using Newtonsoft.Json;
using YLErp.DBModels;
using YLErp.DBModels.Enums;

namespace YLErp.Modules.SwapModule
{
    /// <summary>
    /// 复利 consumedInterest 扣除 - 合成单元测试
    /// ============================================================================
    /// 验证 c6adb3bb 的修复：复利路径平仓时，扣除历史已通过互换结出的利息。
    ///
    /// 核心场景：
    ///   一笔复利交易，N天后做了互换结算（已结N天利息），之后再平仓。
    ///   平仓默认值应 = 从头算的全程利息 - 已结利息（consumedInterest）。
    ///   如果不扣（bug），平仓默认值 = 全程利息（偏大）。
    ///   如果多扣（之前单利的错误），平仓默认值 = 0或负（偏小）。
    ///
    /// 模仿 GetInterestsUnitTest_T0 的 StubSwapDealService 模式。
    /// ============================================================================
    [TestClass]
    public class ConsumedInterestScenarioTest
    {
        #region 常量

        private const decimal Principal = 1000m;
        private const decimal FixedRate = 0.0025m; // 加点利率
        private const double FloatRate = 0.001;   // FR007
        private const decimal TotalRate = FixedRate + (decimal)FloatRate; // 综合年化利率
        private const int AnnualDays = 365;
        private const int ResetPeriod = 3;
        private static readonly DateTime StartDate = new(2026, 4, 27);
        private static readonly DateTime ExerciseDate = new(2027, 4, 27);

        #endregion

        #region Stub：内存 SwapDealService + consumedInterest 注入

        /// <summary>
        /// 继承 SwapDealService，override 两个虚方法：
        /// - TryGetFloatRate：返回固定浮动利率（不连库）
        /// - GetConsumedInterest：返回注入的历史已结利息（不连库）
        /// </summary>
        private sealed class StubSwapDealService : SwapDealService
        {
            private readonly double _floatRate;
            private readonly decimal _consumedInterest;

            public StubSwapDealService(OptUserInfo optUser, double floatRate, decimal consumedInterest)
                : base(optUser)
            {
                _floatRate = floatRate;
                _consumedInterest = consumedInterest;
            }

            protected override bool TryGetFloatRate(DateTime valueDate, string underlyingCode, out double rate)
            {
                rate = _floatRate;
                return true; // 始终返回固定浮动利率
            }

            public override decimal GetConsumedInterest(int tradeId, long positionId, DateTime beforeDate)
            {
                return _consumedInterest; // 返回注入值
            }
        }

        #endregion

        #region 数据构建

        private static trade CreateTrade()
        {
            return new trade
            {
                id = 1, TradeNumber = "UT-CONSUMED-001", ClientId = 999998,
                TradeType = "收益互换", TradeDate = StartDate, StartDate = StartDate,
                ExerciseDate = ExerciseDate, TradeStatus = "确认成交", ValidState = "Valid",
                StructureType = "单标的", QuoteCurrency = "CNY", SettlementCurrency = "CNY",
                trade_extend = new trade_extend
                {
                    TradeId = 1,
                    ExtendJson = JsonConvert.SerializeObject(new TradeExtendJson
                    {
                        AnnualDays = AnnualDays,
                        InterestCalcMode = "10", // 算头不算尾
                        SettlementRules = 0
                    })
                }
            };
        }

        private static swap_position CreateCompoundPosition()
        {
            return new swap_position
            {
                id = 1001, SwapTradeId = 1, PositionType = (int)PositionTypeFlag.Unknown,
                InterestDirection = (int)SwapDirectionEnum.收取, InterestMode = (int)InterestModeEnum.标的期初全价,
                InterestRateDefault = FixedRate, InterestPrincipalFix = Principal,
                PosiStartDate = StartDate, PosiMatuirityDate = ExerciseDate,
                IsInitial = true, Invalid = false, InterestType = (int)InterestTypeEnum.复利,
                IsAnnualized = true, interest_rest_days = ResetPeriod, interest_rule = 0,
                FloatRateUnderlyingCode = "FR007",
                InterestSwapInterval = JsonConvert.SerializeObject(new List<IntervalModel>
                {
                    new IntervalModel { Date = ExerciseDate, Rate = FixedRate, Settlement = 0 }
                })
            };
        }

        /// <summary>调用 GetInterests 获取复利利息（统一调用入口，settment:false走盘中平仓路径）</summary>
        private static swap_flow_event CalcCompoundUnwind(StubSwapDealService service, DateTime unwindDate)
        {
            var td = CreateTrade();
            var position = CreateCompoundPosition();
            var interests = service.GetInterests(td, td.trade_extend, unwindDate, unwindDate,
                new List<eod_swap_position>(), new List<swap_position> { position },
                Principal, Principal, Principal, Principal, 1m,
                (int)SwapEventTypeEnum.平仓, false, false, Principal, Principal,
                add: false, settment: false, newCalcLast: false);
            Assert.AreEqual(1, interests.Count);
            return interests[0];
        }

        private static StubSwapDealService CreateService(decimal consumedInterest)
        {
            return new StubSwapDealService(
                new OptUserInfo(0, nameof(ConsumedInterestScenarioTest), OptUserFrom.UnitTest),
                FloatRate, consumedInterest);
        }

        private static void AssertDecimal(decimal expected, decimal actual, string message = "")
        {
            var tolerance = 1m / (decimal)Math.Pow(10, ConsGlobal.PriceRound - 2);
            Assert.IsTrue(Math.Abs(expected - actual) <= tolerance,
                $"{message} Expected: {expected}, Actual: {actual}, Diff: {expected - actual}");
        }

        #endregion

        // ================================================================
        // 场景1：基线——无历史互换（consumedInterest=0），拿到全程复利利息
        // ================================================================

        /// <summary>
        /// [CI_001] 无历史互换结清，复利平仓利息基线
        /// ---------------------------------------------------------------
        /// consumedInterest=0，平仓利息=从头算的全程复利利息。
        /// 此值作为后续场景的参照基线（避免独立复利计算的精度匹配问题）。
        /// ---------------------------------------------------------------
        /// </summary>
        [TestMethod]
        public void CI_001_无历史互换平仓利息基线()
        {
            var unwindDate = StartDate.AddDays(10); // 4/27+10=5/7，算头不算尾约9天
            var service = CreateService(consumedInterest: 0m);
            var result = CalcCompoundUnwind(service, unwindDate);

            Assert.IsTrue(result.InterestAmount > 0, "无互换时复利利息应>0");
            Console.WriteLine($"基线(consumedInterest=0): InterestAmount={result.InterestAmount:F6}");
        }

        // ================================================================
        // 场景2：consumedInterest>0 → 平仓利息=基线-consumedInterest
        // ================================================================

        /// <summary>
        /// [CI_002] 注入consumedInterest后，平仓利息应=基线-consumedInterest
        /// ---------------------------------------------------------------
        /// 用相同参数但注入不同的consumedInterest，验证：
        ///   利息(有consumed) = 利息(无consumed) - consumedInterest
        /// 这是验证cs:793 `interest -= consumedInterest` 的直接方式。
        /// ---------------------------------------------------------------
        /// </summary>
        [TestMethod]
        public void CI_002_consumedInterest正确扣除()
        {
            var unwindDate = StartDate.AddDays(10);

            // 基线：consumedInterest=0
            var baselineResult = CalcCompoundUnwind(CreateService(0m), unwindDate);
            decimal baseline = baselineResult.InterestAmount;

            // 注入consumedInterest=基线的50%
            decimal consumed = baseline * 0.5m;
            var consumedResult = CalcCompoundUnwind(CreateService(consumed), unwindDate);

            // 期望 = 基线 - consumed
            decimal expected = baseline - consumed;
            AssertDecimal(expected, consumedResult.InterestAmount,
                $"平仓利息应=基线({baseline:F6})-consumed({consumed:F6})={expected:F6}");
            Console.WriteLine($"基线={baseline:F6}, consumed={consumed:F6}");
            Console.WriteLine($"平仓利息={consumedResult.InterestAmount:F6}, 期望={expected:F6} ✅");
        }

        // ================================================================
        // 场景3：守恒——consumed + 平仓利息 = 基线
        // ================================================================

        /// <summary>
        /// [CI_003] 守恒：consumedInterest + 平仓利息(扣后) = 基线(无consumed)
        /// ---------------------------------------------------------------
        /// 注入任意consumedInterest，验证 consumed + 利息 = 基线。
        /// 如果扣多了（守恒不成立→合计<基线）或没扣（合计>基线），测试失败。
        /// ---------------------------------------------------------------
        /// </summary>
        [TestMethod]
        public void CI_003_守恒consumed加平仓等于基线()
        {
            var unwindDate = StartDate.AddDays(10);
            decimal baseline = CalcCompoundUnwind(CreateService(0m), unwindDate).InterestAmount;

            // 注入不同的consumedInterest验证守恒
            decimal[] testConsumed = { baseline * 0.3m, baseline * 0.5m, baseline * 0.8m };
            foreach (var consumed in testConsumed)
            {
                var result = CalcCompoundUnwind(CreateService(consumed), unwindDate);
                decimal actual = consumed + result.InterestAmount;
                AssertDecimal(baseline, actual,
                    $"守恒: consumed({consumed:F6}) + 利息({result.InterestAmount:F6}) = {actual:F6} 应=基线({baseline:F6})");
                Console.WriteLine($"consumed={consumed:F6} + 利息={result.InterestAmount:F6} = {actual:F6} = 基线{baseline:F6} ✅");
            }
        }

        // ================================================================
        // 场景4：consumedInterest=全部基线 → 平仓利息≈0，不为负
        // ================================================================

        /// <summary>
        /// [CI_004] 全部利息已结清(consumedInterest=基线)，再平仓利息应≈0
        /// ---------------------------------------------------------------
        /// 验证不会扣过头变成负数（之前单利双重扣减的错误）。
        /// 复利从头算全程 - 全程consumed = 0，应精确归零或微小正值。
        /// ---------------------------------------------------------------
        /// </summary>
        [TestMethod]
        public void CI_004_全部已结再平仓利息不为负()
        {
            var unwindDate = StartDate.AddDays(10);
            decimal baseline = CalcCompoundUnwind(CreateService(0m), unwindDate).InterestAmount;

            // consumedInterest=全部基线
            var result = CalcCompoundUnwind(CreateService(baseline), unwindDate);

            Console.WriteLine($"基线={baseline:F6}, consumed={baseline:F6}, 平仓利息={result.InterestAmount:F6}");
            Assert.IsTrue(result.InterestAmount >= -0.01m,
                $"全部已结再平仓利息应≈0（实际={result.InterestAmount:F6}），不应为负");
            Console.WriteLine($"全部已结平仓≈0（{result.InterestAmount:F6}）✅");
        }
    }
}