using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Needle.Engine.Codegen;
using Needle.Engine.Core.References;
using Needle.Engine.Utils;
using UnityEditor;

namespace Needle.Engine.ProjectBundle
{
	internal static class NodeModulesComponentGeneration
	{
		private static readonly ComponentGeneratorRunner generator = new ComponentGeneratorRunner();

		/// <summary>
		/// Generate c# component stubs for node_module packages with needle engine typescript components
		/// </summary>
		/// <param name="packageDirectory">The directory to scan for components to generate</param>
		/// <param name="webProjectDirectory">The directory where the web project exists</param>
		internal static async void GenerateComponents(string packageDirectory, string baseDirectory, string versionDirectory, string webProjectDirectory)
		{
			if (!Directory.Exists(webProjectDirectory)) return;

			if (!CodeWatcher.TryFindCodeGeneratorPath(webProjectDirectory, out var generatorInstallPath))
			{
				return;
			}
			generatorInstallPath = Path.GetDirectoryName(generatorInstallPath);
            
			using (new AssemblyReloadLockScope())
			{
				var versionDirInfo = new DirectoryInfo(versionDirectory);
				var outputDirectory = versionDirInfo.FullName + "/codegen";

				// var outputDirectory = $"{baseDirectory}/{version}";
				// If we already generated types once we can skip this step
				if (Directory.Exists(outputDirectory))
				{
					var directoryHasFiles = Directory.EnumerateFiles(outputDirectory, "*", SearchOption.AllDirectories)
						.Any();
					if (directoryHasFiles)
						return;
				}

				if(!versionDirInfo.Exists)
					Directory.CreateDirectory(versionDirInfo.FullName);


				// If the directory doesnt exist we want to scan for all types once more
				TypesGenerator.GenerateTypesIfNecessary(true);

				var types = new List<ImportInfo>();
				TypeScanner.FindTypesExcludingNodeModules(packageDirectory, types);
				foreach (var type in types)
				{
					var relativePath = type.FilePath.RelativeTo(packageDirectory);
					var targetDirectory = $"{outputDirectory}/{Path.GetDirectoryName(relativePath)}";
					await generator.Run(generatorInstallPath, type.FilePath, targetDirectory);
				}

				if (types.Count <= 0)
				{
					File.WriteAllText(outputDirectory + "/empty", "");
				}
				else
				{
					// If no cs file was generated we want to put an empty marker in the directory 
					// Just so we know we dont have to re-generate and can check it into source control
					var anyFiles = Directory.EnumerateFiles(outputDirectory, "*", SearchOption.AllDirectories).Any();
					if (!anyFiles)
					{
						await FileUtils.DeleteDirectoryRecursive(outputDirectory);
					}
				}
			}


			AssetDatabase.Refresh();
		}
	}
}