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

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

namespace Decentralized.Domain
{
    public enum PayMode { Escrow, Advance }
    public enum OrderState { Pending, Ready, Done, Refunded, Lost }

    /// <summary>黑市上的卖家：成交数与好评率公开；是不是骗子是隐藏的。</summary>
    public sealed class BmSeller
    {
        public string Name;
        public int Trades;
        public int Rating;   // 好评率 %
        public bool Scam;
        /// <summary>只有成交数够多的卖家才接受提前放款。</summary>
        public bool Advance => Trades >= Tuning.BmAdvanceMinTrades;
    }

    /// <summary>订单目录里的一件货：卖家、货、价格（订单价，已折扣）。</summary>
    public sealed class BmListing : BmGood
    {
        public int Seller;
    }

    public sealed class BmOrder
    {
        public string Item;
        public string Seller;
        public bool SellerScam;
        public PayMode Mode;
        public string Model, FakeOf;
        public double Health;
        public int Price;
        public string Asset;
        public double Qty;
        /// <summary>付款时留在卖家那边的污点与成本：退款时一并还回，免得"付脏币再退款"洗钱。</summary>
        public double Taint, Basis;
        public int PlacedDay, DueDay;
        /// <summary>被截获后执法选择了上门：到货时快递员是执法人员，签收即记罪证。</summary>
        public bool Controlled;
        public OrderState State = OrderState.Pending;
        /// <summary>终态的原因：done / scam / rug / intercept / theft / refund。</summary>
        public string Why;
    }

    /// <summary>一笔会被追查的交易：到期日、金额（信用点）、来源（honeypot / seller / controlled）。</summary>
    public sealed class BmTrap
    {
        public int Day;
        public double Amount;
        public string Why;
        public string Item;
    }

    /// <summary>夜间发生的订单事件，供日志与新闻使用。</summary>
    public sealed class BmEvent
    {
        public string Kind;   // ready / scam_refund / scam_loss / rug / intercept / reopen
        public BmOrder Order;
        public double Amount;
    }

    public sealed partial class BlackMarket
    {
        public List<BmSeller> Sellers = new List<BmSeller>();
        public List<BmListing> Catalog = new List<BmListing>();
        public List<BmOrder> Orders = new List<BmOrder>();
        public List<string> Forum = new List<string>();
        /// <summary>平台跑路后关闭到这一天（含）。</summary>
        public int ClosedUntil = -1;
        /// <summary>执法接管平台的最后一天（含）；期间的交易之后会被追查。</summary>
        public int HoneypotUntil = -1;
        public List<BmTrap> Traps = new List<BmTrap>();

        public bool Honeypot(int day) => day <= HoneypotUntil;

        public static double HoneypotChance(int secRep) => Math.Min(Tuning.BmHoneypotMax, Tuning.BmHoneypotBase + Math.Max(0, secRep) * Tuning.BmHoneypotPerSecRep);

        private static readonly string[] NameA = { "rat", "grey", "static", "null", "dust", "iron", "pale", "wire", "salt", "ghost" };
        private static readonly string[] NameB = { "king", "mule", "broker", "hand", "cat", "fox", "tooth", "lamp", "nine", "dealer" };

        public bool Closed(int day) => day <= ClosedUntil;

        /// <summary>托管中和已提前放款但尚未交付的资金（信用点），平台跑路的概率随它增加。</summary>
        public double Held => Orders.Where(o => o.State == OrderState.Pending).Sum(o => (double)o.Price);

        public static int OrderPrice(long baseValue, GoodKind k = GoodKind.Contraband) => (int)Math.Max(1, Math.Round(baseValue * (1 + Extra(k)) * (1 - Tuning.BmOrderDiscount)));
        public static int EscrowFee(int price) => (int)Math.Ceiling(price * Tuning.BmEscrowFee);
        /// <summary>下单实付（信用点）：托管 = 订单价 + 托管费；提前放款 = 订单价打折。</summary>
        public static int Pay(int price, PayMode m) => m == PayMode.Escrow ? price + EscrowFee(price) : (int)Math.Round(price * (1 - Tuning.BmAdvanceDiscount));

        public double RugChance => Math.Min(Tuning.BmRugMax, Tuning.BmRugBase + Held / 10000.0 * Tuning.BmRugPerTenK);

        /// <summary>每周重新生成卖家、目录和论坛情报（与现货同一天刷新）。</summary>
        public void RefreshOrders(int day, int rep, Rng rng, Func<string, long> value)
        {
            Sellers.Clear(); Catalog.Clear(); Forum.Clear();
            for (int i = 0; i < Tuning.BmSellerCount; i++)
            {
                bool scam = rng.Chance(Tuning.BmScamSellerShare);
                // 骗子多半是新号，也有刷过好评的老号
                bool fresh = scam ? rng.Chance(0.6) : rng.Chance(0.25);
                var s = new BmSeller
                {
                    Name = NameA[rng.Range(0, NameA.Length - 1)] + "_" + NameB[rng.Range(0, NameB.Length - 1)] + rng.Range(1, 99),
                    Scam = scam,
                    Trades = fresh ? rng.Range(1, 12) : rng.Range(25, 220),
                    Rating = scam && !fresh ? rng.Range(94, 99) : fresh ? rng.Range(70, 100) : rng.Range(90, 99),
                };
                Sellers.Add(s);
                if (scam && rng.Chance(0.5)) Forum.Add("scam:" + s.Name);
            }
            int n = 0;
            foreach (var g in Roll(Tuning.BmSellerCount * 2, day, rep, rng, value, OrderPrice))
                Catalog.Add(new BmListing { Seller = n++ % Sellers.Count, Item = g.Item, Kind = g.Kind, Level = g.Level, Price = g.Price, Model = g.Model, FakeOf = g.FakeOf, Health = g.Health });
            if (RugChance > Tuning.BmRugBase * 3) Forum.Add("rug");
        }

        /// <summary>下单：钱包里的币按实付折算扣除，污点与成本按比例留在卖家那边（记在订单上）。成功返回订单。</summary>
        public BmOrder Place(BmListing l, PayMode mode, Wallet w, string asset, int day, Func<string, double> price)
        {
            if (l == null || asset == Assets.CRC || Closed(day)) return null;
            var seller = Sellers[l.Seller];
            if (mode == PayMode.Advance && !seller.Advance) return null;
            double p = price(asset);
            if (p <= 0) return null;
            int credits = Pay(l.Price, mode);
            double qty = credits / p;
            if (w.Avail(asset) + 1e-9 < qty) return null;
            double total = w.Value(price);
            double share = total > 0 ? Math.Min(1, credits / total) : 0;
            double taint = w.Taint * share, basis = w.Basis * share;
            w.Taint -= taint; w.Basis -= basis;
            w.Add(asset, -qty);
            var o = new BmOrder
            {
                Item = l.Item, Seller = seller.Name, SellerScam = seller.Scam, Mode = mode, Model = l.Model, FakeOf = l.FakeOf, Health = l.Health, Price = credits, Asset = asset, Qty = qty,
                Taint = taint, Basis = basis, PlacedDay = day, DueDay = day + Tuning.BmDoorDays,
            };
            Orders.Add(o);
            if (Honeypot(day)) Traps.Add(new BmTrap { Day = day + Tuning.BmTrapDelay, Amount = credits, Why = "honeypot", Item = l.Item });
            return o;
        }

        private static void Refund(Wallet w, BmOrder o)
        {
            w.Add(o.Asset, o.Qty);
            w.Taint += o.Taint; w.Basis += o.Basis;
        }

        /// <summary>每晚推进订单：平台跑路、到期的订单（卖家跑路、被截获、死投被挖走）、转入可取状态。镇压期间到期顺延一天。</summary>
        public List<BmEvent> Night(int day, bool crackdown, Wallet w, Rng rng, int secRep = 0)
        {
            var ev = new List<BmEvent>();
            if (!Honeypot(day) && rng.Chance(HoneypotChance(secRep))) { HoneypotUntil = day + Tuning.BmHoneypotDays; if (!Forum.Contains("easy")) Forum.Add("easy"); }
            if (ClosedUntil == day) ev.Add(new BmEvent { Kind = "reopen" });
            if (!Closed(day) && Orders.Any(o => o.State == OrderState.Pending) && rng.Chance(RugChance))
            {
                foreach (var o in Orders.Where(o => o.State == OrderState.Pending))
                {
                    o.State = OrderState.Lost; o.Why = "rug";
                    ev.Add(new BmEvent { Kind = "rug", Order = o, Amount = o.Price });
                }
                ClosedUntil = day + Tuning.BmRugClosedDays;
                Offers.Clear(); Catalog.Clear(); Sellers.Clear();
                return ev;
            }
            foreach (var o in Orders.Where(x => x.State == OrderState.Pending).ToList())
            {
                if (day < o.DueDay) continue;
                if (crackdown) { o.DueDay = day + 1; continue; }
                if (o.SellerScam)
                {
                    if (o.Mode == PayMode.Escrow) { Refund(w, o); o.State = OrderState.Refunded; o.Why = "scam"; ev.Add(new BmEvent { Kind = "scam_refund", Order = o, Amount = o.Price }); }
                    else { o.State = OrderState.Lost; o.Why = "scam"; ev.Add(new BmEvent { Kind = "scam_loss", Order = o, Amount = o.Price }); }
                    continue;
                }
                double ic = Tuning.BmInterceptDoor + (crackdown ? Tuning.BmInterceptCrackdown : 0);
                if (rng.Chance(ic))
                {
                    if (rng.Chance(Tuning.BmControlled)) { o.Controlled = true; o.State = OrderState.Ready; ev.Add(new BmEvent { Kind = "ready", Order = o }); continue; }
                    o.State = OrderState.Lost; o.Why = "intercept"; ev.Add(new BmEvent { Kind = "intercept", Order = o, Amount = o.Price }); continue;
                }
                o.State = OrderState.Ready;
                ev.Add(new BmEvent { Kind = "ready", Order = o });
            }
            // 卖家落网：近期成交过的卖家各有小概率被抓，他们留存的订单记录之后会连累买家
            foreach (var name in Orders.Where(x => x.State == OrderState.Done && day - x.DueDay <= 14).Select(x => x.Seller).Distinct().ToList())
            {
                if (!rng.Chance(Tuning.BmSellerBust)) continue;
                foreach (var o in Orders.Where(x => x.State == OrderState.Done && x.Seller == name && day - x.DueDay <= 14))
                    Traps.Add(new BmTrap { Day = day + Tuning.BmTrapDelay, Amount = o.Price, Why = "seller", Item = o.Item });
                Forum.Add("busted:" + name);
            }
            foreach (var t in Traps.Where(x => day >= x.Day).ToList())
            {
                Traps.Remove(t);
                ev.Add(new BmEvent { Kind = "trap", Amount = t.Amount, Order = new BmOrder { Item = t.Item, Seller = t.Why } });
            }
            Orders.RemoveAll(o => o.State != OrderState.Pending && o.State != OrderState.Ready && day - o.DueDay > 14);
            return ev;
        }

        /// <summary>受控交付：签收则当场记罪证（返回金额）并查封，不交货；拒签则损失货款，不留罪证。</summary>
        public double Sign(BmOrder o, bool accept)
        {
            o.State = OrderState.Lost;
            o.Why = accept ? "seized" : "refused";
            return accept ? o.Price : 0;
        }

        public void Deliver(BmOrder o) { o.State = OrderState.Done; o.Why = "done"; }

        public IEnumerable<BmOrder> Ready => Orders.Where(o => o.State == OrderState.Ready);
    }
}