#if UNITY_EDITOR
using UnityEditor;
using UnityEngine;
using UnityEngine.UI;
using TMPro;
using System.Linq;

namespace MegaKoop.EditorTools
{
    public static class UGUIMenuBuilder
    {
        [MenuItem("Tools/MegaKoop/Generate UGUI Main Menu", priority = 0)]
        public static void GenerateUGUIMainMenu()
        {
            // Create or use dedicated UI_Canvas (do NOT bind to a random existing Canvas)
            Canvas canvas = null;
            var canvasGO = GameObject.Find("UI_Canvas");
            if (canvasGO == null)
            {
                canvasGO = new GameObject("UI_Canvas", typeof(Canvas), typeof(CanvasScaler), typeof(GraphicRaycaster));
                Undo.RegisterCreatedObjectUndo(canvasGO, "Create Canvas");
            }
            canvas = canvasGO.GetComponent<Canvas>();
            if (canvas == null) canvas = canvasGO.AddComponent<Canvas>();
            canvas.renderMode = RenderMode.ScreenSpaceOverlay;
            var scaler = canvasGO.GetComponent<CanvasScaler>();
            if (scaler == null) scaler = canvasGO.AddComponent<CanvasScaler>();
            scaler.uiScaleMode = CanvasScaler.ScaleMode.ScaleWithScreenSize;
            scaler.referenceResolution = new Vector2(1920, 1080);
            scaler.matchWidthOrHeight = 0.5f;

            // Ensure EventSystem exists
            if (Object.FindObjectOfType<UnityEngine.EventSystems.EventSystem>() == null)
            {
                var es = new GameObject("EventSystem", typeof(UnityEngine.EventSystems.EventSystem), typeof(UnityEngine.EventSystems.StandaloneInputModule));
                Undo.RegisterCreatedObjectUndo(es, "Create EventSystem");
            }

            // Clean old generated panels if present to avoid duplicates
            void DestroyChildIfExists(Transform parent, string childName)
            {
                var child = parent.Find(childName);
                if (child != null)
                {
                    Undo.DestroyObjectImmediate(child.gameObject);
                }
            }
            DestroyChildIfExists(canvas.transform, "Panel_MainMenu");
            DestroyChildIfExists(canvas.transform, "Panel_Settings");
            DestroyChildIfExists(canvas.transform, "Panel_Lobby");

            // Root panels
            var panelMain = CreatePanel(canvas.transform, "Panel_MainMenu", new Vector2(900, 800));
            var panelSettings = CreatePanel(canvas.transform, "Panel_Settings", new Vector2(900, 800));
            var panelLobby = CreatePanel(canvas.transform, "Panel_Lobby", new Vector2(1100, 820));
            panelSettings.SetActive(false);
            panelLobby.SetActive(false);

            // Main Menu Content
            var mainContainer = CreateVerticalGroup(panelMain.transform, "Main_VLayout", 20, TextAnchor.MiddleCenter, new RectOffset(30, 30, 30, 30));
            CreateText(mainContainer.transform, "Text_Title", "MEGA KOOP", 70, TextAnchor.MiddleCenter, Color.white, FontStyles.Bold);
            CreateText(mainContainer.transform, "Text_Subtitle", "CO-OP ADVENTURE", 20, TextAnchor.MiddleCenter, new Color(0.8f,0.8f,0.8f), FontStyles.Normal);
            CreateSpacer(mainContainer.transform, 20);

            CreateMenuButton(mainContainer.transform, "Button_Multiplayer", "MULTIPLAYER");
            CreateMenuButton(mainContainer.transform, "Button_Settings", "SETTINGS");
            CreateMenuButton(mainContainer.transform, "Button_Quit", "QUIT GAME", isDanger:true);

            // Settings
            var settingsContainer = CreateVerticalGroup(panelSettings.transform, "Settings_VLayout", 16, TextAnchor.UpperCenter, new RectOffset(30,30,30,30));
            CreateText(settingsContainer.transform, "Text_SettingsTitle", "SETTINGS", 48, TextAnchor.MiddleCenter, Color.white, FontStyles.Bold);
            CreateSpacer(settingsContainer.transform, 10);

            var gfxGroup = CreateVerticalGroup(settingsContainer.transform, "Graphics_Group", 10, TextAnchor.UpperLeft, new RectOffset(10,10,10,10));
            CreateText(gfxGroup.transform, "Text_Graphics", "Graphics", 24, TextAnchor.MiddleLeft, Color.white, FontStyles.Bold);
            CreateDropdown(gfxGroup.transform, "Dropdown_Quality", new string[]{"Low","Medium","High","Ultra"});
            CreateToggle(gfxGroup.transform, "Toggle_Fullscreen", "Fullscreen", true);
            CreateDropdown(gfxGroup.transform, "Dropdown_Resolution", new string[]{"1280x720","1920x1080","2560x1440","3840x2160"});

            var settingsButtons = CreateHorizontalGroup(settingsContainer.transform, "Settings_Buttons", 10, TextAnchor.MiddleCenter, new RectOffset(0,0,0,0));
            CreateMenuButton(settingsButtons.transform, "Button_ApplySettings", "APPLY");
            CreateMenuButton(settingsButtons.transform, "Button_BackFromSettings", "BACK");

            // Lobby
            var lobbyContainer = CreateVerticalGroup(panelLobby.transform, "Lobby_VLayout", 16, TextAnchor.UpperCenter, new RectOffset(24,24,24,24));
            var lobbyHeader = CreateHorizontalGroup(lobbyContainer.transform, "Lobby_Header", 10, TextAnchor.MiddleCenter, new RectOffset(0,0,0,10));
            CreateText(lobbyHeader.transform, "Text_LobbyTitle", "MULTIPLAYER LOBBY", 36, TextAnchor.MiddleLeft, new Color(0.7f,1f,0.7f), FontStyles.Bold);
            CreateText(lobbyHeader.transform, "Text_Status", "OFFLINE", 18, TextAnchor.MiddleRight, new Color(0.8f,0.8f,0.8f), FontStyles.Bold);

            // Lobby code area
            var codeGroup = CreateVerticalGroup(lobbyContainer.transform, "Lobby_CodeGroup", 8, TextAnchor.MiddleCenter, new RectOffset(10,10,10,10));
            CreateText(codeGroup.transform, "Text_LobbyCodeLabel", "LOBBY CODE", 16, TextAnchor.MiddleCenter, new Color(0.8f,0.8f,0.8f), FontStyles.Bold);
            var codeRow = CreateHorizontalGroup(codeGroup.transform, "Lobby_CodeRow", 10, TextAnchor.MiddleCenter, new RectOffset(0,0,0,0));
            CreateText(codeRow.transform, "Text_LobbyCodeValue", "------", 44, TextAnchor.MiddleCenter, new Color(0.7f,1f,0.7f), FontStyles.Bold);
            CreateMenuButton(codeRow.transform, "Button_CopyCode", "COPY");
            CreateText(codeGroup.transform, "Text_LobbyCodeHint", "Share this code with friends to invite them", 12, TextAnchor.MiddleCenter, new Color(0.8f,0.8f,0.8f), FontStyles.Normal);

            // Tabs
            var tabs = CreateHorizontalGroup(lobbyContainer.transform, "Lobby_Tabs", 0, TextAnchor.MiddleCenter, new RectOffset(0,0,0,0));
            CreateMenuButton(tabs.transform, "Button_HostTab", "HOST LOBBY");
            CreateMenuButton(tabs.transform, "Button_JoinTab", "JOIN LOBBY");

            // Join content
            var joinGroup = CreateVerticalGroup(lobbyContainer.transform, "Group_Join", 10, TextAnchor.UpperCenter, new RectOffset(10,10,10,10));
            var joinRow = CreateHorizontalGroup(joinGroup.transform, "Join_Row", 10, TextAnchor.MiddleCenter, new RectOffset(0,0,0,0));
            CreateInputField(joinRow.transform, "Input_LobbyCode", "Enter 6-digit code...");
            CreateMenuButton(joinGroup.transform, "Button_Connect", "CONNECT");

            // Host content
            var hostGroup = CreateVerticalGroup(lobbyContainer.transform, "Group_Host", 10, TextAnchor.UpperCenter, new RectOffset(10,10,10,10));
            CreateDropdown(hostGroup.transform, "Dropdown_MaxPlayers", new string[]{"2","3","4","8"});
            CreateToggle(hostGroup.transform, "Toggle_PublicLobby", "Public", true);
            CreateMenuButton(hostGroup.transform, "Button_CreateLobby", "CREATE LOBBY");

            // Players list
            var playersHeader = CreateHorizontalGroup(lobbyContainer.transform, "Players_Header", 10, TextAnchor.MiddleLeft, new RectOffset(0,0,0,0));
            CreateText(playersHeader.transform, "Text_PlayersTitle", "PLAYERS", 20, TextAnchor.MiddleLeft, Color.white, FontStyles.Bold);
            CreateText(playersHeader.transform, "Text_PlayerCount", "0/4", 18, TextAnchor.MiddleRight, new Color(0.7f,1f,0.7f), FontStyles.Bold);

            var scroll = CreateScrollList(lobbyContainer.transform, out var content, "Scroll_Players", "Viewport", "Content_PlayersList");
            var empty = CreateText(lobbyContainer.transform, "Empty_Players", "Waiting for players...", 16, TextAnchor.MiddleCenter, new Color(0.8f,0.8f,0.8f), FontStyles.Italic);

            // Template for player entry
            var template = new GameObject("PlayerItemTemplate", typeof(RectTransform), typeof(HorizontalLayoutGroup));
            template.transform.SetParent(content, false);
            var hlg = template.GetComponent<HorizontalLayoutGroup>();
            hlg.childAlignment = TextAnchor.MiddleLeft; hlg.spacing = 12; hlg.childControlWidth = false; hlg.childForceExpandWidth = true;
            var avatar = CreateImage(template.transform, "Image_Avatar", new Color(0.3f,0.6f,0.3f));
            var name = CreateText(template.transform, "Text_PlayerName", "Player", 18, TextAnchor.MiddleLeft, Color.white, FontStyles.Bold);
            var status = CreateText(template.transform, "Text_PlayerStatus", "NOT READY", 14, TextAnchor.MiddleRight, new Color(0.8f,0.8f,0.8f), FontStyles.Bold);
            ((RectTransform)avatar.transform).sizeDelta = new Vector2(40,40);
            template.SetActive(false);

            // Host controls
            var hostControls = CreateHorizontalGroup(lobbyContainer.transform, "Host_Controls", 10, TextAnchor.MiddleCenter, new RectOffset(0,0,0,0));
            CreateMenuButton(hostControls.transform, "Button_InviteFriends", "INVITE FRIENDS");
            CreateMenuButton(hostControls.transform, "Button_KickSelected", "KICK SELECTED");

            // Friends picker will be a modal overlay under Panel_Lobby (so it doesn't stretch main layout)
            var friendsOverlay = new GameObject("Panel_Friends", typeof(RectTransform), typeof(Image));
            friendsOverlay.transform.SetParent(panelLobby.transform, false);
            var ovRT = (RectTransform)friendsOverlay.transform; ovRT.anchorMin = new Vector2(0,0); ovRT.anchorMax = new Vector2(1,1); ovRT.offsetMin = Vector2.zero; ovRT.offsetMax = Vector2.zero;
            var ovImg = friendsOverlay.GetComponent<Image>(); ovImg.color = new Color(0,0,0,0.55f);
            friendsOverlay.SetActive(false);

            // Transparent background button to close on backdrop click
            var closeBg = new GameObject("Button_CloseFriendsOverlay", typeof(RectTransform), typeof(Image), typeof(Button));
            closeBg.transform.SetParent(friendsOverlay.transform, false);
            var closeBgRT = (RectTransform)closeBg.transform; closeBgRT.anchorMin = new Vector2(0,0); closeBgRT.anchorMax = new Vector2(1,1); closeBgRT.offsetMin = Vector2.zero; closeBgRT.offsetMax = Vector2.zero;
            var closeBgImg = closeBg.GetComponent<Image>(); closeBgImg.color = new Color(0,0,0,0);

            // Center modal window
            var friendsWindow = CreatePanel(friendsOverlay.transform, "Friends_Window", new Vector2(900, 420));
            var friendsV = CreateVerticalGroup(friendsWindow.transform, "Friends_VLayout", 8, TextAnchor.UpperCenter, new RectOffset(16,16,16,16));
            CreateText(friendsV.transform, "Text_FriendsTitle", "INVITE FRIENDS", 24, TextAnchor.MiddleCenter, Color.white, FontStyles.Bold);
            CreateText(friendsV.transform, "Text_FriendsHint", "Select a friend to send a Steam invite.", 12, TextAnchor.MiddleCenter, new Color(0.8f,0.8f,0.8f), FontStyles.Normal);
            var friendsScroll = CreateScrollList(friendsV.transform, out var friendsContent, "Scroll_Friends", "Viewport", "Content_FriendsList");
            // Make friends content a compact grid of icons
            var vlgFriends = friendsContent.GetComponent<VerticalLayoutGroup>();
            if (vlgFriends) Object.DestroyImmediate(vlgFriends);
            var gridFriends = friendsContent.gameObject.AddComponent<GridLayoutGroup>();
            gridFriends.cellSize = new Vector2(72, 72);
            gridFriends.spacing = new Vector2(10, 10);
            gridFriends.startAxis = GridLayoutGroup.Axis.Horizontal;
            var csfFriends = friendsContent.GetComponent<ContentSizeFitter>();
            if (csfFriends == null) csfFriends = friendsContent.gameObject.AddComponent<ContentSizeFitter>();
            csfFriends.verticalFit = ContentSizeFitter.FitMode.PreferredSize;
            CreateText(friendsV.transform, "Empty_Friends", "No friends found.", 14, TextAnchor.MiddleCenter, new Color(0.8f,0.8f,0.8f), FontStyles.Italic);
            var friendsFooter = CreateHorizontalGroup(friendsV.transform, "Friends_Footer", 8, TextAnchor.MiddleCenter, new RectOffset(0,0,0,0));
            CreateMenuButton(friendsFooter.transform, "Button_BackFromFriends", "BACK");

            // Ready
            CreateMenuButton(lobbyContainer.transform, "Button_ToggleReady", "TOGGLE READY");

            // Footer
            var footer = CreateHorizontalGroup(lobbyContainer.transform, "Lobby_Footer", 10, TextAnchor.MiddleCenter, new RectOffset(0,0,0,0));
            CreateMenuButton(footer.transform, "Button_StartGame", "START GAME");
            CreateMenuButton(footer.transform, "Button_LeaveLobby", "LEAVE LOBBY");
            CreateMenuButton(footer.transform, "Button_BackFromLobby", "BACK TO MENU");

            // Controllers
            var mainCtrl = canvas.gameObject.GetComponent<MegaKoop.UI.UGUIMainMenuController>();
            if (mainCtrl == null) mainCtrl = canvas.gameObject.AddComponent<MegaKoop.UI.UGUIMainMenuController>();
            var lobbyCtrl = canvas.gameObject.GetComponent<MegaKoop.UI.UGUIMultiplayerLobbyController>();
            if (lobbyCtrl == null) lobbyCtrl = canvas.gameObject.AddComponent<MegaKoop.UI.UGUIMultiplayerLobbyController>();

            // Inject panel references for reliability
            mainCtrl.SetPanels(panelMain, panelSettings, panelLobby);
            lobbyCtrl.SetLobbyRoot(panelLobby);

            Selection.activeGameObject = canvas.gameObject;

            Debug.Log("[UGUIMenuBuilder] UGUI Main Menu generated successfully. You can press Play and test.");
        }

        private static GameObject CreatePanel(Transform parent, string name, Vector2 size)
        {
            var go = new GameObject(name, typeof(RectTransform), typeof(Image));
            go.transform.SetParent(parent, false);
            var rt = (RectTransform)go.transform;
            rt.anchorMin = rt.anchorMax = new Vector2(0.5f, 0.5f);
            rt.pivot = new Vector2(0.5f, 0.5f);
            rt.sizeDelta = size;
            var img = go.GetComponent<Image>();
            img.color = new Color(0.13f, 0.13f, 0.13f, 0.95f);
            return go;
        }

        private static GameObject CreateVerticalGroup(Transform parent, string name, float spacing, TextAnchor align, RectOffset padding)
        {
            var go = new GameObject(name, typeof(RectTransform), typeof(VerticalLayoutGroup), typeof(ContentSizeFitter));
            go.transform.SetParent(parent, false);
            var rt = (RectTransform)go.transform;
            rt.anchorMin = new Vector2(0, 0); rt.anchorMax = new Vector2(1, 1); rt.offsetMin = new Vector2(0,0); rt.offsetMax = new Vector2(0,0);
            var vlg = go.GetComponent<VerticalLayoutGroup>();
            vlg.spacing = spacing; vlg.childAlignment = align; vlg.padding = padding; vlg.childForceExpandWidth = true; vlg.childControlWidth = true; vlg.childControlHeight = false;
            var fitter = go.GetComponent<ContentSizeFitter>();
            fitter.verticalFit = ContentSizeFitter.FitMode.PreferredSize; fitter.horizontalFit = ContentSizeFitter.FitMode.Unconstrained;
            return go;
        }

        private static GameObject CreateHorizontalGroup(Transform parent, string name, float spacing, TextAnchor align, RectOffset padding)
        {
            var go = new GameObject(name, typeof(RectTransform), typeof(HorizontalLayoutGroup));
            go.transform.SetParent(parent, false);
            var rt = (RectTransform)go.transform;
            rt.anchorMin = new Vector2(0, 0); rt.anchorMax = new Vector2(1, 0); rt.pivot = new Vector2(0.5f, 0.5f);
            rt.sizeDelta = new Vector2(0, 60);
            var hlg = go.GetComponent<HorizontalLayoutGroup>();
            hlg.spacing = spacing; hlg.childAlignment = align; hlg.padding = padding; hlg.childControlWidth = true; hlg.childForceExpandWidth = true;
            return go;
        }

        private static GameObject CreateText(Transform parent, string name, string text, int fontSize, TextAnchor anchor, Color color, FontStyles fontStyle)
        {
            var go = new GameObject(name, typeof(RectTransform), typeof(TextMeshProUGUI), typeof(LayoutElement));
            go.transform.SetParent(parent, false);
            var t = go.GetComponent<TextMeshProUGUI>();
            t.text = text; t.fontSize = fontSize; t.color = color; t.alignment = MapAlignment(anchor); t.fontStyle = fontStyle;
            t.enableWordWrapping = false; // avoid vertical letters
            t.raycastTarget = false; // don't block parent UI clicks
            if (TMP_Settings.defaultFontAsset != null) t.font = TMP_Settings.defaultFontAsset;
            var le = go.GetComponent<LayoutElement>();
            le.minHeight = Mathf.Max(24, fontSize + 12);
            var rt = (RectTransform)go.transform; rt.sizeDelta = new Vector2(0, fontSize + 20);
            return go;
        }

        private static TextAlignmentOptions MapAlignment(TextAnchor anchor)
        {
            switch (anchor)
            {
                case TextAnchor.UpperLeft: return TextAlignmentOptions.TopLeft;
                case TextAnchor.UpperCenter: return TextAlignmentOptions.Top;
                case TextAnchor.UpperRight: return TextAlignmentOptions.TopRight;
                case TextAnchor.MiddleLeft: return TextAlignmentOptions.MidlineLeft;
                case TextAnchor.MiddleCenter: return TextAlignmentOptions.Midline;
                case TextAnchor.MiddleRight: return TextAlignmentOptions.MidlineRight;
                case TextAnchor.LowerLeft: return TextAlignmentOptions.BottomLeft;
                case TextAnchor.LowerCenter: return TextAlignmentOptions.Bottom;
                case TextAnchor.LowerRight: return TextAlignmentOptions.BottomRight;
                default: return TextAlignmentOptions.Center;
            }
        }

        private static GameObject CreateMenuButton(Transform parent, string name, string label, bool isDanger = false)
        {
            var go = new GameObject(name, typeof(RectTransform), typeof(Image), typeof(Button));
            go.transform.SetParent(parent, false);
            var img = go.GetComponent<Image>();
            img.color = isDanger ? new Color(0.5f, 0.15f, 0.15f, 0.9f) : new Color(0.25f, 0.5f, 0.25f, 0.9f);
            var rt = (RectTransform)go.transform; rt.sizeDelta = new Vector2(0, 48);
            var leBtn = go.AddComponent<LayoutElement>();
            leBtn.flexibleWidth = 1; leBtn.minHeight = 48;
            var text = CreateText(go.transform, "Text", label, 20, TextAnchor.MiddleCenter, Color.white, FontStyles.Bold);
            var textRT = (RectTransform)text.transform; textRT.anchorMin = new Vector2(0,0); textRT.anchorMax = new Vector2(1,1); textRT.offsetMin = Vector2.zero; textRT.offsetMax = Vector2.zero;
            return go;
        }

        private static GameObject CreateInputField(Transform parent, string name, string placeholder)
        {
            var go = new GameObject(name, typeof(RectTransform), typeof(Image), typeof(TMP_InputField));
            go.transform.SetParent(parent, false);
            var img = go.GetComponent<Image>(); img.color = new Color(0.1f,0.1f,0.1f,0.9f);
            var rt = (RectTransform)go.transform; rt.sizeDelta = new Vector2(600, 50);
            var viewport = new GameObject("TextViewport", typeof(RectTransform)); viewport.transform.SetParent(go.transform, false);
            var viewportRT = (RectTransform)viewport.transform; viewportRT.anchorMin = new Vector2(0,0); viewportRT.anchorMax = new Vector2(1,1); viewportRT.offsetMin = new Vector2(10,6); viewportRT.offsetMax = new Vector2(-10,-6);
            var text = CreateText(viewport.transform, "Text", string.Empty, 20, TextAnchor.MiddleLeft, Color.white, FontStyles.Normal);
            var placeholderGO = CreateText(viewport.transform, "Placeholder", placeholder, 18, TextAnchor.MiddleLeft, new Color(0.7f,0.7f,0.7f), FontStyles.Italic);
            var input = go.GetComponent<TMP_InputField>();
            input.textViewport = viewportRT;
            input.textComponent = text.GetComponent<TextMeshProUGUI>();
            input.placeholder = placeholderGO.GetComponent<TextMeshProUGUI>();
            var tRT = (RectTransform)text.transform; tRT.anchorMin = new Vector2(0,0); tRT.anchorMax = new Vector2(1,1); tRT.offsetMin = new Vector2(10,0); tRT.offsetMax = new Vector2(-10,0);
            var pRT = (RectTransform)placeholderGO.transform; pRT.anchorMin = new Vector2(0,0); pRT.anchorMax = new Vector2(1,1); pRT.offsetMin = new Vector2(10,0); pRT.offsetMax = new Vector2(-10,0);
            return go;
        }

        private static GameObject CreateDropdown(Transform parent, string name, string[] options)
        {
            var go = new GameObject(name, typeof(RectTransform), typeof(Image), typeof(TMP_Dropdown));
            go.transform.SetParent(parent, false);
            var img = go.GetComponent<Image>(); img.color = new Color(0.2f,0.2f,0.2f,0.9f);
            var rt = (RectTransform)go.transform; rt.sizeDelta = new Vector2(600, 50);

            // Caption label
            var caption = CreateText(go.transform, "Label", options.FirstOrDefault() ?? "Option", 18, TextAnchor.MiddleLeft, Color.white, FontStyles.Normal);
            var arrow = CreateText(go.transform, "Arrow", "▼", 18, TextAnchor.MiddleRight, Color.white, FontStyles.Bold);

            // Template (disabled by default)
            var template = new GameObject("Template", typeof(RectTransform), typeof(Image), typeof(ScrollRect));
            template.transform.SetParent(go.transform, false);
            var templateRT = (RectTransform)template.transform;
            templateRT.anchorMin = new Vector2(0, 0); templateRT.anchorMax = new Vector2(1, 0); templateRT.pivot = new Vector2(0.5f, 1);
            templateRT.sizeDelta = new Vector2(0, 220); // visible dropdown height
            template.SetActive(false);
            var templateImg = template.GetComponent<Image>(); templateImg.color = new Color(0.1f,0.1f,0.1f,0.95f);

            // Viewport
            var viewport = new GameObject("Viewport", typeof(RectTransform), typeof(Mask), typeof(Image));
            viewport.transform.SetParent(template.transform, false);
            var viewportRT = (RectTransform)viewport.transform; viewportRT.anchorMin = new Vector2(0,0); viewportRT.anchorMax = new Vector2(1,1); viewportRT.offsetMin = Vector2.zero; viewportRT.offsetMax = Vector2.zero;
            var vImg = viewport.GetComponent<Image>(); vImg.color = new Color(0,0,0,0.2f);
            viewport.GetComponent<Mask>().showMaskGraphic = false;

            // Scroll content
            var content = new GameObject("Content", typeof(RectTransform), typeof(VerticalLayoutGroup));
            content.transform.SetParent(viewport.transform, false);
            var contentRT = (RectTransform)content.transform; contentRT.anchorMin = new Vector2(0,1); contentRT.anchorMax = new Vector2(1,1); contentRT.pivot = new Vector2(0.5f,1);
            var vlg = content.GetComponent<VerticalLayoutGroup>(); vlg.spacing = 4; vlg.childForceExpandWidth = true; vlg.childControlHeight = true;

            // Item (Toggle)
            var item = new GameObject("Item", typeof(RectTransform), typeof(Toggle));
            item.transform.SetParent(content.transform, false);
            var itemRT = (RectTransform)item.transform; itemRT.sizeDelta = new Vector2(0, 30);
            var itemBG = new GameObject("Item Background", typeof(RectTransform), typeof(Image));
            itemBG.transform.SetParent(item.transform, false);
            var itemBGImg = itemBG.GetComponent<Image>(); itemBGImg.color = new Color(0.2f,0.2f,0.2f,0.9f);
            var itemCheck = new GameObject("Item Checkmark", typeof(RectTransform), typeof(Image));
            itemCheck.transform.SetParent(itemBG.transform, false);
            var itemCheckImg = itemCheck.GetComponent<Image>(); itemCheckImg.color = new Color(0.7f,1f,0.7f,1f);
            var itemLabelGO = CreateText(item.transform, "Item Label", "Option", 18, TextAnchor.MiddleLeft, Color.white, FontStyles.Normal);

            // Position sub-elements
            var bgRT = (RectTransform)itemBG.transform; bgRT.anchorMin = new Vector2(0,0); bgRT.anchorMax = new Vector2(1,1); bgRT.offsetMin = Vector2.zero; bgRT.offsetMax = Vector2.zero;
            var ckRT = (RectTransform)itemCheck.transform; ckRT.anchorMin = new Vector2(0,0.5f); ckRT.anchorMax = new Vector2(0,0.5f); ckRT.pivot = new Vector2(0,0.5f); ckRT.sizeDelta = new Vector2(18,18); ckRT.anchoredPosition = new Vector2(6,0);
            var itemLabelRT = (RectTransform)itemLabelGO.transform; itemLabelRT.anchorMin = new Vector2(0,0); itemLabelRT.anchorMax = new Vector2(1,1); itemLabelRT.offsetMin = new Vector2(28,0); itemLabelRT.offsetMax = new Vector2(-6,0);

            // Toggle wiring
            var tgl = item.GetComponent<Toggle>();
            tgl.targetGraphic = itemBGImg; tgl.graphic = itemCheckImg;

            // Dropdown wiring
            var dd = go.GetComponent<TMP_Dropdown>();
            dd.template = template.GetComponent<RectTransform>();
            dd.captionText = caption.GetComponent<TextMeshProUGUI>();
            dd.itemText = itemLabelGO.GetComponent<TextMeshProUGUI>();
            dd.options = options.Select(o => new TMP_Dropdown.OptionData(o)).ToList();
            dd.RefreshShownValue();

            // ScrollRect wiring
            var scr = template.GetComponent<ScrollRect>();
            scr.viewport = viewport.GetComponent<RectTransform>();
            scr.content = content.GetComponent<RectTransform>();
            scr.horizontal = false; scr.vertical = true;
            return go;
        }

        private static GameObject CreateToggle(Transform parent, string name, string labelText, bool initial)
        {
            var go = new GameObject(name, typeof(RectTransform), typeof(Toggle));
            go.transform.SetParent(parent, false);
            var bg = CreateImage(go.transform, "Background", new Color(0.2f,0.2f,0.2f));
            var check = CreateImage(bg.transform, "Checkmark", new Color(0.7f,1f,0.7f));
            var label = CreateText(go.transform, "Label", labelText, 18, TextAnchor.MiddleLeft, Color.white, FontStyles.Normal);
            var t = go.GetComponent<Toggle>();
            t.isOn = initial; t.graphic = check.GetComponent<Image>(); t.targetGraphic = bg.GetComponent<Image>();
            var rt = (RectTransform)go.transform; rt.sizeDelta = new Vector2(600, 40);
            var bgRT = (RectTransform)bg.transform; bgRT.anchorMin = new Vector2(0,0.5f); bgRT.anchorMax = new Vector2(0,0.5f); bgRT.pivot = new Vector2(0,0.5f); bgRT.sizeDelta = new Vector2(24,24);
            var checkRT = (RectTransform)check.transform; checkRT.anchorMin = checkRT.anchorMax = new Vector2(0.5f,0.5f); checkRT.sizeDelta = new Vector2(16,16);
            var labelRT = (RectTransform)label.transform; labelRT.anchorMin = new Vector2(0,0); labelRT.anchorMax = new Vector2(1,1); labelRT.offsetMin = new Vector2(34,0); labelRT.offsetMax = new Vector2(0,0);
            return go;
        }

        private static GameObject CreateImage(Transform parent, string name, Color color)
        {
            var go = new GameObject(name, typeof(RectTransform), typeof(Image));
            go.transform.SetParent(parent, false);
            var img = go.GetComponent<Image>(); img.color = color;
            return go;
        }

        private static void CreateSpacer(Transform parent, float height)
        {
            var sp = new GameObject("Spacer", typeof(RectTransform));
            sp.transform.SetParent(parent, false);
            var rt = (RectTransform)sp.transform; rt.sizeDelta = new Vector2(0, height);
        }

        private static ScrollRect CreateScrollList(Transform parent, out Transform content, string scrollName, string viewportName, string contentName)
        {
            var scrollGO = new GameObject(scrollName, typeof(RectTransform), typeof(Image), typeof(ScrollRect));
            scrollGO.transform.SetParent(parent, false);
            var srt = (RectTransform)scrollGO.transform; srt.sizeDelta = new Vector2(0, 240);
            var img = scrollGO.GetComponent<Image>(); img.color = new Color(0,0,0,0.3f);
            var viewport = new GameObject(viewportName, typeof(RectTransform), typeof(Mask), typeof(Image));
            viewport.transform.SetParent(scrollGO.transform, false);
            var vImg = viewport.GetComponent<Image>(); vImg.color = new Color(0,0,0,0.1f);
            viewport.GetComponent<Mask>().showMaskGraphic = false;
            var vprt = (RectTransform)viewport.transform; vprt.anchorMin = new Vector2(0,0); vprt.anchorMax = new Vector2(1,1); vprt.offsetMin = Vector2.zero; vprt.offsetMax = Vector2.zero;
            var contentGO = new GameObject(contentName, typeof(RectTransform), typeof(VerticalLayoutGroup));
            contentGO.transform.SetParent(viewport.transform, false);
            var vlg = contentGO.GetComponent<VerticalLayoutGroup>(); vlg.spacing = 8; vlg.childAlignment = TextAnchor.UpperLeft; vlg.childForceExpandWidth = true;
            var crt = (RectTransform)contentGO.transform; crt.anchorMin = new Vector2(0,1); crt.anchorMax = new Vector2(1,1); crt.pivot = new Vector2(0.5f,1); crt.offsetMin = new Vector2(0,0); crt.offsetMax = new Vector2(0,0);
            var csf = contentGO.AddComponent<ContentSizeFitter>(); csf.verticalFit = ContentSizeFitter.FitMode.PreferredSize;
            content = contentGO.transform;
            var scroll = scrollGO.GetComponent<ScrollRect>(); scroll.viewport = (RectTransform)viewport.transform; scroll.content = (RectTransform)content; scroll.horizontal = false; scroll.vertical = true;
            return scroll;
        }
    }
}
#endif