‫نحوه اتصال به دستگاه پوز

using System;
using System.Net.Http;
using System.Threading.Tasks;
using Newtonsoft.Json;
using System.Net.Http.Headers;

namespace Test
{
    public class CentralPCPOSController
    {
        private string accessToken = null;
        private string refreshToken = null;
        private string tokenType = null;

        public CentralPCPOSController()
        {
            // refresh Access Token
            var terminalInfo = TerminalToken.GetLatest();
            if (terminalInfo == null || terminalInfo.ExpiredAt <= DateTime.Now)
            {
                RefreshToken().Wait();
            }
            else
            {
                this.accessToken = terminalInfo.AccessToken;
                this.refreshToken = terminalInfo.RefreshToken;
                this.tokenType = terminalInfo.TokenType;
            }
        }

        public async Task<HttpResponseMessage> StartPayment(HttpRequestMessage httpRequest)
        {
            var requestContent = await httpRequest.Content.ReadAsStringAsync();
            var request = JsonConvert.DeserializeObject<PaymentRequest>(requestContent);

            if (string.IsNullOrEmpty(request.Amount) || string.IsNullOrEmpty(request.ResNum))
            {
                return new HttpResponseMessage(System.Net.HttpStatusCode.BadRequest)
                {
                    Content = new StringContent("Amount and ResNum are required.")
                };
            }

            var terminalId = GetMineTerminal();
            if (terminalId == null)
            {
                return new HttpResponseMessage(System.Net.HttpStatusCode.Conflict)
                {
                    Content = new StringContent("Terminal not found. Error code 409")
                };
            }

            var identifier = GetIdentifierPaymentPCPOS().Result;
            if (identifier == null)
            {
                return new HttpResponseMessage(System.Net.HttpStatusCode.Conflict)
                {
                    Content = new StringContent("Transaction identifier not found. Error code 409")
                };
            }

            var requestBody = new
            {
                TerminalID = terminalId,
                Amount = request.Amount,
                AccountType = 0,
                ResNum = request.ResNum,
                Identifier = identifier,
                UserNotifiable = new
                {
                    FooterMessage = "متن پایین رسید پرداخت",
                    PrintItems = new[] {
                        new {
                            Item = "آیتم اول",
                            Value = "محتوا اول",
                            Alignment = 0,
                            ReceiptType = 0
                        }
                    }
                },
                TransactionType = 0
            };

            try
            {
                using (var client = new HttpClient())
                {
                    var httpResponse = await client.PostAsJsonAsync("https://cpcpos.seppay.ir/v1/PcPosTransaction/StartPayment", requestBody);
                    var responseContent = await httpResponse.Content.ReadAsStringAsync();
                    var access = JsonConvert.DeserializeObject<YourResponseType>(responseContent);

                    if (access.IsSuccess)
                    {
                        // Save successful payment information if needed
                    }

                    return httpResponse;
                }
            }
            catch (HttpRequestException)
            {
                return new HttpResponseMessage(System.Net.HttpStatusCode.NotFound);
            }
            catch (Exception)
            {
                return new HttpResponseMessage(System.Net.HttpStatusCode.InternalServerError);
            }
        }

        private async Task RefreshToken()
        {
            var sepUsername = Setting.GetValue("sep_username") ?? "*********";
            var sepPassword = Setting.GetValue("sep_password") ?? "*********";
            var sepScope = Setting.GetValue("sep_scope") ?? "*********";
            var sepGrantType = Setting.GetValue("sep_grant_type") ?? "*********";

            try
            {
                using (var client = new HttpClient())
                {
                    var response = await client.PostAsync("https://idn.seppay.ir/connect/token", new FormUrlEncodedContent(new[]
                    {
                        new KeyValuePair<string, string>("grant_type", sepGrantType),
                        new KeyValuePair<string, string>("username", sepUsername),
                        new KeyValuePair<string, string>("password", sepPassword),
                        new KeyValuePair<string, string>("scope", sepScope)
                    }));

                    var responseContent = await response.Content.ReadAsStringAsync();
                    var access = JsonConvert.DeserializeObject<TokenResponse>(responseContent);

                    var newToken = new TerminalToken
                    {
                        AccessToken = access.AccessToken,
                        TokenType = access.TokenType,
                        ExpiresIn = access.ExpiresIn,
                        ExpiredAt = DateTime.Now.AddSeconds(access.ExpiresIn),
                        RefreshToken = access.RefreshToken
                    };

                    newToken.Save();

                    this.accessToken = access.AccessToken;
                    this.tokenType = access.TokenType;
                    this.refreshToken = access.RefreshToken;
                }
            }
            catch (HttpRequestException)
            {
                throw new Exception("Request failed");
            }
        }

        private async Task<string> GetIdentifierPaymentPCPOS()
        {
            try
            {
                using (var client = new HttpClient())
                {
                    var response = await client.PostAsync("https://cpcpos.seppay.ir/v1/PcPosTransaction/ReciveIdentifier", null);
                    var responseContent = await response.Content.ReadAsStringAsync();
                    var access = JsonConvert.DeserializeObject<IdentifierResponse>(responseContent);

                    return access.Data.Identifier;
                }
            }
            catch (HttpRequestException)
            {
                return null;
            }
        }

        private string GetMineTerminal()
        {
            var terminalUser = TerminalUser.GetByUserId(this.userId);
            return terminalUser?.Terminal?.Code;
        }
    }

    public class PaymentRequest
    {
        public string Amount { get; set; }
        public string ResNum { get; set; }
    }

    public class YourResponseType
    {
        public bool IsSuccess { get; set; }
        // Other properties...
    }

    public class TokenResponse
    {
        public string AccessToken { get; set; }
        public string TokenType { get; set; }
        public int ExpiresIn { get; set; }
        public string RefreshToken { get; set; }
    }

    public class IdentifierResponse
    {
        public Data Data { get; set; }
    }

    public class Data
    {
        public string Identifier { get; set; }
    }

    // Mock classes for TerminalToken, Setting, TerminalUser, etc.
    public class TerminalToken
    {
        public static TerminalToken GetLatest() => null;
        public string AccessToken { get; set; }
        public string RefreshToken { get; set; }
        public string TokenType { get; set; }
        public DateTime ExpiredAt { get; set; }
        public void Save() { }
    }

    public class Setting
    {
        public static string GetValue(string key) => null;
    }

    public class TerminalUser
    {
        public static TerminalUser GetByUserId(int userId) => null;
        public Terminal Terminal { get; set; }
    }

    public class Terminal
    {
        public string Code { get; set; }
    }
}