using System.Collections;
using Data.CardSystem;
using UnityEngine;
using UnityEngine.Events;

namespace UI.CardSystem
{
    /// <summary>
    /// One-off helper to visually grant a booster pack.
    /// Place this on a UI GameObject with two Image children (a background "glow" and a booster pack image).
    /// Access via BoosterPackGiver.Instance and call GiveBoosterPack().
    /// The sequence:
    /// 1) Shows the object (enables children)
    /// 2) Pulses the glow scale for a fixed duration
    /// 3) Hides the glow, tweens the booster image towards the backpack icon and scales to zero
    /// 4) Invokes OnCompleted
    /// </summary>
    public class BoosterPackGiver : MonoBehaviour
    {
        public static BoosterPackGiver Instance { get; private set; }

        [Header("References")]
        [Tooltip("Canvas that contains these UI elements. If null, will search up the hierarchy.")]
        [SerializeField] private Canvas canvas;
        [Tooltip("Background glow RectTransform (child image)")]
        [SerializeField] private RectTransform backgroundGlow;
        [Tooltip("Booster pack image RectTransform (child image)")]
        [SerializeField] private RectTransform boosterImage;
        [Tooltip("Target RectTransform for the backpack icon (where the booster flies to)")]
        [SerializeField] private RectTransform targetBackpackIcon;

        [Header("Timing")]
        [Tooltip("How long the glow should pulse before the booster flies to the backpack")] 
        [SerializeField] private float pulseDuration = 2.0f;
        [Tooltip("Duration of the flight/scale-down animation")] 
        [SerializeField] private float moveDuration = 0.6f;

        [Header("Glow Pulse")] 
        [Tooltip("Minimum scale during pulse")] [SerializeField] private float glowScaleMin = 0.9f;
        [Tooltip("Maximum scale during pulse")] [SerializeField] private float glowScaleMax = 1.1f;
        [Tooltip("Pulse speed in cycles per second")] [SerializeField] private float glowPulseSpeed = 2.0f;

        [Header("Move/Scale Easing")] 
        [SerializeField] private AnimationCurve moveCurve = AnimationCurve.EaseInOut(0, 0, 1, 1);
        [SerializeField] private AnimationCurve scaleCurve = AnimationCurve.EaseInOut(0, 0, 1, 1);

        [Header("Behaviour")] 
        [Tooltip("Hide visuals when the sequence completes")] [SerializeField] private bool hideOnComplete = true;

        [Header("Events")] 
        public UnityEvent OnCompleted;

        private Coroutine _sequenceCoroutine;
        private Vector3 _boosterInitialScale;
        private Vector2 _boosterInitialAnchoredPos;

        private IEnumerator Start()
        {
            if (Instance != null && Instance != this)
            {
                Debug.LogWarning("[BoosterPackGiver] Duplicate instance detected. Destroying this component.");
                Destroy(this);
                yield break;
            }
            Instance = this;

            if (canvas == null)
            {
                canvas = GetComponentInParent<Canvas>();
            }

            CacheInitialBoosterState();
            // Start hidden (keep GameObject active so the singleton remains accessible)
            SetVisualsActive(false);

            // yield return new WaitForSeconds(1f);

            // GiveBoosterPack();
        }

        private void OnDestroy()
        {
            if (Instance == this)
                Instance = null;
        }

        private void CacheInitialBoosterState()
        {
            if (boosterImage != null)
            {
                _boosterInitialScale = boosterImage.localScale;
                _boosterInitialAnchoredPos = boosterImage.anchoredPosition;
            }
        }

        /// <summary>
        /// Public entry point: run the grant animation.
        /// </summary>
        public void GiveBoosterPack()
        {
            if (backgroundGlow == null || boosterImage == null)
            {
                Debug.LogError("[BoosterPackGiver] Missing references. Assign Background Glow and Booster Image in the inspector.");
                return;
            }

            // Reset and start fresh
            if (_sequenceCoroutine != null)
            {
                StopCoroutine(_sequenceCoroutine);
                _sequenceCoroutine = null;
            }

            // Ensure canvas reference
            if (canvas == null)
            {
                canvas = GetComponentInParent<Canvas>();
            }

            // Reset booster transform
            boosterImage.localScale = _boosterInitialScale;
            boosterImage.anchoredPosition = _boosterInitialAnchoredPos;

            // Show visuals
            SetVisualsActive(true);

            _sequenceCoroutine = StartCoroutine(RunSequence());
        }

        private IEnumerator RunSequence()
        {
            // 1) Pulse the glow
            float elapsed = 0f;
            Vector3 baseGlowScale = backgroundGlow.localScale;
            while (elapsed < pulseDuration)
            {
                elapsed += Time.unscaledDeltaTime;
                float t = Mathf.Sin(elapsed * Mathf.PI * 2f * glowPulseSpeed) * 0.5f + 0.5f; // 0..1
                float s = Mathf.Lerp(glowScaleMin, glowScaleMax, t);
                backgroundGlow.localScale = baseGlowScale * s;
                yield return null;
            }

            // 2) Hide glow
            backgroundGlow.gameObject.SetActive(false);

            // 3) Move booster to backpack icon and scale to zero
            Vector2 startPos = boosterImage.anchoredPosition;
            Vector2 targetPos = startPos;

            // Convert target to booster parent space if available
            if (targetBackpackIcon != null)
            {
                var parentRect = boosterImage.parent as RectTransform;
                if (parentRect != null)
                {
                    Vector2 localPoint;
                    Vector2 screenPoint = RectTransformUtility.WorldToScreenPoint(canvas != null ? canvas.worldCamera : null, targetBackpackIcon.position);
                    if (RectTransformUtility.ScreenPointToLocalPointInRectangle(parentRect, screenPoint, canvas != null ? canvas.worldCamera : null, out localPoint))
                    {
                        targetPos = localPoint;
                    }
                }
            }

            elapsed = 0f;
            while (elapsed < moveDuration)
            {
                elapsed += Time.unscaledDeltaTime;
                float t = Mathf.Clamp01(elapsed / moveDuration);
                float mt = moveCurve != null ? moveCurve.Evaluate(t) : t;
                float st = scaleCurve != null ? scaleCurve.Evaluate(t) : t;

                boosterImage.anchoredPosition = Vector2.LerpUnclamped(startPos, targetPos, mt);
                boosterImage.localScale = Vector3.LerpUnclamped(_boosterInitialScale, Vector3.zero, st);
                yield return null;
            }

            // Ensure final state
            boosterImage.anchoredPosition = targetPos;
            boosterImage.localScale = Vector3.zero;

            if (hideOnComplete)
            {
                SetVisualsActive(false);
                // Restore booster for the next run
                boosterImage.localScale = _boosterInitialScale;
                boosterImage.anchoredPosition = _boosterInitialAnchoredPos;
                backgroundGlow.localScale = Vector3.one; // reset pulse scaling
            }

            _sequenceCoroutine = null;
            OnCompleted?.Invoke();
            CardSystemManager.Instance.AddBoosterPack(1);
        }

        private void SetVisualsActive(bool active)
        {
            if (backgroundGlow != null) backgroundGlow.gameObject.SetActive(active);
            if (boosterImage != null) boosterImage.gameObject.SetActive(active);
        }

        // Optional: quick editor hookup to validate references
#if UNITY_EDITOR
        private void OnValidate()
        {
            if (canvas == null)
            {
                canvas = GetComponentInParent<Canvas>();
            }
            if (boosterImage != null && _boosterInitialScale == Vector3.zero)
            {
                _boosterInitialScale = boosterImage.localScale;
                _boosterInitialAnchoredPos = boosterImage.anchoredPosition;
            }
        }
#endif
    }
}