/*
 * MindTouch Dream - a distributed REST framework 
 * Copyright (C) 2006, 2007 MindTouch, Inc.
 * www.mindtouch.com  oss@mindtouch.com
 *
 * For community documentation and downloads visit www.opengarden.org;
 *  please review the licensing section.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * http://www.gnu.org/copyleft/lesser.html
 */

using System;
using System.Collections.Generic;
using System.Security.Cryptography;
using System.Text;

namespace MindTouch.Dream.Samples {
    internal class Program {

        //--- Constants ---
        private const string AWS_DATE = "X-Amz-Date";

        //--- Class Fields ---
        private static string _public_key;
        private static string _private_key;
        private static Plug _s3 = Plug.New("http://s3.amazonaws.com").WithPreHandler(S3AuthenticationHeader);

        //--- Class Methods ---
        private static void Main(string[] args) {

            // verify argument count
            if(args.Length < 4) {
                ShowUsage();
                return;
            }

            // store public and private keys
            _public_key = args[0];
            _private_key = args[1];

            // check command
            XDoc result = XDoc.Empty;
            switch(args[2]) {
            case "list":

                // get the contents of a bucket (argument 3)
                result = _s3.At(args[3]).GetAsync().Wait().AsDocument();
                break;
            case "add":

                // upload file (argument 4) into a bucket (argument 3)
                result = _s3.At(args[3], System.IO.Path.GetFileName(args[4])).PutAsync(DreamMessage.FromFile(args[4])).Wait().AsDocument();
                break;
            default:

                // unrecognized command
                ShowUsage();
                return;
            }

            // show outcome on console
            Console.WriteLine(result.ToPrettyString());
        }

        private static void ShowUsage() {
            Console.WriteLine("Amazon S3 Utility");
            Console.WriteLine("USAGE: s3.exe <access-key> <private-key> <command> [arg1] ... [argN]");
            Console.WriteLine("    list <bucket>           list contents of a bucket");
            Console.WriteLine("    add <bucket> <file>     add file to a bucket");
        }

        private static DreamMessage S3AuthenticationHeader(string verb, XUri uri, DreamMessage message) {

            // add amazon date header
            string date = DateTime.UtcNow.ToString("r");
            message.Headers[AWS_DATE] = date;

            // add authorization header
            string result = string.Format("{0}\n{1}\n{2}\n\n{3}:{4}\n{5}", verb, message.Headers[DreamMessage.HEADER_CONTENT_MD5], message.ContentType, AWS_DATE.ToLower(), date, uri.Path);
            HMACSHA1 hmac = new HMACSHA1(Encoding.UTF8.GetBytes(_private_key));
            string signature = Convert.ToBase64String(hmac.ComputeHash(Encoding.UTF8.GetBytes(result)));
            message.Headers[DreamMessage.HEADER_AUTHORIZATION] = string.Format("AWS {0}:{1}", _public_key, signature);
            return message;
        }
    }
}