using ZB.MOM.WW.Audit;
using ZB.MOM.WW.ScadaBridge.Commons.Types.Audit;
using ZB.MOM.WW.ScadaBridge.Commons.Types.Debugging;
using ZB.MOM.WW.ScadaBridge.Commons.Types.Enums;

namespace ZB.MOM.WW.ScadaBridge.Commons.Tests.Debugging;

/// <summary>
/// Step-logs design 2026-09-09 D2: a <c>ScriptTrace.ScriptLog</c> row is never a node — it folds onto the
/// step its <c>StepEventId</c> names, else onto its execution's anchor (<c>ScriptRun</c> /
/// <c>InboundRequest</c> / <c>RouteCall</c>), else its execution's first non-<c>Response</c> step, else it is
/// dropped and counted in <see cref="FlowGraph.UnattachedLogLines"/>.
/// </summary>
public class FlowGraphBuilderLogLineTests
{
    private static readonly DateTime T0 = new(2026, 9, 9, 12, 0, 0, DateTimeKind.Utc);

    private static AuditEvent Run(Guid execution, Guid? parent = null, int ms = 0) =>
        ScadaBridgeAuditEventFactory.Create(AuditChannel.ScriptTrace, AuditKind.ScriptRun, AuditStatus.Delivered,
            occurredAtUtc: T0.AddMilliseconds(ms), actor: "SomeScript", target: "SomeScript", sourceNode: "node-a",
            executionId: execution, parentExecutionId: parent, sourceSiteId: "site-a", sourceInstanceId: "M1",
            durationMs: 100, extra: new ScriptTraceExtra { TriggerKind = "call" }.ToJson());

    private static AuditEvent Write(Guid execution, Guid? eventId = null, int ms = 10) =>
        ScadaBridgeAuditEventFactory.Create(AuditChannel.ScriptTrace, AuditKind.AttributeWrite, AuditStatus.Delivered,
            eventId: eventId, occurredAtUtc: T0.AddMilliseconds(ms), actor: "SomeScript", target: "M1.Flag",
            sourceNode: "node-a", executionId: execution, sourceSiteId: "site-a", sourceInstanceId: "M1", durationMs: 2,
            extra: new ScriptTraceExtra { Writes = [new AttributeWriteDetail("M1.Flag", "true", true, null)] }.ToJson());

    private static AuditEvent Inbound(Guid execution, int ms = 0) =>
        ScadaBridgeAuditEventFactory.Create(AuditChannel.ApiInbound, AuditKind.InboundRequest, AuditStatus.Delivered,
            occurredAtUtc: T0.AddMilliseconds(ms), actor: "some-key", target: "SomeMethod", sourceNode: "central-a",
            executionId: execution, durationMs: 50, requestSummary: "{}", responseSummary: "{\"ok\":true}");

    private static AuditEvent RouteCallRoot(Guid execution, int ms = 0) =>
        ScadaBridgeAuditEventFactory.Create(AuditChannel.ScriptTrace, AuditKind.RouteCall, AuditStatus.Delivered,
            occurredAtUtc: T0.AddMilliseconds(ms), actor: "flow-debugger", target: "M1.SomeScript", sourceNode: "central-a",
            executionId: execution, durationMs: 120);

    private static AuditEvent ApiOut(Guid execution, Guid eventId, int ms = 20) =>
        ScadaBridgeAuditEventFactory.Create(AuditChannel.ApiOutbound, AuditKind.ApiCall, AuditStatus.Delivered,
            eventId: eventId, occurredAtUtc: T0.AddMilliseconds(ms), actor: "SomeScript", target: "ERP/orders",
            sourceNode: "node-a", executionId: execution, sourceSiteId: "site-a", durationMs: 30);

    private static AuditEvent Line(Guid execution, Guid? step = null, int? seq = null, string level = "info",
        int ms = 5, string message = "hello") =>
        ScadaBridgeAuditEventFactory.Create(AuditChannel.ScriptTrace, AuditKind.ScriptLog, AuditStatus.Delivered,
            occurredAtUtc: T0.AddMilliseconds(ms), actor: "SomeScript", target: "SomeScript", sourceNode: "node-a",
            executionId: execution, sourceSiteId: "site-a", sourceInstanceId: "M1", requestSummary: message,
            extra: new ScriptTraceExtra { LogLevel = level, LogSource = "script", StepEventId = step, Seq = seq }.ToJson());

    private static FlowStep StepOf(FlowGraph graph, FlowStepKind kind) => Assert.Single(graph.Steps, s => s.Kind == kind);

    [Fact]
    public void LogLine_WithStepEventId_AttachesToThatStep()
    {
        var execution = Guid.NewGuid();
        var writeId = Guid.NewGuid();

        var graph = FlowGraphBuilder.Build([Run(execution), Write(execution, writeId), Line(execution, step: writeId)]);

        var write = StepOf(graph, FlowStepKind.AttributeWrite);
        var line = Assert.Single(write.Logs!);
        Assert.Equal("hello", line.Message);
        Assert.Null(StepOf(graph, FlowStepKind.ScriptRun).Logs);
    }

    [Fact]
    public void LogLine_WithoutStepId_AttachesToTheExecutionAnchor()
    {
        var execution = Guid.NewGuid();

        var graph = FlowGraphBuilder.Build([Run(execution), Write(execution), Line(execution)]);

        Assert.Single(StepOf(graph, FlowStepKind.ScriptRun).Logs!);
        Assert.Null(StepOf(graph, FlowStepKind.AttributeWrite).Logs);
    }

    [Fact]
    public void CentralLine_AttachesToInboundRow_NotResponse()
    {
        var execution = Guid.NewGuid();

        var graph = FlowGraphBuilder.Build([Inbound(execution), Line(execution)]);

        Assert.Single(StepOf(graph, FlowStepKind.InboundRequest).Logs!);
        Assert.Null(StepOf(graph, FlowStepKind.Response).Logs);
    }

    [Fact]
    public void ScriptEntryLine_AttachesToRouteCallRoot()
    {
        var execution = Guid.NewGuid();

        var graph = FlowGraphBuilder.Build([RouteCallRoot(execution), Line(execution)]);

        Assert.Single(StepOf(graph, FlowStepKind.RouteCall).Logs!);
    }

    [Fact]
    public void LogLine_UnknownStepId_FallsBackToAnchor()
    {
        var execution = Guid.NewGuid();

        var graph = FlowGraphBuilder.Build([Run(execution), Line(execution, step: Guid.NewGuid())]);

        Assert.Single(StepOf(graph, FlowStepKind.ScriptRun).Logs!);
        Assert.Equal(0, graph.UnattachedLogLines);
    }

    [Fact]
    public void LogLine_NoAnchor_FallsBackToFirstStep()
    {
        var execution = Guid.NewGuid();

        var graph = FlowGraphBuilder.Build([Write(execution), Line(execution)]);

        Assert.Single(StepOf(graph, FlowStepKind.AttributeWrite).Logs!);
        Assert.Equal(0, graph.UnattachedLogLines);
    }

    [Fact]
    public void LogLine_NoStepInExecution_IsCountedUnattached()
    {
        var execution = Guid.NewGuid();

        var graph = FlowGraphBuilder.Build([Run(execution), Line(Guid.NewGuid())]);

        Assert.Equal(1, graph.UnattachedLogLines);
        Assert.All(graph.Steps, s => Assert.True(s.Logs is null or { Count: 0 }));
    }

    [Fact]
    public void Build_LinesOnly_ReturnsEmptyGraphWithUnattachedCount()
    {
        var graph = FlowGraphBuilder.Build([Line(Guid.NewGuid()), Line(Guid.NewGuid())], logsTruncated: true);

        Assert.Empty(graph.Steps);
        Assert.Empty(graph.Edges);
        Assert.Equal(2, graph.UnattachedLogLines);
        Assert.True(graph.LogsTruncated);
    }

    [Fact]
    public void Lines_OrderBySeqWithinSameMillisecond_NullSeqLast()
    {
        var execution = Guid.NewGuid();

        var graph = FlowGraphBuilder.Build(
        [
            Run(execution),
            Line(execution, seq: 3, ms: 5, message: "three"),
            Line(execution, seq: 1, ms: 5, message: "one"),
            Line(execution, seq: null, ms: 5, message: "null"),
            Line(execution, seq: 2, ms: 5, message: "two"),
        ]);

        var logs = StepOf(graph, FlowStepKind.ScriptRun).Logs!;
        Assert.Equal(new int?[] { 1, 2, 3, null }, logs.Select(l => l.Seq).ToArray());
        Assert.Equal(new[] { "one", "two", "three", "null" }, logs.Select(l => l.Message).ToArray());
    }

    [Fact]
    public void LogLines_NeverBecomeSteps()
    {
        var execution = Guid.NewGuid();
        var events = new List<AuditEvent> { Run(execution) };
        for (var i = 0; i < 5; i++)
            events.Add(Line(execution, seq: i, ms: 1 + i, message: $"line {i}"));
        var lineIds = events.Skip(1).Select(e => e.EventId).ToHashSet();

        var graph = FlowGraphBuilder.Build(events);

        var step = Assert.Single(graph.Steps);
        Assert.Equal(FlowStepKind.ScriptRun, step.Kind);
        Assert.Equal(5, step.Logs!.Count);
        Assert.DoesNotContain(graph.Edges, e => lineIds.Contains(e.FromEventId) || lineIds.Contains(e.ToEventId));
    }

    [Fact]
    public void Build_PassesLogsTruncatedThrough()
    {
        var execution = Guid.NewGuid();

        var graph = FlowGraphBuilder.Build([Run(execution)], truncated: false, logsTruncated: true);

        Assert.True(graph.LogsTruncated);
        Assert.False(graph.Truncated);
    }

    [Fact]
    public void LogLine_OnFoldedOutboundStep_AttachesByFirstRowId()
    {
        var execution = Guid.NewGuid();
        var callId = Guid.NewGuid();

        var graph = FlowGraphBuilder.Build([Run(execution), ApiOut(execution, callId), Line(execution, step: callId)]);

        var call = StepOf(graph, FlowStepKind.ApiCall);
        Assert.Equal(callId, call.EventId);
        Assert.Single(call.Logs!);
        Assert.Null(StepOf(graph, FlowStepKind.ScriptRun).Logs);
    }
}