/*
 *
 * (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.
 *
*/

namespace ASC.FederatedLogin.LoginProviders;

[Scope]
public class VKLoginProvider : BaseLoginProvider<VKLoginProvider>
{
    public override string CodeUrl => "https://oauth.vk.com/authorize";
    public override string AccessTokenUrl => "https://oauth.vk.com/access_token";
    public override string ClientID => this["vkClientId"];
    public override string ClientSecret => this["vkClientSecret"];
    public override string RedirectUri => this["vkRedirectUrl"];
    public override string Scopes => (new[] { 4194304 }).Sum().ToString();

        private readonly RequestHelper _requestHelper;

    private const string VKProfileUrl = "https://api.vk.com/method/users.get?v=5.103";

    public VKLoginProvider() { }

    public VKLoginProvider(
        OAuth20TokenHelper oAuth20TokenHelper,
        TenantManager tenantManager,
        CoreBaseSettings coreBaseSettings,
        CoreSettings coreSettings,
        IConfiguration configuration,
        ICacheNotify<ConsumerCacheItem> cache,
        ConsumerFactory consumerFactory,
        Signature signature,
        InstanceCrypto instanceCrypto,
            RequestHelper requestHelper,
        string name, int order, Dictionary<string, string> props, Dictionary<string, string> additional = null)
        : base(oAuth20TokenHelper, tenantManager, coreBaseSettings, coreSettings, configuration, cache, consumerFactory, signature, instanceCrypto, name, order, props, additional)
    {
            _requestHelper = requestHelper;
    }


    public override LoginProfile ProcessAuthoriztion(HttpContext context, IDictionary<string, string> @params, IDictionary<string, string> additionalStateArgs)
    {
        try
        {
            var token = Auth(context, Scopes, out var redirect, context.Request.Query["access_type"] == "offline"
                ? new Dictionary<string, string>
                {
                        { "revoke", "1" }
                }
                : null, additionalStateArgs);

            if (redirect)
            {
                return null;
            }

            if (token == null)
            {
                throw new Exception("Login failed");
            }

            var loginProfile = GetLoginProfile(token.AccessToken);

            loginProfile.EMail = GetMail(token);

            return loginProfile;
        }
        catch (ThreadAbortException)
        {
            throw;
        }
        catch (Exception ex)
        {
            return LoginProfile.FromError(Signature, InstanceCrypto, ex);
        }
    }

    public override LoginProfile GetLoginProfile(string accessToken)
    {
        if (string.IsNullOrEmpty(accessToken))
        {
            throw new Exception("Login failed");
        }

        return RequestProfile(accessToken);
    }

    private LoginProfile RequestProfile(string accessToken)
    {
        var fields = new[] { "sex" };
            var vkProfile = _requestHelper.PerformRequest(VKProfileUrl + "&fields=" + HttpUtility.UrlEncode(string.Join(",", fields)) + "&access_token=" + accessToken);
        var loginProfile = ProfileFromVK(vkProfile);

        return loginProfile;
    }

    private LoginProfile ProfileFromVK(string strProfile)
    {
        var jProfile = JObject.Parse(strProfile);
        if (jProfile == null)
        {
            throw new Exception("Failed to correctly process the response");
        }

        var error = jProfile.Value<JObject>("error");
        if (error != null)
        {
            throw new Exception(error.Value<string>("error_msg"));
        }

        var profileJson = jProfile.Value<JArray>("response");
        if (profileJson == null)
        {
            throw new Exception("Failed to correctly process the response");
        }

        var vkProfiles = profileJson.ToObject<List<VKProfile>>();
        if (vkProfiles.Count == 0)
        {
            throw new Exception("Failed to correctly process the response");
        }

        var profile = new LoginProfile(Signature, InstanceCrypto)
        {
            Id = vkProfiles[0].Id,
            FirstName = vkProfiles[0].FirstName,
            LastName = vkProfiles[0].LastName,

            Provider = ProviderConstants.VK,
        };

        return profile;
    }

    private class VKProfile
    {
        public string Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
    }

    private static string GetMail(OAuth20Token token)
    {
        if (string.IsNullOrEmpty(token.OriginJson))
        {
            return null;
        }

        var parser = JObject.Parse(token.OriginJson);

        return parser?.Value<string>("email");
    }
}