ScadaBridge/tests/ZB.MOM.WW.ScadaBridge.CentralUI.Tests/Pages/DashboardStateTests.cs

using Bunit;
using Microsoft.Extensions.DependencyInjection;
using NSubstitute;
using ZB.MOM.WW.ScadaBridge.Commons.Entities.Sites;
using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Repositories;
using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Security;
using ZB.MOM.WW.ScadaBridge.Commons.Types.Templates;
using DashboardPage = ZB.MOM.WW.ScadaBridge.CentralUI.Components.Pages.Dashboard;

namespace ZB.MOM.WW.ScadaBridge.CentralUI.Tests.Pages;

/// <summary>Dashboard facts distinguish independent failures, loading and known zero.</summary>
public class DashboardStateTests : BunitContext
{
    private readonly ISiteRepository _sites = Substitute.For<ISiteRepository>();
    private readonly ITemplateEngineRepository _templates = Substitute.For<ITemplateEngineRepository>();
    private readonly IInboundApiKeyAdmin _keys = Substitute.For<IInboundApiKeyAdmin>();
    /// <summary>Registers deterministic read-only dependencies and a signed-in fixture.</summary>
    public DashboardStateTests()
    {
        this.AddAuthorization().SetAuthorized("fixture");
        _sites.GetAllSitesAsync().Returns(Task.FromResult<IReadOnlyList<Site>>([new("A", "a"), new("B", "b")]));
        _sites.GetAllDataConnectionsAsync().Returns(Task.FromResult<IReadOnlyList<DataConnection>>([new("Link", "OpcUa", 1)]));
        _templates.GetTemplateStubsAsync().Returns(Task.FromResult<IReadOnlyList<TemplateStub>>([
            new(1,"A",null,null,false,null), new(2,"B",null,null,false,null), new(3,"C",null,null,false,null)]));
        _keys.ListAsync().Returns(Task.FromResult<IReadOnlyList<InboundApiKeyInfo>>([]));
        Services.AddSingleton(_sites); Services.AddSingleton(_templates); Services.AddSingleton(_keys);
    }
    /// <summary>Each read failure leaves the other facts intact and is never a false zero.</summary>
    [Theory]
    [InlineData("Sites configured")]
    [InlineData("Data connections configured")]
    [InlineData("Templates")]
    [InlineData("API keys")]
    public void CountFailure_DoesNotEraseOtherFactsOrRenderZero(string label)
    {
        if(label=="Sites configured")_sites.GetAllSitesAsync().Returns(Task.FromException<IReadOnlyList<Site>>(new Exception("local failure")));
        if(label=="Data connections configured")_sites.GetAllDataConnectionsAsync().Returns(Task.FromException<IReadOnlyList<DataConnection>>(new Exception("local failure")));
        if(label=="Templates")_templates.GetTemplateStubsAsync().Returns(Task.FromException<IReadOnlyList<TemplateStub>>(new Exception("local failure")));
        if(label=="API keys")_keys.ListAsync().Returns(Task.FromException<IReadOnlyList<InboundApiKeyInfo>>(new Exception("local failure")));
        var cut=Render<DashboardPage>();
        var facts=new Dictionary<string,string>{{"Sites configured","2"},{"Data connections configured","1"},{"Templates","3"},{"API keys","0"}};
        foreach(var (name,count) in facts)
        {
            var fact=cut.Find("[role=region][aria-label='"+name+"']");
            Assert.Contains(name==label?"Unavailable":count,fact.TextContent);
            if(name==label)
            {
                Assert.Contains("Retry "+name,fact.TextContent);
                Assert.DoesNotContain("0",fact.TextContent);
            }
        }
    }
    /// <summary>Only a failed API count is retried, and a real zero is displayed after success.</summary>
    [Fact]
    public void RetryFailure_PreservesSuccessfulFactsAndCanRecoverToZero()
    {
        _keys.ListAsync().Returns(Task.FromException<IReadOnlyList<InboundApiKeyInfo>>(new Exception("local failure")));
        var cut=Render<DashboardPage>();
        Assert.Contains("Unavailable",cut.Find("[aria-label='API keys']").TextContent);
        _keys.ListAsync().Returns(Task.FromResult<IReadOnlyList<InboundApiKeyInfo>>([]));
        cut.Find("[aria-label='API keys'] button").Click();
        Assert.Contains("0",cut.Find("[aria-label='API keys']").TextContent);
        Assert.DoesNotContain("Unavailable",cut.Markup);
        _sites.Received(1).GetAllSitesAsync(); _sites.Received(1).GetAllDataConnectionsAsync(); _templates.Received(1).GetTemplateStubsAsync();
    }
    /// <summary>Early retries share the initial-read gate and duplicate retries remain single-flight.</summary>
    [Fact]
    public async Task RetryDuringNextRead_WaitsWithoutOverlapAndCoalescesDuplicateTarget()
    {
        var connectionRead = new TaskCompletionSource<IReadOnlyList<DataConnection>>(TaskCreationOptions.RunContinuationsAsynchronously);
        _sites.GetAllSitesAsync().Returns(Task.FromException<IReadOnlyList<Site>>(new Exception("local failure")),
            Task.FromResult<IReadOnlyList<Site>>([new("Recovered", "recovered")]));
        _sites.GetAllDataConnectionsAsync().Returns(connectionRead.Task);
        var cut = Render<DashboardPage>();
        Assert.Contains("Unavailable", cut.Find("[aria-label='Sites configured']").TextContent);
        Assert.Contains("Loading", cut.Find("[aria-label='Data connections configured']").TextContent);
        // Model two already-dispatched retries without relying on a stale DOM node.
        var retry = typeof(DashboardPage).GetMethod("LoadSites", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic)!;
        Task first = null!, second = null!;
        await cut.InvokeAsync(() =>
        {
            first = (Task)retry.Invoke(cut.Instance, null)!;
            second = (Task)retry.Invoke(cut.Instance, null)!;
        });
        Assert.Equal(1, _sites.ReceivedCalls().Count(c => c.GetMethodInfo().Name == nameof(ISiteRepository.GetAllSitesAsync)));
        Assert.False(first.IsCompleted);
        await cut.InvokeAsync(() => connectionRead.SetResult([new("Link", "OpcUa", 1)]));
        await Task.WhenAll(first, second);
        cut.WaitForAssertion(() => Assert.Contains("1", cut.Find("[aria-label='Sites configured']").TextContent));
        Assert.Equal(2, _sites.ReceivedCalls().Count(c => c.GetMethodInfo().Name == nameof(ISiteRepository.GetAllSitesAsync)));
        Assert.Equal(1, _sites.ReceivedCalls().Count(c => c.GetMethodInfo().Name == nameof(ISiteRepository.GetAllDataConnectionsAsync)));
    }

    /// <summary>An outstanding read remains loading while already loaded facts are available.</summary>
    [Fact]
    public async Task DelayedRead_RemainsLoadingUntilKnownZeroArrives()
    {
        var pending=new TaskCompletionSource<IReadOnlyList<InboundApiKeyInfo>>(TaskCreationOptions.RunContinuationsAsynchronously);
        _keys.ListAsync().Returns(pending.Task);
        var cut=Render<DashboardPage>();
        Assert.Contains("Loading",cut.Find("[aria-label='API keys']").TextContent);
        Assert.Contains("2",cut.Find("[aria-label='Sites configured']").TextContent);
        await cut.InvokeAsync(()=>pending.SetResult([]));
        cut.WaitForAssertion(()=>Assert.Contains("0",cut.Find("[aria-label='API keys']").TextContent));
        Assert.DoesNotContain("Loading",cut.Find("[aria-label='API keys']").TextContent);
    }
}