using System;
using System.Collections.Generic;

namespace FL
{
    public static class MathUtils
    {
        /// <summary>
        /// 传递一个概率值(1-10000)，返回随机结果是否在概率内
        /// </summary>
        /// <param name="probability">1-10000</param>
        /// <param name="maxExclusive">最大值</param>
        /// <returns></returns>
        public static bool Random(int probability, int maxExclusive = 10000)
        {
            //零固定返回false
            if (probability <= 0) return false;
            if (probability < maxExclusive)
            {
                var random = UnityEngine.Random.Range(0, maxExclusive);
                return random < probability;
            }
            return true;
        }
        /// <summary>
        /// 传递一个权重数组，返回随机结果对应的索引
        /// </summary>
        /// <param name="weights"></param>
        /// <returns></returns>
        public static int Random(IList<int> weights)
        {
            var total = 0;
            foreach (var weight in weights)
            {
                total += weight;
            }
            if (total <= 0)
            {
                return 0;
            }
            var random = UnityEngine.Random.Range(0, total);
            var temp = 0;
            for (var i = 0; i < weights.Count; i++)
            {
                temp += weights[i];
                if (random < temp)
                {
                    return i;
                }
            }
            XGame.Log.Error($"随机数错误。total:{total} total:{random}");
            return 0;
        }
    }
}