using YLErp.DBModels.Enums;
using YLErp.Modules.SwapModule;
using YLErp.Modules.SwapModule.Accrual;
using YLErp.Modules.SwapModule.Penalty;

namespace UnitTestProject.Modules.SwapModule.Penalty
{
    /// <summary>
    /// EQD-6977 罚息冻结利率解析契约测试。
    /// 规则（需求 2.2.2）：冻结为「最后一个重置区间」定盘；终止日为重置日也取上一区间。
    /// </summary>
    [TestClass]
    public class PenaltyLegRateResolverTest
    {
        private const decimal Spread = 0.05m; // +500bp
        private static readonly DateTime UnwindDate = new(2026, 8, 25);

        private static swap_position CreateFloatPosition(int interestRule = 0)
            => new()
            {
                id = 1001, SwapTradeId = 1, PosiDirection = 0,
                InterestDirection = (int)SwapDirectionEnum.支付,
                InterestMode = (int)InterestModeEnum.标的期初全价,
                InterestRateDefault = Spread,
                PosiStartDate = new DateTime(2026, 7, 31),
                interest_rest_days = 7, interest_rule = interestRule,
                FloatRateUnderlyingCode = "FR007",
                FloatRate = 0.0185m
            };

        [TestMethod]
        public void 浮动腿_preEod快照优先_重置日下午仍取上一区间()
        {
            // 8/25 为重置日且下午已出新价的边缘场景：preEod.FloatRate（昨日区间定盘）仍优先，
            // 解析器不做任何取价——「终止日取上一区间」由快照语义天然覆盖。
            var p = CreateFloatPosition();
            var rate = PenaltyLegRateResolver.ResolveFrozenRate(
                p, spread: Spread, preEodFloatRate: 0.0210m,
                unwindDate: UnwindDate, tryGetFixing: _ => throw new AssertFailedException("preEod 在场时不应取价"));

            Assert.AreEqual(Spread + 0.0210m, rate.AllInRate, "冻结 all-in = 利差 + 上一区间定盘");
        }

        [TestMethod]
        public void 浮动腿_无preEod_按前一营业日取价日取定盘()
        {
            var p = CreateFloatPosition(interestRule: 0); // 当前营业日规则
            DateTime? askedDate = null;
            var rate = PenaltyLegRateResolver.ResolveFrozenRate(
                p, spread: Spread, preEodFloatRate: null,
                unwindDate: UnwindDate,
                tryGetFixing: d => { askedDate = d; return 0.0195m; });

            Assert.AreEqual(new DateTime(2026, 8, 24), askedDate, "取价日 = GetFixingDate(8/24, rule=0)");
            Assert.AreEqual(Spread + 0.0195m, rate.AllInRate);
        }

        [TestMethod]
        public void 浮动腿_无preEod_缺价抛异常()
        {
            var p = CreateFloatPosition();
            Assert.ThrowsException<Exception>(() =>
                PenaltyLegRateResolver.ResolveFrozenRate(
                    p, spread: Spread, preEodFloatRate: null,
                    unwindDate: UnwindDate, tryGetFixing: _ => null));
        }

        [TestMethod]
        public void 固定腿_不取价_直接固定利率()
        {
            var p = CreateFloatPosition();
            p.FloatRateUnderlyingCode = null;

            var rate = PenaltyLegRateResolver.ResolveFrozenRate(
                p, spread: Spread, preEodFloatRate: null,
                unwindDate: UnwindDate, tryGetFixing: _ => throw new AssertFailedException("固定腿不应取价"));

            Assert.AreEqual(Spread, rate.AllInRate);
        }
    }
}