using UnityEditor;
using UnityEditor.SceneManagement;
using UnityEngine;
using UnityEngine.SceneManagement;

namespace BrewMonster.Scripts.Utils.Editor
{
	public static class ClearMissingScript
	{
		[MenuItem("Tools/Brew Monster/Clear Missing Script/Active Scene")]
		public static void ClearMissingScriptsInActiveScene()
		{
			var scene = SceneManager.GetActiveScene();
			if (!scene.IsValid())
			{
				EditorUtility.DisplayDialog("Clear Missing Script", "No valid active scene.", "OK");
				return;
			}

			int removedCount = 0;
			var roots = scene.GetRootGameObjects();
			foreach (var root in roots)
			{
				Undo.RegisterFullObjectHierarchyUndo(root, "Clear Missing Scripts");
				removedCount += RemoveMissingScriptsRecursive(root);
			}

			if (removedCount > 0)
			{
				EditorSceneManager.MarkSceneDirty(scene);
			}

			EditorUtility.DisplayDialog("Clear Missing Script", $"Removed {removedCount} missing script(s) from active scene.", "OK");
		}

		[MenuItem("Tools/Brew Monster/Clear Missing Script/Prefabs in Selected Folder", true)]
		public static bool ValidateClearMissingScriptsInSelectedFolder()
		{
			Object selectedObject = Selection.activeObject;
			if (selectedObject == null)
				return false;

			string folderPath = AssetDatabase.GetAssetPath(selectedObject);
			return AssetDatabase.IsValidFolder(folderPath);
		}

		[MenuItem("Tools/Brew Monster/Clear Missing Script/Prefabs in Selected Folder")]
		public static void ClearMissingScriptsInSelectedFolder()
		{
			Object selectedObject = Selection.activeObject;
			if (selectedObject == null)
			{
				EditorUtility.DisplayDialog("Clear Missing Script", 
					"Please select a folder in the Project window first.", "OK");
				return;
			}

			string folderPath = AssetDatabase.GetAssetPath(selectedObject);
			if (!AssetDatabase.IsValidFolder(folderPath))
			{
				EditorUtility.DisplayDialog("Clear Missing Script", 
					"Selected object is not a valid folder. Please select a folder in the Project window.", "OK");
				return;
			}

			if (!EditorUtility.DisplayDialog("Clear Missing Script in Folder", 
				$"This will process all prefabs in:\n{folderPath}\n\nContinue?", 
				"Yes", "Cancel"))
			{
				return;
			}

			ProcessPrefabsInFolder(folderPath);
		}

		[MenuItem("Tools/Brew Monster/Clear Missing Script/All Prefabs")]
		public static void ClearMissingScriptsInPrefabs()
		{
			if (!EditorUtility.DisplayDialog("Clear Missing Script in Prefabs", 
				"This will process all prefabs in the project. This may take a while. Continue?", 
				"Yes", "Cancel"))
			{
				return;
			}

			ProcessPrefabsInFolder("Assets");
		}

		private static void ProcessPrefabsInFolder(string folderPath)
		{
			string[] prefabGUIDs = AssetDatabase.FindAssets("t:Prefab", new[] { folderPath });
			int totalPrefabs = prefabGUIDs.Length;
			
			if (totalPrefabs == 0)
			{
				EditorUtility.DisplayDialog("Clear Missing Script", 
					$"No prefabs found in folder:\n{folderPath}", "OK");
				return;
			}

			int processedCount = 0;
			int totalRemovedCount = 0;
			int prefabsWithRemovals = 0;

			EditorUtility.DisplayProgressBar("Clear Missing Scripts", "Processing prefabs...", 0f);

			try
			{
				foreach (string guid in prefabGUIDs)
				{
					string assetPath = AssetDatabase.GUIDToAssetPath(guid);
					processedCount++;

					EditorUtility.DisplayProgressBar("Clear Missing Scripts", 
						$"Processing: {assetPath} ({processedCount}/{totalPrefabs})", 
						(float)processedCount / totalPrefabs);

					GameObject prefabRoot = PrefabUtility.LoadPrefabContents(assetPath);
					if (prefabRoot != null)
					{
						int removedCount = RemoveMissingScriptsRecursive(prefabRoot);
						
						if (removedCount > 0)
						{
							PrefabUtility.SaveAsPrefabAsset(prefabRoot, assetPath);
							totalRemovedCount += removedCount;
							prefabsWithRemovals++;
							Debug.Log($"[ClearMissingScript] Removed {removedCount} missing script(s) from prefab: {assetPath}");
						}
						
						PrefabUtility.UnloadPrefabContents(prefabRoot);
					}
				}

				AssetDatabase.SaveAssets();
			}
			finally
			{
				EditorUtility.ClearProgressBar();
			}

			EditorUtility.DisplayDialog("Clear Missing Script", 
				$"Processed {processedCount} prefab(s) in folder:\n{folderPath}\n\nRemoved {totalRemovedCount} missing script(s) from {prefabsWithRemovals} prefab(s).", 
				"OK");
		}

		[MenuItem("Tools/Brew Monster/Clear Missing Script/Scene and Prefabs")]
		public static void ClearMissingScriptsInSceneAndPrefabs()
		{
			if (!EditorUtility.DisplayDialog("Clear Missing Script", 
				"This will process the active scene and all prefabs in the project. This may take a while. Continue?", 
				"Yes", "Cancel"))
			{
				return;
			}

			int sceneRemovedCount = 0;
			var scene = SceneManager.GetActiveScene();
			if (scene.IsValid())
			{
				var roots = scene.GetRootGameObjects();
				foreach (var root in roots)
				{
					Undo.RegisterFullObjectHierarchyUndo(root, "Clear Missing Scripts");
					sceneRemovedCount += RemoveMissingScriptsRecursive(root);
				}

				if (sceneRemovedCount > 0)
				{
					EditorSceneManager.MarkSceneDirty(scene);
				}
			}

			string[] prefabGUIDs = AssetDatabase.FindAssets("t:Prefab");
			int totalPrefabs = prefabGUIDs.Length;
			int processedCount = 0;
			int prefabRemovedCount = 0;
			int prefabsWithRemovals = 0;

			EditorUtility.DisplayProgressBar("Clear Missing Scripts", "Processing prefabs...", 0f);

			try
			{
				foreach (string guid in prefabGUIDs)
				{
					string assetPath = AssetDatabase.GUIDToAssetPath(guid);
					processedCount++;

					EditorUtility.DisplayProgressBar("Clear Missing Scripts", 
						$"Processing: {assetPath} ({processedCount}/{totalPrefabs})", 
						(float)processedCount / totalPrefabs);

					GameObject prefabRoot = PrefabUtility.LoadPrefabContents(assetPath);
					if (prefabRoot != null)
					{
						int removedCount = RemoveMissingScriptsRecursive(prefabRoot);
						
						if (removedCount > 0)
						{
							PrefabUtility.SaveAsPrefabAsset(prefabRoot, assetPath);
							prefabRemovedCount += removedCount;
							prefabsWithRemovals++;
						}
						
						PrefabUtility.UnloadPrefabContents(prefabRoot);
					}
				}

				AssetDatabase.SaveAssets();
			}
			finally
			{
				EditorUtility.ClearProgressBar();
			}

			int totalRemoved = sceneRemovedCount + prefabRemovedCount;
			EditorUtility.DisplayDialog("Clear Missing Script", 
				$"Scene: Removed {sceneRemovedCount} missing script(s).\n" +
				$"Prefabs: Processed {processedCount} prefab(s), removed {prefabRemovedCount} missing script(s) from {prefabsWithRemovals} prefab(s).\n" +
				$"Total: {totalRemoved} missing script(s) removed.", 
				"OK");
		}

		private static int RemoveMissingScriptsRecursive(GameObject gameObject)
		{
			int removed = GameObjectUtility.RemoveMonoBehavioursWithMissingScript(gameObject);
			for (int i = 0; i < gameObject.transform.childCount; i++)
			{
				removed += RemoveMissingScriptsRecursive(gameObject.transform.GetChild(i).gameObject);
			}
			return removed;
		}
	}
}