using UnityEditor;
using UnityEngine;
using System.Linq;
using System.Collections.Generic;

public class PrefabBrowserWindow : EditorWindow
{
    private PrefabBrowserDatabase database;
    private int selectedGroupIndex = -1;
    private string newGroupName = "New Group";
    private Vector2 leftPaneScroll;
    private Vector2 rightPaneScroll;
    private GUIStyle frameStyle;

    private float iconSize = 80f;
    private string searchFilter = "";
    private const float ListViewThreshold = 61f;

    private GameObject selectedPrefab = null;

    private void OnEnable()
    {
        LoadDatabase();
        iconSize = EditorPrefs.GetFloat("PrefabBrowser_IconSize", 80f);
    }

    private void OnFocus()
    {
        LoadDatabase();
        Repaint();
    }

    [MenuItem("Tools/Prefab Browser")]
    public static void ShowWindow()
    {
        GetWindow<PrefabBrowserWindow>("Prefab Browser");
    }

    private void LoadDatabase()
    {
        string[] guids = AssetDatabase.FindAssets("t:PrefabBrowserDatabase");
        if (guids.Length > 0)
        {
            string path = AssetDatabase.GUIDToAssetPath(guids[0]);
            database = AssetDatabase.LoadAssetAtPath<PrefabBrowserDatabase>(path);
        }
        else
        {
            database = null;
        }
    }

    private void OnGUI()
    {
        if (database == null)
        {
            EditorGUILayout.HelpBox("Prefab Browser Database not found. Please create one via:\nAssets -> Create -> Tools -> Prefab Browser Database", MessageType.Warning);
            if (GUILayout.Button("Try to Reload Database")) LoadDatabase();
            return;
        }

        if (frameStyle == null)
        {
            frameStyle = new GUIStyle(GUI.skin.box);
            frameStyle.margin = new RectOffset(4, 4, 0, 5);
            frameStyle.padding = new RectOffset(2, 2, 2, 2);
        }

        EditorGUILayout.BeginHorizontal();
        DrawLeftPane();
        DrawRightPane();
        EditorGUILayout.EndHorizontal();
    }

    private void DrawLeftPane()
    {
        EditorGUILayout.BeginVertical(GUI.skin.box, GUILayout.Width(200), GUILayout.ExpandHeight(true));
        EditorGUILayout.LabelField("Prefab Groups", EditorStyles.boldLabel);
        leftPaneScroll = EditorGUILayout.BeginScrollView(leftPaneScroll);

        if (database.groups != null)
        {
            for (int i = 0; i < database.groups.Count; i++)
            {
                var group = database.groups[i];

                EditorGUILayout.BeginVertical(frameStyle);
                {
                    Color rowBackgroundColor = (i == selectedGroupIndex) ? new Color(0.24f, 0.48f, 0.85f) : group.groupColor;
                    Color textColor = (i == selectedGroupIndex) ? Color.white : (group.useLightText ? Color.white : Color.black);

                    Rect coloredBarRect = GUILayoutUtility.GetRect(GUIContent.none, GUIStyle.none, GUILayout.Height(22));
                    EditorGUI.DrawRect(coloredBarRect, rowBackgroundColor);

                    GUIStyle labelStyle = new GUIStyle(EditorStyles.label) { normal = { textColor = textColor } };
                    labelStyle.fontStyle = FontStyle.Bold;
                    labelStyle.padding.left = 5;
                    GUI.Label(new Rect(coloredBarRect.x, coloredBarRect.y, coloredBarRect.width - 25, coloredBarRect.height), group.groupName, labelStyle);

                    Rect settingsIconRect = new Rect(coloredBarRect.x + coloredBarRect.width - 22, coloredBarRect.y + 2, 18, 18);
                    GUI.DrawTexture(settingsIconRect, EditorGUIUtility.IconContent("d_Settings").image);

                    Event currentEvent = Event.current;
                    if (currentEvent.type == EventType.MouseDown && currentEvent.button == 0)
                    {
                        if (settingsIconRect.Contains(currentEvent.mousePosition))
                        {
                            PrefabGroupSettingsWindow.ShowAsDropDown(settingsIconRect, group, database);
                            currentEvent.Use();
                        }
                        else if (coloredBarRect.Contains(currentEvent.mousePosition))
                        {
                            if (selectedGroupIndex != i)
                            {
                                selectedPrefab = null;
                            }
                            selectedGroupIndex = i;
                            Repaint();
                            currentEvent.Use();
                        }
                    }
                }
                EditorGUILayout.EndVertical();
            }
        }

        EditorGUILayout.EndScrollView();
        EditorGUILayout.Space();
        EditorGUILayout.LabelField("Create New Group:", EditorStyles.miniBoldLabel);
        newGroupName = EditorGUILayout.TextField(newGroupName);
        if (GUILayout.Button("Add Group") && !string.IsNullOrWhiteSpace(newGroupName))
        {
            database.groups.Add(new PrefabGroup { groupName = newGroupName });
            newGroupName = "New Group";
            EditorUtility.SetDirty(database);
            AssetDatabase.SaveAssets();
        }
        EditorGUILayout.EndVertical();
    }

    private void DrawRightPane()
    {
        EditorGUILayout.BeginVertical(GUI.skin.box, GUILayout.ExpandWidth(true), GUILayout.ExpandHeight(true));

        if (selectedGroupIndex < 0 || database.groups == null || selectedGroupIndex >= database.groups.Count)
        {
            EditorGUILayout.LabelField("Select a group from the left panel.", EditorStyles.centeredGreyMiniLabel);
            EditorGUILayout.EndVertical();
            return;
        }

        var selectedGroup = database.groups[selectedGroupIndex];

        Color headerBgColor = selectedGroup.groupColor;
        Color headerTextColor = selectedGroup.useLightText ? Color.white : Color.black;
        GUIStyle headerStyle = new GUIStyle(EditorStyles.boldLabel) { alignment = TextAnchor.MiddleCenter, padding = new RectOffset(5, 5, 5, 5) };
        Texture2D headerBgTexture = new Texture2D(1, 1);
        headerBgTexture.SetPixel(0, 0, headerBgColor);
        headerBgTexture.Apply();
        headerStyle.normal.background = headerBgTexture;
        headerStyle.normal.textColor = headerTextColor;
        GUILayout.Label($"Prefabs in '{selectedGroup.groupName}'", headerStyle, GUILayout.ExpandWidth(true));

        EditorGUILayout.BeginHorizontal(EditorStyles.toolbar);
        searchFilter = EditorGUILayout.TextField(searchFilter, EditorStyles.toolbarSearchField);
        if (GUILayout.Button("X", EditorStyles.toolbarButton, GUILayout.Width(22)))
        {
            searchFilter = "";
            GUI.FocusControl(null);
        }
        EditorGUILayout.EndHorizontal();

        rightPaneScroll = EditorGUILayout.BeginScrollView(rightPaneScroll);

        var filteredPrefabs = selectedGroup.prefabs.Where(p => p != null &&
            (string.IsNullOrWhiteSpace(searchFilter) || p.name.ToLowerInvariant().Contains(searchFilter.ToLowerInvariant()))
        ).ToList();

        if (iconSize < ListViewThreshold)
        {
            foreach (var prefab in filteredPrefabs)
            {
                DrawPrefabListItem(prefab, selectedGroup);
            }
        }
        else
        {
            float cellWidth = iconSize + 20;
            int gridCols = Mathf.Max(1, Mathf.FloorToInt((position.width - 220) / cellWidth));

            if (filteredPrefabs.Count > 0)
            {
                for (int i = 0; i < filteredPrefabs.Count; i += gridCols)
                {
                    EditorGUILayout.BeginHorizontal();
                    for (int j = 0; j < gridCols; j++)
                    {
                        if (i + j < filteredPrefabs.Count)
                        {
                            DrawPrefabIcon(filteredPrefabs[i + j], selectedGroup, iconSize);
                        }
                        else GUILayout.Space(cellWidth);
                    }
                    GUILayout.FlexibleSpace();
                    EditorGUILayout.EndHorizontal();
                }
            }
        }

        EditorGUILayout.EndScrollView();
        DrawBottomControls();
        EditorGUILayout.EndVertical();
    }

    private void DrawBottomControls()
    {
        EditorGUILayout.BeginHorizontal();
        GUILayout.FlexibleSpace();
        float newIconSize = GUILayout.HorizontalSlider(iconSize, 60f, 120f, GUILayout.Width(150));
        if (newIconSize != iconSize)
        {
            iconSize = newIconSize;
            EditorPrefs.SetFloat("PrefabBrowser_IconSize", iconSize);
        }
        EditorGUILayout.EndHorizontal();

        Rect dropArea = GUILayoutUtility.GetRect(0.0f, 50.0f, GUILayout.ExpandWidth(true));
        GUI.Box(dropArea, "Drag & Drop Prefabs Here");
        HandleDragAndDrop(dropArea);
    }

    // --- NOWA FUNKCJA POMOCNICZA: Rysuje ramkę wokół prostokąta ---
    private void DrawSelectionFrame(Rect rect, Color color, int thickness)
    {
        // Rysujemy 4 prostokąty (góra, dół, lewo, prawo), aby stworzyć ramkę
        // Używamy białej tekstury i zabarwiamy ją na pożądany kolor - to standardowa i wydajna technika w edytorze.
        Texture2D texture = EditorGUIUtility.whiteTexture;
        GUI.color = color;
        GUI.DrawTexture(new Rect(rect.x, rect.y, rect.width, thickness), texture); // Góra
        GUI.DrawTexture(new Rect(rect.x, rect.yMax - thickness, rect.width, thickness), texture); // Dół
        GUI.DrawTexture(new Rect(rect.x, rect.y, thickness, rect.height), texture); // Lewo
        GUI.DrawTexture(new Rect(rect.xMax - thickness, rect.y, thickness, rect.height), texture); // Prawo
        GUI.color = Color.white; // Resetujemy kolor do domyślnego
    }

    private void DrawPrefabListItem(GameObject prefab, PrefabGroup group)
    {
        EditorGUILayout.BeginHorizontal(GUI.skin.box);

        Texture icon = AssetPreview.GetMiniThumbnail(prefab);
        GUILayout.Label(icon, GUILayout.Width(20), GUILayout.Height(20));
        EditorGUILayout.LabelField(prefab.name);
        GUILayout.FlexibleSpace();
        if (GUILayout.Button("Remove", GUILayout.Width(60)))
        {
            group.prefabs.Remove(prefab);
            EditorUtility.SetDirty(database);
        }

        EditorGUILayout.EndHorizontal();
        Rect itemRect = GUILayoutUtility.GetLastRect();

        // --- ZMIANA: Rysujemy ramkę zamiast półprzezroczystego tła ---
        if (selectedPrefab == prefab)
        {
            DrawSelectionFrame(itemRect, new Color(0.24f, 0.48f, 0.85f, 1f), 1); // Cieńsza ramka dla listy
        }

        Event currentEvent = Event.current;
        // Rozdzielamy logikę: kliknięcie zaznacza, przeciąganie rozpoczyna się, gdy mysz jest wciśnięta i się rusza
        if (itemRect.Contains(currentEvent.mousePosition))
        {
            if (currentEvent.type == EventType.MouseDown && currentEvent.button == 0)
            {
                selectedPrefab = prefab;
                Repaint();
                currentEvent.Use();
            }
            if (currentEvent.type == EventType.MouseDrag && currentEvent.button == 0 && selectedPrefab == prefab)
            {
                DragAndDrop.PrepareStartDrag();
                DragAndDrop.objectReferences = new Object[] { prefab };
                DragAndDrop.StartDrag(prefab.name);
                currentEvent.Use();
            }
        }
    }

    private void DrawPrefabIcon(GameObject prefab, PrefabGroup group, float currentIconSize)
    {
        if (prefab == null) return;
        float cellWidth = currentIconSize + 20;
        EditorGUILayout.BeginVertical(GUILayout.Width(cellWidth));
        Texture2D preview = AssetPreview.GetAssetPreview(prefab) ?? AssetPreview.GetMiniTypeThumbnail(typeof(GameObject));

        Rect previewRect = GUILayoutUtility.GetRect(currentIconSize, currentIconSize);
        GUI.Box(previewRect, preview);

        // --- ZMIANA: Rysujemy ramkę zamiast półprzezroczystego tła ---
        if (selectedPrefab == prefab)
        {
            DrawSelectionFrame(previewRect, new Color(0.24f, 0.48f, 0.85f, 1f), 2); // Grubsza ramka dla siatki
        }

        Event currentEvent = Event.current;
        // Rozdzielamy logikę: kliknięcie zaznacza, przeciąganie rozpoczyna się, gdy mysz jest wciśnięta i się rusza
        if (previewRect.Contains(currentEvent.mousePosition))
        {
            if (currentEvent.type == EventType.MouseDown && currentEvent.button == 0)
            {
                selectedPrefab = prefab;
                Repaint();
                currentEvent.Use();
            }
            if (currentEvent.type == EventType.MouseDrag && currentEvent.button == 0 && selectedPrefab == prefab)
            {
                DragAndDrop.PrepareStartDrag();
                DragAndDrop.objectReferences = new Object[] { prefab };
                DragAndDrop.StartDrag(prefab.name);
                currentEvent.Use();
            }
        }

        EditorGUILayout.LabelField(prefab.name, EditorStyles.miniLabel, GUILayout.Width(currentIconSize));
        if (GUILayout.Button("Remove", EditorStyles.miniButton))
        {
            group.prefabs.Remove(prefab);
            EditorUtility.SetDirty(database);
        }
        EditorGUILayout.EndVertical();
    }

    private void HandleDragAndDrop(Rect dropArea)
    {
        Event currentEvent = Event.current;
        if (currentEvent.type != EventType.DragUpdated && currentEvent.type != EventType.DragPerform) return;
        if (!dropArea.Contains(currentEvent.mousePosition)) return;

        DragAndDrop.visualMode = DragAndDropVisualMode.Copy;
        if (currentEvent.type == EventType.DragPerform)
        {
            DragAndDrop.AcceptDrag();
            var selectedPrefabs = DragAndDrop.objectReferences
                .OfType<GameObject>()
                .Where(go => PrefabUtility.IsPartOfPrefabAsset(go) && !database.groups[selectedGroupIndex].prefabs.Contains(go));

            database.groups[selectedGroupIndex].prefabs.AddRange(selectedPrefabs);
            EditorUtility.SetDirty(database);
        }
        currentEvent.Use();
    }
}