package org.keycloak.authentication.authenticators.directgrant;

import org.jboss.logging.Logger;
import org.keycloak.Config;
import org.keycloak.OAuth2Constants;
import org.keycloak.authentication.AuthenticationProcessor;
import org.keycloak.authentication.Authenticator;
import org.keycloak.authentication.AuthenticatorContext;
import org.keycloak.authentication.AuthenticatorFactory;
import org.keycloak.authentication.authenticators.browser.AbstractFormAuthenticator;
import org.keycloak.events.Details;
import org.keycloak.events.Errors;
import org.keycloak.models.AuthenticationExecutionModel;
import org.keycloak.models.KeycloakSession;
import org.keycloak.models.KeycloakSessionFactory;
import org.keycloak.models.ModelDuplicateException;
import org.keycloak.models.RealmModel;
import org.keycloak.models.UserModel;
import org.keycloak.models.utils.KeycloakModelUtils;
import org.keycloak.provider.ProviderConfigProperty;
import org.keycloak.services.managers.AuthenticationManager;
import org.keycloak.services.messages.Messages;

import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.Response;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

/**
 * @author <a href="mailto:bill@burkecentral.com">Bill Burke</a>
 * @version $Revision: 1 $
 */
public class ValidateUsername extends AbstractDirectGrantAuthenticator {

    private static final Logger logger = Logger.getLogger(ValidateUsername.class);
    public static final String PROVIDER_ID = "direct-grant-validate-username";

    @Override
    public void authenticate(AuthenticatorContext context) {
        MultivaluedMap<String, String> inputData = context.getHttpRequest().getDecodedFormParameters();
        String username = inputData.getFirst(AuthenticationManager.FORM_USERNAME);
        if (username == null) {
            context.getEvent().error(Errors.USER_NOT_FOUND);
            Response challengeResponse = errorResponse(Response.Status.UNAUTHORIZED.getStatusCode(), "invalid_request", "Missing parameter: username");
            context.failure(AuthenticationProcessor.Error.INVALID_USER, challengeResponse);
            return;
        }
        context.getEvent().detail(Details.USERNAME, username);
        context.getClientSession().setNote(AbstractFormAuthenticator.ATTEMPTED_USERNAME, username);

        UserModel user = null;
        try {
            user = KeycloakModelUtils.findUserByNameOrEmail(context.getSession(), context.getRealm(), username);
        } catch (ModelDuplicateException mde) {
            logger.error(mde.getMessage(), mde);
            Response challengeResponse = errorResponse(Response.Status.UNAUTHORIZED.getStatusCode(), "invalid_request", "Invalid user credentials");
            context.failure(AuthenticationProcessor.Error.INVALID_USER, challengeResponse);
            return;
        }


        if (user == null) {
            context.getEvent().error(Errors.INVALID_USER_CREDENTIALS);
            Response challengeResponse = errorResponse(Response.Status.UNAUTHORIZED.getStatusCode(), "invalid_grant", "Invalid user credentials");
            context.failure(AuthenticationProcessor.Error.INVALID_USER, challengeResponse);
            return;
        }
        if (!user.isEnabled()) {
            context.getEvent().user(user);
            context.getEvent().error(Errors.USER_DISABLED);
            Response challengeResponse = errorResponse(Response.Status.BAD_REQUEST.getStatusCode(), "invalid_grant", "Account disabled");
            context.failure(AuthenticationProcessor.Error.INVALID_USER, challengeResponse);
            return;
        }
        if (context.getRealm().isBruteForceProtected()) {
            if (context.getProtector().isTemporarilyDisabled(context.getSession(), context.getRealm(), user.getUsername())) {
                context.getEvent().user(user);
                context.getEvent().error(Errors.USER_TEMPORARILY_DISABLED);
                Response challengeResponse = errorResponse(Response.Status.BAD_REQUEST.getStatusCode(), "invalid_grant", "Account temporarily disabled");
                context.failure(AuthenticationProcessor.Error.INVALID_USER, challengeResponse);
                return;
            }
        }
        context.setUser(user);
        context.success();
    }

    @Override
    public boolean requiresUser() {
        return false;
    }

    @Override
    public boolean configuredFor(KeycloakSession session, RealmModel realm, UserModel user) {
        return true;
    }

    @Override
    public void setRequiredActions(KeycloakSession session, RealmModel realm, UserModel user) {

    }

    @Override
    public boolean isUserSetupAllowed() {
        return false;
    }


    @Override
    public String getDisplayType() {
        return "Username Validation";
    }

    @Override
    public String getReferenceCategory() {
        return null;
    }

    @Override
    public boolean isConfigurable() {
        return false;
    }

    public static final AuthenticationExecutionModel.Requirement[] REQUIREMENT_CHOICES = {
            AuthenticationExecutionModel.Requirement.REQUIRED
    };

    @Override
    public AuthenticationExecutionModel.Requirement[] getRequirementChoices() {
        return REQUIREMENT_CHOICES;
    }

    @Override
    public String getHelpText() {
        return "Validates the username supplied as a 'username' form parameter in direct grant request";
    }

    @Override
    public List<ProviderConfigProperty> getConfigProperties() {
        return new LinkedList<>();
    }

    @Override
    public String getId() {
        return PROVIDER_ID;
    }
}
