using System.Collections;
using TMPro;
using Unity.Mathematics;
using UnityEngine;
using UnityEngine.UI;

public class ChatBubble : MonoBehaviour
{
    [SerializeField] private Collider RootParentCollider;
    [SerializeField] private float3 Offset;
    [SerializeField] private TextMeshProUGUI speechText;
    private Image bubbleImage;

    private bool IsCoroutineRunning;
    private IEnumerator messageCoroutine;
    private IEnumerator fadeCoroutine;
    private Camera Camera;

    private CanvasGroup canvasGroup;
    private const float fadeOutDuration = 1.5f;
    private WaitForSeconds FullOpacityText;
    private readonly WaitForSeconds FadeDuration = new WaitForSeconds(fadeOutDuration);

    private void Awake()
    {
        bubbleImage = GetComponent<Image>();
        canvasGroup = GetComponentInParent<CanvasGroup>();
        StartCoroutine(FadeSpeechBubble(1, 0, 0));
    }

    private void Start()
    {
        Camera = GameObject.Find("FirstPerson_Camera").GetComponent<Camera>();
    }

    private void Update()
    {
        Plane[] planes = GeometryUtility.CalculateFrustumPlanes(Camera);
        bool isSeen = GeometryUtility.TestPlanesAABB(planes, RootParentCollider.bounds) && Vector3.Distance(RootParentCollider.gameObject.transform.position, Camera.transform.position) < 10.0f;
        speechText.enabled = isSeen;
        bubbleImage.canvasRenderer.cull = !isSeen;
    }

    private void LateUpdate()
    {
        if (Player.Instance != null)
            transform.forward = Player.Instance.cameraController.playerCam.transform.forward;
    }

    public void DisplayMessage(string text)
    {
        if (IsCoroutineRunning)
        {
            // stop the coroutines if another messages is sent and restart them.
            StopCoroutine(messageCoroutine);
            StopCoroutine(fadeCoroutine);
            IsCoroutineRunning = false;
        }

        if (gameObject.activeInHierarchy)
        {
            fadeCoroutine = FadeSpeechBubble(0, 1, 0.75f);
            messageCoroutine = Co_DisplayMessage(text);
            StartCoroutine(messageCoroutine);
            StartCoroutine(fadeCoroutine);
        }


    }

    private IEnumerator Co_DisplayMessage(string text)
    {
        IsCoroutineRunning = true;
        speechText.text = text;
        speechText.ForceMeshUpdate();
        int textLength = text.Length;

        if (textLength <= 10) { FullOpacityText = new WaitForSeconds(3f); }
        else if (textLength > 10 && textLength <= 20) { FullOpacityText = new WaitForSeconds(5.0f); }
        else if (textLength > 20 && textLength <= 40) { FullOpacityText = new WaitForSeconds(7.0f); }
        else { FullOpacityText = new WaitForSeconds(10.0f); }

        yield return FullOpacityText;
        StopCoroutine(fadeCoroutine);
        fadeCoroutine = FadeSpeechBubble(1, 0, fadeOutDuration);
        StartCoroutine(fadeCoroutine);
        yield return FadeDuration;
        IsCoroutineRunning = false;
    }

    private IEnumerator FadeSpeechBubble(float startAlpha, float endAlpha, float maxDuration)
    {
        float duration = 0;

        while (duration < 1)
        {
            canvasGroup.alpha = Mathf.Lerp(startAlpha, endAlpha, duration);
            duration += Time.deltaTime / maxDuration;
            yield return null;
        }

        canvasGroup.alpha = endAlpha;
    }

}