using System.Collections.Generic;
using TMPro;
using UnityEngine;
using WarGame.Data;
using WarGame.Managers;

namespace WarGame.UI
{
    public class ShopUI : MonoBehaviour
    {
        [Header("UI References")]
        [SerializeField] private TMP_Text goldDisplayText;
        [SerializeField] private Transform cardsContainer;
        [SerializeField] private GameObject cardPrefab;
        [SerializeField] private GameObject shopPanel;

        [Header("Shop Catalog")]
        [SerializeField] private List<UnitDataSO> purchasableUnits = new List<UnitDataSO>();

        private readonly List<ShopCardUI> spawnedCards = new List<ShopCardUI>();

        private void Start()
        {
            if (BattleManager.Instance != null)
            {
                BattleManager.Instance.OnGoldChanged += HandleGoldChanged;
                BattleManager.Instance.OnBattleStateChanged += HandleBattleStateChanged;
                HandleGoldChanged(BattleManager.Instance.CurrentGold);
            }

            BuildShopCards();
        }

        private void OnDestroy()
        {
            if (BattleManager.Instance != null)
            {
                BattleManager.Instance.OnGoldChanged -= HandleGoldChanged;
                BattleManager.Instance.OnBattleStateChanged -= HandleBattleStateChanged;
            }
        }

        public void SetCatalog(List<UnitDataSO> units)
        {
            purchasableUnits = units;
            BuildShopCards();
        }

        private void BuildShopCards()
        {
            if (cardsContainer == null || cardPrefab == null) return;

            // Clear previous
            foreach (Transform child in cardsContainer)
            {
                Destroy(child.gameObject);
            }
            spawnedCards.Clear();

            for (int i = 0; i < purchasableUnits.Count; i++)
            {
                UnitDataSO data = purchasableUnits[i];
                if (data == null) continue;

                GameObject cardObj = Instantiate(cardPrefab, cardsContainer);
                ShopCardUI card = cardObj.GetComponent<ShopCardUI>();
                if (card != null)
                {
                    card.Setup(data);
                    spawnedCards.Add(card);
                }
            }

            UpdateAllCards();
        }

        private void HandleGoldChanged(int newGold)
        {
            if (goldDisplayText != null)
            {
                goldDisplayText.text = $"Gold: {newGold}";
            }
            UpdateAllCards();
        }

        private void HandleBattleStateChanged(BattleState newState)
        {
            if (shopPanel != null)
            {
                // Only allow recruiting during Preparation phase
                shopPanel.SetActive(newState == BattleState.Preparation);
            }
            UpdateAllCards();
        }

        private void UpdateAllCards()
        {
            for (int i = 0; i < spawnedCards.Count; i++)
            {
                if (spawnedCards[i] != null)
                {
                    spawnedCards[i].UpdateInteractability();
                }
            }
        }
    }
}