package edu.stanford.rt.credential;

//imports Apache Xerces API
import org.apache.xerces.parsers.DOMParser;

import org.xml.sax.InputSource;
import org.w3c.dom.*;

import java.util.*;
import java.io.*;

import edu.stanford.rt.parser.RTParser;
import edu.stanford.rt.util.*;
/**
 * @author Ninghui Li, Sandra Qiu <br>
 * 
 * RTContext contains the info about <code>ApplicationDomainSecification</code>s and 
 * <code>Principal</code>s in the system.
 */
public class RTContext
{
	/**
	 * Index for <code>ApplicationDomain</code> objects.<br>
	 * 
	 * Key: <code>HashID</code> <br>
	 * Value: <code>ApplicationDomain</code>
	 */
	private HashMap applicationDomains;

	/**
	 * Index for <code>Principal</code> objects.<br>
	 * 
	 * Key: <code>PublicKeyPrincipal</code> <br>
	 * Value: <code>PublicKeyPrincipalInfo</code>
	 */
	private HashMap principals;

	/**
	 * The built-in system domain. 
	 */
	private ApplicationDomain systemDomain;

	/**
	 * Constructor for RTContext.
	 */
	public RTContext(RTParser rtParser) throws Exception
	{
		this.applicationDomains = new HashMap();
		this.principals = new HashMap();
        // others need to call parseSystemDomain(InputStream).        
		this.systemDomain = rtParser.createSystemDomain();
	}

	/**
	 * Method getSystemDomain.
	 * @return ApplicationDomain
	 */
	public ApplicationDomain getSystemDomain()
	{
		return systemDomain;
	}

	/**
	 * Method getApplicationDomain.
	 * @param id
	 * @return ApplicationDomain
	 */
	public ApplicationDomain getApplicationDomain(String id)
	{
		return getApplicationDomain(
			new HashID(HashID.APPLICATION_DOMAIN, id));
	}

	/**
	 * Method getApplicationDomain.
	 * @param id
	 * @return ApplicationDomain
	 */
	public ApplicationDomain getApplicationDomain(HashID id)
	{
		RTUtil.debugInfo("RTContex.getApplicationDomain() .... ");
		RTUtil.debugInfo("      id = " + id.toString());
		return (ApplicationDomain) applicationDomains.get(id);
	}

	/**
	 * Method addApplicationDomain.
	 * @param id
	 * @param appDomain
	 * @throws DomainSpecException
	 */
	public synchronized void addApplicationDomain(
		HashID id,
		ApplicationDomain appDomain)
		throws DomainSpecException
	{
//		RTUtil.debugInfo("RTContex.addApplicationDomain() .... ");
//		RTUtil.debugInfo("      id = " + id.toString());
//		RTUtil.debugInfo("&&&&& ");
//		RTUtil.debugInfo(appDomain.toString(" "));
//		RTUtil.debugInfo("&&&&& ");

		if (this.applicationDomains.get(id) != null)
			throw new DomainSpecException("Duplicated domains in CredentialStore.");
		this.applicationDomains.put(id, appDomain);
	}

	/**
	 * Method getPrincipal.
	 * @param id
	 * @return PublicKeyPrincipalInfo
	 */
	public PublicKeyPrincipalInfo getPrincipal(PublicKeyPrincipal id)
	{
		return (PublicKeyPrincipalInfo) principals.get(id);
	}

	/**
	 * Method addPrincipals.
	 * @param id
     *  the hash value of the principal
	 * @param principal
     *  the public key info of the principal
	 * @throws DomainSpecException
	 */
	public synchronized void addPrincipal(
		PublicKeyPrincipal id,
		PublicKeyPrincipalInfo principal)
		throws DomainSpecException
	{
		if (this.principals.get(id) != null)
			throw new DomainSpecException("Duplicated");
		this.principals.put(id, principal);
	}
	/**
	 * Method hasDomainWithID.
     *  checks if there is an ApplicationDomain object with given hash id.
	 * @param idref
	 * @return boolean
	 */
	public boolean hasDomainWithID(String idref)
	{
		boolean exists = true;
		if (getApplicationDomain(idref) == null)
			exists = false;
		return exists;
	}

	public String toString(String indent)
	{
		StringBuffer sb = new StringBuffer();
		String thisIndent = indent + "  ";

		sb.append(
			"********** RTContext: **********\n\n");
		sb.append(thisIndent).append("System Domain: \n");
		sb.append(systemDomain.toString(thisIndent));

		sb.append(thisIndent).append("Imported Domains: \n");
		Set entries = applicationDomains.entrySet();
		Iterator it = entries.iterator();
		while (it.hasNext())
		{
			Map.Entry entry = (Map.Entry) it.next();
			ApplicationDomain domain =
				(ApplicationDomain) entry.getValue();
			sb.append(domain.toString(thisIndent));
            sb.append("\n");
		}

		sb.append(thisIndent).append("Principals: \n");
		entries = principals.entrySet();
		it = entries.iterator();
		while (it.hasNext())
		{
			Map.Entry entry = (Map.Entry) it.next();
			PublicKeyPrincipalInfo principal =
				(PublicKeyPrincipalInfo) entry.getValue();
			sb.append(principal.toString(thisIndent));
            sb.append("\n");
		}

		return sb.toString();
	}
}