//
// System.Web.StaticFileHandler
//
// Authors:
//	Gonzalo Paniagua Javier (gonzalo@ximian.com)
//
// (C) 2002 Ximian, Inc (http://www.ximian.com)
// (C) 2003-2009 Novell, Inc (http://novell.com)
//

//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.Globalization;
using System.IO;
using System.Web.Util;
using System.Web.Hosting;

namespace System.Web
{
	class StaticFileHandler : IHttpHandler
	{
		static bool ValidFileName (string fileName)
		{
			if (!RuntimeHelpers.RunningOnWindows)
				return true;

			if (fileName == null || fileName.Length == 0)
				return false;

			return (!StrUtils.EndsWith (fileName, " ") && !StrUtils.EndsWith (fileName, "."));
		}
		
		public void ProcessRequest (HttpContext context)
		{
			HttpRequest request = context.Request;
			HttpResponse response = context.Response;

			if (HostingEnvironment.HaveCustomVPP) {
				VirtualFile vf = null;
				VirtualPathProvider vpp = HostingEnvironment.VirtualPathProvider;
				string vpath = request.FilePath;
				
				if (vpp.FileExists (vpath))
					vf = vpp.GetFile (vpath);

				if (vf == null)
					throw new HttpException (404, "Path '" + vpath + "' was not found.", vpath);

				response.ContentType = MimeTypes.GetMimeType (vpath);
				response.TransmitFile (vf, true);
				return;
			}
			
			string fileName = request.PhysicalPath;
			FileInfo fi = new FileInfo (fileName);
			if (!fi.Exists || !ValidFileName (fileName))
				throw new HttpException (404, "Path '" + request.FilePath + "' was not found.", request.FilePath);

			if ((fi.Attributes & FileAttributes.Directory) != 0) {
				response.Redirect (request.Path + '/');
				return;
			}
			
			string strHeader = request.Headers ["If-Modified-Since"];
			try {
				if (strHeader != null) {
					DateTime dtIfModifiedSince = DateTime.ParseExact (strHeader, "r", null);
					DateTime ftime;
					ftime = fi.LastWriteTime.ToUniversalTime ();
					if (ftime <= dtIfModifiedSince) {
						response.ContentType = MimeTypes.GetMimeType (fileName);
						response.StatusCode = 304;
						return;
					}
				}
			} catch { } 

			try {
				DateTime lastWT = fi.LastWriteTime.ToUniversalTime ();
				response.AddHeader ("Last-Modified", lastWT.ToString ("r"));
				response.ContentType = MimeTypes.GetMimeType (fileName);
				response.TransmitFile (fileName, true);
			} catch (Exception) {
				throw new HttpException (403, "Forbidden.");
			}
		}

		public bool IsReusable {
			get { return true; }
		}
	}
}