using System.IO;
using System.Linq;
using TMPro;
using UnityEngine;
using UnityEngine.UI;

namespace AibisDream.UI
{
    public class SavesPanel : MonoBehaviour, IUIPanel
    {
        public bool IsOpen => gameObject.activeSelf;
        public bool IsCloseable => true;
        
        private static readonly string SaveFilePath = Application.streamingAssetsPath + "/SaveFiles";

        #region 索引
        public Button buttonPrefab;
        public Transform buttonParent;
        #endregion

        #region 打开和关闭

        public void Show()
        {
            InitLevelBtn();
            gameObject.SetActive(true);
            RegisterButton();
        }

        public void Hide()
        {
            gameObject.SetActive(false);
            UnRegisterButton();
        }
        
        private void RegisterButton()
        {
            var returnBtn = transform.Find("Return").GetComponent<Button>();
            returnBtn.onClick.AddListener(() => UIManager.Instance.HidePanel<SavesPanel>());
        }
        
        private void UnRegisterButton()
        {
            var returnBtn = transform.Find("Return").GetComponent<Button>();
            returnBtn.onClick.RemoveAllListeners();
        }

        #endregion

        private void InitLevelBtn()
        {
            // 清空旧按钮
            foreach (Transform child in buttonParent)
            {
                Destroy(child.gameObject);
            }

            // 加载存档文件
            string[] saveFiles = Directory.GetFiles(SaveFilePath, "*.json");
            var orderedSaveFiles = saveFiles.OrderByDescending(item => item).ToArray();
            foreach (var saveFile in orderedSaveFiles)
            {
                var button = Instantiate(buttonPrefab, buttonParent);
                button.GetComponentInChildren<TMP_Text>().text = Path.GetFileNameWithoutExtension(saveFile);
                button.onClick.AddListener(() => OnSaveFileSelected(saveFile));
            }
        }
        
        private void OnSaveFileSelected(string saveFileName)
        {
            // 隐藏UI
            gameObject.SetActive(false);
            // 开始游戏
            GameManager.Instance.StartWithSaveFile(saveFileName);
        }
    }
}