using AppUI.Localization;
using System;
using System.Text.RegularExpressions;
using JCUnityLib;
using TMPro;
using UnityEngine;
using UnityEngine.Events;

namespace AppUI.Util.Input
{
    /// <summary>输入用途，决定校验规则与 <see cref="TMP_InputField"/> 默认配置。</summary>
    public enum AppUIInputKind
    {
        Generic,
        Nickname,
        Password,
        Email,
        Phone,
        SmsCode,
    }

    /// <summary>校验结果，供外部逻辑分支处理。</summary>
    public readonly struct AppUIInputValidation
    {
        public bool IsValid { get; }
        /// <summary>失败时已本地化的提示文案。</summary>
        public string Message { get; }

        public static AppUIInputValidation Ok => new AppUIInputValidation(true, null);

        public AppUIInputValidation(bool isValid, string message)
        {
            IsValid = isValid;
            Message = message;
        }
    }

    /// <summary>
    /// 挂在 <c>TMPInput</c> 预制体根节点，统一管理左侧 Title、<see cref="TMP_InputField"/> 及可选 <see cref="TMP_InputFieldActionBar"/>。
    /// 外部通过 <see cref="Text"/> / <see cref="Validate"/> / 事件获取输入，无需直接操作子节点。
    /// </summary>
    [DisallowMultipleComponent]
    [ExecuteAlways]
    public class AppUITMPInputField : MonoBehaviour
    {
        const string PathTitleLabel = "Content/Title/Label";
        const string PathInputField = "Content/InputField (TMP)";

        [Header("展示")]
        [Tooltip("多语言 key；非空时优先于 Title 文案")]
        [SerializeField]
        string titleKey;

        [Tooltip("左侧 Title/Label 文案；titleKey 为空时使用，Editor 预览用")]
        [SerializeField]
        string title = "Password";

        [Tooltip("Placeholder 多语言 key；非空时优先于 Placeholder 文案")]
        [SerializeField]
        string placeholderKey;

        [Tooltip("占位符；placeholderKey 为空时使用；两者都为空则不修改预制体 Placeholder")]
        [SerializeField]
        string placeholder = "";

        [SerializeField]
        AppUIInputKind kind = AppUIInputKind.Generic;

        [Header("引用（可留空，运行时按路径自动绑定）")]
        [SerializeField]
        TMP_Text titleLabel;

        [SerializeField]
        TMP_InputField inputField;

        [SerializeField]
        TMP_InputFieldActionBar actionBar;

        [Header("校验（0 表示使用类型默认值）")]
        [SerializeField]
        int minLength;

        [SerializeField]
        int maxLength;

        [SerializeField]
        bool required = true;

        [Header("仅点击（不弹出键盘）")]
        [Tooltip("开启后输入框只读，点击时触发 OnClick，可在 Inspector 绑定其他对象方法")]
        [SerializeField]
        bool clickOnly;

        [SerializeField]
        UnityEvent onClick = new UnityEvent();

        static readonly Regex PasswordAlphanumeric = new Regex("[^A-Za-z0-9]");

        /// <summary>左侧标题文案。</summary>
        public string Title
        {
            get => title;
            set
            {
                title = value ?? string.Empty;
                ApplyTitleToLabel();
            }
        }

        public AppUIInputKind Kind => kind;

        /// <summary>原始输入（未 Trim）。</summary>
        public string Text => inputField != null ? inputField.text : string.Empty;

        /// <summary>去除首尾空白后的输入，提交表单时优先使用。</summary>
        public string TrimmedText => Text.Trim();

        public bool HasValue => TrimmedText.Length > 0;

        public TMP_InputField InputField => inputField;

        public TMP_InputFieldActionBar ActionBar => actionBar;

        public bool ClickOnly => clickOnly;

        public string TitleKey => titleKey;

        public string PlaceholderKey => placeholderKey;

        /// <summary>Inspector 中 <c>onClick</c> 的代码订阅入口。</summary>
        public event Action OnClicked;

        /// <summary>输入内容变化（与 TMP 一致，参数为当前全文）。</summary>
        public event Action<string> OnValueChanged;

        /// <summary>结束编辑（失焦 / 提交）。</summary>
        public event Action<string> OnEndEdit;

        void Awake()
        {
            ResolveReferences();
            ApplyKindSettings();
        }

        void OnEnable()
        {
            ResolveReferences();
            ApplyLocalizedTexts();
            ApplyClickOnlyMode();
            BindInputListeners();
            AppUILocalization.OnLanguageChanged += HandleLanguageChanged;
        }

        void OnDisable()
        {
            AppUILocalization.OnLanguageChanged -= HandleLanguageChanged;
            UnbindInputListeners();
        }

#if UNITY_EDITOR
        void OnValidate()
        {
            ResolveReferences();
            ApplyLocalizedTexts();
            if (!Application.isPlaying)
                ApplyKindSettings();
            if (inputField != null)
                inputField.readOnly = clickOnly;
        }
#endif

        void ResolveReferences()
        {
            if (titleLabel == null)
            {
                var labelTr = transform.Find(PathTitleLabel);
                if (labelTr != null)
                    titleLabel = labelTr.GetComponent<TMP_Text>();
            }

            if (inputField == null)
            {
                var fieldTr = transform.Find(PathInputField);
                if (fieldTr != null)
                    inputField = fieldTr.GetComponent<TMP_InputField>();
                if (inputField == null)
                    inputField = GetComponentInChildren<TMP_InputField>(true);
            }

            if (actionBar == null)
                actionBar = GetComponentInChildren<TMP_InputFieldActionBar>(true);
        }

        void BindInputListeners()
        {
            if (inputField == null)
                return;
            inputField.onValueChanged.RemoveListener(HandleValueChanged);
            inputField.onEndEdit.RemoveListener(HandleEndEdit);
            inputField.onSelect.RemoveListener(HandleClickOnlySelect);
            if (!clickOnly)
            {
                inputField.onValueChanged.AddListener(HandleValueChanged);
                inputField.onEndEdit.AddListener(HandleEndEdit);
            }
            else
                inputField.onSelect.AddListener(HandleClickOnlySelect);
        }

        void UnbindInputListeners()
        {
            if (inputField == null)
                return;
            inputField.onValueChanged.RemoveListener(HandleValueChanged);
            inputField.onEndEdit.RemoveListener(HandleEndEdit);
            inputField.onSelect.RemoveListener(HandleClickOnlySelect);
        }

        /// <summary>同步只读状态；运行中切换 <see cref="clickOnly"/> 时会重新绑定监听。</summary>
        public void ApplyClickOnlyMode()
        {
            if (inputField == null)
                return;
            inputField.readOnly = clickOnly;
            if (isActiveAndEnabled)
                BindInputListeners();
        }

        void HandleClickOnlySelect(string _)
        {
            if (!clickOnly)
                return;
            if (inputField != null)
                inputField.DeactivateInputField();
            InvokeClick();
        }

        /// <summary>供外部 Button 等转发调用，与点击输入区域效果相同。</summary>
        public void InvokeClick()
        {
            onClick?.Invoke();
            OnClicked?.Invoke();
        }

        void HandleValueChanged(string value)
        {
            var filtered = value;
            var changed = false;

            if (kind == AppUIInputKind.Password)
                changed = FilterPasswordAlphanumeric(ref filtered);
            else if (kind == AppUIInputKind.SmsCode || kind == AppUIInputKind.Phone)
                changed = FilterDigitsOnly(ref filtered, GetEffectiveMaxLength());

            if (changed && inputField != null)
                inputField.SetTextWithoutNotify(filtered);

            OnValueChanged?.Invoke(inputField != null ? inputField.text : filtered);
        }

        void HandleEndEdit(string value) => OnEndEdit?.Invoke(value);

        void HandleLanguageChanged(LanguageEnum _) => ApplyLocalizedTexts();

        /// <summary>按 titleKey / placeholderKey（或明文 fallback）刷新 Title 与 Placeholder。</summary>
        public void ApplyLocalizedTexts()
        {
#if UNITY_EDITOR
            if (!Application.isPlaying)
                AppUILocalization.Reload();
#endif
            ApplyTitleToLabel();
            ApplyPlaceholder();
        }

        void ApplyTitleToLabel()
        {
            if (titleLabel == null)
                return;
            if (string.IsNullOrEmpty(titleKey) && string.IsNullOrEmpty(title))
                return;
            titleLabel.text = ResolveDisplayText(titleKey, title);
        }

        void ApplyPlaceholder()
        {
            if (inputField == null)
                return;
            string text = ResolveDisplayText(placeholderKey, placeholder);
            if (string.IsNullOrEmpty(text))
                return;
            if (inputField.placeholder is TMP_Text ph)
                ph.text = text;
        }

        static string ResolveDisplayText(string key, string fallback)
        {
            if (!string.IsNullOrEmpty(key))
            {
                AppUILocalization.Init();
                return AppUILocalization.GetTextByKey(key);
            }

            return fallback ?? string.Empty;
        }

        /// <summary>按 <see cref="kind"/> 配置 ContentType、长度与密码过滤等。</summary>
        public void ApplyKindSettings()
        {
            if (inputField == null)
                return;

            inputField.lineType = TMP_InputField.LineType.SingleLine;
            inputField.characterValidation = TMP_InputField.CharacterValidation.None;

            switch (kind)
            {
                case AppUIInputKind.Password:
                    inputField.contentType = TMP_InputField.ContentType.Password;
                    break;
                case AppUIInputKind.Email:
                    inputField.contentType = TMP_InputField.ContentType.EmailAddress;
                    break;
                case AppUIInputKind.Phone:
                    inputField.contentType = TMP_InputField.ContentType.IntegerNumber;
                    break;
                case AppUIInputKind.SmsCode:
                    inputField.contentType = TMP_InputField.ContentType.IntegerNumber;
                    break;
                case AppUIInputKind.Nickname:
                    inputField.contentType = TMP_InputField.ContentType.Standard;
                    break;
                default:
                    inputField.contentType = TMP_InputField.ContentType.Standard;
                    break;
            }

            inputField.characterLimit = GetEffectiveMaxLength();
            inputField.ForceLabelUpdate();
        }

        int GetEffectiveMaxLength()
        {
            if (maxLength > 0)
                return maxLength;
            switch (kind)
            {
                case AppUIInputKind.Phone:
                    return 11;
                case AppUIInputKind.SmsCode:
                    return 6;
                case AppUIInputKind.Nickname:
                    return 32;
                default:
                    return 0;
            }
        }

        int GetEffectiveMinLength()
        {
            if (minLength > 0)
                return minLength;
            if (kind == AppUIInputKind.Password)
                return 6;
            return required ? 1 : 0;
        }

        static bool FilterPasswordAlphanumeric(ref string value)
        {
            var match = PasswordAlphanumeric.Match(value);
            if (!match.Success)
                return false;
            value = value.Replace(match.Value, string.Empty);
            return true;
        }

        static bool FilterDigitsOnly(ref string value, int maxLen)
        {
            if (string.IsNullOrEmpty(value))
                return false;

            var filtered = string.Empty;
            foreach (var c in value)
            {
                if (!char.IsDigit(c))
                    continue;
                filtered += c;
                if (maxLen > 0 && filtered.Length >= maxLen)
                    break;
            }

            if (filtered == value)
                return false;
            value = filtered;
            return true;
        }

        public void SetText(string value)
        {
            if (inputField == null)
                return;
            inputField.text = value ?? string.Empty;
        }

        public void Clear() => SetText(string.Empty);

        public void Focus() => inputField?.ActivateInputField();

        /// <summary>按类型做格式/非空校验，返回本地化提示文案（失败时）。</summary>
        public AppUIInputValidation Validate()
        {
            var text = TrimmedText;
            var min = GetEffectiveMinLength();

            if (required && text.Length == 0)
                return Fail(EmptyMessageForKind());

            if (min > 0 && text.Length > 0 && text.Length < min)
                return Fail(TooShortMessageForKind(min));

            switch (kind)
            {
                case AppUIInputKind.Email:
                    if (text.Length > 0 && !ValidateHelper.IsEmail(text))
                        return Fail(AppUILocalization.GetTextByKey("RelateValidateView-a0"));
                    break;
                case AppUIInputKind.Phone:
                    if (text.Length > 0 && !ValidateHelper.IsMobilePhone(text))
                        return Fail(AppUILocalization.GetTextByKey("RelateValidateView-a1"));
                    break;
                case AppUIInputKind.SmsCode:
                    if (text.Length > 0 && (text.Length != 6 || !int.TryParse(text, out _)))
                        return Fail(AppUILocalization.GetTextByKey("RelateValidateView-a3"));
                    break;
            }

            return AppUIInputValidation.Ok;
        }

        /// <summary>校验是否通过。</summary>
        public bool TryValidate(out string errorMessage)
        {
            var result = Validate();
            errorMessage = result.IsValid ? null : result.Message;
            return result.IsValid;
        }

        static AppUIInputValidation Fail(string message) =>
            new AppUIInputValidation(false, message);

        string EmptyMessageForKind()
        {
            switch (kind)
            {
                case AppUIInputKind.Nickname:
                    return AppUILocalization.GetTextByCNKey("请输入游戏昵称");
                case AppUIInputKind.Password:
                    return AppUILocalization.GetTextByCNKey("请输入密码");
                case AppUIInputKind.Email:
                    return AppUILocalization.GetTextByKey("RelateValidateView-a0");
                case AppUIInputKind.Phone:
                    return AppUILocalization.GetTextByKey("RelateValidateView-a1");
                case AppUIInputKind.SmsCode:
                    return AppUILocalization.GetTextByKey("RelateValidateView-a3");
                default:
                    return AppUILocalization.GetTextByCNKey("请输入账号");
            }
        }

        string TooShortMessageForKind(int min)
        {
            if (kind == AppUIInputKind.Password)
                return AppUILocalization.GetTextByCNKey("密码长度至少6位");
            return AppUILocalization.GetTextByCNKey("请输入账号");
        }
    }
}