namespace ZB.MOM.WW.ScadaBridge.HealthMonitoring.Tests;

/// <summary>
/// Deferred-work register row 73 — <c>SiteHealthReport.StartupReconcilerActive</c> surfaces
/// whether a site node spawned its <c>SiteReconciliationActor</c> at boot.
/// </summary>
/// <remarks>
/// The skip used to be a single boot Warning and nothing else, so a node that lost its whole
/// self-heal path went on reporting itself perfectly healthy. The field is tri-state and the
/// three cases must stay distinct: null = not reported (central self-report, or a pre-row-73
/// site build), true = running, false = skipped because no <c>IDeploymentConfigFetcher</c>
/// was available. Collapsing null into false would badge every site the moment central is
/// upgraded ahead of them.
/// </remarks>
public class StartupReconcilerHealthFieldTests
{
    [Fact]
    public void CollectReport_NeverTold_LeavesTheFieldNull()
    {
        // "Not reported" — NOT "the reconciler is missing". This is the state of central's
        // own self-report and of every test host that never calls the setter.
        var collector = new SiteHealthCollector();

        var report = collector.CollectReport("TestSite");

        Assert.Null(report.StartupReconcilerActive);
    }

    [Fact]
    public void CollectReport_ReconcilerSpawned_ReportsTrue()
    {
        var collector = new SiteHealthCollector();

        collector.SetStartupReconcilerActive(true);

        Assert.True(collector.CollectReport("TestSite").StartupReconcilerActive);
    }

    [Fact]
    public void CollectReport_ReconcilerSkipped_ReportsFalse_NotNull()
    {
        // The case the row exists for: false must be distinguishable from "not reported",
        // because false is what central badges.
        var collector = new SiteHealthCollector();

        collector.SetStartupReconcilerActive(false);

        var report = collector.CollectReport("TestSite");
        Assert.NotNull(report.StartupReconcilerActive);
        Assert.False(report.StartupReconcilerActive);
    }

    [Fact]
    public void CollectReport_IsPointInTime_NotDrainedOnCollect()
    {
        // A latched boot fact, not a per-interval counter: every subsequent report must
        // carry it, or the badge would flicker off after the first report.
        var collector = new SiteHealthCollector();
        collector.SetStartupReconcilerActive(false);

        collector.CollectReport("TestSite");
        var second = collector.CollectReport("TestSite");

        Assert.False(second.StartupReconcilerActive);
    }

    [Fact]
    public void SetStartupReconcilerActive_IsNotWriteOnce()
    {
        // Nothing in the Host calls this twice today, but a latch that silently ignored a
        // correction would be a nasty way to find that out.
        var collector = new SiteHealthCollector();

        collector.SetStartupReconcilerActive(false);
        collector.SetStartupReconcilerActive(true);

        Assert.True(collector.CollectReport("TestSite").StartupReconcilerActive);
    }
}