/*
 *
 * (c) Copyright Ascensio System Limited 2010-2018
 *
 * This program is freeware. You can redistribute it and/or modify it under the terms of the GNU 
 * General Public License (GPL) version 3 as published by the Free Software Foundation (https://www.gnu.org/copyleft/gpl.html). 
 * In accordance with Section 7(a) of the GNU GPL its Section 15 shall be amended to the effect that 
 * Ascensio System SIA expressly excludes the warranty of non-infringement of any third-party rights.
 *
 * THIS PROGRAM IS DISTRIBUTED WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY OR
 * FITNESS FOR A PARTICULAR PURPOSE. For more details, see GNU GPL at https://www.gnu.org/copyleft/gpl.html
 *
 * You can contact Ascensio System SIA by email at sales@onlyoffice.com
 *
 * The interactive user interfaces in modified source and object code versions of ONLYOFFICE must display 
 * Appropriate Legal Notices, as required under Section 5 of the GNU GPL version 3.
 *
 * Pursuant to Section 7 § 3(b) of the GNU GPL you must retain the original ONLYOFFICE logo which contains 
 * relevant author attributions when distributing the software. If the display of the logo in its graphic 
 * form is not reasonably feasible for technical reasons, you must include the words "Powered by ONLYOFFICE" 
 * in every copy of the program you distribute. 
 * Pursuant to Section 7 § 3(e) we decline to grant you any rights under trademark law for use of our trademarks.
 *
*/


using System;
using System.Collections.Generic;
using ASC.Common.Utils;
using ASC.FederatedLogin.Profile;
using ASC.Security.Cryptography;
using DotNetOpenAuth.Messaging;
using DotNetOpenAuth.OpenId;
using DotNetOpenAuth.OpenId.Extensions.AttributeExchange;
using DotNetOpenAuth.OpenId.Extensions.SimpleRegistration;
using DotNetOpenAuth.OpenId.RelyingParty;
using Microsoft.AspNetCore.Http;

namespace ASC.FederatedLogin.LoginProviders
{
    class OpenIdLoginProvider : ILoginProvider
    {
        private static readonly OpenIdRelyingParty Openid = new OpenIdRelyingParty();

        public OpenIdLoginProvider(Signature signature, InstanceCrypto instanceCrypto)
        {
            Signature = signature;
            InstanceCrypto = instanceCrypto;
        }

        public LoginProfile ProcessAuthoriztion(HttpContext context, IDictionary<string, string> @params)
        {
            var response = Openid.GetResponse();
            if (response == null)
            {
                if (Identifier.TryParse(@params["oid"], out var id))
                {
                    try
                    {
                        IAuthenticationRequest request;

                        var realmUrlString = string.Empty;

                        if (@params.ContainsKey("realmUrl"))
                            realmUrlString = @params["realmUrl"];

                        if (!string.IsNullOrEmpty(realmUrlString))
                            request = Openid.CreateRequest(id, new Realm(realmUrlString));
                        else
                            request = Openid.CreateRequest(id);

                        request.AddExtension(new ClaimsRequest
                        {
                            Email = DemandLevel.Require,
                            Nickname = DemandLevel.Require,
                            Country = DemandLevel.Request,
                            Gender = DemandLevel.Request,
                            PostalCode = DemandLevel.Request,
                            TimeZone = DemandLevel.Request,
                            FullName = DemandLevel.Request,


                        });
                        var fetch = new FetchRequest();
                        fetch.Attributes.AddRequired(WellKnownAttributes.Contact.Email);
                        //Duplicating attributes
                        fetch.Attributes.AddRequired("http://schema.openid.net/contact/email");//Add two more
                        fetch.Attributes.AddRequired("http://openid.net/schema/contact/email");
                        fetch.Attributes.AddRequired(WellKnownAttributes.Name.Alias);
                        fetch.Attributes.AddRequired(WellKnownAttributes.Name.First);
                        fetch.Attributes.AddRequired(WellKnownAttributes.Media.Images.Default);
                        fetch.Attributes.AddRequired(WellKnownAttributes.Name.Last);
                        fetch.Attributes.AddRequired(WellKnownAttributes.Name.Middle);
                        fetch.Attributes.AddRequired(WellKnownAttributes.Person.Gender);
                        fetch.Attributes.AddRequired(WellKnownAttributes.BirthDate.WholeBirthDate);
                        request.AddExtension(fetch);
                        request.RedirectToProvider();
                        //context.Response.End();//TODO This will throw thread abort

                    }
                    catch (ProtocolException ex)
                    {
                        return LoginProfile.FromError(Signature, InstanceCrypto, ex);
                    }
                }
                else
                {
                    return LoginProfile.FromError(Signature, InstanceCrypto, new Exception("invalid OpenID identifier"));
                }
            }
            else
            {
                // Stage 3: OpenID Provider sending assertion response
                switch (response.Status)
                {
                    case AuthenticationStatus.Authenticated:
                        var spprofile = response.GetExtension<ClaimsResponse>();
                        var fetchprofile = response.GetExtension<FetchResponse>();

                        var realmUrlString = string.Empty;
                        if (@params.ContainsKey("realmUrl"))
                            realmUrlString = @params["realmUrl"];

                        var profile = ProfileFromOpenId(spprofile, fetchprofile, response.ClaimedIdentifier.ToString(), realmUrlString);
                        return profile;
                    case AuthenticationStatus.Canceled:
                        return LoginProfile.FromError(Signature, InstanceCrypto, new Exception("Canceled at provider"));
                    case AuthenticationStatus.Failed:
                        return LoginProfile.FromError(Signature, InstanceCrypto, response.Exception);
                }
            }
            return null;
        }

        public LoginProfile GetLoginProfile(string accessToken)
        {
            throw new NotImplementedException();
        }

        public string Scopes { get { return ""; } }
        public string CodeUrl { get { return ""; } }
        public string AccessTokenUrl { get { return ""; } }
        public string RedirectUri { get { return ""; } }
        public string ClientID { get { return ""; } }
        public string ClientSecret { get { return ""; } }
        public bool IsEnabled { get { return GoogleLoginProvider.Instance.IsEnabled; } }

        public Signature Signature { get; }
        public InstanceCrypto InstanceCrypto { get; }

        internal LoginProfile ProfileFromOpenId(ClaimsResponse spprofile, FetchResponse fetchprofile, string claimedId, string realmUrlString)
        {
            var profile = new LoginProfile(Signature, InstanceCrypto)
            {
                Link = claimedId,
                Id = claimedId,
                Provider = ProviderConstants.OpenId,
            };
            if (spprofile != null)
            {
                //Fill
                profile.BirthDay = spprofile.BirthDateRaw;
                profile.DisplayName = spprofile.FullName;
                profile.EMail = spprofile.Email;
                profile.Name = spprofile.Nickname;
                profile.Gender = spprofile.Gender.HasValue ? spprofile.Gender.Value.ToString() : "";
                profile.TimeZone = spprofile.TimeZone;
                profile.Locale = spprofile.Language;
            }
            if (fetchprofile != null)
            {
                profile.Name = fetchprofile.GetAttributeValue(WellKnownAttributes.Name.Alias);
                profile.LastName = fetchprofile.GetAttributeValue(WellKnownAttributes.Name.Last);
                profile.FirstName = fetchprofile.GetAttributeValue(WellKnownAttributes.Name.First);
                profile.DisplayName = fetchprofile.GetAttributeValue(WellKnownAttributes.Name.FullName);
                profile.MiddleName = fetchprofile.GetAttributeValue(WellKnownAttributes.Name.Middle);
                profile.Salutation = fetchprofile.GetAttributeValue(WellKnownAttributes.Name.Prefix);
                profile.Avatar = fetchprofile.GetAttributeValue(WellKnownAttributes.Media.Images.Default);
                profile.EMail = fetchprofile.GetAttributeValue(WellKnownAttributes.Contact.Email);
                profile.Gender = fetchprofile.GetAttributeValue(WellKnownAttributes.Person.Gender);
                profile.BirthDay = fetchprofile.GetAttributeValue(WellKnownAttributes.BirthDate.WholeBirthDate);
            }
            profile.RealmUrl = realmUrlString;
            return profile;
        }
    }
}