using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
using ZB.MOM.WW.Audit;
using ZB.MOM.WW.ScadaBridge.Commons.Types.Audit;

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

/// <summary>
/// Flow Debugger step logs (design 2026-09-09 D7): the central <c>Log</c> global's per-message cap.
/// Final review M2 — the site runtime's <c>ScriptLogger.Clip</c> already backed off a char when the
/// cap landed between the halves of a surrogate pair; this side did not, so an emoji straddling the
/// boundary left a LONE surrogate on the row (which breaks JSON serialization further down the pipe).
/// </summary>
public class InboundScriptLoggerTests
{
    private static (InboundScriptLogger Logger, List<AuditEvent> Rows) MakeTraced(int maxLines = 200)
    {
        var rows = new List<AuditEvent>();
        var logger = new InboundScriptLogger(
            NullLogger.Instance, rows.Add, maxLines, "DelmiaRecipeDownload", Guid.NewGuid(), "central-a");
        return (logger, rows);
    }

    [Fact]
    public void ASurrogatePairStraddlingTheCap_IsDroppedWhole()
    {
        var (logger, rows) = MakeTraced();
        var straddling = new string('x', InboundScriptLogger.MaxMessageChars - 1) + "🚀" + new string('y', 10);

        logger.Info(straddling);

        var message = Assert.Single(rows).AsRow().RequestSummary!;
        Assert.Equal(InboundScriptLogger.MaxMessageChars, message.Length);
        Assert.EndsWith("…", message);
        Assert.DoesNotContain(message, static c => char.IsSurrogate(c));
    }

    [Fact]
    public void AnOverlongMessageWithNoSurrogateAtTheBoundary_KeepsTheFullCap()
    {
        var (logger, rows) = MakeTraced();

        logger.Info(new string('x', InboundScriptLogger.MaxMessageChars + 500));

        var message = Assert.Single(rows).AsRow().RequestSummary!;
        Assert.Equal(InboundScriptLogger.MaxMessageChars + 1, message.Length); // cap + the ellipsis
        Assert.Equal(new string('x', InboundScriptLogger.MaxMessageChars) + "…", message);
    }

    [Fact]
    public void AMessageExactlyAtTheCap_PassesThroughUnclipped()
    {
        var (logger, rows) = MakeTraced();
        var exact = new string('x', InboundScriptLogger.MaxMessageChars);

        logger.Info(exact);

        Assert.Equal(exact, Assert.Single(rows).AsRow().RequestSummary);
    }
}