using System.Collections;
using System.Reflection;
using Stardust.Data.Monitors;
using Stardust.Server.Services;
using Xunit;

namespace ServerTest.Services;

/// <summary>追踪统计服务单元测试。验证热门窗口门控、内存查询与分层周期的关键行为</summary>
public class TraceStatServiceTests
{
    /// <summary>创建关闭定时器的统计服务，避免测试期间触发后台任务与数据库访问</summary>
    private static TraceStatService CreateService() => new(null)
    {
        FlowPeriod = 0,
        BatchPeriod = 0,
    };

    private static TraceData CreateTrace(Int32 appId, String name)
    {
        var now = DateTime.Now;
        return new TraceData
        {
            AppId = appId,
            Name = name,
            StatDate = now.Date,
            StatHour = now.Date.AddHours(now.Hour),
            StatMinute = now.Date.AddHours(now.Hour).AddMinutes(now.Minute / 5 * 5),
        };
    }

    private static Object GetField(Object target, String name)
    {
        var field = typeof(TraceStatService).GetField(name, BindingFlags.NonPublic | BindingFlags.Instance);
        Assert.NotNull(field);

        return field.GetValue(target);
    }

    /// <summary>非热门应用不登记小时/日包，只保留分钟包与当天活跃登记，交由巡检按周期重算</summary>
    [Fact]
    [Trait("Category", "Monitor")]
    public void Add_NonHotApp_OnlyMinuteBag()
    {
        var svc = CreateService();
        svc.Add([CreateTrace(101, "api/test")]);

        Assert.Empty((IEnumerable)GetField(svc, "_bagDay"));
        Assert.Empty((IEnumerable)GetField(svc, "_bagHour"));
        Assert.NotEmpty((IEnumerable)GetField(svc, "_bagMinute"));
        Assert.NotEmpty((IEnumerable)GetField(svc, "_dayActive"));
    }

    /// <summary>热门应用保持事件驱动重算，上报数据时登记小时与日包</summary>
    [Fact]
    [Trait("Category", "Monitor")]
    public void Add_HotApp_RegistersAllBags()
    {
        var svc = CreateService();

        // 直接注入热窗口标记，避免 SetHotApp 内部的手动重算登记影响断言
        ((IDictionary)GetField(svc, "_hotApps"))[102] = DateTime.Now;

        svc.Add([CreateTrace(102, "api/test")]);

        Assert.NotEmpty((IEnumerable)GetField(svc, "_bagDay"));
        Assert.NotEmpty((IEnumerable)GetField(svc, "_bagHour"));
        Assert.NotEmpty((IEnumerable)GetField(svc, "_bagMinute"));
    }

    /// <summary>设置热门应用时立即登记重算，保证打开监控页面后分钟槽、小时与当天统计即时刷新</summary>
    [Fact]
    [Trait("Category", "Monitor")]
    public void SetHotApp_RegistersRecompute()
    {
        var svc = CreateService();
        svc.SetHotApp(104);

        Assert.True(((IDictionary)GetField(svc, "_hotApps")).Contains(104));
        Assert.NotEmpty((IEnumerable)GetField(svc, "_bagDay"));
        Assert.NotEmpty((IEnumerable)GetField(svc, "_bagHour"));
        Assert.NotEmpty((IEnumerable)GetField(svc, "_bagMinute"));
    }

    /// <summary>手动补算（如网页重新统计）不受热门门控影响，始终登记小时/日包</summary>
    [Fact]
    [Trait("Category", "Monitor")]
    public void AddManually_NonHotApp_RegistersAllBags()
    {
        var svc = CreateService();
        svc.Add(103, DateTime.Now);

        Assert.NotEmpty((IEnumerable)GetField(svc, "_bagDay"));
        Assert.NotEmpty((IEnumerable)GetField(svc, "_bagHour"));
        Assert.NotEmpty((IEnumerable)GetField(svc, "_bagMinute"));
    }

    /// <summary>内存查询与紧急落盘在队列未初始化时安全返回，不抛异常</summary>
    [Fact]
    [Trait("Category", "Monitor")]
    public void LiveQuery_And_Flush_NullSafe()
    {
        var svc = CreateService();

        Assert.Null(svc.GetLiveMinute(1, 2, DateTime.Now));
        Assert.Null(svc.GetLiveAppMinute(1, DateTime.Now));

        svc.TriggerFlush();
        svc.Flush();
    }

    /// <summary>周期默认值。落盘放宽到300秒，巡检600秒（活跃窗口为巡检周期3倍）</summary>
    [Fact]
    [Trait("Category", "Monitor")]
    public void Defaults_MonitorPeriods()
    {
        var svc = new TraceStatService(null);

        Assert.Equal(300, svc.SavePeriod);
        Assert.Equal(600, svc.PatrolPeriod);
    }

    /// <summary>告警辅助函数：错误率现场计算；内存值优先于数据库值，数据库值更新时取数据库值</summary>
    [Fact]
    [Trait("Category", "Monitor")]
    public void AlarmHelpers_CalcErrorRate_And_SelectLatest()
    {
        var alarmType = typeof(AlarmService);
        var calc = alarmType.GetMethod("CalcErrorRate", BindingFlags.NonPublic | BindingFlags.Static);
        Assert.NotNull(calc);
        Assert.Equal(0D, (Double)calc.Invoke(null, [0L, 5L]));
        Assert.Equal(0.1D, (Double)calc.Invoke(null, [100L, 10L]));

        var select = alarmType.GetMethod("SelectLatest", BindingFlags.NonPublic | BindingFlags.Static);
        Assert.NotNull(select);

        var live = new TraceMinuteStat { Total = 100, Errors = 10 };
        var db = new TraceMinuteStat { Total = 50, Errors = 5 };

        Assert.Same(live, select.Invoke(null, [live, db]));
        Assert.Same(live, select.Invoke(null, [live, null]));
        Assert.Same(db, select.Invoke(null, [null, db]));

        // 数据库值更新（错误数更大）时取数据库值
        var db2 = new TraceMinuteStat { Total = 200, Errors = 20 };
        Assert.Same(db2, select.Invoke(null, [live, db2]));
    }
}