using System.Collections.Concurrent;

using System.Text;

namespace System.Web.Optimization

{

    public static class Script

    {

        private static readonly ConcurrentDictionary<string, string> Bundles = new ConcurrentDictionary<string, string>();

        public static IHtmlString Src(params string[] paths)

        {

            string bundlePath = RegisterBundles(paths);

            if (string.IsNullOrEmpty(bundlePath))

            {

                return RenderOrignal(paths);

            }

            return Scripts.RenderFormat(Scripts.DefaultTagFormat, bundlePath);

        }

        private static IHtmlString RenderOrignal(params string[] paths)

        {

            StringBuilder stringBuilder = new StringBuilder();

            for (int i = ; i < paths.Length; i++)

            {

                string path = paths[i];

                if (path.StartsWith("~"))

                {

                    path = path.Substring();

                }

                stringBuilder.AppendFormat(Scripts.DefaultTagFormat, path);

            }

            return (IHtmlString)new HtmlString(stringBuilder.ToString());

        }

        private static string RegisterBundles(params string[] paths)

        {

            string key = string.Join(null, paths);

            if (Bundles.ContainsKey(key))

            {

                string bundlePath;

                if (Bundles.TryGetValue(key, out bundlePath))

                {

                    return bundlePath;

                }

            }

            else

            {

                string bundlePath = "~/Scripts/" + Math.Abs(key.GetHashCode());

                var bundle = BundleTable.Bundles.GetBundleFor(bundlePath);

                if (bundle == null)

                {

                    var scriptBundle = new ScriptBundle(bundlePath);

                    scriptBundle.Include(paths);

                    BundleTable.Bundles.Add(scriptBundle);

                }

                if (Bundles.TryAdd(key, bundlePath))

                {

                    return bundlePath;

                }

            }

            return null;

        }

    }

}