/*-
 * ============LICENSE_START=======================================================
 * ONAP Policy Engine
 * ================================================================================
 * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
 * Modified Copyright (C) 2018 Samsung Electronics Co., Ltd.
 * ================================================================================
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * ============LICENSE_END=========================================================
 */

package org.onap.policy.admin;

import java.io.File;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.Properties;

import javax.mail.MessagingException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.script.SimpleBindings;

import org.onap.policy.common.logging.flexlogger.FlexLogger;
import org.onap.policy.common.logging.flexlogger.Logger;
import org.onap.policy.controller.PolicyController;
import org.onap.policy.rest.dao.CommonClassDao;
import org.onap.policy.rest.jpa.PolicyVersion;
import org.onap.policy.rest.jpa.WatchPolicyNotificationTable;
import org.onap.policy.xacml.api.XACMLErrorConstants;
import org.springframework.beans.factory.annotation.Configurable;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.mail.javamail.JavaMailSenderImpl;
import org.springframework.mail.javamail.MimeMessageHelper;

/**
 * Send policy notification mail depending on the mode for every policy being watched
 */
@Configurable
public class PolicyNotificationMail{
    private static final String POLICY_WATCHING_MESSAGE = "The Policy Which you are watching in  ";
    private static final String EMAIL_MESSAGE_POSTSCRIPT = "Policy Notification System  (please don't respond to this email)";
    private static final String ACTIVE_VERSION = "Active Version  : ";
    private static Logger policyLogger	= FlexLogger.getLogger(PolicyNotificationMail.class);

    @Bean
    public JavaMailSenderImpl javaMailSenderImpl(){
        JavaMailSenderImpl mailSender = new JavaMailSenderImpl();
        mailSender.setHost(PolicyController.getSmtpHost());
        mailSender.setPort(Integer.parseInt(PolicyController.getSmtpPort()));
        mailSender.setUsername(PolicyController.getSmtpUsername());
        mailSender.setPassword(PolicyController.getSmtpPassword());
        Properties prop = mailSender.getJavaMailProperties();
        prop.put("mail.transport.protocol", "smtp");
        prop.put("mail.smtp.auth", "true");
        prop.put("mail.smtp.starttls.enable", "true");
        prop.put("mail.debug", "true");
        return mailSender;
    }

    /**
     * Depending on the mode of operation on the policy, compose the subject and message.
     * Invoke another internal method to actual send the mail. If the watch list is empty , then
     * this method returns without sending notification mail
     * @param entityItem Database item from which policy name could be extracted
     * @param policyName Name of the policy for which notification is to be sent
     * @param mode kind of operation done on the policy
     * @param policyNotificationDao database access object for policy
     * @throws MessagingException
     */
    public void sendMail(PolicyVersion entityItem, String policyName, String mode, CommonClassDao policyNotificationDao) throws MessagingException {

        String subject = "";
        String message = "";
        DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
        Date date = new Date();
        if("EditPolicy".equalsIgnoreCase(mode)){
            subject = "Policy has been Updated : "+entityItem.getPolicyName();
            message = POLICY_WATCHING_MESSAGE + PolicyController.getSmtpApplicationName() + " has been Updated" + '\n'  + '\n'  + '\n'+ "Scope + Policy Name  : "  + policyName + '\n' + ACTIVE_VERSION +entityItem.getActiveVersion()
                     + '\n'  + '\n' + "Modified By : " +entityItem.getModifiedBy() + '\n' + "Modified Time  : " +dateFormat.format(date) + '\n' + '\n' + '\n' + '\n' + EMAIL_MESSAGE_POSTSCRIPT;
        }
        if("Rename".equalsIgnoreCase(mode)){
            subject = "Policy has been Renamed : "+entityItem.getPolicyName();
            message = POLICY_WATCHING_MESSAGE + PolicyController.getSmtpApplicationName() + " has been Renamed" + '\n'  + '\n'  + '\n'+ "Scope + Policy Name  : "  + policyName + '\n' + ACTIVE_VERSION +entityItem.getActiveVersion()
                     + '\n'  + '\n' + "Renamed By : " +entityItem.getModifiedBy() + '\n' + "Renamed Time  : " +dateFormat.format(date) + '\n' + '\n' + '\n' + '\n' + EMAIL_MESSAGE_POSTSCRIPT;
        }
        if("DeleteAll".equalsIgnoreCase(mode)){
            subject = "Policy has been Deleted : "+entityItem.getPolicyName();
            message = POLICY_WATCHING_MESSAGE + PolicyController.getSmtpApplicationName() + " has been Deleted with All Versions" + '\n'  + '\n'  + '\n'+ "Scope + Policy Name  : "  + policyName + '\n'
                     + '\n'  + '\n' + "Deleted By : " +entityItem.getModifiedBy() + '\n' + "Deleted Time  : " +dateFormat.format(date) + '\n' + '\n' + '\n' + '\n' + EMAIL_MESSAGE_POSTSCRIPT;
        }
        if("DeleteOne".equalsIgnoreCase(mode)){
            subject = "Policy has been Deleted : "+entityItem.getPolicyName();
            message = POLICY_WATCHING_MESSAGE + PolicyController.getSmtpApplicationName() + " has been Deleted" + '\n'  + '\n'  + '\n'+ "Scope + Policy Name  : "  + policyName + '\n'  +"Policy Version : " +entityItem.getActiveVersion()
                     + '\n'  + '\n' + "Deleted By : " +entityItem.getModifiedBy() + '\n' + "Deleted Time  : " +dateFormat.format(date) + '\n' + '\n' + '\n' + '\n' + EMAIL_MESSAGE_POSTSCRIPT;
        }
        if("DeleteScope".equalsIgnoreCase(mode)){
            subject = "Scope has been Deleted : "+entityItem.getPolicyName();
            message = "The Scope Which you are watching in  " + PolicyController.getSmtpApplicationName() + " has been Deleted" + '\n'  + '\n'  + '\n'+ "Scope + Scope Name  : "  + policyName + '\n'
                     + '\n'  + '\n' + "Deleted By : " +entityItem.getModifiedBy() + '\n' + "Deleted Time  : " +dateFormat.format(date) + '\n' + '\n' + '\n' + '\n' + EMAIL_MESSAGE_POSTSCRIPT;
        }
        if("SwitchVersion".equalsIgnoreCase(mode)){
            subject = "Policy has been SwitchedVersion : "+entityItem.getPolicyName();
            message = POLICY_WATCHING_MESSAGE + PolicyController.getSmtpApplicationName() + " has been SwitchedVersion" + '\n'  + '\n'  + '\n'+ "Scope + Policy Name  : "  + policyName + '\n' + ACTIVE_VERSION +entityItem.getActiveVersion()
                     + '\n'  + '\n' + "Switched By : " +entityItem.getModifiedBy() + '\n' + "Switched Time  : " +dateFormat.format(date) + '\n' + '\n' + '\n' + '\n' + EMAIL_MESSAGE_POSTSCRIPT;
        }
        if("Move".equalsIgnoreCase(mode)){
            subject = "Policy has been Moved to Other Scope : "+entityItem.getPolicyName();
            message = POLICY_WATCHING_MESSAGE + PolicyController.getSmtpApplicationName() + " has been Moved to Other Scope" + '\n'  + '\n'  + '\n'+ "Scope + Policy Name  : "  + policyName + '\n' + ACTIVE_VERSION +entityItem.getActiveVersion()
                     + '\n'  + '\n' + "Moved By : " +entityItem.getModifiedBy() + '\n' + "Moved Time  : " +dateFormat.format(date) + '\n' + '\n' + '\n' + '\n' + EMAIL_MESSAGE_POSTSCRIPT;
        }
        String policyFileName = entityItem.getPolicyName();
        String checkPolicyName = policyName;
        if(checkPolicyName.endsWith(".xml") || checkPolicyName.contains(".")){
            checkPolicyName = checkPolicyName.substring(0, checkPolicyName.indexOf('.'));
        }
        if(policyFileName.contains("/")){
            policyFileName = policyFileName.substring(0, policyFileName.indexOf('/'));
            policyFileName = policyFileName.replace("/", File.separator);
        }
        if(policyFileName.contains("\\")){
            policyFileName = policyFileName.substring(0, policyFileName.indexOf('\\'));
            policyFileName = policyFileName.replace("\\", "\\\\");
        }

        policyFileName += "%";
        String query = "from WatchPolicyNotificationTable where policyName like:policyFileName";

        SimpleBindings params = new SimpleBindings();
        params.put("policyFileName", policyFileName);
        List<Object> watchList;
        if(PolicyController.isjUnit()){
            watchList = policyNotificationDao.getDataByQuery(query, null);
        }else{
            watchList = policyNotificationDao.getDataByQuery(query, params);
        }

        if(watchList == null || watchList.isEmpty()) {
            policyLogger.debug("List of policy being watched is either null or empty, hence return without sending mail");
            return;
        }

        composeAndSendMail(mode, policyNotificationDao, subject, message, checkPolicyName, watchList);
    }

    /**
     * For every policy being watched and when the policy name is one of the Config_, Action_ or Decision_,
     * send the notification
     * @param mode
     * @param policyNotificationDao
     * @param subject
     * @param message
     * @param checkPolicyName
     * @param watchList
     */
    private void composeAndSendMail(String mode, CommonClassDao policyNotificationDao, String subject, String message, String checkPolicyName, List<Object> watchList) {
        String from = PolicyController.getSmtpUsername();
        String to;
        for(Object watch : watchList){
            WatchPolicyNotificationTable list = (WatchPolicyNotificationTable) watch;
            String watchPolicyName = list.getPolicyName();
            //this conditino check for specific stringin policy name being watched and
            //also if the policy being checked is different from the watched ones,
            //then there is no need to send mail, hence continue with next policy in the loop
            if((watchPolicyName.contains("Config_") || watchPolicyName.contains("Action_") || watchPolicyName.contains("Decision_"))
                    && !watchPolicyName.equals(checkPolicyName)){
                continue;
            }
            try (AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext()) {
                to = list.getLoginIds()+"@"+PolicyController.getSmtpEmailExtension();
                to = to.trim();
                ctx.register(PolicyNotificationMail.class);
                ctx.refresh();
                JavaMailSenderImpl mailSender = ctx.getBean(JavaMailSenderImpl.class);
                MimeMessage mimeMessage = mailSender.createMimeMessage();
                MimeMessageHelper mailMsg = new MimeMessageHelper(mimeMessage);
                mailMsg.setFrom(new InternetAddress(from, "Policy Notification System"));
                mailMsg.setTo(to);
                mailMsg.setSubject(subject);
                mailMsg.setText(message);
                mailSender.send(mimeMessage);
                if("Rename".equalsIgnoreCase(mode) || mode.contains("Delete") || mode.contains("Move")){
                    policyNotificationDao.delete(watch);
                }
            } catch (Exception e) {
                policyLogger.error(XACMLErrorConstants.ERROR_PROCESS_FLOW+"Exception Occured in Policy Notification" +e);
            }

        }
    }
}