using System;
using System.Collections;
using System.Collections.Specialized; using System.IO;
using System.Net; using System.Text; using System.Data;
using System.Configuration; using System.Web;
using WingtipToys;
using WingtipToys.Models;
using System.Collections.Generic;
using System.Linq;

public class NVPAPICaller
{
//Flag that determines the PayPal environment (live or sandbox)
private const bool bSandbox = true;
private const string CVV2 = "CVV2";

// Live strings.
private string pEndPointURL = "https://api-3t.paypal.com/nvp";
private string host = "www.paypal.com";

// Sandbox strings.
private string pEndPointURL_SB = "https://api-3t.sandbox.paypal.com/nvp";
private string host_SB = "www.sandbox.paypal.com";

private const string SIGNATURE = "SIGNATURE";
private const string PWD = "PWD";
private const string ACCT = "ACCT";

//Replace <Your API Username> with your API Username
//Replace <Your API Password> with your API Password
//Replace <Your Signature> with your Signature public string APIUsername = "<Your API Username>"; private string APIPassword = "<Your API Password>"; private string APISignature = "<Your Signature>"; private string Subject = "";

public string APIUsername = "nathaniel.fischer - facilitator_api1.southeasttech.edu";
private string APIPassword = "UBCNLZM7EVN28BM4";
private string Subject = "";
private string APISignature = "AFcWxV21C7fd0v3bYYYRCpSSRl31A4WZlOsS1Z0P5fOHXQ4a4uNPAHMS";
private string BNCode = "PP-ECWizard";

//HttpWebRequest Timeout specified in milliseconds

private const int Timeout = 15000;
private static readonly string[] SECURED_NVPS = new string[] { ACCT, CVV2, SIGNATURE, PWD };

public void SetCredentials(string Userid, string Pwd, string Signature)
{
APIUsername = Userid;
APIPassword = Pwd;
APISignature = Signature;
}

public bool ShortcutExpressCheckout(string amt, ref string token, ref string retMsg)
{
    if (bSandbox)
{
        pEndPointURL = pEndPointURL_SB;
        host = host_SB;
}

    string returnURL = "http://localhost:34368/Checkout/CheckoutReview.aspx";
    string cancelURL = "http://localhost:34368/Checkout/CheckoutCancel.aspx";

NVPCodec encoder = new NVPCodec();
encoder["METHOD"] = "SetExpressCheckout";
encoder["RETURNURL"] = returnURL;
encoder["CANCELURL"] = cancelURL;
encoder["BRANDNAME"] = "Wingtip Toys Sample Application";
encoder["PAYMENTREQUEST_0_AMT"] = amt;
encoder["PAYMENTREQUEST_0_ITEMAMT"] = amt;
encoder["PAYMENTREQUEST_0_PAYMENTACTION"] = "Sale";
encoder["PAYMENTREQUEST_0_CURRENCYCODE"] = "USD";

// Get the Shopping Cart Products
using (WingtipToys.Logic.ShoppingCartActions myCartOrders = new WingtipToys.Logic.ShoppingCartActions())
{
List<CartItem> myOrderList = myCartOrders.GetCartItems();

for (int i = 0; i < myOrderList.Count; i++)
{
encoder["L_PAYMENTREQUEST_0_NAME" + i] = myOrderList[i].Product.ProductName.ToString();
encoder["L_PAYMENTREQUEST_0_AMT" + i] = myOrderList[i].Product.UnitPrice.ToString();
encoder["L_PAYMENTREQUEST_0_QTY" + i] = myOrderList[i].Quantity.ToString();
}
}

string pStrrequestforNvp = encoder.Encode();
string pStresponsenvp = HttpCall(pStrrequestforNvp);

NVPCodec decoder = new NVPCodec(); decoder.Decode(pStresponsenvp);

string strAck = decoder["ACK"].ToLower();
if (strAck != null && (strAck == "success" || strAck == "successwithwarning"))
{
token = decoder["TOKEN"];
string ECURL = "https://" + host + "/cgi-bin/webscr?cmd=_express- checkout" + "&token=" + token;
retMsg = ECURL; return true;
}
else
{
retMsg = "ErrorCode=" + decoder["L_ERRORCODE0"] + "&" + "Desc=" + decoder["L_SHORTMESSAGE0"] + "&" + "Desc2=" + decoder["L_LONGMESSAGE0"];
return false;
}
}

public bool GetCheckoutDetails(string token, ref string PayerID, ref NVPCodec decoder, ref string retMsg)
{
if (bSandbox)
{
pEndPointURL = pEndPointURL_SB;
}

NVPCodec encoder = new NVPCodec(); encoder["METHOD"] = "GetExpressCheckoutDetails"; encoder["TOKEN"] = token;

string pStrrequestforNvp = encoder.Encode();
string pStresponsenvp = HttpCall(pStrrequestforNvp);

decoder = new NVPCodec(); decoder.Decode(pStresponsenvp);

string strAck = decoder["ACK"].ToLower();
if (strAck != null && (strAck == "success" || strAck == "successwithwarning"))
{
PayerID = decoder["PAYERID"]; return true;
}
else
{
retMsg = "ErrorCode=" + decoder["L_ERRORCODE0"] + "&" + "Desc=" + decoder["L_SHORTMESSAGE0"] + "&" + "Desc2=" + decoder["L_LONGMESSAGE0"];

return false;
}
}

public bool DoCheckoutPayment(string finalPaymentAmount, string token, string PayerID, ref NVPCodec decoder, ref string retMsg)
{
if (bSandbox)
{
pEndPointURL = pEndPointURL_SB;
}

NVPCodec encoder = new NVPCodec(); encoder["METHOD"] = "DoExpressCheckoutPayment"; encoder["TOKEN"] = token;
encoder["PAYERID"] = PayerID; encoder["PAYMENTREQUEST_0_AMT"] = finalPaymentAmount; encoder["PAYMENTREQUEST_0_CURRENCYCODE"] = "USD"; encoder["PAYMENTREQUEST_0_PAYMENTACTION"] = "Sale";

string pStrrequestforNvp = encoder.Encode();
string pStresponsenvp = HttpCall(pStrrequestforNvp);

decoder = new NVPCodec(); decoder.Decode(pStresponsenvp);

string strAck = decoder["ACK"].ToLower();
if (strAck != null && (strAck == "success" || strAck == "successwithwarning"))
{
return true;
}
else
{
retMsg = "ErrorCode=" + decoder["L_ERRORCODE0"] + "&" + "Desc=" + decoder["L_SHORTMESSAGE0"] + "&" + "Desc2=" + decoder["L_LONGMESSAGE0"];

return false;
}
}

public string HttpCall(string NvpRequest)
{
string url = pEndPointURL;

string strPost = NvpRequest + "&" + buildCredentialsNVPString(); strPost = strPost + "&BUTTONSOURCE=" + HttpUtility.UrlEncode(BNCode);

HttpWebRequest objRequest = (HttpWebRequest)WebRequest.Create(url); objRequest.Timeout = Timeout;
objRequest.Method = "POST"; objRequest.ContentLength = strPost.Length;

try
{
using (StreamWriter myWriter = new StreamWriter(objRequest.GetRequestStream()))
{
myWriter.Write(strPost);
}
}
catch (Exception e)
{
    // Log the exception.
    WingtipToys.Logic.ExceptionUtility.LogException(e, "HttpCall in PayPalFunction.cs");
}

//Retrieve the Response returned from the NVP API call to PayPal.
  HttpWebResponse objResponse = (HttpWebResponse)objRequest.GetResponse(); string result;
using (StreamReader sr = new StreamReader(objResponse.GetResponseStream()))
{
result = sr.ReadToEnd();
}

return result;
}

private string buildCredentialsNVPString()
{
NVPCodec codec = new NVPCodec();

if (!IsEmpty(APIUsername)) codec["USER"] = APIUsername;

if (!IsEmpty(APIPassword)) codec[PWD] = APIPassword;

if (!IsEmpty(APISignature)) codec[SIGNATURE] = APISignature;

if (!IsEmpty(Subject)) codec["SUBJECT"] = Subject;

codec["VERSION"] = "88.0";

return codec.Encode();
}

public static bool IsEmpty(string s)
{
return s == null || s.Trim() == string.Empty;
}
}

public sealed class NVPCodec : NameValueCollection
{
private const string AMPERSAND = "&"; private const string EQUALS = "=";
private static readonly char[] AMPERSAND_CHAR_ARRAY = AMPERSAND.ToCharArray();
private static readonly char[] EQUALS_CHAR_ARRAY = EQUALS.ToCharArray();

public string Encode()
{
StringBuilder sb = new StringBuilder(); bool firstPair = true;
foreach (string kv in AllKeys)
{
string name = HttpUtility.UrlEncode(kv);
string value = HttpUtility.UrlEncode(this[kv]); if (!firstPair)
{
sb.Append(AMPERSAND);
}
sb.Append(name).Append(EQUALS).Append(value); firstPair = false;
}
return sb.ToString();
}

public void Decode(string nvpstring)
{
Clear();
foreach (string nvp in nvpstring.Split(AMPERSAND_CHAR_ARRAY))
{
string[] tokens = nvp.Split(EQUALS_CHAR_ARRAY); if (tokens.Length >= 2)
{
string name = HttpUtility.UrlDecode(tokens[0]); string value = HttpUtility.UrlDecode(tokens[1]); Add(name, value);
}
}
}

public void Add(string name, string value, int index)
{
this.Add(GetArrayName(index, name), value);
}

public void Remove(string arrayName, int index)
{
this.Remove(GetArrayName(index, arrayName));
}

public string this[string name, int index]
{
get
{
return this[GetArrayName(index, name)];
}
set
{
this[GetArrayName(index, name)] = value;
}
}

private static string GetArrayName(int index, string name)
{
if (index < 0)
{
throw new ArgumentOutOfRangeException("index", "index cannot be negative: " + index);
}
return name + index;
}
}