using ZB.MOM.WW.ScadaBridge.Commons.Types.Debugging;
using ZB.MOM.WW.ScadaBridge.ScriptAnalysis;

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

/// <summary>
/// Tests for <see cref="FlowShapePredictor"/> (Flow Debugger design 2026-09-05 §5.5) against
/// the Delmia recipe-download scripts verbatim from
/// <c>docs/api-specs/Delmia-Recipe-Download-API.md</c> §4.
/// </summary>
public class FlowShapePredictorTests
{
    private const string DelmiaMethodScript = """
        try {
          System.Func<string, object> P = k => Parameters.ContainsKey(k) ? Parameters[k] : null;
          var code = (P("MachineCode") as string ?? "").Trim();
          if (string.IsNullOrEmpty(code)) return new { Result = false, ResultText = "MachineCode is required" };
          var suf = code.Substring(code.Length - 1);

          return await Route.To(code).Call("ProcessRecipeDownload", new {
              DownloadPath    = P("DownloadPath"),
              WorkOrderNumber = P("WorkOrderNumber"),
              PartNumber      = P("PartNumber"),
              JobStepNumber   = P("JobStepNumber"),
              Username        = P("Username"),
          });
        } catch (Exception ex) {
          return new { Result = false, ResultText = "RecipeDownload failed: " + ex.Message };
        }
        """;

    private const string DelmiaSiteScript = """
        // Generic DELMIA recipe-download — performed DIRECTLY on the composed DelmiaReceiver child
        var recv = Children["DelmiaRecv"];
        System.Func<object,bool> IsTrue = v => { var s=v?.ToString(); return (v is bool b && b)||s=="1"||string.Equals(s,"true",System.StringComparison.OrdinalIgnoreCase); };
        System.Func<string,object?> P = k => Parameters.ContainsKey(k) ? Parameters[k] : null;
        if (!IsTrue(recv.Attributes["ReadyFlag"]))
            return new { Result=false, ResultText="Receiver ready flag not set to true" };
        try {
            recv.Attributes["RecipeProcessedFlag"] = false;
            var data = new System.Collections.Generic.Dictionary<string, object?> {
                { "DownloadPath", P("DownloadPath") },
                { "WorkOrderNumber", P("WorkOrderNumber") },
                { "PartNumber", P("PartNumber") },
                { "JobStepNumber", P("JobStepNumber") },
                { "Username", P("Username") },
            };
            if (!await recv.Attributes.WriteBatchAndWaitAsync(data, "RecipeDownloadFlag", true, "RecipeProcessedFlag", true, System.TimeSpan.FromSeconds(25)))
                return new { Result=false, ResultText="Timeout waiting for recipe to be processed" };
            return new {
                Result = IsTrue(recv.Attributes["RecipeProcessResult"]),
                ResultText = recv.Attributes["RecipeProcessResultText"]?.ToString() ?? ""
            };
        } catch (Exception ex) {
            return new { Result=false, ResultText="RecipeDownload failed: " + ex.Message };
        }
        """;

    private static string? AnySiteScript(string instanceCode, string scriptName)
        => scriptName == "ProcessRecipeDownload" ? DelmiaSiteScript : null;

    [Fact]
    public void Delmia_MethodPlusSiteScript_PredictsTheFullSwimlaneShape()
    {
        var flow = FlowShapePredictor.PredictInboundMethod("DelmiaRecipeDownload", DelmiaMethodScript, AnySiteScript);

        // Request → route call → site run → RecipeProcessedFlag write → batch write → wait → response.
        // (The InboundRequest node IS the method-script run: the real graph records no separate
        // "method script" step, so the prediction mirrors that to keep the overlay honest.)
        var kinds = flow.Nodes.Select(n => (n.Kind, n.Lane)).ToList();
        Assert.Equal(
        [
            (FlowStepKind.InboundRequest, FlowLane.Central),
            (FlowStepKind.RouteCall, FlowLane.Central),
            (FlowStepKind.ScriptRun, FlowLane.Site),
            (FlowStepKind.AttributeWrite, FlowLane.Tags),
            (FlowStepKind.AttributeWrite, FlowLane.Tags),
            (FlowStepKind.AttributeWait, FlowLane.Site),
            (FlowStepKind.Response, FlowLane.Central),
        ], kinds);

        Assert.Equal("POST /api/DelmiaRecipeDownload", flow.Nodes[0].Title);

        // The route target is `code`, computed from Parameters — input-dependent.
        var route = flow.Nodes[1];
        Assert.True(route.InputDependent);
        Assert.Contains("Route.To(code)", route.Title);
        Assert.Contains("ProcessRecipeDownload", route.Title);
        // The early-return guard that precedes the route call is surfaced on it.
        Assert.Contains("early return: string.IsNullOrEmpty(code)", route.Note);

        Assert.Equal("ProcessRecipeDownload", flow.Nodes[2].Title);
        Assert.Contains("RecipeProcessedFlag", flow.Nodes[3].Title);
        Assert.Contains("early return: !IsTrue(recv.Attributes[\"ReadyFlag\"])", flow.Nodes[3].Note);
        Assert.Contains("RecipeDownloadFlag", flow.Nodes[4].Title);
        Assert.Contains("RecipeProcessedFlag", flow.Nodes[5].Title);
        Assert.False(flow.Nodes[5].InputDependent);

        // Chain edges: n1→n2 (central), n2→n3 crosses, n3→n4, n4→n5, n5→n6, n6→n7 crosses back.
        Assert.Equal(6, flow.Edges.Count);
        Assert.All(flow.Edges.Zip(flow.Nodes.Skip(1)), pair => Assert.Equal(pair.Second.Id, pair.First.To));
        Assert.True(flow.Edges[1].CrossesBoundary);
        Assert.False(flow.Edges[2].CrossesBoundary);
        Assert.True(flow.Edges[^1].CrossesBoundary);
    }

    [Fact]
    public void ConstantRouteTarget_IsNotInputDependent_AndQualifiesSiteTitles()
    {
        const string script = """
            return await Route.To("Z28061Sim").Call("ProcessRecipeDownload", new { A = 1 });
            """;

        var flow = FlowShapePredictor.PredictInboundMethod("M", script, AnySiteScript);

        var route = flow.Nodes.Single(n => n.Kind == FlowStepKind.RouteCall);
        Assert.False(route.InputDependent);
        Assert.Equal("Z28061Sim.ProcessRecipeDownload", route.Title);
        Assert.Null(route.Note);

        var run = flow.Nodes.Single(n => n.Kind == FlowStepKind.ScriptRun);
        Assert.Equal("Z28061Sim.ProcessRecipeDownload", run.Title);
        var write = flow.Nodes.First(n => n.Kind == FlowStepKind.AttributeWrite);
        Assert.StartsWith("Z28061Sim.", write.Title);
    }

    [Fact]
    public void ResolverReturningNull_LeavesTheSiteRunUnexpanded()
    {
        const string script = """return await Route.To("X").Call("S");""";

        var flow = FlowShapePredictor.PredictInboundMethod("M", script, (_, _) => null);

        Assert.Equal(
        [
            FlowStepKind.InboundRequest, FlowStepKind.RouteCall, FlowStepKind.ScriptRun, FlowStepKind.Response,
        ], flow.Nodes.Select(n => n.Kind).ToList());
    }

    [Fact]
    public void NoRecognisedCall_YieldsOnlyRequestAndResponse()
    {
        var flow = FlowShapePredictor.PredictInboundMethod("Ping", "return new { Ok = true };", AnySiteScript);

        Assert.Equal(2, flow.Nodes.Count);
        Assert.Equal(FlowStepKind.InboundRequest, flow.Nodes[0].Kind);
        Assert.Equal(FlowStepKind.Response, flow.Nodes[1].Kind);
        Assert.Null(flow.Nodes[0].Note);
        var edge = Assert.Single(flow.Edges);
        Assert.False(edge.CrossesBoundary);
    }

    [Fact]
    public void Recursion_StopsAtMaxDepth()
    {
        // Each site script calls the next one; the resolver always answers.
        static string? Chain(string _, string name) => $"""await Scripts.Call("{name}x");""";
        const string method = """return await Route.To("I").Call("A");""";

        var shallow = FlowShapePredictor.PredictInboundMethod("M", method, Chain, maxDepth: 2);
        var deep = FlowShapePredictor.PredictInboundMethod("M", method, Chain, maxDepth: 4);

        // maxDepth 2: A's body is walked at depth 1 (adds Ax), Ax's at depth 2 (adds Axx),
        // Axx is not expanded → 3 runs. maxDepth 4 → A, Ax, Axx, Axxx, Axxxx = 5.
        Assert.Equal(3, shallow.Nodes.Count(n => n.Kind == FlowStepKind.ScriptRun));
        Assert.Equal(5, deep.Nodes.Count(n => n.Kind == FlowStepKind.ScriptRun));
        Assert.Contains(shallow.Nodes, n => n.Note?.Contains("depth limit") == true);
        Assert.True(deep.Nodes.Count > shallow.Nodes.Count);
    }

    [Fact]
    public void MalformedCode_NeverThrows_AndNotesTheParseError()
    {
        var flow = FlowShapePredictor.PredictInboundMethod("M", "return await Route.To(\"X\").Call(", AnySiteScript);

        Assert.Equal(2, flow.Nodes.Count);
        Assert.Equal(FlowShapePredictor.ParseErrorNote, flow.Nodes[0].Note);
        Assert.Equal(FlowStepKind.Response, flow.Nodes[1].Kind);

        var site = FlowShapePredictor.PredictSiteScript("S", "if (");
        var root = Assert.Single(site.Nodes);
        Assert.Equal(FlowShapePredictor.ParseErrorNote, root.Note);
    }

    [Fact]
    public void PredictSiteScript_RootsAtTheScriptRun_AndRecognisesAttributeOps()
    {
        const string body = """
            await Attributes.SetAsync("Cmd", 1);
            await Attributes.WaitAsync("Ack", true, System.TimeSpan.FromSeconds(5));
            var r = await ExternalSystem.Call("Mes", "Post", new { });
            await Notify.Send("ops", "done");
            """;

        var flow = FlowShapePredictor.PredictSiteScript("Handshake", body);

        Assert.Equal(
        [
            (FlowStepKind.ScriptRun, "Handshake"),
            (FlowStepKind.AttributeWrite, "Cmd"),
            (FlowStepKind.AttributeWait, "Ack"),
            (FlowStepKind.ApiCall, "ExternalSystem.Call(Mes)"),
            (FlowStepKind.Notify, "Notify.Send"),
        ], flow.Nodes.Select(n => (n.Kind, n.Title)).ToList());
        Assert.DoesNotContain(flow.Nodes, n => n.Lane == FlowLane.Central);
        Assert.All(flow.Edges, e => Assert.False(e.CrossesBoundary));
    }

    [Fact]
    public void InputDependentAttributeName_IsFlagged()
    {
        var flow = FlowShapePredictor.PredictSiteScript("S", """Attributes[name] = 1;""");

        var write = flow.Nodes.Single(n => n.Kind == FlowStepKind.AttributeWrite);
        Assert.True(write.InputDependent);
        Assert.Equal("name", write.Title);
    }
}