using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

/// <summary>
/// Runtime UI feed for skill triggers.
/// Writes to "score/Skill" in the active scene:
/// - newest entry at the top
/// - keeps last 5 entries
/// If "score/Skill" does not exist, it will be created under "score".
/// </summary>
public static class SkillTriggerFeedUI
{
    public static bool RuntimeEnabled = false;
    private const int MaxEntries = 5;
    private static readonly List<string> s_entries = new List<string>(MaxEntries);

    // Per request: use legacy UI.Text only (not TMP).
    private static Text s_feedText;

    private static int s_boundTextInstanceId;
    private static bool s_warnedMissingScore;

    public static void Push(string idolName, string skillName)
    {
        if (!RuntimeEnabled)
        {
            TryHideLegacyFeedRoot();
            return;
        }

        if (string.IsNullOrWhiteSpace(idolName)) idolName = "Unknown";
        if (string.IsNullOrWhiteSpace(skillName)) skillName = "UnknownSkill";

        EnsureBound();
        if (!HasBoundText()) return;

        s_entries.Insert(0, $"{idolName} - {skillName}");
        if (s_entries.Count > MaxEntries)
        {
            s_entries.RemoveRange(MaxEntries, s_entries.Count - MaxEntries);
        }
        UpdateText();
    }

    public static void Clear()
    {
        if (!RuntimeEnabled)
        {
            TryHideLegacyFeedRoot();
            return;
        }

        s_entries.Clear();
        UpdateText();
    }

    private static bool HasBoundText()
    {
        if (s_feedText != null && !s_feedText) s_feedText = null;
        return s_feedText != null;
    }

    private static void EnsureBound()
    {
        if (HasBoundText()) return;

        GameObject skillRoot = GameObject.Find("score/Skill");
        if (skillRoot == null)
        {
            var score = GameObject.Find("score");
            if (score == null)
            {
                if (!s_warnedMissingScore)
                {
                    Debug.LogWarning("[SkillTriggerFeedUI] Cannot find GameObject 'score'. Skill trigger feed UI is disabled in this scene.");
                    s_warnedMissingScore = true;
                }
                return;
            }

            // Create a minimal "score/Skill" container if missing.
            skillRoot = new GameObject("Skill", typeof(RectTransform));
            skillRoot.transform.SetParent(score.transform, false);

            var rt = skillRoot.GetComponent<RectTransform>();
            rt.anchorMin = new Vector2(0.5f, 0.5f);
            rt.anchorMax = new Vector2(0.5f, 0.5f);
            rt.pivot = new Vector2(0.5f, 0.5f);
            rt.anchoredPosition = new Vector2(776f, 277f);
             rt.sizeDelta = new Vector2(160f, 30f);
         }

        // Prefer using the existing "sumScoreText" node as an anchor (it is already positioned correctly in the scene),
        // but render with legacy UI.Text (Chinese glyphs require the same font as the UI, not builtin Arial).
        Transform feed = skillRoot.transform.Find("SkillFeedText");
        RectTransform referenceRect = null;
        var sumScore = skillRoot.transform.Find("sumScoreText");
        if (sumScore != null) referenceRect = sumScore as RectTransform;
        if (feed == null && sumScore != null) feed = sumScore;
        if (feed == null)
        {
            var go = new GameObject("SkillFeedText", typeof(RectTransform));
            go.transform.SetParent(skillRoot.transform, false);
            feed = go.transform;
        }

        s_feedText = feed.GetComponent<Text>();
        if (s_feedText == null) s_feedText = feed.gameObject.AddComponent<Text>();
        if (s_feedText != null) s_feedText.enabled = true;
        if (feed != null && feed.gameObject != null && !feed.gameObject.activeSelf) feed.gameObject.SetActive(true);

        // If this node used to be TMP (e.g. "sumScoreText"), ensure TMP renderer is disabled so we only use legacy Text.
        try
        {
            var tmp = feed.GetComponent("TMP_Text") as Behaviour;
            if (tmp != null) tmp.enabled = false;
        }
        catch { }

        // Configure for multi-line feed (legacy Text)
        s_feedText.raycastTarget = false;
        // Use the same font as the header under score/Skill so Chinese characters can render.
        var headerText = skillRoot.GetComponent<Text>();
        if (headerText != null && headerText.font != null)
            s_feedText.font = headerText.font;
        if (s_feedText.font == null)
            s_feedText.font = Resources.GetBuiltinResource<Font>("LegacyRuntime.ttf");
        s_feedText.fontSize = 20;
        s_feedText.color = Color.black;
        s_feedText.alignment = TextAnchor.UpperLeft;
        s_feedText.horizontalOverflow = HorizontalWrapMode.Overflow;
        s_feedText.verticalOverflow = VerticalWrapMode.Overflow;
        s_feedText.text = string.Empty;

        var frt = feed.GetComponent<RectTransform>();
        if (frt != null)
        {
            if (referenceRect != null)
            {
                frt.anchorMin = referenceRect.anchorMin;
                frt.anchorMax = referenceRect.anchorMax;
                frt.pivot = referenceRect.pivot;
                frt.anchoredPosition = referenceRect.anchoredPosition;
                frt.sizeDelta = referenceRect.sizeDelta;
            }
            else
            {
                frt.anchorMin = new Vector2(0.5f, 0.5f);
                frt.anchorMax = new Vector2(0.5f, 0.5f);
                frt.pivot = new Vector2(0.5f, 0.5f);
                frt.anchoredPosition = new Vector2(49.8f, 0f);
                frt.sizeDelta = new Vector2(200f, 50f);
            }
        }

        int newId = 0;
        if (s_feedText != null) newId = s_feedText.GetInstanceID();

        // If we re-bound (new scene/play session), clear old entries to avoid leaking previous runs.
        if (newId != 0 && newId != s_boundTextInstanceId)
        {
            s_boundTextInstanceId = newId;
            s_entries.Clear();
            UpdateText();
        }
    }

    private static void UpdateText()
    {
        if (!HasBoundText()) return;

        // Newest first.
        s_feedText.text = string.Join("\n", s_entries);
    }

    private static void TryHideLegacyFeedRoot()
    {
        GameObject feed = GameObject.Find("score/Skill");
        if (feed != null && feed.activeSelf)
            feed.SetActive(false);
    }
}