using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using Kill.Managers;
using Kill.Network;
using Kill.UI;

public class SelectCountry : MonoBehaviour
{
    public GameObject countryPrefab;
    public Transform countryParent;
    public Button submitButton;
    public Button backButton;
    public InputField searchInput;
    public ScrollRect scrollRect;
    LanguageManager.Country selectCountry;
    private bool _hasSelection;
    private string _originalCode;
    /// <summary>
    /// 未选中 选中
    /// </summary>
    public Color[] textColors;

    private List<SelectCountryItem> _items = new List<SelectCountryItem>();

    /// <summary>
    /// 确认回调：code 为选中的国家代码，null 表示返回/取消
    /// </summary>
    public System.Action<string> onConfirm;

    /// <summary>
    /// 初始化
    /// </summary>
    /// <param name="code">当前选中的国家代码</param>
    /// <param name="showBackButton">是否显示返回按钮（主页不显示）</param>
    public void Init(string code, bool showBackButton = true)
    {
        _originalCode = code;

        countryPrefab.SetActive(false);
        // 清理旧 item
        foreach (var item in _items)
            Destroy(item.gameObject);
        _items.Clear();
        _hasSelection = false;

        // 返回按钮
        if (backButton != null)
        {
            backButton.gameObject.SetActive(showBackButton);
            backButton.onClick.RemoveAllListeners();
            backButton.onClick.AddListener(OnBack);
            if (showBackButton)
                UIManager.Instance.RegisterBackAction(OnBack);
        }

        if (LanguageManager.Instance == null || LanguageManager.Instance.countryList == null)
            return;

        foreach (var country in LanguageManager.Instance.countryList)
        {
            var go = Instantiate(countryPrefab, countryParent);
            var item = go.AddComponent<SelectCountryItem>();
            item.Init(this, country);
            _items.Add(item);
            item.gameObject.SetActive(true);
        }

        // 绑定搜索
        if (searchInput != null)
        {
            searchInput.onValueChanged.RemoveAllListeners();
            searchInput.onValueChanged.AddListener(OnSearchChanged);
        }

        // 设置默认选中（code 为空时不选中）
        if (!string.IsNullOrEmpty(code))
            SelectCountryByCode(code);

        // 自动滚动到选中项
        ScrollToSelected();

        UpdateSubmitButton();
    }

    /// <summary>
    /// 返回按钮点击
    /// </summary>
    private void OnBack()
    {
        onConfirm?.Invoke(null);
    }

    /// <summary>
    /// 滚动到当前选中的国家项（居中显示）
    /// </summary>
    private void ScrollToSelected()
    {
        if (scrollRect == null || !_hasSelection) return;

        int index = _items.FindIndex(i => i.Country.code == selectCountry.code);
        if (index < 0) return;

        Canvas.ForceUpdateCanvases();

        var itemRect = _items[index].GetComponent<RectTransform>();
        float contentHeight = scrollRect.content.rect.height;
        float viewportHeight = scrollRect.viewport.rect.height;

        if (contentHeight <= viewportHeight) return;

        // 计算目标滚动位置：使选中项居中
        float maxScrollY = contentHeight - viewportHeight;
        float itemCenterY = Mathf.Abs(itemRect.anchoredPosition.y) + itemRect.rect.height / 2;
        float targetScrollY = itemCenterY - viewportHeight / 2;
        targetScrollY = Mathf.Clamp(targetScrollY, 0, maxScrollY);

        scrollRect.verticalNormalizedPosition = 1f - targetScrollY / maxScrollY;
    }

    private void OnSearchChanged(string keyword)
    {
        foreach (var item in _items)
        {
            item.gameObject.SetActive(item.MatchKeyword(keyword));
        }
    }

    public void SelectCountryByCode(string code)
    {
        _hasSelection = !string.IsNullOrEmpty(code);
        foreach (var item in _items)
        {
            bool isSelected = _hasSelection && item.Country.code == code;
            item.SetSelected(isSelected);
            if (isSelected)
                selectCountry = item.Country;
        }
        UpdateSubmitButton();
    }

    public string GetSelectedCode()
    {
        return _hasSelection ? selectCountry.code : null;
    }

    private void UpdateSubmitButton()
    {
        if (submitButton != null)
        {
            submitButton.gameObject.SetActive(_hasSelection);
            submitButton.onClick.RemoveAllListeners();
            submitButton.onClick.AddListener(OnSubmit);
        }
    }

    private async void OnSubmit()
    {
        if (!_hasSelection) return;
        await UpdateCountryCodeAsync(selectCountry.code);
    }

    /// <summary>
    /// 更新用户国家代码
    /// </summary>
    private async System.Threading.Tasks.Task UpdateCountryCodeAsync(string code)
    {
        try
        {
            var requestData = new CountryCodeRequest
            {
                country_code = code
            };

            var response = await NetworkCtrl.Instance.Put<NoDataResponse>("/api/v1/user/country-code", requestData);

            ResponseCodeHandler.HandleResponse(response,
                onSuccess: (data) =>
                {
                    if (DataManager.Instance.userInfo != null)
                        DataManager.Instance.userInfo.country_code = code;
                    onConfirm?.Invoke(code);
                },
                onError: null
            );
        }
        catch (Exception ex)
        {
            Debug.LogError($"更新国家代码失败: {ex.Message}");
        }
    }
}

internal class SelectCountryItem : MonoBehaviour
{
    public LanguageManager.Country Country { get; private set; }
    private SelectCountry _parent;
    private Text _nameText;
    private GameObject _selectGo;
    private Color _selectedColor;
    private Color _unselectedColor;

    public void Init(SelectCountry parent, LanguageManager.Country country)
    {
        _parent = parent;
        Country = country;

        _nameText = transform.Find("name")?.GetComponent<Text>();
        _selectGo = transform.Find("选中")?.gameObject;

        _selectedColor = parent.textColors.Length > 0 ? parent.textColors[0] : Color.white;
        _unselectedColor = parent.textColors.Length > 1 ? parent.textColors[1] : Color.gray;

        // 显示国家名称（根据当前语言）
        bool isChinese = LanguageManager.Instance != null && LanguageManager.Instance.languageType == LanguageManager.LanguageType.Chinese;
        if (_nameText != null)
            _nameText.text = isChinese ? country.name_zh : country.name_en;

        // 点击事件
        var btn = GetComponent<Button>();
        if (btn == null)
            btn = gameObject.AddComponent<Button>();
        btn.onClick.AddListener(OnClick);
    }

    public void SetSelected(bool selected)
    {
        if (_nameText != null)
            _nameText.color = selected ? _selectedColor : _unselectedColor;
        if (_selectGo != null)
            _selectGo.SetActive(selected);
    }

    public bool MatchKeyword(string keyword)
    {
        if (string.IsNullOrEmpty(keyword))
            return true;
        var k = keyword.ToLower();
        return Country.name_zh.ToLower().Contains(k)
            || Country.name_en.ToLower().Contains(k)
            || Country.code.ToLower().Contains(k);
    }

    private void OnClick()
    {
        _parent.SelectCountryByCode(Country.code);
    }
}