using System;
using IvfTl.ControlHost.Debug;
using IvfTl.ControlHost.Tests.Fakes;
using Xunit;
namespace IvfTl.ControlHost.Tests
{
    public class DebugSessionManagerTests
    {
        private DateTime _now = new DateTime(2026, 6, 23, 0, 0, 0);
        private (DebugSessionManager mgr, FakeGate gate) New(bool canAcquire = true)
        {
            var serial = new FakeSerial();
            var gate = new FakeGate(5, serial) { CanAcquire = canAcquire };
            var mgr = new DebugSessionManager(sn => gate, () => _now, ttlMs: 10000, log: _ => { });
            return (mgr, gate);
        }
        [Fact]
        public void Acquire_Returns_SessionId_And_Pauses()
        {
            var (mgr, gate) = New();
            var r = mgr.Acquire(5);
            Assert.True(r.Ok);
            Assert.False(string.IsNullOrEmpty((string)r.Result));
            Assert.True(gate.IsCapturePaused);
        }
        [Fact]
        public void Acquire_Busy_Returns_BUSY()
        {
            var (mgr, _) = New(canAcquire: false);
            var r = mgr.Acquire(5);
            Assert.False(r.Ok);
            Assert.Equal("BUSY", r.Code);
        }
        [Fact]
        public void Release_Disposes_Lease_And_Resumes()
        {
            var (mgr, gate) = New();
            string sid = (string)mgr.Acquire(5).Result;
            var r = mgr.Release(sid);
            Assert.True(r.Ok);
            Assert.True(gate.LastLease.Disposed);
        }
        [Fact]
        public void Release_Unknown_Session_Is_Idempotent_Ok()
        {
            var (mgr, _) = New();
            Assert.True(mgr.Release("not-a-session").Ok);
        }
        [Fact]
        public void Sweep_Reclaims_After_Ttl_And_Resumes()
        {
            var (mgr, gate) = New();
            string sid = (string)mgr.Acquire(5).Result;
            _now = _now.AddMilliseconds(11000);
            int reclaimed = mgr.SweepExpired();
            Assert.Equal(1, reclaimed);
            Assert.True(gate.LastLease.Disposed);
            Assert.False(gate.IsCapturePaused);
            Assert.Equal("SESSION_EXPIRED", mgr.Heartbeat(sid).Code);
        }
        [Fact]
        public void Heartbeat_Keeps_Session_Alive()
        {
            var (mgr, gate) = New();
            string sid = (string)mgr.Acquire(5).Result;
            _now = _now.AddMilliseconds(8000); mgr.Heartbeat(sid);
            _now = _now.AddMilliseconds(8000);
            Assert.Equal(0, mgr.SweepExpired());
            Assert.False(gate.LastLease.Disposed);
        }

        // ── Critical 并发修复:会话关闭(Release/Sweep)在 lease.Dispose 之前先触发 onSessionClosing 回调 ──
        // 装配时回调接到 calibMgr.StopAndWait(sid),先停标定并等当前孔跑完,之后才 Dispose lease、恢复采集,
        // 消除"标定后台线程操作已 Dispose 的 lease + 与已恢复的采集线程争同一硬件"的窗口。
        // 验证两点:① 回调被调且传入正确 sid;② 回调发生在 lease.Dispose 之前(用 FakeLease.Disposed 在回调里取快照)。

        private (DebugSessionManager mgr, FakeGate gate, System.Collections.Generic.List<(string sid, bool disposedAtCallback)> log)
            NewWithClosing()
        {
            var serial = new FakeSerial();
            var gate = new FakeGate(5, serial) { CanAcquire = true };
            var log = new System.Collections.Generic.List<(string, bool)>();
            // 回调里读 LastLease.Disposed:若回调真在 Dispose 之前调,这里应为 false。
            var mgr = new DebugSessionManager(sn => gate, () => _now, ttlMs: 10000, log: _ => { },
                onSessionClosing: sid => log.Add((sid, gate.LastLease.Disposed)));
            return (mgr, gate, log);
        }

        [Fact]
        public void Release_Invokes_OnSessionClosing_Before_Dispose()
        {
            var (mgr, gate, log) = NewWithClosing();
            string sid = (string)mgr.Acquire(5).Result;
            mgr.Release(sid);

            Assert.Single(log);
            Assert.Equal(sid, log[0].sid);
            Assert.False(log[0].disposedAtCallback);   // 回调时 lease 尚未 Dispose
            Assert.True(gate.LastLease.Disposed);       // 之后已 Dispose
        }

        [Fact]
        public void Sweep_Invokes_OnSessionClosing_Before_Dispose()
        {
            var (mgr, gate, log) = NewWithClosing();
            string sid = (string)mgr.Acquire(5).Result;
            _now = _now.AddMilliseconds(11000);
            int n = mgr.SweepExpired();

            Assert.Equal(1, n);
            Assert.Single(log);
            Assert.Equal(sid, log[0].sid);
            Assert.False(log[0].disposedAtCallback);   // 超时回收路径同样:回调先于 Dispose
            Assert.True(gate.LastLease.Disposed);
        }
    }
}