using Core;
using UI.CardSystem.StateMachine;
using UnityEngine;

namespace UI.CardSystem
{
    /// <summary>
    /// Manages card enlarge system: backdrop display and card reparenting.
    /// Created and owned by AlbumViewPage (not a Unity component).
    /// </summary>
    public class CardEnlargeController
    {
        private readonly GameObject _backdrop;
        private readonly Transform _enlargedContainer;
        
        /// <summary>
        /// Constructor - called by AlbumViewPage's lazy property
        /// </summary>
        public CardEnlargeController(GameObject backdrop, Transform enlargedContainer)
        {
            _backdrop = backdrop;
            _enlargedContainer = enlargedContainer;
        }
        
        /// <summary>
        /// Subscribe to a placed card's enlarged state events
        /// </summary>
        public void RegisterCard(StateMachine.Card card)
        {
            if (card == null) return;
            
            var enlargeState = card.GetStateComponent<StateMachine.States.CardAlbumEnlargedState>(CardStateNames.AlbumEnlarged);
            if (enlargeState != null)
            {
                enlargeState.OnEnlargeRequested += OnCardEnlargeRequested;
                enlargeState.OnShrinkRequested += OnCardShrinkRequested;
            }
        }
        
        /// <summary>
        /// Unsubscribe from a card's enlarged state events
        /// </summary>
        public void UnregisterCard(StateMachine.Card card)
        {
            if (card == null) return;
            
            var enlargeState = card.GetStateComponent<StateMachine.States.CardAlbumEnlargedState>(CardStateNames.AlbumEnlarged);
            if (enlargeState != null)
            {
                enlargeState.OnEnlargeRequested -= OnCardEnlargeRequested;
                enlargeState.OnShrinkRequested -= OnCardShrinkRequested;
            }
        }
        
        /// <summary>
        /// Clean up enlarged card state (on page close)
        /// </summary>
        public void CleanupEnlargedState()
        {
            // Hide backdrop if visible
            if (_backdrop != null && _backdrop.activeSelf)
            {
                _backdrop.SetActive(false);
            }
            
            // If there's an enlarged card in the container, return it to its slot
            if (_enlargedContainer != null && _enlargedContainer.childCount > 0)
            {
                for (int i = _enlargedContainer.childCount - 1; i >= 0; i--)
                {
                    Transform cardTransform = _enlargedContainer.GetChild(i);
                    var card = cardTransform.GetComponent<StateMachine.Card>();
                    var state = cardTransform.GetComponentInChildren<StateMachine.States.CardAlbumEnlargedState>(true);
                    if (card != null && state != null)
                    {
                        Transform originalParent = state.GetOriginalParent();
                        if (originalParent != null)
                        {
                            cardTransform.SetParent(originalParent, true);
                            cardTransform.localPosition = state.GetOriginalLocalPosition();
                            cardTransform.localRotation = state.GetOriginalLocalRotation();
                        }
                    }
                }
            }
        }
        
        #region Event Handlers
        
        private void OnCardEnlargeRequested(StateMachine.States.CardAlbumEnlargedState state)
        {
            if (state == null) return;
            
            // Show backdrop
            if (_backdrop != null)
            {
                _backdrop.SetActive(true);
            }
            
            // Reparent card root to enlarged container preserving world transform
            if (_enlargedContainer != null)
            {
                var ctx = state.GetComponentInParent<StateMachine.CardContext>();
                if (ctx != null)
                {
                    ctx.RootTransform.SetParent(_enlargedContainer, true);
                    ctx.RootTransform.SetAsLastSibling();
                }
            }
        }
        
        private void OnCardShrinkRequested(StateMachine.States.CardAlbumEnlargedState state)
        {
            if (state == null) return;
            
            // Hide backdrop; state will animate back to slot and reparent on completion
            if (_backdrop != null)
            {
                _backdrop.SetActive(false);
            }
            
            // Do not reparent here; reverse animation is orchestrated by the state
        }
        
        #endregion
    }
}