using System;
using System.Collections.Generic;
using UnityEngine;

public interface ILoader<T>
{
    List<T> GetList() { throw new Exception("NOT IMPLEMENT"); }

    T GetSingle() { throw new Exception("NOT IMPLEMENT"); }

}

public class DataManager : IManager
{
    private Dictionary<string, object> _cache = new Dictionary<string, object>();
    
    public Dictionary<TKey, TValue> LoadToDict<TLoader, TKey, TValue>(string path, System.Func<TValue, TKey> keySelector) where TLoader : ILoader<TValue>
    {
        if (_cache.TryGetValue(path, out object cachedDict)) return (Dictionary<TKey, TValue>)cachedDict;
        
        TLoader load = LoadJson<TLoader, TValue>(path);
        List<TValue> list = load.GetList();
        
        Dictionary<TKey, TValue> dict = new Dictionary<TKey, TValue>();
        foreach (TValue item in list)
        {
            dict.Add(keySelector(item), item);
        }
        
        _cache.Add(path, dict);
        return dict;
    }
    
    public T LoadSingle<TLoader, T>(string path) where TLoader : ILoader<T>
    {
        if (_cache.TryGetValue(path, out object cachedItem)) return (T)cachedItem;
        
        // List<T> list = LoadJson<TLoader, T>(path);
        // if (list.Count == 0) throw new Exception("HAVE NOT ITEM"); 
        // if (list.Count > 1) throw new Exception("MANY ITEM");
        //
        // T item = list[0];
        // _cache.Add(path, item);
        // LoadJson을 호출하는 대신, 아래와 같이 직접 로드하고 GetSingle()을 호출합니다.
        
        
        TLoader load = LoadJson<TLoader, T>(path);
        T single = load.GetSingle();
        
        _cache.Add(path, single);

        return single;
    }
    
    // private List<T> LoadJson<TLoader, T>(string path) where TLoader : ILoader<T>
    // {
    //     TextAsset textAsset = Manager.Resource.Load<TextAsset>($"{path}");
    //     TLoader data = JsonUtility.FromJson<TLoader>(textAsset.text);
    //     return data.GetList();
    // }
    private TLoader LoadJson<TLoader, T>(string path) where TLoader : ILoader<T>
    {
        TextAsset textAsset = Manager.Resource.Load<TextAsset>($"{path}");
        TLoader data = JsonUtility.FromJson<TLoader>(textAsset.text);
        return data;
    }

    public void Clear()
    {
        _cache.Clear();
    }
}