using UnityEngine;
using UnityEditor;
using UnityEditor.SceneManagement;
using Core.SaveLoad;
using System.Collections.Generic;
using System.Linq;

namespace Editor
{
    /// <summary>
    /// Editor utility to migrate StateMachine components to SaveableStateMachine.
    /// </summary>
    public class StateMachineMigrationTool : EditorWindow
    {
        private Vector2 scrollPosition;
        private List<StateMachineInfo> foundStateMachines = new List<StateMachineInfo>();
        private bool showPrefabs = true;
        private bool showScenes = true;

        [MenuItem("Tools/AppleHills/Migrate StateMachines to Saveable")]
        public static void ShowWindow()
        {
            var window = GetWindow<StateMachineMigrationTool>("StateMachine Migration");
            window.minSize = new Vector2(600, 400);
            window.Show();
        }

        private void OnGUI()
        {
            EditorGUILayout.LabelField("StateMachine → SaveableStateMachine Migration", EditorStyles.boldLabel);
            EditorGUILayout.Space();

            EditorGUILayout.HelpBox(
                "This tool will replace all StateMachine components with SaveableStateMachine.\n" +
                "All properties and references will be preserved.",
                MessageType.Info
            );

            EditorGUILayout.Space();

            // Scan options
            EditorGUILayout.LabelField("Scan Options:", EditorStyles.boldLabel);
            showPrefabs = EditorGUILayout.Toggle("Include Prefabs", showPrefabs);
            showScenes = EditorGUILayout.Toggle("Include Scenes", showScenes);

            EditorGUILayout.Space();

            if (GUILayout.Button("Scan Project", GUILayout.Height(30)))
            {
                ScanProject();
            }

            EditorGUILayout.Space();

            // Display results
            if (foundStateMachines.Count > 0)
            {
                EditorGUILayout.LabelField($"Found {foundStateMachines.Count} StateMachine(s):", EditorStyles.boldLabel);

                scrollPosition = EditorGUILayout.BeginScrollView(scrollPosition);

                foreach (var info in foundStateMachines)
                {
                    // Set background color for migrated items
                    Color originalBgColor = GUI.backgroundColor;
                    if (info.isAlreadySaveable)
                    {
                        GUI.backgroundColor = new Color(0.5f, 1f, 0.5f); // Light green
                    }
                    
                    EditorGUILayout.BeginHorizontal("box");
                    
                    GUI.backgroundColor = originalBgColor; // Reset for content
                    
                    EditorGUILayout.LabelField(info.name, GUILayout.Width(200));
                    EditorGUILayout.LabelField(info.path, GUILayout.ExpandWidth(true));
                    
                    // Ping button (for scene objects or prefabs)
                    if (GUILayout.Button("Ping", GUILayout.Width(50)))
                    {
                        PingObject(info);
                    }
                    
                    if (info.isAlreadySaveable)
                    {
                        // Green checkmark with bold style
                        GUIStyle greenStyle = new GUIStyle(GUI.skin.label);
                        greenStyle.normal.textColor = new Color(0f, 0.6f, 0f);
                        greenStyle.fontStyle = FontStyle.Bold;
                        EditorGUILayout.LabelField("✓ Migrated", greenStyle, GUILayout.Width(120));
                    }
                    else
                    {
                        if (GUILayout.Button("Migrate", GUILayout.Width(80)))
                        {
                            if (MigrateSingle(info))
                            {
                                // Refresh the list to show updated status
                                ScanProject();
                                return;
                            }
                        }
                    }

                    EditorGUILayout.EndHorizontal();
                    
                    GUI.backgroundColor = originalBgColor; // Final reset
                }

                EditorGUILayout.EndScrollView();

                EditorGUILayout.Space();

                int migrateCount = foundStateMachines.Count(sm => !sm.isAlreadySaveable);
                if (migrateCount > 0)
                {
                    if (GUILayout.Button($"Migrate All ({migrateCount})", GUILayout.Height(40)))
                    {
                        if (EditorUtility.DisplayDialog(
                            "Confirm Migration",
                            $"This will migrate {migrateCount} StateMachine(s) to SaveableStateMachine.\n\nContinue?",
                            "Yes, Migrate All",
                            "Cancel"))
                        {
                            MigrateAll();
                        }
                    }
                }
            }
            else
            {
                EditorGUILayout.HelpBox("Click 'Scan Project' to find StateMachine components.", MessageType.Info);
            }
        }

        private void ScanProject()
        {
            foundStateMachines.Clear();

            // Find all prefabs
            if (showPrefabs)
            {
                string[] prefabGuids = AssetDatabase.FindAssets("t:Prefab");
                foreach (string guid in prefabGuids)
                {
                    string path = AssetDatabase.GUIDToAssetPath(guid);
                    GameObject prefab = AssetDatabase.LoadAssetAtPath<GameObject>(path);

                    if (prefab != null)
                    {
                        // Use GetComponents to find Pixelplacement.StateMachine
                        var components = prefab.GetComponentsInChildren<Component>(true);
                        foreach (var component in components)
                        {
                            if (component == null) continue;
                            
                            var componentType = component.GetType();
                            if (componentType.Name == "StateMachine" && componentType.Namespace == "Pixelplacement")
                            {
                                bool isAlreadySaveable = component is AppleMachine;
                                foundStateMachines.Add(new StateMachineInfo
                                {
                                    name = component.gameObject.name,
                                    path = path,
                                    isPrefab = true,
                                    isAlreadySaveable = isAlreadySaveable,
                                    assetPath = path
                                });
                            }
                        }
                    }
                }
            }

            // Find all in scenes
            if (showScenes)
            {
                string[] sceneGuids = AssetDatabase.FindAssets("t:Scene");
                foreach (string guid in sceneGuids)
                {
                    string scenePath = AssetDatabase.GUIDToAssetPath(guid);
                    var scene = EditorSceneManager.OpenScene(scenePath, OpenSceneMode.Additive);

                    var allComponents = GameObject.FindObjectsOfType<Component>(true);
                    foreach (var component in allComponents)
                    {
                        if (component == null || component.gameObject.scene != scene) continue;
                        
                        var componentType = component.GetType();
                        if (componentType.Name == "StateMachine" && componentType.Namespace == "Pixelplacement")
                        {
                            bool isAlreadySaveable = component is AppleMachine;
                            foundStateMachines.Add(new StateMachineInfo
                            {
                                name = component.gameObject.name,
                                path = $"{scenePath} → {component.transform.GetHierarchyPath()}",
                                isPrefab = false,
                                isAlreadySaveable = isAlreadySaveable,
                                assetPath = scenePath,
                                gameObject = component.gameObject
                            });
                        }
                    }

                    EditorSceneManager.CloseScene(scene, true);
                }
            }

            Debug.Log($"[StateMachine Migration] Found {foundStateMachines.Count} StateMachine(s)");
        }

        private void PingObject(StateMachineInfo info)
        {
            if (info.isPrefab)
            {
                // Load and ping the prefab asset
                GameObject prefab = AssetDatabase.LoadAssetAtPath<GameObject>(info.assetPath);
                if (prefab != null)
                {
                    EditorGUIUtility.PingObject(prefab);
                    Selection.activeObject = prefab;
                }
            }
            else
            {
                // For scene objects, we need to open the scene if it's not already open
                var currentScene = UnityEngine.SceneManagement.SceneManager.GetActiveScene();
                
                if (currentScene.path != info.assetPath)
                {
                    // Scene is not currently open
                    if (EditorUtility.DisplayDialog(
                        "Open Scene?",
                        $"The object is in scene:\n{info.assetPath}\n\nDo you want to open this scene?",
                        "Yes, Open Scene",
                        "Cancel"))
                    {
                        if (EditorSceneManager.SaveCurrentModifiedScenesIfUserWantsTo())
                        {
                            EditorSceneManager.OpenScene(info.assetPath, OpenSceneMode.Single);
                            
                            // Find the object in the newly opened scene
                            if (info.gameObject != null)
                            {
                                // The gameObject reference might be stale, find by path
                                GameObject obj = GameObject.Find(info.gameObject.name);
                                if (obj != null)
                                {
                                    Selection.activeGameObject = obj;
                                    EditorGUIUtility.PingObject(obj);
                                }
                            }
                        }
                    }
                }
                else
                {
                    // Scene is already open
                    if (info.gameObject != null)
                    {
                        Selection.activeGameObject = info.gameObject;
                        EditorGUIUtility.PingObject(info.gameObject);
                        // Also scroll to it in hierarchy
                        EditorApplication.ExecuteMenuItem("Window/General/Hierarchy");
                    }
                }
            }
        }

        private void MigrateAll()
        {
            int migratedCount = 0;
            int errorCount = 0;

            foreach (var info in foundStateMachines)
            {
                if (!info.isAlreadySaveable)
                {
                    if (MigrateSingle(info))
                    {
                        migratedCount++;
                    }
                    else
                    {
                        errorCount++;
                    }
                }
            }

            AssetDatabase.SaveAssets();
            AssetDatabase.Refresh();

            EditorUtility.DisplayDialog(
                "Migration Complete",
                $"Migrated: {migratedCount}\nErrors: {errorCount}",
                "OK"
            );

            // Refresh list to show green highlighting for newly migrated items
            ScanProject();
        }

        private bool MigrateSingle(StateMachineInfo info)
        {
            try
            {
                if (info.isPrefab)
                {
                    return MigratePrefab(info.assetPath);
                }
                else
                {
                    return MigrateSceneObject(info.assetPath, info.gameObject);
                }
            }
            catch (System.Exception ex)
            {
                Debug.LogError($"[StateMachine Migration] Error migrating '{info.name}': {ex.Message}");
                return false;
            }
        }

        private bool MigratePrefab(string prefabPath)
        {
            GameObject prefabRoot = PrefabUtility.LoadPrefabContents(prefabPath);

            try
            {
                var components = prefabRoot.GetComponentsInChildren<Component>(true);
                int migratedInPrefab = 0;

                foreach (var component in components)
                {
                    if (component == null) continue;
                    
                    var componentType = component.GetType();
                    if (componentType.Name == "StateMachine" && 
                        componentType.Namespace == "Pixelplacement" &&
                        !(component is AppleMachine))
                    {
                        if (MigrateComponent(component.gameObject, component))
                        {
                            migratedInPrefab++;
                        }
                    }
                }

                PrefabUtility.SaveAsPrefabAsset(prefabRoot, prefabPath);
                Debug.Log($"[StateMachine Migration] Migrated {migratedInPrefab} component(s) in prefab: {prefabPath}");
                return true;
            }
            finally
            {
                PrefabUtility.UnloadPrefabContents(prefabRoot);
            }
        }

        private bool MigrateSceneObject(string scenePath, GameObject gameObject)
        {
            var scene = EditorSceneManager.OpenScene(scenePath, OpenSceneMode.Additive);

            try
            {
                var components = gameObject.GetComponents<Component>();
                foreach (var component in components)
                {
                    if (component == null) continue;
                    
                    var componentType = component.GetType();
                    if (componentType.Name == "StateMachine" && 
                        componentType.Namespace == "Pixelplacement" &&
                        !(component is AppleMachine))
                    {
                        bool success = MigrateComponent(gameObject, component);

                        if (success)
                        {
                            EditorSceneManager.MarkSceneDirty(scene);
                            EditorSceneManager.SaveScene(scene);
                            Debug.Log($"[StateMachine Migration] Migrated component in scene: {scenePath}");
                        }

                        return success;
                    }
                }
                
                return false;
            }
            finally
            {
                EditorSceneManager.CloseScene(scene, false);
            }
        }

        private bool MigrateComponent(GameObject gameObject, Component oldComponent)
        {
            // Capture old component data using SerializedObject
            SerializedObject oldSO = new SerializedObject(oldComponent);
            
            var defaultState = oldSO.FindProperty("defaultState");
            var verbose = oldSO.FindProperty("verbose");
            var allowReentry = oldSO.FindProperty("allowReentry");
            var returnToDefaultOnDisable = oldSO.FindProperty("returnToDefaultOnDisable");
            var onStateExited = oldSO.FindProperty("OnStateExited");
            var onStateEntered = oldSO.FindProperty("OnStateEntered");
            var onFirstStateEntered = oldSO.FindProperty("OnFirstStateEntered");
            var onFirstStateExited = oldSO.FindProperty("OnFirstStateExited");
            var onLastStateEntered = oldSO.FindProperty("OnLastStateEntered");
            var onLastStateExited = oldSO.FindProperty("OnLastStateExited");

            // Remove old component
            Object.DestroyImmediate(oldComponent);

            // Add new component
            var newSM = gameObject.AddComponent<AppleMachine>();

            // Restore data using SerializedObject
            SerializedObject newSO = new SerializedObject(newSM);
            CopySerializedProperty(defaultState, newSO.FindProperty("defaultState"));
            CopySerializedProperty(verbose, newSO.FindProperty("verbose"));
            CopySerializedProperty(allowReentry, newSO.FindProperty("allowReentry"));
            CopySerializedProperty(returnToDefaultOnDisable, newSO.FindProperty("returnToDefaultOnDisable"));
            CopySerializedProperty(onStateExited, newSO.FindProperty("OnStateExited"));
            CopySerializedProperty(onStateEntered, newSO.FindProperty("OnStateEntered"));
            CopySerializedProperty(onFirstStateEntered, newSO.FindProperty("OnFirstStateEntered"));
            CopySerializedProperty(onFirstStateExited, newSO.FindProperty("OnFirstStateExited"));
            CopySerializedProperty(onLastStateEntered, newSO.FindProperty("OnLastStateEntered"));
            CopySerializedProperty(onLastStateExited, newSO.FindProperty("OnLastStateExited"));
            
            // Set a custom Save ID based on GameObject name (simple and readable)
            // Users can customize this in the inspector if needed
            var customSaveIdProperty = newSO.FindProperty("customSaveId");
            if (customSaveIdProperty != null)
            {
                // Use GameObject name as the custom ID (scene name will be added automatically by GetSaveId)
                customSaveIdProperty.stringValue = gameObject.name;
                Debug.Log($"[Migration] Set custom Save ID: '{customSaveIdProperty.stringValue}' for '{gameObject.name}'");
            }
            
            newSO.ApplyModifiedProperties();

            EditorUtility.SetDirty(gameObject);

            return true;
        }

        private void CopySerializedProperty(SerializedProperty source, SerializedProperty dest)
        {
            if (source == null || dest == null) return;

            switch (source.propertyType)
            {
                case SerializedPropertyType.Integer:
                    dest.intValue = source.intValue;
                    break;
                case SerializedPropertyType.Boolean:
                    dest.boolValue = source.boolValue;
                    break;
                case SerializedPropertyType.Float:
                    dest.floatValue = source.floatValue;
                    break;
                case SerializedPropertyType.String:
                    dest.stringValue = source.stringValue;
                    break;
                case SerializedPropertyType.Color:
                    dest.colorValue = source.colorValue;
                    break;
                case SerializedPropertyType.ObjectReference:
                    dest.objectReferenceValue = source.objectReferenceValue;
                    break;
                case SerializedPropertyType.LayerMask:
                    dest.intValue = source.intValue;
                    break;
                case SerializedPropertyType.Enum:
                    dest.enumValueIndex = source.enumValueIndex;
                    break;
                case SerializedPropertyType.Vector2:
                    dest.vector2Value = source.vector2Value;
                    break;
                case SerializedPropertyType.Vector3:
                    dest.vector3Value = source.vector3Value;
                    break;
                case SerializedPropertyType.Vector4:
                    dest.vector4Value = source.vector4Value;
                    break;
                case SerializedPropertyType.Rect:
                    dest.rectValue = source.rectValue;
                    break;
                case SerializedPropertyType.ArraySize:
                    dest.arraySize = source.arraySize;
                    break;
                case SerializedPropertyType.Character:
                    dest.intValue = source.intValue;
                    break;
                case SerializedPropertyType.AnimationCurve:
                    dest.animationCurveValue = source.animationCurveValue;
                    break;
                case SerializedPropertyType.Bounds:
                    dest.boundsValue = source.boundsValue;
                    break;
                case SerializedPropertyType.Quaternion:
                    dest.quaternionValue = source.quaternionValue;
                    break;
                case SerializedPropertyType.Generic:
                    // Handle UnityEvent and other generic types by copying children
                    CopyGenericProperty(source, dest);
                    break;
            }
        }

        private void CopyGenericProperty(SerializedProperty source, SerializedProperty dest)
        {
            // For arrays and lists
            if (source.isArray)
            {
                dest.arraySize = source.arraySize;
                for (int i = 0; i < source.arraySize; i++)
                {
                    CopySerializedProperty(source.GetArrayElementAtIndex(i), dest.GetArrayElementAtIndex(i));
                }
            }
            else
            {
                // For complex objects, copy all children
                SerializedProperty sourceIterator = source.Copy();
                SerializedProperty destIterator = dest.Copy();
                
                bool enterChildren = true;
                while (sourceIterator.Next(enterChildren))
                {
                    // Only process immediate children
                    if (!sourceIterator.propertyPath.StartsWith(source.propertyPath + "."))
                        break;
                        
                    enterChildren = false;
                    
                    // Find corresponding property in destination
                    string relativePath = sourceIterator.propertyPath.Substring(source.propertyPath.Length + 1);
                    SerializedProperty destChild = dest.FindPropertyRelative(relativePath);
                    
                    if (destChild != null)
                    {
                        CopySerializedProperty(sourceIterator, destChild);
                    }
                }
            }
        }

        private class StateMachineInfo
        {
            public string name;
            public string path;
            public bool isPrefab;
            public bool isAlreadySaveable;
            public string assetPath;
            public GameObject gameObject;
        }
    }


    public static class TransformExtensions
    {
        public static string GetHierarchyPath(this Transform transform)
        {
            string path = transform.name;
            while (transform.parent != null)
            {
                transform = transform.parent;
                path = transform.name + "/" + path;
            }
            return path;
        }
    }
}