package ldap

import javax.naming.AuthenticationException
import javax.naming.Context
import javax.naming.InvalidNameException
import javax.naming.NamingException
import javax.naming.directory.InitialDirContext
import javax.persistence.NoResultException

import net.datenwerke.rs.authenticator.client.login.dto.UserPasswordAuthToken
import net.datenwerke.rs.authenticator.client.login.pam.UserPasswordClientPAM
import net.datenwerke.rs.utils.crypto.PasswordHasher;
import net.datenwerke.security.client.login.AuthToken
import net.datenwerke.security.service.authenticator.AuthenticationResult
import net.datenwerke.security.service.authenticator.ReportServerPAM
import net.datenwerke.security.service.authenticator.hooks.PAMHook
import net.datenwerke.security.service.usermanager.UserManagerService
import net.datenwerke.security.service.usermanager.entities.User

import com.google.inject.Inject


final LdapPAM ldapPam = GLOBALS.injector.getInstance(LdapPAM.class);
GLOBALS.services.callbackRegistry.attachHook("LDAP_PAM", PAMHook.class, new PAMHook(){

    public void beforeStaticPamConfig(LinkedHashSet<ReportServerPAM> pams){
        pams.add(ldapPam);
    }
    public void afterStaticPamConfig(LinkedHashSet<ReportServerPAM> pams){

    }

});


public class LdapPAM implements ReportServerPAM {

    private static final String CLIENT_MODULE_NAME = UserPasswordClientPAM.class.getName();
    private UserManagerService userManagerService;
    private PasswordHasher passwordHasher;

    @Inject
    public LdapPAM(UserManagerService userManagerService, PasswordHasher passwordHasher) {
        this.userManagerService = userManagerService;
        this.passwordHasher = passwordHasher;
    }


    public AuthenticationResult authenticate(AuthToken[] tokens) {
        for(Object token : tokens){
            if(token instanceof UserPasswordAuthToken){
                UserPasswordAuthToken credentials = (UserPasswordAuthToken) token;
                User u = authenticate(credentials.getUsername(), credentials.getPassword());
                if(null != u){
                    System.out.println("####### LdapPAM: authenticate success (usr=" + u.getUsername() + ")")
                    return new AuthenticationResult(true, u, true);
                }else{
                    User usr = getUserOrNull(credentials.getUsername());
                    boolean authoritive = (null == usr || (null != usr.getOrigin() && usr.getOrigin().toLowerCase().startsWith("ldap://")) || (null != usr.getPassword() && !usr.getPassword().isEmpty()));
                    System.out.println("####### LdapPAM: authenticate failed (result=AuthenticationResult(false, " + u.getUsername() + ", "+authoritive+")")
                    return new AuthenticationResult(false, usr, authoritive);
                }
            }
        }
        System.out.println("####### LdapPAM: authenticate notoken (result=AuthenticationResult(false, null, false)")
        return new AuthenticationResult(false, null, false);
    }


    protected User getUserOrNull(String username){
        try{
            return userManagerService.getUserByName(username);
        }catch(NoResultException ex){
            return null;
        }
    }


    public User authenticate(String username, String cleartextPassword){
        User user = getUserOrNull(username);
        if(null == user)
            return null;

        if(null != user.getPassword() && !user.getPassword().isEmpty() && passwordHasher.validatePassword(user.getPassword(), cleartextPassword)){
            System.out.println("####### LdapPAM: authenticate with local password: success")
            return user;
        }else{
            SSystem.out.println("####### LdapPAM: authenticate with local password: fail")
        }

        LdapAuthenticator authenticator = new LdapAuthenticator();
        if(authenticator.authenticate(user, cleartextPassword)){
            System.out.println("####### LdapPAM: authenticate against directory server: success")
            return user;
        }else{
            System.out.println("####### LdapPAM: authenticate against directory server: failed")
            return null;
        }
    }

    public String getClientModuleName() {
        return CLIENT_MODULE_NAME;
    }

}


public class LdapAuthenticator {

    public boolean authenticate(User user, String password){
        if(null == user.getOrigin() || null == user.getGuid())
            return false;

        Properties props = new Properties();

        props.setProperty(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
        props.setProperty(Context.PROVIDER_URL, getProvider(user));
        props.setProperty(Context.URL_PKG_PREFIXES, "com.sun.jndi.url");
        props.setProperty(Context.SECURITY_AUTHENTICATION, "simple");

        props.setProperty(Context.SECURITY_PRINCIPAL, getPrincipal(user));
        props.setProperty(Context.SECURITY_CREDENTIALS, password);

        try {
            InitialDirContext ctx = new InitialDirContext(props);
            ctx.getAttributes(getPrincipal(user));
            return true;
        } catch (AuthenticationException e) {
            return false;
        } catch (InvalidNameException e) {
            throw new RuntimeException(e);
        } catch (NamingException e) {
            if(e.getMessage().contains("LdapErr: DSID-0C0906E8")){
                return false;
            }

        }

    }

    private String getProvider(User user) {
        String origin = user.getOrigin();
        int i = origin.lastIndexOf("/");

        return origin.substring(0, i);
    }

    private String getPrincipal(User user) {
        String origin = user.getOrigin();

        int i = user.getOrigin().lastIndexOf("/");
        return origin.substring(i + 1);
    }

}