shoc-backend/SeaHaven.Services/Helpers/WorkOrderMediaFileRules.cs

using Microsoft.AspNetCore.Http;

namespace SeaHaven.Services.Helpers
{
    /// <summary>SH-116 media type allowlist for board work-order uploads.</summary>
    public static class WorkOrderMediaFileRules
    {
        private static readonly HashSet<string> AllowedContentTypes = new(StringComparer.OrdinalIgnoreCase)
        {
            "image/jpeg",
            "image/png",
            "video/mp4",
            "video/quicktime"
        };

        private static readonly HashSet<string> AllowedExtensions = new(StringComparer.OrdinalIgnoreCase)
        {
            ".jpg",
            ".jpeg",
            ".png",
            ".mp4",
            ".mov"
        };

        public static bool IsAllowed(IFormFile file)
        {
            if (file == null)
                return false;

            var contentTypeOk = !string.IsNullOrWhiteSpace(file.ContentType)
                && AllowedContentTypes.Contains(file.ContentType.Trim());

            var extension = Path.GetExtension(file.FileName ?? "");
            var extensionOk = !string.IsNullOrWhiteSpace(extension)
                && AllowedExtensions.Contains(extension);

            // Accept when either MIME or extension matches the advertised contract (JPG/PNG/MP4/MOV).
            return contentTypeOk || extensionOk;
        }

        public static void EnsureAllowed(IFormFile file)
        {
            if (!IsAllowed(file))
            {
                throw new Exceptions.WorkOrderBoardValidationException(
                    "UnsupportedMediaType",
                    "Supported media types are JPG, PNG, MP4, and MOV.");
            }
        }
    }
}