/*----------------------------------------------------------------------------------

// Copyright 2019 Huawei Technologies Co.,Ltd.

// Licensed under the Apache License, Version 2.0 (the "License"); you may not use

// this file except in compliance with the License.  You may obtain a copy of the

// License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software distributed

// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR

// CONDITIONS OF ANY KIND, either express or implied.  See the License for the

// specific language governing permissions and limitations under the License.

//----------------------------------------------------------------------------------*/

using System;

using System.Collections.Generic;

using System.Globalization;



namespace OBS.Internal.Auth

{

    internal abstract class Signer

    {



        internal void DoAuth(HttpRequest request, HttpContext context, IHeaders iheaders)

        {

            if (request.Headers.ContainsKey(Constants.CommonHeaders.Authorization))

            {

                request.Headers.Remove(Constants.CommonHeaders.Authorization);

            }



            if (request.Headers.ContainsKey(Constants.CommonHeaders.Date))

            {

                request.Headers.Remove(Constants.CommonHeaders.Date);

            }



            //date

            if (!request.Headers.ContainsKey(iheaders.DateHeader()))

            {

                request.Headers.Add(Constants.CommonHeaders.Date, DateTime.UtcNow.ToString(Constants.RFC822DateFormat, Constants.CultureInfo));

            }



            //host

            string endpoint = string.IsNullOrEmpty(context.RedirectLocation) ? request.Endpoint : context.RedirectLocation;

            request.Headers[Constants.CommonHeaders.Host] = request.GetHost(endpoint);



            // anonymous user

            if (string.IsNullOrEmpty(context.SecurityProvider.Ak) || string.IsNullOrEmpty(context.SecurityProvider.Sk))

            {

                return;

            }



            if (!string.IsNullOrEmpty(context.SecurityProvider.Token) && !request.Headers.ContainsKey(iheaders.SecurityTokenHeader()))

            {

                request.Headers.Add(iheaders.SecurityTokenHeader(), context.SecurityProvider.Token.Trim());

            }

            this._DoAuth(request, context, iheaders);

        }



        internal abstract IDictionary<string,string> GetSignature(HttpRequest request, HttpContext context, IHeaders iheaders);



        protected abstract void _DoAuth(HttpRequest request, HttpContext context, IHeaders iheaders);

    }

}