using System;
using System.Collections.Generic;
using AppUI.Localization;
using TMPro;
using UnityEngine;
using UnityEngine.UI;

/// <summary>
/// AppUI Prefab 用多语言组件。行为对齐 <see cref="TextAutoLanguage2"/>，但查词走 <see cref="AppUILocalization"/>（新表优先 + 旧表回退）。
/// </summary>
[ExecuteAlways]
public class AppUITextAutoLanguage : MonoBehaviour
{
    internal static readonly HashSet<AppUITextAutoLanguage> RegisteredComponents = new HashSet<AppUITextAutoLanguage>();

    [SerializeField] string textKey;

    [Tooltip("textKey 为空时使用的明文；有 key 时仅作 Editor 预览 fallback")]
    [SerializeField]
    string fallbackText;

    [SerializeField] RectTransform layoutRebuildObject;
    public object[] textFormatArgs = { };
    [SerializeField] LanguageFontSize[] languageFontSizes = {};

    int defaultFontSize = -1;

    void Awake()
    {
        AppUILocalization.Init();
    }

    void OnEnable()
    {
        AppUILocalization.OnLanguageChanged += HandleLanguageChanged;
        if (!string.IsNullOrEmpty(textKey) || !string.IsNullOrEmpty(fallbackText))
            ApplyToText();
    }

    void Start()
    {
        RegisteredComponents.Add(this);
        ApplyToText();
    }

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

    void OnDestroy()
    {
        RegisteredComponents.Remove(this);
    }

#if UNITY_EDITOR
    void OnValidate()
    {
        if (string.IsNullOrEmpty(textKey) && string.IsNullOrEmpty(fallbackText))
            return;
        ApplyToText();
    }
#endif

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

    public void SetTextKey(string key)
    {
        textKey = key;
        ApplyResolvedText();
    }

    void ApplyResolvedText()
    {
        string text = ResolveDisplayText();
        if (textFormatArgs != null && textFormatArgs.Length > 0)
            text = string.Format(text, textFormatArgs);
        else if (text != null && text.IndexOf("{0}", StringComparison.Ordinal) >= 0)
            return;

        Text textComp = GetComponent<Text>();
        if (textComp != null)
        {
            textComp.text = text;
            ApplyFontSize(textComp, value => textComp.fontSize = value, value => textComp.lineSpacing = value);
            if (layoutRebuildObject)
                LayoutRebuilder.ForceRebuildLayoutImmediate(layoutRebuildObject);
            return;
        }

        ApplyLocalizationToTmpText(text);
    }

    string ResolveDisplayText()
    {
        if (!string.IsNullOrEmpty(textKey))
        {
#if UNITY_EDITOR
            if (!Application.isPlaying)
                AppUILocalization.Reload();
#endif
            AppUILocalization.Init();
            return AppUILocalization.ResolveText(textKey);
        }

        return fallbackText ?? string.Empty;
    }

    static TMP_Text ResolveTmpTextTarget(TMP_InputField inputField, TextMeshProUGUI tmpOnSameObject)
    {
        if (inputField != null)
        {
            if (inputField.placeholder != null && inputField.placeholder is TMP_Text placeholderTmp)
                return placeholderTmp;
            if (inputField.textComponent != null)
                return inputField.textComponent;
            return tmpOnSameObject;
        }

        return tmpOnSameObject;
    }

    void ApplyLocalizationToTmpText(string text)
    {
        TMP_InputField tmpInput = GetComponent<TMP_InputField>();
        TextMeshProUGUI tmpUgUi = GetComponent<TextMeshProUGUI>();
        TMP_Text tmpTarget = ResolveTmpTextTarget(tmpInput, tmpUgUi);
        if (tmpTarget == null)
            return;

        tmpTarget.text = text;
        ApplyFontSize(tmpTarget, value => tmpTarget.fontSize = value, value => tmpTarget.lineSpacing = value);
    }

    void ApplyFontSize(TMP_Text tmpTarget, Action<float> setFontSize, Action<float> setLineSpacing)
    {
        if (defaultFontSize == -1)
            defaultFontSize = (int)tmpTarget.fontSize;
        else
            tmpTarget.fontSize = defaultFontSize;

        if (languageFontSizes == null || languageFontSizes.Length == 0)
            return;

        LanguageEnum language = AppUILocalization.GetLanguage();
        foreach (var languageFontSize in languageFontSizes)
        {
            if (languageFontSize.language != language)
                continue;

            if (languageFontSize.fontSize > 0)
                setFontSize(languageFontSize.fontSize);
            if (languageFontSize.lineSpacing > 0)
                setLineSpacing(languageFontSize.lineSpacing);
            break;
        }
    }

    void ApplyFontSize(Text textComp, Action<int> setFontSize, Action<float> setLineSpacing)
    {
        if (defaultFontSize == -1)
            defaultFontSize = textComp.fontSize;
        else
            textComp.fontSize = defaultFontSize;

        if (languageFontSizes == null || languageFontSizes.Length == 0)
            return;

        LanguageEnum language = AppUILocalization.GetLanguage();
        foreach (var languageFontSize in languageFontSizes)
        {
            if (languageFontSize.language != language)
                continue;

            if (languageFontSize.fontSize > 0)
                setFontSize(languageFontSize.fontSize);
            if (languageFontSize.lineSpacing > 0)
                setLineSpacing(languageFontSize.lineSpacing);
            break;
        }
    }

    public string GetTextKey()
    {
        return textKey;
    }

    public void ApplyToText()
    {
        ApplyResolvedText();
        Text text = GetComponent<Text>();
        if (text)
            onApplyToNext?.Invoke(text);
    }

    /// <summary>Editor 刷新按钮 / 改 json 后手动调用。</summary>
    public void RefreshLocalizedPreview()
    {
#if UNITY_EDITOR
        if (!Application.isPlaying)
            AppUILocalization.Reload();
#endif
        ApplyToText();
    }

    public Action<Text> onApplyToNext;
}