using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Extensions.Logging;
using RestSharp;
using RestSharp.Authenticators;
using xCommons.Constants;
using xCommons.Extensions;
using xCommons.Providers;
using xExceptions.Constants;
using xHttpService.Constants;
using xIdentityModels.Constants;
using xIdentityModels.Extensions;
using xIdentityModels.Models;
using xIdentityService.Constants;
using xIdentityService.Interfaces;
using xIdentityService.Models;

namespace xAiService.Base
{
    public interface IXBaseIdentityHttpProvider
    {
        string BaseUrl { get; }
        ILogger Logger { get; }
        string XPoweredValue { get; }
        int DefaultClientTimeout { get; }
        XValidationProvider ValidationProvider { get; }

        HttpClient GetHttpClient();
        RestClient GetRestClient(XTokenResponse tokens = null);
        RestRequest GetRestRequet(
            Enum endpoint,
            bool addXPoweredValue = true,
            IDictionary<string, string> @params = null,
            IDictionary<string, string> headers = null,
            IDictionary<string, string> queryStrings = null
        );

        Task<T> RunRestRequest<T>(
            RestClient client,
            RestRequest request,
            XHttpMethod method,
            bool supportRefreshingTokens = true,
            CancellationToken cancellationToken = default
        );

        Task<XBaseRestResponse<T>> RunRestRequestByResponse<T>(
            RestClient client,
            RestRequest request,
            XHttpMethod method,
            bool supportRefreshingTokens = true,
            CancellationToken cancellationToken = default
        );

        string GetUserSelectByParam(
            XActionRequest model,
            bool forceNotNull = true,
            ICollection<XUserSelectBy> excludes = null
        );
    }

    public abstract class XBaseIdentityHttpProvider : IXBaseIdentityHttpProvider
    {
        public string BaseUrl { get; }
        public ILogger Logger { get; }
        public string XPoweredValue { get; }
        public int DefaultClientTimeout { get; }
        public XValidationProvider ValidationProvider { get; }

        private readonly IXTokenProvider tokenProvider;
        private readonly IXIdentityProvider identityProvider;

        public XBaseIdentityHttpProvider(
            string baseUrl,
            ILogger logger,
            string poweredValue,
            int defaultClientTimeout,
            IXTokenProvider tokenProvider,
            IXIdentityProvider identityProvider,
            XValidationProvider validationProvider
        )
        {
            //
            Logger = logger;
            BaseUrl = baseUrl;
            XPoweredValue = poweredValue;
            this.tokenProvider = tokenProvider;
            ValidationProvider = validationProvider;
            this.identityProvider = identityProvider;
            DefaultClientTimeout = defaultClientTimeout;
        }

        //
        #region Tools ...
        /// <summary>
        /// Get an Instance of Http Client 
        /// </summary>
        /// <returns></returns>
        public HttpClient GetHttpClient()
        {
            //
            HttpClient httpClient = null;

            //
            // httpClient = new HttpClient ();
            var httpClientHandler = new HttpClientHandler()
            {
                ServerCertificateCustomValidationCallback = (sender, cert, chain, sslPolicyErrors) =>
                {
                    //
                    Logger.LogInformation(
                        $"XSSL Handler: {Environment.NewLine}, sender: {sender}, {Environment.NewLine} cert: {cert}, {Environment.NewLine} chain: {chain}, {Environment.NewLine} sslPolicyErrors: {sslPolicyErrors}"
                    );

                    //
                    return true;
                },
                ClientCertificateOptions = ClientCertificateOption.Manual,
            };
            httpClient = new HttpClient(httpClientHandler);

            //
            // Set Timeout ...
            // TODO: Fix this ...
            // httpClient.Timeout = TimeSpan
            //     .FromSeconds (identityConfiguration.DefaultClientTimeout);

            //
            return httpClient;
        }

        /// <summary>
        /// Get an Instance of RestClient
        /// </summary>
        /// <returns></returns>
        public RestClient GetRestClient(XTokenResponse tokens = null)
        {
            //
            var client = new RestClient(BaseUrl);

            //
            // Set Authenticator ...
            if (!tokens.IsNull() &&
                !tokens.AccessToken.IsNullOrEmpty())
            {
                client.Authenticator = new JwtAuthenticator(tokens.AccessToken);
            }

            //
            // Refresh Token ...
            if (!tokens.IsNull() &&
                !tokens.RefreshToken.IsNullOrEmpty())
            {
                client.AddDefaultHeader(XAuthorization.RefreshToken, tokens.RefreshToken);
            }

            //
            // ExpiresAt ...
            if (!tokens.IsNull() &&
                tokens.ExpiresAt > 0)
            {
                client.AddDefaultHeader(XAuthorization.ExpiresAt, tokens.ExpiresAt.AsHttpParamString());
            }

            //
            // Set Default Timeout ...
            client.Timeout = DefaultClientTimeout;

            //
            // SSL Validation Handler ...
            client.RemoteCertificateValidationCallback = (sender, cert, chain, sslPolicyErrors) =>
            {
                //
                Logger.LogInformation(
                    $"XSSL Handler: {Environment.NewLine}, sender: {sender}, {Environment.NewLine} cert: {cert}, {Environment.NewLine} chain: {chain}, {Environment.NewLine} sslPolicyErrors: {sslPolicyErrors}"
                );

                //
                return true;
            };

            //
            return client;
        }

        /// <summary>
        /// Get an Instance of RestRequest 
        /// </summary>
        public RestRequest GetRestRequet(
            Enum endpoint,
            bool addXPoweredValue = true,
            IDictionary<string, string> @params = null,
            IDictionary<string, string> headers = null,
            IDictionary<string, string> queryStrings = null
        )
        {
            //
            var url = endpoint.GetStringValue();

            //
            // Add Route Payloads ...
            if (!@params.IsNull() && @params.Count > 0)
            {
                //
                var enumerator = @params.GetEnumerator();
                while (enumerator.MoveNext())
                {
                    //
                    var item = enumerator.Current;

                    //
                    url = url.Replace(item.Key, item.Value.ToUrlEncoded());
                }
            }

            //
            // Add Query Strings ...
            if (!queryStrings.IsNull() && queryStrings.Count > 0)
            {
                //
                url = $"{url}?";
                var enumerator = queryStrings.GetEnumerator();
                while (enumerator.MoveNext())
                {
                    //
                    var item = enumerator.Current;

                    //
                    url += $"{item.Key}={item.Value.ToUrlEncoded()}&";
                }

                //
                // remove lates & ...
                if (url.EndsWith("&"))
                {
                    url = url.Substring(0, url.Length - 1);
                }
            }

            //
            // Create request ...
            var request = new RestRequest(url, DataFormat.Json);

            //
            if (addXPoweredValue)
            {
                request.AddHeader(XAuthorization.XPoweredBy, XPoweredValue);
            }

            //
            // Add Headers to request ...
            if (!headers.IsNull() && headers.Count > 0)
            {
                //
                var enumerator = headers.GetEnumerator();
                while (enumerator.MoveNext())
                {
                    //
                    var item = enumerator.Current;
                    request.AddHeader(item.Key, item.Value);
                }
            }

            //
            return request;
        }

        /// <summary>
        /// Handle Call Specific Request and retrieve Response
        /// </summary>
        /// <param name="client"></param>
        /// <param name="request"></param>
        /// <param name="method"></param>
        /// <typeparam name="T"></typeparam>
        /// <returns></returns>
        public async Task<T> RunRestRequest<T>(
            RestClient client,
            RestRequest request,
            XHttpMethod method,
            bool supportRefreshingTokens = true,
            CancellationToken cancellationToken = default
        )
        {
            //
            var response = await Task.Run(async () =>
            {
                //
                IRestResponse resp = null;

                //
                // Call Endpoint Service using Specified Method ...
                switch (method)
                {
                    //
                    // Get ...
                    case XHttpMethod.GET:
                        resp = client.Get(request);
                        break;

                    //
                    // Put ...
                    case XHttpMethod.PUT:
                        resp = client.Put(request);
                        break;

                    //
                    // Post ...
                    case XHttpMethod.POST:
                        resp = client.Post(request);
                        break;

                    //
                    // Delete ...
                    case XHttpMethod.DELETE:
                        resp = client.Delete(request);
                        break;
                }

                //
                if (!resp.IsSuccessful)
                {
                    //
                    // Log Exception ...
                    Logger.LogError($"Error: {resp.ErrorMessage}");
                    Logger.LogError($"Exception: {resp.ErrorException.ToJSON()}");
                    if (!resp.ErrorMessage.IsNullOrEmpty() &&
                        resp.ErrorMessage.Contains("timed out"))
                    {
                        XException.Timeout.Throw();
                    }

                    //
                    // TODO: Check UnAuthorized Status here for
                    // Refresh Tokens or Issue Correct Exception ...
                    if (supportRefreshingTokens &&
                        resp.StatusCode == System.Net.HttpStatusCode.Unauthorized)
                    {
                        //
                        var isRefreshed = request.Parameters.Any(rp =>
                            rp.Name == XParam.XIsRefreshed.GetStringValue() &&
                            rp.Value.ToString().ToNormalString() == true.ToJSON());

                        //
                        Logger.LogInformation($"isRefreshed: {isRefreshed}");

                        //
                        // Get Access Token ...
                        XTokenResponse tokens = null;
                        var accessToken = request.Parameters.FirstOrDefault(rp =>
                            rp.Name.ToNormalString() == XAuthorization.Header.ToNormalString()).Value.ToString();
                        if (!accessToken.IsNullOrEmpty())
                        {
                            //
                            accessToken = accessToken.Replace(XAuthorization.TokenIdentifier, "");

                            //
                            if (!accessToken.IsNullOrEmpty())
                            {
                                tokens = await tokenProvider.RetrieveToken(accessToken);
                            }
                        }

                        //
                        // Refresh Token and then re do request ...
                        if (!isRefreshed &&
                            !accessToken.IsNullOrEmpty() &&
                            !tokens.IsNull() &&
                            tokens.IsRefreshable())
                        {
                            //
                            request.AddHeader(XParam.XIsRefreshed.GetStringValue(), true.ToJSON());

                            //
                            // Refreshe Tokens ...
                            var refreshedTokens = await identityProvider
                                .RefreshTokens(tokens);

                            //
                            // Renew Rest Client with Refreshed Tokens ...
                            var timeout = client.Timeout;
                            client = GetRestClient(refreshedTokens);
                            client.Timeout = Timeout.Infinite;

                            //
                            // Do Request Again using renew Client ...
                            return await RunRestRequest<T>(
                                client: client,
                                request: request,
                                method: method);
                        }
                    }

                    //
                    var ex = resp.Content.ToXError();
                    if (!ex.IsNull())
                    {
                        throw ex.ToException();
                    }

                    //
                    // UnAuthorized ...
                    if (resp.StatusCode == System.Net.HttpStatusCode.Unauthorized)
                    {
                        XException.NotAuthorized.Throw();
                    }

                    //
                    // NotFound ...
                    if (resp.StatusCode == System.Net.HttpStatusCode.NotFound)
                    {
                        XException.NotFound.Throw();
                    }

                    //
                    XException.ActionFailed.Throw();
                }

                //
                var result = resp.Content.FromJSON<T>();
                return result;
            },
            cancellationToken: cancellationToken);

            //
            return response;
        }
        public async Task<XBaseRestResponse<T>> RunRestRequestByResponse<T>(
            RestClient client,
            RestRequest request,
            XHttpMethod method,
            bool supportRefreshingTokens = true,
            CancellationToken cancellationToken = default
        )
        {
            //
            var response = await Task.Run(async () =>
            {
                //
                IRestResponse resp = null;

                //
                // Call Endpoint Service using Specified Method ...
                switch (method)
                {
                    //
                    // Get ...
                    case XHttpMethod.GET:
                        resp = client.Get(request);
                        break;

                    //
                    // Put ...
                    case XHttpMethod.PUT:
                        resp = client.Put(request);
                        break;

                    //
                    // Post ...
                    case XHttpMethod.POST:
                        resp = client.Post(request);
                        break;

                    //
                    // Delete ...
                    case XHttpMethod.DELETE:
                        resp = client.Delete(request);
                        break;
                }

                //
                if (!resp.IsSuccessful)
                {
                    //
                    // Log Exception ...
                    Logger.LogError($"Error: {resp.ErrorMessage}");
                    Logger.LogError($"Exception: {resp.ErrorException.ToJSON()}");
                    if (!resp.ErrorMessage.IsNullOrEmpty() &&
                        resp.ErrorMessage.Contains("timed out"))
                    {
                        XException.Timeout.Throw();
                    }

                    //
                    // TODO: Check UnAuthorized Status here for
                    // Refresh Tokens or Issue Correct Exception ...
                    if (supportRefreshingTokens &&
                        resp.StatusCode == System.Net.HttpStatusCode.Unauthorized)
                    {
                        //
                        var isRefreshed = request.Parameters.Any(rp =>
                            rp.Name == XParam.XIsRefreshed.GetStringValue() &&
                            rp.Value.ToString().ToNormalString() == true.ToJSON());

                        //
                        Logger.LogInformation($"isRefreshed: {isRefreshed}");

                        //
                        // Get Access Token ...
                        XTokenResponse tokens = null;
                        var accessToken = request.Parameters.FirstOrDefault(rp =>
                            rp.Name.ToNormalString() == XAuthorization.Header.ToNormalString()).Value.ToString();
                        if (!accessToken.IsNullOrEmpty())
                        {
                            //
                            accessToken = accessToken.Replace(XAuthorization.TokenIdentifier, "");

                            //
                            if (!accessToken.IsNullOrEmpty())
                            {
                                tokens = await tokenProvider.RetrieveToken(accessToken);
                            }
                        }

                        //
                        // Refresh Token and then re do request ...
                        if (!isRefreshed &&
                            !accessToken.IsNullOrEmpty() &&
                            !tokens.IsNull() &&
                            tokens.IsRefreshable())
                        {
                            //
                            request.AddHeader(XParam.XIsRefreshed.GetStringValue(), true.ToJSON());

                            //
                            // Refreshe Tokens ...
                            var refreshedTokens = await identityProvider
                                .RefreshTokens(tokens);

                            //
                            // Renew Rest Client with Refreshed Tokens ...
                            var timeout = client.Timeout;
                            client = GetRestClient(refreshedTokens);
                            client.Timeout = Timeout.Infinite;

                            //
                            // Do Request Again using renew Client ...
                            return await RunRestRequestByResponse<T>(
                                client: client,
                                request: request,
                                method: method
                            );
                        }
                    }

                    //
                    var ex = resp.Content.ToXError();
                    if (!ex.IsNull())
                    {
                        throw ex.ToException();
                    }

                    //
                    // UnAuthorized ...
                    if (resp.StatusCode == System.Net.HttpStatusCode.Unauthorized)
                    {
                        XException.NotAuthorized.Throw();
                    }

                    //
                    // NotFound ...
                    if (resp.StatusCode == System.Net.HttpStatusCode.NotFound)
                    {
                        XException.NotFound.Throw();
                    }

                    //
                    XException.ActionFailed.Throw();
                }

                //
                var result = new XBaseRestResponse<T>
                {
                    Response = resp,
                    Model = resp.Content.FromJSON<T>()
                };

                //
                return result;
            },
            cancellationToken: cancellationToken);

            //
            return response;
        }

        /// <summary>
        /// Get User SelectBy Param 
        /// </summary>
        /// <param name="model"></param>
        /// <param name="forceNotNull"></param>
        /// <param name="excludes"></param>
        /// <returns></returns>
        public string GetUserSelectByParam(
            XActionRequest model,
            bool forceNotNull = true,
            ICollection<XUserSelectBy> excludes = null
        )
        {
            //
            // Validate Args ...
            ValidationProvider.NotNull(model);

            //
            var id = model.UserId;
            var userName = model.UserName;
            var email = model.Email;
            var phoneNumber = model.MobileNumber;

            //
            if (excludes != null)
            {
                //
                if (excludes.Contains(XUserSelectBy.ID))
                {
                    id = null;
                }
                if (excludes.Contains(XUserSelectBy.Email))
                {
                    email = null;
                }
                if (excludes.Contains(XUserSelectBy.MobileNumber))
                {
                    phoneNumber = null;
                }
                if (excludes.Contains(XUserSelectBy.Username))
                {
                    userName = null;
                }
            }

            var selectByParam =
                id.IsNullOrEmpty() ?
                userName.IsNullOrEmpty() ?
                email.IsNullOrEmpty() ?
                phoneNumber.IsNullOrEmpty() ? null : phoneNumber : email : userName : id;

            //
            // Check result ...
            if (forceNotNull &&
                selectByParam.IsNullOrEmpty())
            {
                XException.InvalidData.Throw();
            }

            //
            return selectByParam;
        }
        #endregion        
    }
}