ScadaBridge/tests/ZB.MOM.WW.ScadaBridge.SiteRuntime.Tests/Scripts/ScopeAccessorTests.cs

using ZB.MOM.WW.ScadaBridge.Commons.Types;
using ZB.MOM.WW.ScadaBridge.Commons.Types.Scripts;
using ZB.MOM.WW.ScadaBridge.SiteRuntime.Scripts;

namespace ZB.MOM.WW.ScadaBridge.SiteRuntime.Tests.Scripts;

/// <summary>
/// Phase 1 of the script-scope rollout: verify path arithmetic for the new
/// Attributes / Children / Parent accessors. The actor-mediated reads/writes
/// are exercised end-to-end in Phase 2 once flattening carries scope info.
/// </summary>
public class ScopeAccessorTests
{
    [Fact]
    public void Root_SelfPath_Empty()
    {
        Assert.Equal("", ScriptScope.Root.SelfPath);
        Assert.Null(ScriptScope.Root.ParentPath);
        Assert.False(ScriptScope.Root.HasParent);
    }

    [Fact]
    public void CompositionScope_HasParent()
    {
        var scope = new ScriptScope("TempSensor", "");
        Assert.True(scope.HasParent);
        Assert.Equal("", scope.ParentPath);
    }

    [Fact]
    public void AttributeAccessor_RootScope_ResolvesBareKey()
    {
        var acc = new AttributeAccessor(null!, "");
        Assert.Equal("Temperature", acc.Resolve("Temperature"));
    }

    [Fact]
    public void AttributeAccessor_ComposedScope_PrependsPath()
    {
        var acc = new AttributeAccessor(null!, "TempSensor");
        Assert.Equal("TempSensor.Temperature", acc.Resolve("Temperature"));
    }

    [Fact]
    public void AttributeAccessor_NestedScope_ChainsPath()
    {
        var acc = new AttributeAccessor(null!, "Motor.TempSensor");
        Assert.Equal("Motor.TempSensor.Temperature", acc.Resolve("Temperature"));
    }

    [Fact]
    public void CompositionAccessor_AttributesShareScope()
    {
        var comp = new CompositionAccessor(null!, "TempSensor");
        Assert.Equal("TempSensor", comp.Path);
        Assert.Equal("TempSensor", comp.Attributes.ScopePrefix);
    }

    [Fact]
    public void CompositionAccessor_ResolveScript_PrependsPath()
    {
        var comp = new CompositionAccessor(null!, "TempSensor");
        Assert.Equal("TempSensor.Sample", comp.ResolveScript("Sample"));
    }

    [Fact]
    public void CompositionAccessor_EmptyPath_LeavesScriptNameBare()
    {
        var comp = new CompositionAccessor(null!, "");
        Assert.Equal("Sample", comp.ResolveScript("Sample"));
    }

    [Fact]
    public void ChildrenAccessor_FromRoot_GivesUnpathedChild()
    {
        var children = new ChildrenAccessor(null!, "");
        var temp = children["TempSensor"];
        Assert.Equal("TempSensor", temp.Path);
    }

    [Fact]
    public void ChildrenAccessor_FromComposition_PrefixesChild()
    {
        var children = new ChildrenAccessor(null!, "Motor");
        var temp = children["TempSensor"];
        Assert.Equal("Motor.TempSensor", temp.Path);
    }

    // --- AttributeAccessor encoding contract ----------------------------------
    //
    // AttributeAccessor.this[key].set and SetAsync both route through
    // ScriptRuntimeContext.SetAttribute(name, encodedString), which requires
    // a live Akka IActorRef; ScriptRuntimeContext has no virtual members and
    // its constructor cannot be satisfied without a real ActorSystem, so a
    // full-round-trip unit test through the accessor+context is not viable
    // without a heavy Akka harness.
    //
    // Instead we test the encoding decision directly: AttributeAccessor is now
    // documented to delegate value serialisation to AttributeValueCodec.Encode.
    // These tests verify that contract at the codec level, which is exactly what
    // the fix makes the accessor invoke.

    [Fact]
    public void AttributeValueCodec_Encode_List_ProducesJsonArray()
    {
        // A List<string> must encode to a JSON array, not the garbage
        // "System.Collections.Generic.List`1[System.String]" that .ToString() produced.
        var list = new List<string> { "a", "b" };
        var encoded = AttributeValueCodec.Encode(list);
        Assert.Equal("[\"a\",\"b\"]", encoded);
    }

    [Fact]
    public void AttributeValueCodec_Encode_Scalar_PassesThrough()
    {
        // A plain string scalar must be returned unchanged (byte-identical to
        // the historical value?.ToString() path for strings).
        var encoded = AttributeValueCodec.Encode("x");
        Assert.Equal("x", encoded);
    }

    [Fact]
    public void AttributeValueCodec_Encode_Null_ReturnsNull()
    {
        // AttributeAccessor coalesces null → "" at the call site,
        // but the codec itself must return null for null input.
        Assert.Null(AttributeValueCodec.Encode(null));
    }

    [Fact]
    public void AttributeValueCodec_Encode_IntList_ProducesJsonArray()
    {
        // Integer list elements encode via InvariantCulture IFormattable.
        var list = new List<int> { 1, 2, 3 };
        var encoded = AttributeValueCodec.Encode(list);
        Assert.Equal("[\"1\",\"2\",\"3\"]", encoded);
    }
}