using UnityEngine;
using UnityEngine.UI;

namespace Unheimlich.Features.Hallucination
{
    /// <summary>
    /// Plays a full-screen image flash on the HUD canvas.
    /// Fades are handled via LeanTween.
    /// Call <see cref="Play"/> to trigger the flash.
    /// </summary>
    public class HallucinationFlash : MonoBehaviour
    {
        [Header("Target")]
        [SerializeField] private Image _image;

        [Header("Timings")]
        [SerializeField, Min(0f)] private float _fadeIn  = 0.1f;
        [SerializeField, Min(0f)] private float _hold    = 0.2f;
        [SerializeField, Min(0f)] private float _fadeOut = 0.5f;

        // ─── State ─────────────────────────────────────────────────────────────

        private int _tweenId = -1;

        // ─── Public API ────────────────────────────────────────────────────────

        /// <summary>
        /// Plays the flash sequence.
        /// Interrupts any flash already in progress.
        /// Safe to wire to any UnityEvent with no arguments.
        /// </summary>
        public void Play()
        {
            _image.color = new Color(_image.color.r, _image.color.g, _image.color.b, 0f);

            CancelCurrent();

            _tweenId = LeanTween.value(gameObject, 0f, 1f, _fadeIn)
                .setEase(LeanTweenType.easeOutQuad)
                .setOnUpdate(SetAlpha)
                .setOnComplete(() =>
                {
                    _tweenId = LeanTween.value(gameObject, 1f, 1f, _hold)
                        .setOnComplete(() =>
                        {
                            _tweenId = LeanTween.value(gameObject, 1f, 0f, _fadeOut)
                                .setEase(LeanTweenType.easeInQuad)
                                .setOnUpdate(SetAlpha)
                                .id;
                        }).id;
                }).id;
        }

        // ─── Private ───────────────────────────────────────────────────────────

        private void CancelCurrent()
        {
            if (_tweenId == -1) return;
            LeanTween.cancel(_tweenId);
            _tweenId = -1;
        }

        private void SetAlpha(float alpha)
        {
            Color c  = _image.color;
            c.a      = alpha;
            _image.color = c;
        }
    }
}