using System;
using System.Web.Optimization;
using System.IO;
using System.Web.Hosting;

namespace Weee.Extensions
{
    internal static class BundleExtensions
    {
        /// <summary>
        /// Versioning for Bundles
        /// Source: H-Dog's answer  https://stackoverflow.com/questions/15005481/mvc4-stylebundle-can-you-add-a-cache-busting-query-string-in-debug-mode
        /// </summary>
        /// <param name="sb"></param>
        /// <returns></returns>
        public static Bundle WithLastModifiedToken(this Bundle sb)
        {
            sb.Transforms.Add(new LastModifiedBundleTransform());
            return sb;
        }
        public class LastModifiedBundleTransform : IBundleTransform
        {
            public void Process(BundleContext context, BundleResponse response)
            {
                foreach (var file in response.Files)
                {
                    // require some exception handle here to avoid illegal characters in the filename
                    if (!file.IncludedVirtualPath.Contains("?v=")) {
                        var lastWrite = File.GetLastWriteTime(HostingEnvironment.MapPath(file.IncludedVirtualPath)).Ticks.ToString();
                        file.IncludedVirtualPath = string.Concat(file.IncludedVirtualPath, "?v=", lastWrite);
                    }

                }
            }
        }
    }
}