using UnityEngine;
using UnityEngine.UI;

namespace Kill.UI.Components
{
    /// <summary>
    /// autofill 语义类型（对应 Android autofillHints）
    /// </summary>
    public enum AutofillHint
    {
        EmailAddress,   // emailAddress
        Username,       // username
        Password,       // password
    }

    /// <summary>
    /// 隐形原生输入桥（Android 谷歌密码自动填充）
    ///
    /// 用法：AutofillBridge.Attach(inputField, AutofillHint.Password)
    /// Attach 后会在 InputField 上叠一层透明按钮拦截点击：点击不再激活 Unity 自带键盘，
    /// 而是在 InputField 的屏幕位置弹出带 autofillHints 的隐形原生 EditText，
    /// 由谷歌密码管理器提供填充建议；输入内容实时同步回 Unity InputField 显示。
    /// 登录成功时调用 Commit() 触发"保存密码"提示。
    /// </summary>
    public static class AutofillBridge
    {
        private const string JavaClass = "com.photonmatrix.autofill.AutofillBridge";
        private const string ReceiverGoName = "AutofillBridgeReceiver";

        private static AndroidJavaClass sJava;
        private static GameObject sReceiverGo;
        private static InputField sActiveField;

        /// <summary>密码页配套的账号（保存凭据时账号密码成对）</summary>
        public static string CompanionUsername { get; set; } = "";

        public static bool Supported =>
            !Application.isEditor && Application.platform == RuntimePlatform.Android;

        /// <summary>
        /// 绑定 InputField：叠加透明按钮拦截点击，改由原生输入桥承接
        /// </summary>
        public static void Attach(InputField field, AutofillHint hint)
        {
            if (field == null || !Supported) return;
            EnsureReceiver();

            var blockerGo = new GameObject(field.name + "_AutofillBlocker", typeof(RectTransform), typeof(Image), typeof(Button));
            var blockerRt = blockerGo.GetComponent<RectTransform>();
            var fieldRt = field.transform as RectTransform;
            blockerRt.SetParent(fieldRt.parent, false);
            // 复制 InputField 的布局，完全重合
            blockerRt.anchorMin = fieldRt.anchorMin;
            blockerRt.anchorMax = fieldRt.anchorMax;
            blockerRt.pivot = fieldRt.pivot;
            blockerRt.anchoredPosition = fieldRt.anchoredPosition;
            blockerRt.sizeDelta = fieldRt.sizeDelta;
            blockerRt.localScale = Vector3.one;
            blockerRt.SetAsLastSibling(); // 保持在 InputField 之上，优先接收点击

            var img = blockerGo.GetComponent<Image>();
            img.color = new Color(0, 0, 0, 0); // 全透明，仅用于接收射线

            var btn = blockerGo.GetComponent<Button>();
            btn.transition = Selectable.Transition.None;
            btn.onClick.AddListener(() => Show(field, hint));
        }

        /// <summary>
        /// 显示隐形原生输入框（一般由 Attach 的拦截按钮触发）
        /// </summary>
        public static void Show(InputField field, AutofillHint hint)
        {
            if (field == null || !Supported) return;
            EnsureReceiver();

            GetScreenRect(field, out int x, out int y, out int w, out int h);
            sActiveField = field;

            GetJava().CallStatic("show",
                ToHintString(hint),
                field.text ?? "",
                x, y, w, h,
                field.characterLimit,
                CompanionUsername ?? "");
        }

        /// <summary>隐藏输入桥（切换页面时调用）</summary>
        public static void Hide()
        {
            if (!Supported) return;
            sActiveField = null;
            GetJava().CallStatic("hide", false);
        }

        /// <summary>
        /// 触发 autofill 保存流程（弹出"保存密码"提示）
        /// 登录点击时调用：先 Commit 再 Hide
        /// </summary>
        public static void Commit()
        {
            if (!Supported) return;
            GetJava().CallStatic("commit");
        }

        /// <summary>提交并隐藏（登录按钮常用组合）</summary>
        public static void CommitAndHide()
        {
            if (!Supported) return;
            sActiveField = null;
            GetJava().CallStatic("hide", true);
        }

        /// <summary>原生文本变化回调（Java 端 UnitySendMessage 进入）</summary>
        internal static void DispatchNativeText(string text)
        {
            if (sActiveField != null)
                sActiveField.text = text;
        }

        private static AndroidJavaClass GetJava()
        {
            if (sJava == null)
                sJava = new AndroidJavaClass(JavaClass);
            return sJava;
        }

        private static void EnsureReceiver()
        {
            if (sReceiverGo != null) return;
            var existing = GameObject.Find(ReceiverGoName);
            sReceiverGo = existing != null ? existing : new GameObject(ReceiverGoName);
            if (existing == null)
                sReceiverGo.AddComponent<AutofillBridgeReceiver>();
        }

        /// <summary>
        /// InputField 的屏幕像素矩形，并转换为 Android 坐标系（原点左上、y 向下）
        /// </summary>
        private static void GetScreenRect(InputField field, out int x, out int y, out int w, out int h)
        {
            var rt = field.transform as RectTransform;
            var canvas = field.GetComponentInParent<Canvas>();

            Camera cam = null;
            if (canvas != null && canvas.renderMode != RenderMode.ScreenSpaceOverlay)
                cam = canvas.worldCamera;

            var corners = new Vector3[4];
            rt.GetWorldCorners(corners); // [0]左下 [2]右上
            Vector2 p0 = RectTransformUtility.WorldToScreenPoint(cam, corners[0]);
            Vector2 p2 = RectTransformUtility.WorldToScreenPoint(cam, corners[2]);

            int minX = Mathf.RoundToInt(Mathf.Min(p0.x, p2.x));
            int maxX = Mathf.RoundToInt(Mathf.Max(p0.x, p2.x));
            int minY = Mathf.RoundToInt(Mathf.Min(p0.y, p2.y));
            int maxY = Mathf.RoundToInt(Mathf.Max(p0.y, p2.y));

            x = minX;
            w = maxX - minX;
            h = maxY - minY;
            // Unity y 向上 → Android y 向下
            y = Screen.height - maxY;
        }

        private static string ToHintString(AutofillHint hint)
        {
            switch (hint)
            {
                case AutofillHint.Password: return "password";
                case AutofillHint.Username: return "username";
                default: return "emailAddress";
            }
        }
    }

    /// <summary>
    /// Java 端 UnitySendMessage 的接收者（GameObject 名固定为 AutofillBridgeReceiver）
    /// </summary>
    public class AutofillBridgeReceiver : MonoBehaviour
    {
        public void OnNativeTextChanged(string text) => AutofillBridge.DispatchNativeText(text);
    }
}