using System;
using System.Collections.Generic;
using Data;
using Entity;
using Prefab;
using UnityEngine;
using Utils;
using Random = System.Random;

namespace Managers
{
    class EventManager:Singleton<EventManager>,ILaunchManager
    {
        private static Random _random = new();
        public EventDef[] EventDefs { get; private set; }
        public string StepDescription => "正在载入事件";

        public void Init()
        {
            if(EventDefs!=null)
                return;
            EventDefs = DefineManager.Instance.QueryDefinesByType<EventDef>();
        }

        public void Clear()
        {
            EventDefs = null;
        }

        public static void ExecuteEvent(EventDef eventDef)
        {
            if(eventDef == null)
                return;
            if (eventDef.hediffEvent != null)
            {
                var entityList = EntityManage.Instance.FindEntitiesByFaction(Program.Instance.FocusedDimensionId,
                    eventDef.hediffEvent.affiliation.defName);
                List<Entity.Entity> filteredEntitiesTraditional = new();
                foreach (var prefab in entityList)
                {
                    var entity = prefab.entity;
                    if (entity is Character || entity is Monster) 
                    {
                        filteredEntitiesTraditional.Add(entity);
                    }
                }
                var selectedElements = SelectRandomElements_FisherYates(filteredEntitiesTraditional, eventDef.hediffEvent.specificPawnCount);
                foreach (var selectedElement in selectedElements)
                {
                    
                }
            }
        }
        public static List<T> SelectRandomElements_FisherYates<T>(List<T> sourceList, int count)
        {
            if (sourceList == null) throw new ArgumentNullException(nameof(sourceList));
            if (count < 0) throw new ArgumentOutOfRangeException(nameof(count), "Count cannot be negative.");
            if (count == 0) return new List<T>();
            if (count >= sourceList.Count) return new List<T>(sourceList); // 如果n大于等于列表大小，则返回所有元素副本

            List<T> result = new List<T>(count); // 预分配容量
            List<T> temp = new List<T>(sourceList); // 创建一个副本以避免修改原始列表

            int n = temp.Count;
            for (int i = 0; i < count; i++)
            {
                int k = _random.Next(i, n);
                result.Add(temp[k]);
                (temp[k], temp[i]) = (temp[i], temp[k]);
            }
            return result;
        }

    }
}