package dk.portalprotect.sample.plugins;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Properties;
import java.util.Vector;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import dk.itp.portalprotect.useradmin.data.Acl;
import dk.itp.portalprotect.useradmin.data.Challenge;
import dk.itp.portalprotect.useradmin.data.Group;
import dk.itp.portalprotect.useradmin.data.QuickUser;
import dk.itp.portalprotect.useradmin.data.User;
import dk.itp.pp.useradmin.client.IUserAdmin;
import dk.itp.pp.useradmin.client.UserAdminAgent;
import dk.itp.pp.useradmin.client.UserAdminException;
import dk.itp.security.authorization.IAuthorizationPlugin;
import dk.itp.security.authorization.IAuthorizationPluginUserGetter;
import dk.itp.security.authorization.client.ACLEntry;
import dk.itp.security.authorization.client.GroupEntry;
import dk.itp.security.authorization.client.OperationNotSupportedException;
import dk.itp.security.authorization.client.PermissionEntry;
import dk.itp.security.authorization.client.URLEntry;
import dk.itp.security.authorization.client.UserEntry;
import dk.itp.security.passticket.AuthTypes;
import dk.itp.security.passticket.PTException;

/**
 * This Authorization plugin reads usergroups from the useradmin database, 
 * and, acls and protected URLs from files.
 * 
 * @author Kim Rasmussen
 * @version $Revision$
 * 
 * <pre>
 * PortalProtect - Security infrastructure
 * Copyright(c) 2001, IT Practice A/S, All rights reserved.
 * 
 * This source code is confidential.
 * </pre>
 */
public class UAAuthorizationPlugin implements IAuthorizationPlugin, IAuthorizationPluginUserGetter {
	private Vector protectedURLs;
	private static Logger log = LoggerFactory.getLogger(UAAuthorizationPlugin.class);

	/**
	 * @see IAuthorizationPlugin#getACLsForUser(String)
	 */
	public Vector getACLsForUser(String principal) throws OperationNotSupportedException {
		throw new OperationNotSupportedException("Not supported");
	}

	/**
	 * @see IAuthorizationPlugin#getAuthorizationType()
	 */
	public int getAuthorizationType() {
		return AuthTypes.AUTHORIZATIONTYPE_USERADMINISTRATION;
	}

	/**
	 * @see IAuthorizationPlugin#getAvailableACLs(String)
	 */
	public Vector getAvailableACLs(String identifier) throws OperationNotSupportedException {
		Vector ret = new Vector();
		Hashtable ht = new Hashtable();
		
		IUserAdmin ua = UserAdminAgent.getInstance();
		
		try {
			Acl[] acls = ua.listAcls();
		
			for(int i = 0; i < acls.length; i++) {
				String name = acls[i].getName();
				String permission = "*";
				int ofs = name.lastIndexOf('.');
				
				if (ofs >= 0) {
					permission = name.substring(ofs+1);
					name = name.substring(0, ofs);
				}
				
				ACLEntry entry = (ACLEntry)ht.get(name);
				if (entry == null) {
					entry = new ACLEntry(name);
					ht.put(name, entry);
					ret.addElement(entry);
				}
				PermissionEntry pe = new PermissionEntry(permission);
				entry.addPermission(pe);
				
				Group[] groups = acls[i].getGroups();
				for( int n = 0; groups != null && n < groups.length; n++) {
					Group grp = groups[n];
					pe.addMember(grp.getName());
				}
				
				QuickUser[] users = acls[i].getUsers();
				for( int n = 0; users != null && n < users.length; n++) {
					QuickUser usr = users[n];
					pe.addMember("uid:"+usr.getID());
				}
			}
		} catch (Throwable e) {
			log.error("Unable to read acls from UserAdmin server", e);
		}
		return ret;
	}

	/**
	 * @see IAuthorizationPlugin#getAvailableGroups(String)
	 */
	public Vector getAvailableGroups(String identifier) throws OperationNotSupportedException {
		Vector usergroups = new Vector();

		IUserAdmin ua = UserAdminAgent.getInstance();
		
		try {
			Group[] groups = ua.getAllGroups();
			for(int i = 0; i < groups.length; i++) {
				GroupEntry entry = new GroupEntry(groups[i].getName(), groups[i].getName());
				
				// Do not fill in the list of group members, since group membership is stored
				// on the individual user record, since it scales a lot better than storing all users that are
				// member of a group in the group itself.
				
				usergroups.addElement(entry);
			}
		} catch (Throwable e) {
			log.error("Unable to read user groups from UserAdmin server", e);
		}
		
		return usergroups;
	}

	/**
	 * @see IAuthorizationPlugin#getName()
	 */
	public String getName() {
		return "Useradmin DB authorization plugin";
	}
	
	/**
	 * Returns known users for the given criterias.<br>
	 * Note that this method is most suited for exposing known users to an administration interface, like weblogics portal administration.
	 * @param wildcard The wildcard to match, could be * or part of the username/id
	 * @param groupName If not null, searches for users within the specified group
	 * @param searchSpec Additional search parameters, can be used for limiting searches if not null
	 * @param maxReturns Maximum number of user entries to return
	 * @param identifier Either identifies the server name, or null for non-server specific
	 * @return Vector of UserEntry records
	 * @throws PTException. This is thrown if some error occurs.
	 */
	public Vector getAvailableUsers(String wildcard, String groupName, String searchSpec, int maxReturns, String identifier) throws PTException {
		Vector users = new Vector();

		IUserAdmin ua = UserAdminAgent.getInstance();
		
		try {
			Challenge[] challenges = ua.searchChallenges(wildcard.replace('*', '%'), groupName, maxReturns);
			for(int i = 0; i < challenges.length; i++) {
				UserEntry entry = new UserEntry(challenges[i].getLogonID(), null);
				users.addElement(entry);
			}
		} catch (Throwable e) {
			log.error("Unable to read user groups from UserAdmin server", e);
		}
		
		return users;
	}
	

	/**
	 * @see IAuthorizationPlugin#getSpecificACL(String, String)
	 */
	public Object getSpecificACL(String identifier, String name) throws OperationNotSupportedException {
		Vector v = getAvailableACLs(identifier);
		if (v == null)
			return null;
			
		Enumeration enumeration = v.elements();
		while(enumeration.hasMoreElements()) {
			ACLEntry entry = (ACLEntry)enumeration.nextElement();
			
			if (entry.getName().equals(name))
				return entry;
		}
		
		return null;
	}

	/**
	 * @see IAuthorizationPlugin#getSpecificGroup(String, String)
	 */
	public Object getSpecificGroup(String identifier, String name) throws OperationNotSupportedException {
		IUserAdmin ua = UserAdminAgent.getInstance();
		
		try {
			Group[] groups = ua.getAllGroups();
			for(int i = 0; i < groups.length; i++) {
				if (name.equals(groups[i].getName()))
					return new GroupEntry(groups[i].getName(), groups[i].getName());
			}
		} catch (Throwable e) {
			log.error("Unable to read user groups from UserAdmin server", e);
		}
		
		return null;
	}

	/**
	 * @see IAuthorizationPlugin#getProtectedURLs(String)
	 */
	public Vector getProtectedURLs(String identifier) throws OperationNotSupportedException {
		return protectedURLs;
	}

	/**
	 * @see IAuthorizationPlugin#setConfiguration(Properties)
	 */
	public void setConfiguration(Properties props) {
		System.getProperties().setProperty("useradmin.server", props.getProperty("useradminservers", "localhost:15000"));

		String userid = props.getProperty("ua_userid", "userid");
		String password = props.getProperty("ua_credentials", "password");

		try {
			UserAdminAgent.getInstance().login(userid, password);
		} catch (UserAdminException e) {
			log.error("Unable to login to user administration", e);
		}
		
		protectedURLs = new Vector();

		String filename = props.getProperty("protectedUrlsFile", "protectedurls.txt");
		log.info("Reading protected URLs from " + filename);
		FileReader fr = null;
		try {
			fr = new FileReader(filename);
			BufferedReader br = new BufferedReader(fr);
			String line = br.readLine();
			while (line != null) {
				while (line != null && line.trim().length() == 0)
					line = br.readLine();
				if (line == null)
					break;

				String url = line.trim();
				URLEntry entry = new URLEntry(url);
				// Now, read the permissions required to access this URL - they are all indented at least one whitespace
				// when the next line does not start with a whitespace, it is probably another URL

				do {
					line = br.readLine();
					while (line != null && line.trim().length() == 0)
						line = br.readLine();
					if (line == null)
						break;
					if (!Character.isWhitespace(line.charAt(0))) {
						break;
					}
					entry.addPrincipal(line.trim());
				}
				while (line != null && Character.isWhitespace(line.charAt(0)));
				protectedURLs.addElement(entry);
				log.info("Added protected URL: " + entry);
			}

			log.info("Finished reading URLs");
		} catch (Exception e) {
			log.error("Unable to read protected URLs", e);
		} finally {
			if (fr != null)
				try {
					fr.close();
				} catch (IOException e) {}
		}
	}

	/**
	 * @see IAuthorizationPlugin#getStatusText()
	 */
	public String getStatusText() {
		return null;
	}

	/**
	 * @see dk.itp.security.authorization.IAuthorizationPluginUserGetter#getUserGroups(java.lang.String)
	 */
	public String[] getUserGroups(String userid) throws PTException, OperationNotSupportedException {
		try {
			User user = UserAdminAgent.getInstance().getUser(userid, -1);
			Group[] groups = UserAdminAgent.getInstance().getGroups(user.getID());
			String[] result = new String[groups.length];
			for(int i = 0; i < groups.length; i++) {
				result[i] = groups[i].getName();
			}
			return result;
		} catch(UserAdminException e) {
			if (e.getErrorCode() == UserAdminException.ERROR_NOROWSFOUND)
				return new String[0];
			log.warn("Problem reading users groups, user: " + userid, e);
			
			// Don't throw a UserAdminException, since the client (which is probably a weblogic realm) does not have this exception class)
			throw new PTException(e.toString(), e.getErrorCode(), e.getErrorText());
		}
	}
}