mxaccessgw/src/MxGateway.Server/Diagnostics/GatewayRequestLoggingMiddlewareExtensions.cs

using Microsoft.Extensions.Primitives;

namespace MxGateway.Server.Diagnostics;

public static class GatewayRequestLoggingMiddlewareExtensions
{
    public const string SessionIdHeaderName = "x-session-id";
    public const string WorkerProcessIdHeaderName = "x-worker-process-id";
    public const string CorrelationIdHeaderName = "x-correlation-id";
    public const string CommandMethodHeaderName = "x-command-method";

    public static IApplicationBuilder UseGatewayRequestLoggingScope(this IApplicationBuilder app)
    {
        ArgumentNullException.ThrowIfNull(app);

        return app.Use(async (context, next) =>
        {
            ILogger logger = context.RequestServices
                .GetRequiredService<ILoggerFactory>()
                .CreateLogger("MxGateway.Request");

            using IDisposable? scope = logger.BeginGatewayScope(new GatewayLogScope(
                SessionId: ReadHeader(context, SessionIdHeaderName),
                WorkerProcessId: ReadInt32Header(context, WorkerProcessIdHeaderName),
                CorrelationId: ReadUInt64Header(context, CorrelationIdHeaderName),
                CommandMethod: ReadHeader(context, CommandMethodHeaderName),
                ClientIdentity: ReadHeader(context, "authorization")));

            await next(context);
        });
    }

    private static string? ReadHeader(HttpContext context, string headerName)
    {
        return context.Request.Headers.TryGetValue(headerName, out StringValues values)
            ? values.ToString()
            : null;
    }

    private static int? ReadInt32Header(HttpContext context, string headerName)
    {
        string? value = ReadHeader(context, headerName);

        return int.TryParse(value, out int parsedValue)
            ? parsedValue
            : null;
    }

    private static ulong? ReadUInt64Header(HttpContext context, string headerName)
    {
        string? value = ReadHeader(context, headerName);

        return ulong.TryParse(value, out ulong parsedValue)
            ? parsedValue
            : null;
    }
}