using Aisu.SIM1.Face.Core;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace Aisu.SIM1.Face.Samples.FaceDetectionDemo
{
    /// <summary>
    /// 人脸检测 Demo 场景 UI 动态构建器。
    /// </summary>
    public sealed class FaceDetectionDemoBootstrap : MonoBehaviour
    {
        private Font m_font; // UI 字体。

        private void Awake()
        {
            Build();
        }

        /// <summary>
        /// 构建 MVP 测试页面。
        /// </summary>
        public void Build()
        {
            m_font = Resources.GetBuiltinResource<Font>("Arial.ttf");
            EnsureEventSystem();

            var manager = FindObjectOfType<FaceModuleManager>() ?? new GameObject("FaceModuleManager").AddComponent<FaceModuleManager>();
            var camera = gameObject.AddComponent<FaceDetectionDemoCamera>();
            var logger = gameObject.AddComponent<FaceDetectionDemoLogger>();
            var userList = gameObject.AddComponent<FaceDetectionDemoUserList>();
            var controller = gameObject.AddComponent<FaceDetectionDemoController>();

            var canvasGo = Create("FaceDetectionDemoCanvas", transform);
            var canvas = canvasGo.AddComponent<Canvas>();
            canvas.renderMode = RenderMode.ScreenSpaceOverlay;
            canvasGo.AddComponent<GraphicRaycaster>();
            var scaler = canvasGo.AddComponent<CanvasScaler>();
            scaler.uiScaleMode = CanvasScaler.ScaleMode.ScaleWithScreenSize;
            scaler.referenceResolution = new Vector2(1280, 720);

            var root = Create("Root", canvasGo.transform);
            Stretch(root.GetComponent<RectTransform>());
            var rootLayout = root.AddComponent<VerticalLayoutGroup>();
            rootLayout.padding = new RectOffset(16, 16, 16, 16);
            rootLayout.spacing = 10;
            rootLayout.childControlWidth = true;
            rootLayout.childForceExpandWidth = true;

            var title = Text(root.transform, "SI-M1 Face Detection Demo", 28, TextAnchor.MiddleLeft);
            title.color = new Color(0.05f, 0.07f, 0.1f);

            var statusText = Text(root.transform, "摄像头未打开 | 模组未连接", 20, TextAnchor.MiddleLeft);
            statusText.color = new Color(0.12f, 0.18f, 0.24f);

            var body = Create("Body", root.transform);
            body.AddComponent<LayoutElement>().flexibleHeight = 1f;
            var bodyLayout = body.AddComponent<HorizontalLayoutGroup>();
            bodyLayout.spacing = 12;
            bodyLayout.childControlHeight = true;
            bodyLayout.childForceExpandHeight = true;

            var left = Panel(body.transform, "LeftPanel", new Color(0.95f, 0.97f, 1f));
            left.AddComponent<LayoutElement>().flexibleWidth = 1f;
            var leftLayout = left.AddComponent<VerticalLayoutGroup>();
            leftLayout.padding = new RectOffset(10, 10, 10, 10);
            leftLayout.spacing = 8;
            leftLayout.childControlWidth = true;
            leftLayout.childForceExpandWidth = true;

            var right = Panel(body.transform, "RightPanel", new Color(0.98f, 0.98f, 0.96f));
            right.AddComponent<LayoutElement>().preferredWidth = 430;
            var rightLayout = right.AddComponent<VerticalLayoutGroup>();
            rightLayout.padding = new RectOffset(10, 10, 10, 10);
            rightLayout.spacing = 8;
            rightLayout.childControlWidth = true;
            rightLayout.childForceExpandWidth = true;

            var cameraDropdown = Dropdown(left.transform, "未发现摄像头");
            var cameraRow = Row(left.transform);
            var refreshCameraButton = Button(cameraRow.transform, "刷新摄像头");
            var openCameraButton = Button(cameraRow.transform, "打开摄像头");
            var closeCameraButton = Button(cameraRow.transform, "关闭摄像头");

            var previewFrame = Panel(left.transform, "CameraPreview", Color.black);
            previewFrame.AddComponent<LayoutElement>().flexibleHeight = 1f;
            var preview = Create("Preview", previewFrame.transform).AddComponent<RawImage>();
            preview.color = Color.white;
            var previewRect = preview.GetComponent<RectTransform>();
            previewRect.anchorMin = Vector2.zero;
            previewRect.anchorMax = Vector2.one;
            previewRect.offsetMin = Vector2.zero;
            previewRect.offsetMax = Vector2.zero;
            var aspect = preview.gameObject.AddComponent<AspectRatioFitter>();
            aspect.aspectMode = AspectRatioFitter.AspectMode.FitInParent;

            Text(right.transform, "串口 / 模组", 22, TextAnchor.MiddleLeft);
            var serialDropdown = Dropdown(right.transform, "手动输入串口");
            var serialInput = Input(right.transform, "串口名，例如 COM3 或 /dev/ttyUSB0");
            var baudInput = Input(right.transform, "115200");
            var serialRow = Row(right.transform);
            var refreshSerialButton = Button(serialRow.transform, "刷新串口");
            var connectButton = Button(serialRow.transform, "连接模组");
            var disconnectButton = Button(serialRow.transform, "断开模组");

            Text(right.transform, "人脸操作", 22, TextAnchor.MiddleLeft);
            var userNameInput = Input(right.transform, "User");
            var adminToggle = Toggle(right.transform, "管理员", false);
            var faceRow = Row(right.transform);
            var enrollButton = Button(faceRow.transform, "录入人脸");
            var verifyButton = Button(faceRow.transform, "检测人脸");

            var resultText = Text(right.transform, "结果: -", 20, TextAnchor.UpperLeft);
            resultText.gameObject.AddComponent<LayoutElement>().preferredHeight = 58;

            Text(right.transform, "人脸数据", 22, TextAnchor.MiddleLeft);
            var userButtonRow = Row(right.transform);
            var refreshUsersButton = Button(userButtonRow.transform, "刷新用户列表");
            var userScroll = ScrollView(right.transform, out var userContent);
            userScroll.GetComponent<LayoutElement>().preferredHeight = 170;

            Text(root.transform, "操作日志", 22, TextAnchor.MiddleLeft);
            var logRow = Row(root.transform);
            var clearLogButton = Button(logRow.transform, "清空日志");
            var logScroll = ScrollView(root.transform, out var logContent);
            logScroll.GetComponent<LayoutElement>().preferredHeight = 150;
            var logText = Text(logContent, string.Empty, 18, TextAnchor.UpperLeft);
            logText.font = m_font;
            logText.color = Color.white;
            logText.horizontalOverflow = HorizontalWrapMode.Wrap;
            logText.verticalOverflow = VerticalWrapMode.Overflow;
            logText.gameObject.AddComponent<LayoutElement>().flexibleWidth = 1f;
            logContent.gameObject.GetComponent<Image>().color = new Color(0.07f, 0.08f, 0.09f);

            camera.Bind(preview, aspect, logger);
            logger.Bind(logText, logScroll);
            userList.Bind(userContent, m_font, controller.DeleteUser);
            controller.Bind(manager, camera, logger, userList, cameraDropdown, serialDropdown, serialInput, baudInput, userNameInput, adminToggle, statusText, resultText);

            refreshCameraButton.onClick.AddListener(controller.RefreshCameras);
            openCameraButton.onClick.AddListener(controller.OpenCamera);
            closeCameraButton.onClick.AddListener(controller.CloseCamera);
            refreshSerialButton.onClick.AddListener(controller.RefreshSerialPorts);
            connectButton.onClick.AddListener(controller.ConnectModule);
            disconnectButton.onClick.AddListener(controller.DisconnectModule);
            enrollButton.onClick.AddListener(controller.EnrollFace);
            verifyButton.onClick.AddListener(controller.VerifyFace);
            refreshUsersButton.onClick.AddListener(controller.RefreshUsers);
            clearLogButton.onClick.AddListener(logger.Clear);
        }

        private static void EnsureEventSystem()
        {
            if (FindObjectOfType<EventSystem>() != null)
            {
                return;
            }

            var eventSystem = new GameObject("EventSystem");
            eventSystem.AddComponent<EventSystem>();
            eventSystem.AddComponent<StandaloneInputModule>();
        }

        private GameObject Panel(Transform parent, string name, Color color)
        {
            var go = Create(name, parent);
            go.AddComponent<Image>().color = color;
            return go;
        }

        private GameObject Row(Transform parent)
        {
            var row = Create("Row", parent);
            var layout = row.AddComponent<HorizontalLayoutGroup>();
            layout.spacing = 8;
            layout.childControlWidth = true;
            layout.childForceExpandWidth = true;
            row.AddComponent<LayoutElement>().preferredHeight = 44;
            return row;
        }

        private Button Button(Transform parent, string text)
        {
            var go = Create(text, parent);
            go.AddComponent<Image>().color = new Color(0.78f, 0.86f, 0.95f);
            var button = go.AddComponent<Button>();
            go.AddComponent<LayoutElement>().preferredHeight = 42;
            var label = Text(go.transform, text, 20, TextAnchor.MiddleCenter);
            Stretch(label.GetComponent<RectTransform>());
            return button;
        }

        private InputField Input(Transform parent, string placeholder)
        {
            var go = Create("InputField", parent);
            go.AddComponent<Image>().color = Color.white;
            go.AddComponent<LayoutElement>().preferredHeight = 42;
            var input = go.AddComponent<InputField>();

            var text = Text(go.transform, string.Empty, 20, TextAnchor.MiddleLeft);
            var textRect = text.GetComponent<RectTransform>();
            Stretch(textRect);
            textRect.offsetMin = new Vector2(10, 0);
            textRect.offsetMax = new Vector2(-10, 0);
            input.textComponent = text;

            var placeholderText = Text(go.transform, placeholder, 20, TextAnchor.MiddleLeft);
            placeholderText.color = new Color(0.45f, 0.48f, 0.52f);
            var placeholderRect = placeholderText.GetComponent<RectTransform>();
            Stretch(placeholderRect);
            placeholderRect.offsetMin = new Vector2(10, 0);
            placeholderRect.offsetMax = new Vector2(-10, 0);
            input.placeholder = placeholderText;
            return input;
        }

        private Toggle Toggle(Transform parent, string label, bool value)
        {
            var row = Row(parent);
            row.GetComponent<HorizontalLayoutGroup>().childForceExpandWidth = false;
            var toggleGo = Create("Toggle", row.transform);
            toggleGo.AddComponent<LayoutElement>().preferredWidth = 34;
            var toggle = toggleGo.AddComponent<Toggle>();
            var background = Create("Background", toggleGo.transform).AddComponent<Image>();
            background.color = Color.white;
            Stretch(background.GetComponent<RectTransform>());
            var checkmark = Create("Checkmark", background.transform).AddComponent<Image>();
            checkmark.color = new Color(0.18f, 0.45f, 0.85f);
            var checkRect = checkmark.GetComponent<RectTransform>();
            checkRect.anchorMin = new Vector2(0.2f, 0.2f);
            checkRect.anchorMax = new Vector2(0.8f, 0.8f);
            checkRect.offsetMin = Vector2.zero;
            checkRect.offsetMax = Vector2.zero;
            toggle.targetGraphic = background;
            toggle.graphic = checkmark;
            toggle.isOn = value;
            Text(row.transform, label, 20, TextAnchor.MiddleLeft).gameObject.AddComponent<LayoutElement>().flexibleWidth = 1f;
            return toggle;
        }

        private Dropdown Dropdown(Transform parent, string initial)
        {
            var go = Create("Dropdown", parent);
            var image = go.AddComponent<Image>();
            image.color = Color.white;
            go.AddComponent<LayoutElement>().preferredHeight = 42;
            var dropdown = go.AddComponent<Dropdown>();
            dropdown.targetGraphic = image;
            var label = Text(go.transform, initial, 20, TextAnchor.MiddleLeft);
            var labelRect = label.GetComponent<RectTransform>();
            Stretch(labelRect);
            labelRect.offsetMin = new Vector2(10, 0);
            labelRect.offsetMax = new Vector2(-30, 0);
            var arrow = Text(go.transform, "v", 18, TextAnchor.MiddleCenter);
            var arrowRect = arrow.GetComponent<RectTransform>();
            arrowRect.anchorMin = new Vector2(1f, 0f);
            arrowRect.anchorMax = Vector2.one;
            arrowRect.pivot = new Vector2(1f, 0.5f);
            arrowRect.sizeDelta = new Vector2(30, 0);
            arrowRect.anchoredPosition = Vector2.zero;
            dropdown.template = CreateDropdownTemplate(go.transform, out var itemText);
            dropdown.captionText = label;
            dropdown.itemText = itemText;
            dropdown.options.Add(new Dropdown.OptionData(initial));
            dropdown.value = 0;
            return dropdown;
        }

        private RectTransform CreateDropdownTemplate(Transform parent, out Text itemText)
        {
            var template = Panel(parent, "Template", Color.white);
            template.SetActive(false);
            var templateRect = template.GetComponent<RectTransform>();
            templateRect.anchorMin = new Vector2(0f, 0f);
            templateRect.anchorMax = new Vector2(1f, 0f);
            templateRect.pivot = new Vector2(0.5f, 1f);
            templateRect.sizeDelta = new Vector2(0f, 180f);
            templateRect.anchoredPosition = new Vector2(0f, 2f);
            var scrollRect = template.AddComponent<ScrollRect>();
            scrollRect.horizontal = false;

            var viewport = Panel(template.transform, "Viewport", new Color(1f, 1f, 1f, 0.98f));
            viewport.AddComponent<Mask>().showMaskGraphic = false;
            Stretch(viewport.GetComponent<RectTransform>());

            var contentGo = Create("Content", viewport.transform);
            var contentRect = contentGo.GetComponent<RectTransform>();
            contentRect.anchorMin = new Vector2(0f, 1f);
            contentRect.anchorMax = Vector2.one;
            contentRect.pivot = new Vector2(0.5f, 1f);
            contentRect.offsetMin = Vector2.zero;
            contentRect.offsetMax = Vector2.zero;
            contentGo.AddComponent<VerticalLayoutGroup>().childForceExpandWidth = true;
            contentGo.AddComponent<ContentSizeFitter>().verticalFit = ContentSizeFitter.FitMode.PreferredSize;

            var itemGo = Create("Item", contentGo.transform);
            var itemToggle = itemGo.AddComponent<Toggle>();
            itemGo.AddComponent<LayoutElement>().preferredHeight = 36;
            var itemBackground = itemGo.AddComponent<Image>();
            itemBackground.color = Color.white;
            itemToggle.targetGraphic = itemBackground;

            var checkmark = Text(itemGo.transform, "✓", 18, TextAnchor.MiddleCenter);
            var checkRect = checkmark.GetComponent<RectTransform>();
            checkRect.anchorMin = new Vector2(0f, 0f);
            checkRect.anchorMax = new Vector2(0f, 1f);
            checkRect.pivot = new Vector2(0f, 0.5f);
            checkRect.sizeDelta = new Vector2(28f, 0f);
            checkRect.anchoredPosition = Vector2.zero;
            itemToggle.graphic = checkmark;

            var itemLabel = Text(itemGo.transform, "Option", 18, TextAnchor.MiddleLeft);
            var itemLabelRect = itemLabel.GetComponent<RectTransform>();
            Stretch(itemLabelRect);
            itemLabelRect.offsetMin = new Vector2(32f, 0f);
            itemLabelRect.offsetMax = new Vector2(-8f, 0f);

            scrollRect.viewport = viewport.GetComponent<RectTransform>();
            scrollRect.content = contentRect;
            itemText = itemLabel;
            return templateRect;
        }

        private ScrollRect ScrollView(Transform parent, out Transform content)
        {
            var root = Panel(parent, "ScrollView", new Color(0.12f, 0.13f, 0.15f));
            var scrollRect = root.AddComponent<ScrollRect>();
            scrollRect.horizontal = false;
            root.AddComponent<LayoutElement>().preferredHeight = 160;

            var viewport = Panel(root.transform, "Viewport", new Color(0.12f, 0.13f, 0.15f));
            viewport.AddComponent<Mask>().showMaskGraphic = false;
            Stretch(viewport.GetComponent<RectTransform>());

            var contentGo = Panel(viewport.transform, "Content", new Color(0.12f, 0.13f, 0.15f));
            content = contentGo.transform;
            var contentRect = contentGo.GetComponent<RectTransform>();
            contentRect.anchorMin = new Vector2(0, 1);
            contentRect.anchorMax = new Vector2(1, 1);
            contentRect.pivot = new Vector2(0.5f, 1f);
            contentRect.offsetMin = new Vector2(8, 0);
            contentRect.offsetMax = new Vector2(-8, 0);
            contentGo.AddComponent<VerticalLayoutGroup>().spacing = 6;
            contentGo.AddComponent<ContentSizeFitter>().verticalFit = ContentSizeFitter.FitMode.PreferredSize;

            scrollRect.viewport = viewport.GetComponent<RectTransform>();
            scrollRect.content = contentRect;
            return scrollRect;
        }

        private Text Text(Transform parent, string value, int size, TextAnchor alignment)
        {
            var go = Create("Text", parent);
            var text = go.AddComponent<Text>();
            text.font = m_font;
            text.fontSize = size;
            text.color = Color.black;
            text.alignment = alignment;
            text.text = value;
            text.horizontalOverflow = HorizontalWrapMode.Wrap;
            text.verticalOverflow = VerticalWrapMode.Overflow;
            return text;
        }

        private static GameObject Create(string name, Transform parent)
        {
            var go = new GameObject(name, typeof(RectTransform));
            go.transform.SetParent(parent, false);
            return go;
        }

        private static void Stretch(RectTransform rect)
        {
            rect.anchorMin = Vector2.zero;
            rect.anchorMax = Vector2.one;
            rect.offsetMin = Vector2.zero;
            rect.offsetMax = Vector2.zero;
        }
    }
}