using System;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;
using UnityEngine.Events;
using Random = UnityEngine.Random;

namespace Ichni
{
    public static class GeneralExtensions
    {
        public static void Invoke(this Dictionary<string, UnityAction> dictionary)
        {
            foreach (var action in dictionary.Values)
            {
                action.Invoke();
            }
        }

        public static void Invoke<T>(this Dictionary<string, UnityAction<T>> dictionary, T arg)
        {
            foreach (var action in dictionary.Values)
            {
                action.Invoke(arg);
            }
        }
        
        public static void Invoke<T1, T2>(this Dictionary<string, UnityAction<T1, T2>> dictionary, T1 arg1, T2 arg2)
        {
            foreach (var action in dictionary.Values)
            {
                action.Invoke(arg1, arg2);
            }
        }
        
        /// <summary>
        /// 遍历列表中的每个元素并执行指定的操作，用于foreach不能遍历的情况，例如在foreach中删除元素
        /// </summary>
        public static void For<T>(this IList<T> list, UnityAction<T> action)
        {
            for (int i = 0; i < list.Count; i++)
            {
                action.Invoke(list[i]);
            }
        }

        /// <summary>
        /// 将列表中的元素从此列表转移到另一个列表
        /// </summary>
        public static void Transfer<T>(this List<T> fromList, List<T> toList, T item)
        {
            if (fromList.Contains(item))
            {
                fromList.Remove(item);
                toList.Add(item);
            }
            else
            {
                Debug.LogError($"Item {item} not found in this List.");
            }
        }

        /// <summary>
        /// 在列表中交换两个元素
        /// </summary>
        public static void Swap<T>(this IList<T> list, int i, int j)
        {
            (list[i], list[j]) = (list[j], list[i]);
        }

        /// <summary>
        /// 随机打乱列表中的元素
        /// </summary>
        public static void Shuffle<T>(this IList<T> list)
        {
            for (int i = 0; i < list.Count; i++)
            {
                list.Swap(i, Random.Range(i, list.Count));
            }
        }

        /// <summary>
        /// 随机获取列表中的元素
        /// </summary>
        public static List<T> GetRandomElements<T>(this List<T> list, int count)
        {
            List<T> randomElements = new List<T>();

            if (count >= list.Count)
            {
                randomElements = new List<T>(list);
                return randomElements;
            }

            List<int> randomIndices = new List<int>();
            while (randomIndices.Count < count)
            {
                int randomIndex = Random.Range(0, list.Count);
                if (!randomIndices.Contains(randomIndex))
                {
                    randomIndices.Add(randomIndex);
                    randomElements.Add(list[randomIndex]);
                }
            }

            return randomElements;
        }
        
        /// <summary>
        /// 删除所有满足 predicate 的键值对。
        /// </summary>
        public static void RemoveWhere<TKey, TValue>(this IDictionary<TKey, TValue> dict, Func<TKey, TValue, bool> predicate)
        {
            dict.Where(pair => predicate(pair.Key, pair.Value)).Select(pair => pair.Key).ToList().ForEach(key => dict.Remove(key));
        }
        
        /// <summary>
        /// 获取所有子物体
        /// </summary>
        public static List<Transform> GetAllChildren(this Transform parent)
        {
            return parent.Cast<Transform>().ToList();
        }
    }
}