probably-decentralized/src/Decentralized.Domain/BmSales.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace Decentralized.Domain
{
    public enum SaleState { Listed, Sold, Paid, Lost, Delisted }

    /// <summary>玩家在黑市上架的一件货。货交给平台（从储藏区拿走），成交后货款托管几天再到钱包，可能带污点。</summary>
    public sealed class BmSale
    {
        public string Item;
        public string Model, FakeOf;
        public double Health;
        /// <summary>标价倍率与标价（信用点）。</summary>
        public double Mult;
        public int ListPrice;
        public int ListedDay, PayDay;
        public SaleState State = SaleState.Listed;
        /// <summary>成交后扣掉抽成的货款（信用点）与其中带的污点。</summary>
        public int Proceeds;
        public double Taint;
        /// <summary>终态原因：fake（买家看穿假卡退货）/ rug / delist。</summary>
        public string Why;
    }

    public sealed partial class BlackMarket
    {
        public List<BmSale> Sales = new List<BmSale>();
        /// <summary>玩家作为卖家的好评（%）：影响成交速度；卖假卡被看穿会下降，每笔成交回升一点。</summary>
        public int Rating = Tuning.BmRatingStart;

        /// <summary>期望成交天数：倍率 ≤0.9 一天，1.0 两天，1.8 十四天，之间插值（0.9–1.0 线性，1.0 以上指数）。</summary>
        public static double ExpectedDays(double m)
        {
            if (m <= 0.9) return Tuning.BmSellDaysFast;
            if (m < 1.0) return Tuning.BmSellDaysFast + (m - 0.9) / 0.1 * (Tuning.BmSellDays1 - Tuning.BmSellDaysFast);
            return Tuning.BmSellDays1 * Math.Pow(Tuning.BmSellDaysMax / Tuning.BmSellDays1, (m - 1.0) / (Tuning.BmSellMax - 1.0));
        }

        private static double T(double m) => Math.Max(0, Math.Min(1, (m - Tuning.BmSellMin) / (Tuning.BmSellMax - Tuning.BmSellMin)));
        /// <summary>货款带污点的概率与（带的时候）污点占货款的比例：都随标价倍率上升。</summary>
        public static double TaintChance(double m) => Tuning.BmSaleTaintChanceMin + T(m) * (Tuning.BmSaleTaintChanceMax - Tuning.BmSaleTaintChanceMin);
        public static double TaintRatio(double m) => Tuning.BmSaleTaintRatioMin + T(m) * (Tuning.BmSaleTaintRatioMax - Tuning.BmSaleTaintRatioMin);

        /// <summary>每晚成交的概率：1 / 期望天数，乘好评系数（好评 90 为 1，封顶 1.1），最多 1。</summary>
        public double SaleChance(double m) => Math.Min(1, 1 / ExpectedDays(m) * Math.Min(1.1, Rating / (double)Tuning.BmRatingStart));

        /// <summary>近 7 天成交额推高的污点加成：出售量越大，货款越容易带污点、比例越高。</summary>
        public double VolumeTaint(int day)
        {
            double v = Sales.Where(x => (x.State == SaleState.Sold || x.State == SaleState.Paid) && day - (x.PayDay - Tuning.BmSaleHold) <= 7).Sum(x => (double)x.Proceeds);
            return Math.Min(Tuning.BmVolumeTaintMax, v / Tuning.BmVolumeRef * Tuning.BmVolumeTaintMax);
        }

        public static int ListPriceOf(long refValue, double m) => (int)Math.Max(1, Math.Round(refValue * m));
        public static int ListFee(int listPrice) => (int)Math.Ceiling(listPrice * Tuning.BmListFee);

        /// <summary>上架：交付一件货，收上架费（付给 feeAsset 币，污点与成本按比例带走）。倍率超出范围、平台关闭或余额不足返回 null。</summary>
        public BmSale List(string item, string model, string fakeOf, double health, long refValue, double m, Wallet w, string feeAsset, int day, Func<string, double> price)
        {
            if (m < Tuning.BmSellMin - 1e-9 || m > Tuning.BmSellMax + 1e-9 || refValue <= 0 || Closed(day) || feeAsset == Assets.CRC) return null;
            int listPrice = ListPriceOf(refValue, m);
            double p = price(feeAsset);
            if (p <= 0) return null;
            double qty = ListFee(listPrice) / p;
            if (w.Avail(feeAsset) + 1e-9 < qty) return null;
            double total = w.Value(price);
            double share = total > 0 ? Math.Min(1, ListFee(listPrice) / total) : 0;
            w.Taint -= w.Taint * share; w.Basis -= w.Basis * share;
            w.Add(feeAsset, -qty);
            var s = new BmSale { Item = item, Model = model, FakeOf = fakeOf, Health = health, Mult = m, ListPrice = listPrice, ListedDay = day };
            Sales.Add(s);
            return s;
        }

        public void Delist(BmSale s) { s.State = SaleState.Delisted; s.Why = "delist"; }

        /// <summary>未到账的货款（信用点）：跑路时一并归零，也推高跑路概率。</summary>
        public double HeldSales => Sales.Where(x => x.State == SaleState.Sold).Sum(x => (double)x.Proceeds);

        /// <summary>每晚推进出售：上架的货按概率成交（假卡可能被看穿退货），成交的货款托管到期后进钱包。镇压期间平台下线，不推进。</summary>
        private void SalesNight(int day, bool crackdown, Wallet w, Func<string, double> price, Rng rng, List<BmEvent> ev)
        {
            if (crackdown) return;
            foreach (var s in Sales.Where(x => x.State == SaleState.Listed && x.ListedDay < day).ToList())
            {
                if (!rng.Chance(SaleChance(s.Mult))) continue;
                if (s.FakeOf != null && rng.Chance(Tuning.BmFakeDetect))
                {
                    s.State = SaleState.Delisted; s.Why = "fake";
                    Rating = Math.Max(0, Rating - Tuning.BmRatingFakeLoss);
                    ev.Add(new BmEvent { Kind = "sale_fake", Sale = s });
                    continue;
                }
                s.State = SaleState.Sold;
                s.Proceeds = (int)Math.Round(s.ListPrice * (1 - Tuning.BmCommission));
                double vb = VolumeTaint(day);
                s.Taint = rng.Chance(Math.Min(1, TaintChance(s.Mult) + vb)) ? s.Proceeds * Math.Min(1, TaintRatio(s.Mult) + vb) : 0;
                s.PayDay = day + Tuning.BmSaleHold;
                Rating = Math.Min(100, Rating + 1);
                if (Honeypot(day)) Traps.Add(new BmTrap { Day = day + Tuning.BmTrapDelay, Amount = s.Proceeds, Why = "honeypot", Item = s.Item });
                ev.Add(new BmEvent { Kind = "sale_sold", Sale = s, Amount = s.Proceeds });
            }
            foreach (var s in Sales.Where(x => x.State == SaleState.Sold && day >= x.PayDay).ToList())
            {
                double p = price(Assets.CRT);
                if (p <= 0) continue;
                w.Add(Assets.CRT, s.Proceeds / p);
                w.Taint += s.Taint;
                w.Basis += s.Proceeds;
                s.State = SaleState.Paid;
                ev.Add(new BmEvent { Kind = "sale_paid", Sale = s, Amount = s.Proceeds });
            }
            // 买家落网：近期到账的出售记录会连累卖家（玩家）
            var recent = Sales.Where(x => x.State == SaleState.Paid && day - x.PayDay <= 14).ToList();
            if (recent.Count > 0 && rng.Chance(Tuning.BmSellerBust))
            {
                foreach (var s in recent) Traps.Add(new BmTrap { Day = day + Tuning.BmTrapDelay, Amount = s.Proceeds, Why = "seller", Item = s.Item });
                Forum.Add("busted_buyer");
            }
            Sales.RemoveAll(x => (x.State == SaleState.Paid || x.State == SaleState.Delisted || x.State == SaleState.Lost) && day - Math.Max(x.ListedDay, x.PayDay) > 14);
        }

    }
}