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

namespace VMdemo.UI
{
    public class SimulationTimelineView : MonoBehaviour
    {
        [SerializeField] private RectTransform logContainer;
        [SerializeField] private TMP_Text logItemPrefab;
        [SerializeField] private ScrollRect logScrollRect;
        [SerializeField] private int maxLogEntries = 200;

        private readonly Queue<TMP_Text> _logItems = new Queue<TMP_Text>();

        public void Append(string message)
        {
            if (logContainer == null || logItemPrefab == null)
            {
                return;
            }

            var item = Instantiate(logItemPrefab, logContainer);
            item.gameObject.SetActive(true);
            item.text = message;
            item.ForceMeshUpdate();

            var autoSize = item.GetComponent<TimelineLogItemAutoSize>();
            if (autoSize != null)
            {
                autoSize.RefreshLayout();
            }
            else
            {
                // Fallback: adapt this text object's rect to preferred content size.
                var preferred = item.GetPreferredValues(item.text, logContainer.rect.width, 0f);
                var rect = item.rectTransform;
                rect.SetSizeWithCurrentAnchors(RectTransform.Axis.Horizontal, preferred.x);
                rect.SetSizeWithCurrentAnchors(RectTransform.Axis.Vertical, preferred.y);
            }

            _logItems.Enqueue(item);

            while (_logItems.Count > Mathf.Max(1, maxLogEntries))
            {
                var old = _logItems.Dequeue();
                if (old != null)
                {
                    Destroy(old.gameObject);
                }
            }

            LayoutRebuilder.ForceRebuildLayoutImmediate(logContainer);
            Canvas.ForceUpdateCanvases();
            if (logScrollRect != null)
            {
                logScrollRect.verticalNormalizedPosition = 0f;
            }
        }

        public void Clear()
        {
            while (_logItems.Count > 0)
            {
                var item = _logItems.Dequeue();
                if (item != null)
                {
                    Destroy(item.gameObject);
                }
            }
        }
    }
}