using System.Collections.Generic;
using TMPro;
using UnityEngine;
using UnityEngine.InputSystem;
using UnityEngine.UI;
using Northbound.Data;

namespace Northbound
{
    /// <summary>
    /// 업그레이드 목록 팝업 UI 컨트롤러
    /// </summary>
    public class UpgradeListPopup : MonoBehaviour
    {
        [Header("References")]
        [SerializeField] private Transform _contentParent;
        [SerializeField] private GameObject _listItemPrefab;
        [SerializeField] private TextMeshProUGUI _manaText;
        [SerializeField] private Button _closeButton;

        private PlayerUpgradeManager _playerUpgradeManager;
        private PlayerStats _playerStats;
        private List<UpgradeListItem> _listItems = new List<UpgradeListItem>();

        private void Awake()
        {
            if (_closeButton != null)
            {
                _closeButton.onClick.AddListener(Close);
            }
        }

        private void Update()
        {
            // ESC 키로 닫기
            if (Keyboard.current != null && Keyboard.current.escapeKey.wasPressedThisFrame)
            {
                Close();
            }

            // 마나 텍스트 업데이트
            UpdateManaDisplay();
        }

        /// <summary>
        /// 팝업 초기화
        /// </summary>
        public void Initialize(PlayerUpgradeManager upgradeManager, PlayerStats playerStats)
        {
            _playerUpgradeManager = upgradeManager;
            _playerStats = playerStats;

            RefreshList();
            UpdateManaDisplay();

            gameObject.SetActive(true);
        }

        /// <summary>
        /// 업그레이드 목록 갱신
        /// </summary>
        public void RefreshList()
        {
            // 기존 아이템 제거
            ClearList();

            if (_playerUpgradeManager == null) return;

            var database = UpgradeDatabase.Instance;
            if (database == null)
            {
                Debug.LogWarning("[UpgradeListPopup] UpgradeDatabase를 찾을 수 없습니다.");
                return;
            }

            // 개인 업그레이드 목록 가져오기
            var allUpgrades = database.GetPersonalUpgrades();
            var ownedIds = _playerUpgradeManager.GetOwnedUpgradeIdSet();

            foreach (var upgrade in allUpgrades)
            {
                if (upgrade == null) continue;

                bool isOwned = ownedIds.Contains(upgrade.id);
                bool prerequisitesMet = database.ArePrerequisitesMet(upgrade.id, ownedIds);

                // 이미 구매했거나, 선행조건이 충족된 항목만 표시
                if (!isOwned && !prerequisitesMet) continue;

                bool canPurchase = !isOwned && prerequisitesMet;
                CreateListItem(upgrade, isOwned, canPurchase);
            }
        }

        /// <summary>
        /// 리스트 아이템 생성
        /// </summary>
        private void CreateListItem(UpgradeData upgrade, bool isOwned, bool canPurchase)
        {
            if (_listItemPrefab == null || _contentParent == null) return;

            GameObject itemObj = Instantiate(_listItemPrefab, _contentParent);
            var listItem = itemObj.GetComponent<UpgradeListItem>();

            if (listItem != null)
            {
                listItem.Setup(upgrade, isOwned, canPurchase, this);
                _listItems.Add(listItem);
            }
            else
            {
                // UpgradeListItem 컴포넌트가 없으면 추가
                listItem = itemObj.AddComponent<UpgradeListItem>();
                listItem.Setup(upgrade, isOwned, canPurchase, this);
                _listItems.Add(listItem);
            }
        }

        /// <summary>
        /// 리스트 비우기
        /// </summary>
        private void ClearList()
        {
            foreach (var item in _listItems)
            {
                if (item != null && item.gameObject != null)
                {
                    Destroy(item.gameObject);
                }
            }
            _listItems.Clear();
        }

        /// <summary>
        /// 업그레이드 구매 요청
        /// </summary>
        public void RequestPurchase(int upgradeId)
        {
            if (_playerUpgradeManager == null) return;

            _playerUpgradeManager.RequestPurchaseUpgrade(upgradeId);

            // 구매 후 목록 갱신
            RefreshList();
            UpdateManaDisplay();
        }

        /// <summary>
        /// 마나 표시 업데이트
        /// </summary>
        private void UpdateManaDisplay()
        {
            if (_manaText == null) return;

            var core = CoreResourceManager.Instance?.mainCore;
            if (core != null)
            {
                _manaText.text = $"MANA: {core.TotalResources}";
            }
        }

        /// <summary>
        /// 팝업 닫기
        /// </summary>
        public void Close()
        {
            gameObject.SetActive(false);
        }

        private void OnDestroy()
        {
            ClearList();
        }
    }
}