ProjectGenerationFlag |= preference;
			}
		}

		internal void ResetPackageInfoCache()
		{
			m_PackageInfoCache.Clear();
		}

		public void ResetProjectGenerationFlag()
		{
			ProjectGenerationFlag = ProjectGenerationFlag.None;
		}

		public string GetAssemblyName(string assemblyOutputPath, string assemblyName)
		{
			if (assemblyOutputPath == PlayerAssemblyOutput)
				return assemblyName + ".Player";

			return assemblyName;
		}
	}
}