using System;
using System.IO;
using System.Xml;
using System.Security;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;


namespace GroundZero.KeyCodes
{
	/// <summary>
	/// AyaNova .net key generator
	/// </summary>
	public class KeyGen
	{
		private string _RegisteredTo;
		private int _ScheduleableUsers;
		private bool _FeatureWebInterface;
		System.DateTime _Expires;
		private bool _FeatureQuickBooksInterface;

		public KeyGen()
		{
			_FeatureWebInterface=false;
			_FeatureQuickBooksInterface=false;
			_Expires=System.DateTime.Today;

		}

		public string RegisteredTo
		{
			get
			{
				return _RegisteredTo;
			}
			set
			{
				_RegisteredTo=value;
			}
		}

		public int ScheduleableUsers
		{
			get
			{
				return _ScheduleableUsers;
			}
			set
			{
				_ScheduleableUsers=value;
			}
		}

		public bool FeatureWebInterface
		{
			get
			{
				return _FeatureWebInterface;
			}
			set
			{
				_FeatureWebInterface=value;
			}
		}

		public DateTime Expires
		{
			get
			{
				return _Expires;
			}
			set
			{
				_Expires=value;
			}
		}

		public bool FeatureQuickBooksInterface
		{
			get
			{
				return _FeatureQuickBooksInterface;
			}
			set
			{
				_FeatureQuickBooksInterface=value;
			}
		}

		/// <summary>
		/// Generate keycode based on passed in data
		/// </summary>
		/// <returns></returns>
		public string Generate()
		{
			if(_RegisteredTo==null || _RegisteredTo=="") 
				throw new ArgumentException("RegisteredTo is required","RegisteredTo");
			
			System.Text.StringBuilder sb = new System.Text.StringBuilder();

			System.Xml.XmlTextWriter w = new System.Xml.XmlTextWriter(new StringWriter(sb));
			w.Formatting = System.Xml.Formatting.Indented;	
			
			w.WriteStartDocument(true);
			//w.WriteDocType("KeyDocument",null,null,null);
			double dSchemaVersion=1.1;
			w.WriteStartElement("AyaNovaLicenseKey");
			w.WriteElementString("SchemaVersion",XmlConvert.ToString(dSchemaVersion));
		
			w.WriteElementString("Created",XmlConvert.ToString(System.DateTime.Now));
		
			
			
			w.WriteElementString("RegisteredTo",_RegisteredTo);
			
			
			w.WriteElementString("InstallableUntil",XmlConvert.ToString(System.DateTime.Today.AddDays(7)));
			w.WriteElementString("TotalScheduleableUsers",XmlConvert.ToString(_ScheduleableUsers));
			if(!System.DateTime.Today.Date.Equals(_Expires.Date))
				w.WriteElementString("Expires",XmlConvert.ToString(_Expires.Date));


			//w.WriteElementString("PermanentKey",XmlConvert.ToString(_TemporaryKey));
			w.WriteElementString("FeatureWebBrowserInterface",XmlConvert.ToString(_FeatureWebInterface));
			w.WriteElementString("FeatureQuickBooksInterface",XmlConvert.ToString(_FeatureQuickBooksInterface));


			w.WriteEndElement();
			w.WriteEndDocument();
			
			w.Flush();
			w.Close();


			// Load the license request file.
			XmlDocument xmldoc = new XmlDocument();
			try
			{

				xmldoc.LoadXml(sb.ToString());
			}
			catch(Exception ex)
			{
				return (ex.Message + ":\r\n\r\n" + sb.ToString());
			}

			// Get the key pair from the key store.
			
			CspParameters parms = new CspParameters(1);			// PROV_RSA_FULL
			parms.Flags = CspProviderFlags.UseMachineKeyStore;	// Use Machine store
			parms.KeyContainerName = "AyaNovaLicenseContainer";				// "CodeProject" container
			parms.KeyNumber = 2;								// AT_SIGNATURE
			try{
			RSACryptoServiceProvider csp = new RSACryptoServiceProvider(parms);
			
			// Creating the XML signing object.
			SignedXml sxml = new SignedXml(xmldoc);
			sxml.SigningKey = csp;
			
			// Set the canonicalization method for the document.
			sxml.SignedInfo.CanonicalizationMethod = 
				SignedXml.XmlDsigCanonicalizationUrl; // No comments.

			// Create an empty reference (not enveloped) for the XPath
			// transformation.
			Reference r = new Reference("");

			// Create the XPath transform and add it to the reference list.
			r.AddTransform(new XmlDsigEnvelopedSignatureTransform(false));

			// Add the reference to the SignedXml object.
			sxml.AddReference(r);

			// Compute the signature.
			sxml.ComputeSignature();

			// Get the signature XML and add it to the document element.
			XmlElement sig = sxml.GetXml();
			xmldoc.DocumentElement.AppendChild(sig);

			// Write-out formatted signed XML to console (allow for redirection).
			System.Text.StringBuilder sbFinal = new System.Text.StringBuilder();
			XmlTextWriter writer = new XmlTextWriter(new StringWriter(sbFinal));
			writer.Formatting = Formatting.Indented;
			
			try
			{
				xmldoc.WriteTo(writer);
			}
			finally
			{
				writer.Flush();
				writer.Close();
			}
			
			
			return sbFinal.ToString();
			}
			catch(Exception ex)
			{
				return (ex.Message + ":\r\n\r\n" + sb.ToString());
			}
		}

		



		

	}
}