shoc-backend/Api.SeaHavenIndustries/Middleware/LegacyDeprecationMiddleware.cs

using Api.SeaHavenIndustries.Options;
using Microsoft.Extensions.Options;

namespace Api.SeaHavenIndustries.Middleware
{
    /// <summary>Adds Sunset/Deprecation headers to legacy WorkOrder REST routes.</summary>
    public class LegacyDeprecationMiddleware
    {
        private static readonly HashSet<string> LegacyPathSegments = new(StringComparer.OrdinalIgnoreCase)
        {
            "GetWorkOrderList",
            "AddWorkorder",
            "EditWorkorder",
            "ChangeStatus",
            "ChangeAssignment",
            "DeleteWorkorder",
            "GetWorkorderById"
        };

        private readonly RequestDelegate _next;
        private readonly LegacyEndpointOptions _options;

        public LegacyDeprecationMiddleware(RequestDelegate next, IOptions<LegacyEndpointOptions> options)
        {
            _next = next;
            _options = options.Value;
        }

        public async Task InvokeAsync(HttpContext context)
        {
            await _next(context);

            if (!_options.DeprecationEnabled)
                return;

            var path = context.Request.Path.Value ?? "";
            if (!path.Contains("/WorkOrder", StringComparison.OrdinalIgnoreCase)
                && !path.Contains("/workorders", StringComparison.OrdinalIgnoreCase))
                return;

            if (!LegacyPathSegments.Any(seg => path.Contains(seg, StringComparison.OrdinalIgnoreCase)))
                return;

            context.Response.Headers["Deprecation"] = "true";
            if (!string.IsNullOrWhiteSpace(_options.SunsetDate))
                context.Response.Headers["Sunset"] = _options.SunsetDate;
            context.Response.Headers["Link"] = "</api/workorders/board>; rel=\"successor-version\"";
        }
    }
}