package org.gcube.portal.ldapexport;

import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import javax.naming.Context;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.Attribute;
import javax.naming.directory.Attributes;
import javax.naming.directory.BasicAttribute;
import javax.naming.directory.BasicAttributes;
import javax.naming.directory.DirContext;
import javax.naming.directory.InitialDirContext;
import javax.naming.directory.SearchControls;
import javax.naming.directory.SearchResult;

import org.gcube.common.portal.PortalContext;
import org.gcube.portal.custom.communitymanager.OrganizationsUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.liferay.portal.kernel.cache.CacheRegistryUtil;
import com.liferay.portal.kernel.exception.PortalException;
import com.liferay.portal.kernel.exception.SystemException;
import com.liferay.portal.model.Organization;
import com.liferay.portal.model.User;
import com.liferay.portal.service.OrganizationLocalServiceUtil;
import com.liferay.portal.service.UserLocalServiceUtil;

public class LDAPSync implements Runnable {
	private static final Logger _log = LoggerFactory.getLogger(LDAPSync.class);

	private String ldapUrl;
	private String filter; 
	private String principal;
	private String pwd;
	
	
	public LDAPSync(String ldapUrl, String filter, String principal, String pwd) {
		this.ldapUrl = ldapUrl;
		this.filter = filter;
		this.principal = principal;
		this.pwd = pwd;
		_log.info("Starting LDAPSync over " + ldapUrl);
	}

	@Override
	public void run() {
		_log.debug("Reading Portal Users ...");
		List<User> users = null; 
		try {
			users = getAllLiferayUsers();
			_log.debug("\n\n\n ******** Read " + users.size() + " from LR DB\n\n");
		} catch (Exception e1) {
			e1.printStackTrace();
		}

		_log.debug("Initializing LDAP exporter ...");

		Properties env = new Properties();
		env.put(Context.INITIAL_CONTEXT_FACTORY,"com.sun.jndi.ldap.LdapCtxFactory");
		env.put(Context.PROVIDER_URL, ldapUrl);
		env.put(Context.SECURITY_PRINCIPAL, principal);
		env.put(Context.SECURITY_CREDENTIALS, pwd);

		try {
			DirContext ctx = new InitialDirContext(env);
			_log.debug("Initiating LDAP Sync ...");
			for (User user : users) {
				updateUserInLDAP(user.getScreenName(), user.getFirstName(), user.getLastName(), user.getFullName(), user.getEmailAddress(), "{SHA}"+user.getPassword(), ctx, filter);
				//_log.debug("Updated " + user.getScreenName());
			}			
			_log.debug("LDAP Sync cycle done");

		} catch (NamingException e) {
			_log.error("Something went Wrong during LDAP Sync");
			e.printStackTrace();
		}			
		if (! users.isEmpty())
			_log.info("LDAP Sync Completed OK!");
		else
			_log.warn("LDAP Sync cycle skipped this time");

	}

	private String getSubContext(String username) {
		return "uid="+username+",ou=People,o=Liferay,ou=Organizations,dc=d4science,dc=org";
	}


	private boolean checkIfLDAPUserExists(String username, DirContext ctx, String filter) {
		SearchControls ctls = new SearchControls();
		ctls.setSearchScope(SearchControls.SUBTREE_SCOPE);
		NamingEnumeration<SearchResult> answer;
		try {
			answer = ctx.search(getSubContext(username), filter, ctls);
		} catch (NamingException e) {
			_log.info("user: " + username + " not found in LDAP, trying to export it");
			return false;
		}
		return answer.hasMoreElements();
	}
	/**
	 * 
	 * @param username
	 * @param name
	 * @param lastName
	 * @param email
	 * @param passwd
	 * @param ctx
	 * @throws NamingException
	 */
	private void updateUserInLDAP(String username, String name, String lastName, String fullName, String email, String passwd, DirContext ctx, String filter) throws NamingException {
		Attributes attributes=new BasicAttributes();
		Attribute objectClass=new BasicAttribute("objectClass");
		objectClass.add("inetOrgPerson");
		attributes.put(objectClass);

		//the main ldap server uses 'givenName' for the First name, 'cn' for "first name last name', 'sn' for the last name
		Attribute givenName = new BasicAttribute("givenName");
		Attribute cn = new BasicAttribute("cn");
		Attribute sn = new BasicAttribute("sn");		
		Attribute mail = new BasicAttribute("mail");
		Attribute userPassword = new BasicAttribute("userPassword");

		givenName.add(name);
		cn.add(fullName);
		sn.add(lastName);		
		mail.add(email);
		userPassword.add(passwd);

		attributes.put(givenName);
		attributes.put(cn);
		attributes.put(sn);		
		attributes.put(mail);
		attributes.put(userPassword);

		if (checkIfLDAPUserExists(username, ctx, filter)) {
			//_log.debug("User " +  username + " already exists, replacing attributes");
			ctx.modifyAttributes(getSubContext(username), DirContext.REPLACE_ATTRIBUTE, attributes);
		}
		else {
			ctx.createSubcontext(getSubContext(username),attributes);
			_log.debug("New User Found with uid=" +  username + " created");
		}
	}

	private List<User> getAllLiferayUsers() {
		String infraName = PortalContext.getConfiguration().getInfrastructureName();		
		_log.info("TRY Reading non chached users belonging to: /" + infraName);

		List<User> toReturn = new ArrayList<User>();
		Organization rootInfra;
		try {
			CacheRegistryUtil.clear();
			rootInfra = OrganizationLocalServiceUtil.getOrganization(OrganizationsUtil.getCompany().getCompanyId(), infraName);
			toReturn = UserLocalServiceUtil.getOrganizationUsers(rootInfra.getOrganizationId());
		} catch (PortalException | SystemException e) {
			_log.error("Error during LDAP Sync, could not retrieve users from LR DB: " + e.getMessage());
		}
		return toReturn;
	}
}