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

namespace OTGIntegrated.UI
{
    public sealed class NotificationUI : MonoBehaviour
    {
        public RectTransform stackRoot;
        public Font uiFont;
        public float visibleSeconds = 2.4f;
        public int maxMessages = 5;

        private readonly Queue<GameObject> activeMessages = new Queue<GameObject>();

        private void OnEnable()
        {
            GameEvents.OnNotificationRequested += Show;
        }

        private void OnDisable()
        {
            GameEvents.OnNotificationRequested -= Show;
        }

        public void Show(string message)
        {
            if (string.IsNullOrWhiteSpace(message) || stackRoot == null)
            {
                return;
            }

            GameObject root = new GameObject("Notification", typeof(RectTransform), typeof(CanvasGroup), typeof(Image));
            root.transform.SetParent(stackRoot, false);
            root.GetComponent<RectTransform>().sizeDelta = new Vector2(520f, 42f);
            root.GetComponent<Image>().color = new Color(0.05f, 0.06f, 0.08f, 0.86f);

            Text text = CreateText(root.transform, "Text", message, 16, TextAnchor.MiddleCenter);
            text.rectTransform.anchorMin = Vector2.zero;
            text.rectTransform.anchorMax = Vector2.one;
            text.rectTransform.offsetMin = new Vector2(12f, 0f);
            text.rectTransform.offsetMax = new Vector2(-12f, 0f);

            activeMessages.Enqueue(root);
            while (activeMessages.Count > maxMessages)
            {
                GameObject old = activeMessages.Dequeue();
                if (old != null)
                {
                    Destroy(old);
                }
            }

            StartCoroutine(FadeAndDestroy(root));
        }

        private IEnumerator FadeAndDestroy(GameObject root)
        {
            CanvasGroup group = root.GetComponent<CanvasGroup>();
            float age = 0f;
            while (age < visibleSeconds)
            {
                age += Time.deltaTime;
                if (group != null)
                {
                    group.alpha = age < visibleSeconds - 0.45f ? 1f : Mathf.Clamp01((visibleSeconds - age) / 0.45f);
                }

                yield return null;
            }

            if (root != null)
            {
                Destroy(root);
            }
        }

        private Text CreateText(Transform parent, string name, string value, int fontSize, TextAnchor anchor)
        {
            GameObject textObject = new GameObject(name, typeof(RectTransform), typeof(Text));
            textObject.transform.SetParent(parent, false);
            Text text = textObject.GetComponent<Text>();
            UITheme.ApplyText(text, uiFont, fontSize, anchor);
            text.text = value;
            return text;
        }
    }
}