using System;
using UnityEngine;
using UnityEngine.UI;

namespace Kill.UI.Components
{
    /// <summary>
    /// 验证码输入组件
    /// 使用方式：
    /// 1. 在场景中创建一个空物体，挂载此脚本
    /// 2. 创建n个Text作为验证码显示位
    /// 3. 创建一个InputField作为隐藏输入框（可设置为透明或移出屏幕外）
    /// 4. 在Inspector中配置digitTexts和inputField
    /// </summary>
    public class VerificationCodeInput : MonoBehaviour
    {
        [Header("验证码配置")]
        [Tooltip("验证码位数")]
        [Range(1, 10)]
        public int codeLength = 6;

        [Tooltip("是否自动验证 - 输入完成后自动触发OnCodeCompleted事件")]
        public bool autoSubmit = true;

        [Tooltip("是否只允许数字")]
        public bool numericOnly = true;

        [Header("UI引用")]
        [Tooltip("验证码显示文本数组，按顺序从左到右")]
        public Text[] digitTexts;

        [Tooltip("隐藏的输入框（用于接收用户输入）")]
        public InputField inputField;

        [Header("样式配置")]
        [Tooltip("未输入时的占位字符")]
        public string placeholderChar = "-";

        [Tooltip("输入完成后的字符（如需要隐藏可设为*）")]
        public string displayChar = "";

        public event Action<string> OnCodeCompleted;
        public event Action<string> OnCodeChanged;

        private string currentCode = "";

        private void Awake()
        {
            Initialize();
        }

        private void OnEnable()
        {
            if (inputField != null)
            {
                inputField.onValueChanged.AddListener(HandleInputChanged);
                inputField.onEndEdit.AddListener(HandleEndEdit);
            }
        }

        private void OnDisable()
        {
            if (inputField != null)
            {
                inputField.onValueChanged.RemoveListener(HandleInputChanged);
                inputField.onEndEdit.RemoveListener(HandleEndEdit);
            }
        }

        private void Start()
        {
            RefreshDisplay();
        }

        /// <summary>
        /// 初始化组件
        /// </summary>
        private void Initialize()
        {
            if (inputField == null)
            {
                inputField = GetComponentInChildren<InputField>();
            }

            if (digitTexts == null || digitTexts.Length == 0)
            {
                digitTexts = GetComponentsInChildren<Text>();
            }

            if (digitTexts != null && digitTexts.Length > 0)
            {
                codeLength = Mathf.Min(codeLength, digitTexts.Length);
            }

            if (inputField != null)
            {
                inputField.characterLimit = codeLength;
                inputField.contentType = numericOnly
                    ? InputField.ContentType.IntegerNumber
                    : InputField.ContentType.Alphanumeric;

                var inputText = inputField.textComponent;
                if (inputText != null)
                {
                    inputText.color = new Color(1, 1, 1, 0);
                }

                if (inputField.placeholder != null)
                {
                    var placeholder = inputField.placeholder.GetComponent<Text>();
                    if (placeholder != null)
                    {
                        placeholder.color = new Color(1, 1, 1, 0);
                    }
                }
            }
        }

        /// <summary>
        /// 处理输入变化
        /// </summary>
        private void HandleInputChanged(string value)
        {
            if (numericOnly)
            {
                value = FilterNumeric(value);
                if (inputField != null && inputField.text != value)
                {
                    inputField.text = value;
                    return;
                }
            }

            if (value.Length > codeLength)
            {
                value = value.Substring(0, codeLength);
                if (inputField != null)
                {
                    inputField.text = value;
                    return;
                }
            }

            currentCode = value;
            RefreshDisplay();

            OnCodeChanged?.Invoke(currentCode);

            if (autoSubmit && currentCode.Length == codeLength)
            {
                Debug.Log("自动提交");
                OnCodeCompleted?.Invoke(currentCode);
            }
        }

        /// <summary>
        /// 处理结束编辑（用户按下回车或失去焦点）
        /// </summary>
        private void HandleEndEdit(string value)
        {
            if (!autoSubmit && currentCode.Length == codeLength)
            {
                OnCodeCompleted?.Invoke(currentCode);
            }
        }

        /// <summary>
        /// 刷新显示
        /// </summary>
        private void RefreshDisplay()
        {
            if (digitTexts == null) return;

            for (int i = 0; i < digitTexts.Length; i++)
            {
                if (digitTexts[i] == null) continue;

                if (i < currentCode.Length)
                {
                    char c = currentCode[i];
                    digitTexts[i].text = string.IsNullOrEmpty(displayChar) ? c.ToString() : displayChar;
                }
                else
                {
                    digitTexts[i].text = placeholderChar;
                }
            }
        }

        /// <summary>
        /// 过滤非数字字符
        /// </summary>
        private string FilterNumeric(string input)
        {
            var result = "";
            foreach (char c in input)
            {
                if (char.IsDigit(c))
                {
                    result += c;
                }
            }
            return result;
        }

        /// <summary>
        /// 获取当前验证码
        /// </summary>
        public string GetCode()
        {
            return currentCode;
        }

        /// <summary>
        /// 设置验证码（用于自动填充等）
        /// </summary>
        public void SetCode(string code)
        {
            if (code == null)
            {
                code = "";
            }
            
            if (code.Length > codeLength)
            {
                code = code.Substring(0, codeLength);
            }

            currentCode = code;

            if (inputField != null)
            {
                inputField.text = currentCode;
            }
            
            RefreshDisplay();
            OnCodeChanged?.Invoke(currentCode);

            if (currentCode.Length == codeLength)
            {
                OnCodeCompleted?.Invoke(currentCode);
            }
        }

        /// <summary>
        /// 清空输入
        /// </summary>
        public void Clear()
        {
            currentCode = "";
            if (inputField != null)
            {
                inputField.text = "";
            }
            RefreshDisplay();
        }

        /// <summary>
        /// 让输入框获得焦点
        /// </summary>
        public void Focus()
        {
            if (inputField != null)
            {
                inputField.ActivateInputField();
            }
        }

        /// <summary>
        /// 检查验证码是否输入完整
        /// </summary>
        public bool IsComplete()
        {
            return currentCode.Length == codeLength;
        }
    }
}