///////////////////////////////////////////////////////////////////////////////
//
//  Microsoft Research Singularity
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//
//  File:   Browser.sg
//
//  Note:   The Browser web app (serves files and supports browsing)
//

using System;
using System.Collections;
using System.Diagnostics;
using Microsoft.SingSharp;
using Microsoft.SingSharp.Runtime;
using Microsoft.Singularity.Channels;
using Microsoft.Singularity.Directory;
using Microsoft.Singularity.WebApps;
using Microsoft.Singularity.WebApps.Contracts;
using System.Text;
using System.Web;
using FileSystem.Utils;

using Microsoft.Singularity.Io;
using Microsoft.Singularity.Configuration;
using Microsoft.SingSharp.Reflection;
using Microsoft.Singularity.Applications;
[assembly: Transform(typeof(WebAppResourceTransform))]

namespace Microsoft.Singularity.WebApps
{
    [Category("WebApp")]
    internal sealed class Parameters
    {
        [Endpoint]
        public readonly TRef<WebAppContract.Exp:Start> webAppRef;

        [StringParameter( "prefix", Position=0, Default=null, HelpMessage="prefix")]
        internal string prefix;

        reflective private Parameters();
    }

    public class BrowserWebApp : IWebApp
    {
        private string pathPrefix = null;
        private TRef<DirectoryServiceContract.Imp:Ready>! epNS;

        public BrowserWebApp(string prefix)
        {
            pathPrefix = prefix;
            epNS = new TRef<DirectoryServiceContract.Imp:Ready>(DirectoryService.NewClientEndpoint());
        }

        public void ProcessRequest(IHttpRequest! request)
        {
            // The Singularity WebServer uses QueryStrings to express the file to be
            // browsed.  But Cassini uses the UriPath.  (In the Singularity WebServer,
            // the UriPath indicates which application should service the request).
            // Try to support both conventions:
            string uri = request.GetQueryString();

            if ((uri == null) || (uri.Length == 0)) {
                uri = request.GetUriPath();
                if ((uri == null) || (uri.Length == 0)) {
                    uri = "/";
                }
            }

            if (pathPrefix != null) {
                uri = pathPrefix + uri;
            }

            DirectoryServiceContract.Imp:Ready! nsImp = epNS.Acquire();

            try {
                WebAppFSUtils.ServeFSPath(uri, request, nsImp);
            }
            finally {
                epNS.Release(nsImp);
            }
        }

        // ======================================================
        // The code below gets used when this webapp is compiled
        // to a stand-alone executable
        internal static int AppMain(Parameters! config)
        {
            WebAppContract.Exp conn = (config.webAppRef).Acquire();
            if (conn == null) {
                // Wrong contract type!
                return -1;
            }

            conn.SendWebAppReady();

            string prefix = config.prefix;

            BrowserWebApp webApp = new BrowserWebApp(prefix);
            Driver.ServiceChannel(webApp, conn);
            delete conn;
            return 0;
        }
    }
}