using YLErp.Modules.DataProviderModule;

namespace YLErp.Modules.DataProviderModule
{
    /// <summary>
    /// Fr007FixingCache 快照缓存行为契约（纯内存，不连库；Loader/时钟均为注入接缝）：
    /// ① 首次访问批量预载、命中 O(1)；② miss 不进快照（负缓存防线——当日发布前 miss、发布后须能查到）；
    /// ③ 写侧版本失效：Invalidate 后立即重载取到新值（不等 TTL）；④ TTL 过期自动重载（直改库兜底）；
    /// ⑤ TTL 窗口内无写入不重载（零查询稳态）。
    /// </summary>
    [TestClass]
    public class Fr007FixingCacheTest
    {
        private static readonly DateTime D1 = new(2026, 7, 6);
        private static readonly DateTime D2 = new(2026, 7, 13);
        private int _loadCount;
        private Dictionary<DateTime, double> _market;

        [TestInitialize]
        public void Init()
        {
            _loadCount = 0;
            _market = new Dictionary<DateTime, double> { [D1] = 0.0142, [D2] = 0.01425 };
            Fr007FixingCache.ResetForTest();
            Fr007FixingCache.LoadSnapshot = () => { _loadCount++; return new Dictionary<DateTime, double>(_market); };
        }

        [TestCleanup]
        public void Cleanup() => Fr007FixingCache.ResetForTest();

        private static void AdvanceClock(long ticks) => Fr007FixingCache.NowTicks = () => ticks;

        [TestMethod]
        public void 首次访问预载并命中()
        {
            Fr007FixingCache.NowTicks = () => 1_000_000L;
            Assert.IsTrue(Fr007FixingCache.TryGet(D1, out var p1), "预载后历史定盘应命中");
            Assert.AreEqual(0.0142, p1, 1e-12);
            Assert.AreEqual(1, _loadCount, "首次访问恰好装载一次");
            Assert.IsTrue(Fr007FixingCache.TryGet(D2, out var p2), "同快照内多次命中");
            Assert.AreEqual(0.01425, p2, 1e-12);
            Assert.AreEqual(1, _loadCount, "命中不应重复装载");
        }

        [TestMethod]
        public void miss不进快照_当日新发布经直查兜底后TTL内可见()
        {
            Fr007FixingCache.NowTicks = () => 1_000_000L;
            var today = new DateTime(2026, 8, 18);
            Assert.IsFalse(Fr007FixingCache.TryGet(today, out _), "快照无该行应 miss（调用方直查库兜底）");
            Assert.AreEqual(1, _loadCount);

            // 直查库发现了新发布的当日行 → 写侧失效（SwapFlowService 场景）→ 重载后可见
            _market[today] = 0.0143;
            Fr007FixingCache.Invalidate();
            Assert.IsTrue(Fr007FixingCache.TryGet(today, out var p), "写侧失效重载后当日行应可见");
            Assert.AreEqual(0.0143, p, 1e-12);
            Assert.AreEqual(2, _loadCount);
        }

        [TestMethod]
        public void 写侧失效立即重载取到修正值_不等TTL()
        {
            Fr007FixingCache.NowTicks = () => 1_000_000L;
            Fr007FixingCache.TryGet(D1, out _);
            Assert.AreEqual(1, _loadCount);

            _market[D1] = 0.0150; // 界面修正错价
            Fr007FixingCache.Invalidate();

            // 时钟只走了 1 tick（远小于 TTL），仍必须重载
            Fr007FixingCache.NowTicks = () => 1_000_001L;
            Assert.IsTrue(Fr007FixingCache.TryGet(D1, out var p), "修正后仍应命中");
            Assert.AreEqual(0.0150, p, 1e-12, "TTL 未到也必须看到写侧修正值");
            Assert.AreEqual(2, _loadCount, "版本失效应立即触发重载");
        }

        [TestMethod]
        public void TTL过期自动重载_直改库兜底()
        {
            Fr007FixingCache.NowTicks = () => 1_000_000L;
            Fr007FixingCache.TryGet(D1, out _);
            Assert.AreEqual(1, _loadCount);

            _market[D1] = 0.0160; // 直改库（无 Invalidate）
            Fr007FixingCache.NowTicks = () => 1_000_000L + TimeSpan.FromMinutes(1).Ticks + 1; // TTL+1 tick

            Assert.IsTrue(Fr007FixingCache.TryGet(D1, out var p));
            Assert.AreEqual(0.0160, p, 1e-12, "TTL 过期后应重载并看到直改库的新值");
            Assert.AreEqual(2, _loadCount);
        }

        [TestMethod]
        public void TTL窗口内无写入零重载()
        {
            Fr007FixingCache.NowTicks = () => 1_000_000L;
            Fr007FixingCache.TryGet(D1, out _);

            Fr007FixingCache.NowTicks = () => 1_000_000L + TimeSpan.FromMinutes(1).Ticks - 1; // TTL-1 tick：稳态窗口
            for (int i = 0; i < 10; i++) Fr007FixingCache.TryGet(D1, out _);

            Assert.AreEqual(1, _loadCount, "稳态窗口内多次读取零重载（零查询）");
        }

        [TestMethod]
        public void TTL过期重载失败_保留旧快照不抛_且窗口内不重试()
        {
            Fr007FixingCache.NowTicks = () => 1_000_000L;
            Assert.IsTrue(Fr007FixingCache.TryGet(D1, out _), "先成功装载一次");
            Assert.AreEqual(1, _loadCount);

            Fr007FixingCache.LoadSnapshot = () => { _loadCount++; throw new InvalidOperationException("db down"); };
            Fr007FixingCache.NowTicks = () => 1_000_000L + TimeSpan.FromMinutes(1).Ticks + 1; // TTL 过期 → 触发重载 → 失败

            // 不抛：历史定盘不可变，命中继续走旧快照（异常会直接 fail 本用例）
            Assert.IsTrue(Fr007FixingCache.TryGet(D1, out var p), "重载失败应保留旧快照继续命中");
            Assert.AreEqual(0.0142, p, 1e-12, "旧快照值不变");
            Assert.AreEqual(2, _loadCount, "失败的重载尝试恰好一次");

            Fr007FixingCache.TryGet(D2, out _); // TTL 时钟已被重置：窗口内不再重试（防重试风暴）
            Assert.AreEqual(2, _loadCount, "失败后TTL窗口内不得反复重试全表SELECT");
        }

        [TestMethod]
        public void 首次装载失败_miss不抛_窗口内不重试()
        {
            Fr007FixingCache.LoadSnapshot = () => { _loadCount++; throw new InvalidOperationException("db down"); };
            Fr007FixingCache.NowTicks = () => 1_000_000L;

            Assert.IsFalse(Fr007FixingCache.TryGet(D1, out _), "装载失败=空快照miss（调用方直查库兜底，新数据该响仍响）");
            Assert.AreEqual(1, _loadCount);

            Fr007FixingCache.TryGet(D1, out _);
            Assert.AreEqual(1, _loadCount, "失败后TTL窗口内不重试");
        }
    }
}