/*-
 * ============LICENSE_START=======================================================
 * ONAP Policy Engine
 * ================================================================================
 * Copyright (C) 2017, 2019 AT&T Intellectual Property. All rights reserved.
 * Modified Copyright (C) 2018 Samsung Electronics Co., Ltd.
 * Modifications Copyright (C) 2019 Bell Canada
 * ================================================================================
 * 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.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Properties;

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 final String SCOPE_POLICY_NAME = "Scope + Policy Name  : ";
    private static final String DELETED_TIME = "Deleted Time  : ";
    private static final String DELETED_BY = "Deleted By : ";
    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
     */
    public void sendMail(PolicyVersion entityItem, String policyName, String mode,
            CommonClassDao policyNotificationDao) {

        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 checkPolicyName = findCheckPolicyName(policyName);

        String policyFileName = findPolicyFileName(entityItem);
        String query = "from WatchPolicyNotificationTable where policyName like:policyFileName";
        List<Object> watchList = findWatchList(policyNotificationDao, policyFileName, query);
        if (!watchList.isEmpty()) {
            composeAndSendMail(mode, policyNotificationDao, subject, message, checkPolicyName, watchList);
        }
    }

    private List<Object> findWatchList(CommonClassDao policyNotificationDao, String policyFileName, String query) {
        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");
            watchList = new ArrayList<>();
        }
        return watchList;
    }

    private String findPolicyFileName(PolicyVersion entityItem) {
        String policyFileName = entityItem.getPolicyName();
        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 += "%";
        return policyFileName;
    }

    private String findCheckPolicyName(String policyName) {
        String checkPolicyName = policyName;
        if (checkPolicyName.endsWith(".xml") || checkPolicyName.contains(".")) {
            checkPolicyName = checkPolicyName.substring(0, checkPolicyName.indexOf('.'));
        }
        return checkPolicyName;
    }

    /**
     * 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);
            }

        }
    }
}