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

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

namespace Decentralized.Domain
{
    /// <summary>
    /// 一个链上地址：各币种余额，加上整个地址的污点额与成本（信用点等值）。
    /// 污点和成本按转出的价值比例随币走。
    /// </summary>
    public sealed class Wallet
    {
        public string Address;
        public Dictionary<string, double> Balances = new Dictionary<string, double>();
        /// <summary>污点额（信用点等值）。</summary>
        public double Taint;
        /// <summary>成本（信用点）：出金时只对超出成本的部分征税。</summary>
        public double Basis;
        /// <summary>被执法标记。</summary>
        public bool Flagged;

        /// <summary>买入记录：每种币买入的数量与花费（信用点等值），用来显示买入均价。卖出或转出时按比例减少。</summary>
        public Dictionary<string, double> BuyQty = new Dictionary<string, double>(), BuyCost = new Dictionary<string, double>();

        public void RecordBuy(string asset, double qty, double costCredits)
        {
            if (qty <= 0) return;
            BuyQty[asset] = (BuyQty.TryGetValue(asset, out var q) ? q : 0) + qty;
            BuyCost[asset] = (BuyCost.TryGetValue(asset, out var c) ? c : 0) + Math.Max(0, costCredits);
        }

        /// <summary>买入均价（信用点）；没有买入记录（例如全是挖出来的）返回 null。</summary>
        public double? AvgBuy(string asset) => BuyQty.TryGetValue(asset, out var q) && q > 1e-9 ? BuyCost[asset] / q : (double?)null;

        public double Get(string asset) => Balances.TryGetValue(asset, out var v) ? v : 0;

        public void Add(string asset, double amount)
        {
            if (amount == 0) return;
            if (amount < 0 && BuyQty.TryGetValue(asset, out var bq))
            {
                double before = Get(asset), keep = before > 1e-12 ? Math.Max(0, 1 + amount / before) : 0;
                BuyQty[asset] = bq * keep; BuyCost[asset] *= keep;
                if (BuyQty[asset] < 1e-9) { BuyQty.Remove(asset); BuyCost.Remove(asset); }
            }
            double v = Get(asset) + amount;
            if (v < -1e-9) throw new InvalidOperationException($"{Address}: {asset} 余额不足");
            if (Math.Abs(v) < 1e-12) Balances.Remove(asset);
            else Balances[asset] = v;
        }

        /// <summary>按价格表估值（信用点）。</summary>
        public double Value(Func<string, double> price) => Balances.Sum(kv => kv.Value * price(kv.Key));

        /// <summary>
        /// 转出：taint 和 basis 按转出价值占地址总价值的比例带走。Ponero 等不可追踪资产转入时，污点不随之进入目标地址。
        /// </summary>
        public static void Transfer(Wallet from, Wallet to, string asset, double amount, Func<string, double> price)
        {
            if (amount <= 0) return;
            double total = from.Value(price);
            double share = total > 0 ? Math.Min(1.0, amount * price(asset) / total) : 0;
            double taint = from.Taint * share, basis = from.Basis * share;
            from.Add(asset, -amount);
            from.Taint -= taint;
            from.Basis -= basis;
            to.Add(asset, amount);
            var spec = Assets.Get(asset);
            if (spec == null || spec.Traceable) to.Taint += taint;
            to.Basis += basis;
        }
    }
}