/**
 * Copyright 2005-2016 The Kuali Foundation
 *
 * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
 *
 * 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.
 */
package org.kuali.rice.kcb.deliverer.impl;

import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.Set;

import org.apache.commons.validator.EmailValidator;
import org.apache.log4j.Logger;
import org.kuali.rice.kcb.bo.MessageDelivery;
import org.kuali.rice.kcb.deliverer.MessageDeliverer;
import org.kuali.rice.kcb.exception.ErrorList;
import org.kuali.rice.kcb.api.exception.MessageDeliveryException;
import org.kuali.rice.kcb.api.exception.MessageDismissalException;
import org.kuali.rice.kcb.service.EmailService;
import org.kuali.rice.kcb.service.GlobalKCBServiceLocator;
import org.kuali.rice.kcb.service.RecipientPreferenceService;

/**
 * This class is responsible for describing the email delivery mechanism for
 * the system.
 * @author Kuali Rice Team (rice.collab@kuali.org)
 */
public class EmailMessageDeliverer implements MessageDeliverer {
    private static Logger LOG = Logger.getLogger(EmailMessageDeliverer.class);

    private EmailService emailService;
    private RecipientPreferenceService recipientPreferenceService;

    public static final String NAME = "Email";
    public static final String EMAIL_ADDR_PREF_KEY = "email_address";
    public static final String EMAIL_DELIV_FRMT_PREF_KEY = "email_delivery_format";

    /**
     * Constructs a EmailMessageDeliverer.java.
     */
    public EmailMessageDeliverer() {
        this.emailService = GlobalKCBServiceLocator.getInstance().getEmailService();
        this.recipientPreferenceService = GlobalKCBServiceLocator.getInstance().getRecipientPreferenceService();
    }

    /**
     * This implementation uses the email service to deliver a notification.
     * @see org.kuali.rice.kcb.deliverer.MessageDeliverer#deliver(MessageDelivery)
     */
    public void deliver(MessageDelivery messageDelivery) throws MessageDeliveryException {
        try {
            // figure out the proper recipient email address
            String recipientEmailAddressPrefKey = getName()+"."+EMAIL_ADDR_PREF_KEY;
            String recipientEmailFormatPrefKey = getName()+"."+EMAIL_DELIV_FRMT_PREF_KEY;

            String recipientEmailAddress = recipientPreferenceService.getRecipientPreference(messageDelivery.getMessage().getRecipient(), recipientEmailAddressPrefKey).getValue();
            String recipientEmailFormat = recipientPreferenceService.getRecipientPreference(messageDelivery.getMessage().getRecipient(), recipientEmailFormatPrefKey).getValue();

            //String recipientEmailAddress = GlobalNotificationServiceLocator.getInstance().getKENAPIService().getRecipientPreference(messageDelivery.getMessage().getRecipient(), recipientEmailAddressPrefKey);
            //String recipientEmailFormat = GlobalNotificationServiceLocator.getInstance().getKENAPIService().getRecipientPreference(messageDelivery.getMessage().getRecipient(), recipientEmailFormatPrefKey);

            Long emailMessageId = emailService.sendEmail(messageDelivery, recipientEmailAddress, recipientEmailFormat);

            String deliverySystemId = null;
            if (emailMessageId != null) {
                deliverySystemId = emailMessageId.toString();
            }
            messageDelivery.setDelivererSystemId(deliverySystemId);
        } catch (Exception we) {
            LOG.error("Error delivering email notification", we);
            throw new MessageDeliveryException("Error delivering email notification", we);
        }
    }

    /**
     * This implementation does an auto-remove by "canceling" the workflow email with the message delivery record. 
     * In the case of email, it's a noop 
     * @see org.kuali.rice.kcb.deliverer.MessageDeliverer#autoRemoveMessageDelivery(org.kuali.rice.ken.bo.NotificationMessageDelivery)
     */
    public void autoRemoveMessageDelivery(MessageDelivery messageDelivery) /*throws NotificationAutoRemoveException*/ {
        // we can't remove an email message once it has been sent
    }

    /**
     * @see org.kuali.rice.kcb.deliverer.MessageDeliverer#dismiss(org.kuali.rice.kcb.bo.MessageDelivery, java.lang.String, java.lang.String)
     */
    public void dismiss(MessageDelivery messageDelivery, String user, String cause) throws MessageDismissalException {
        // we can't remove an email message once it has been sent
    }

    /**
     * @see org.kuali.rice.kcb.deliverer.MessageDeliverer#getDescription()
     */
    public String getDescription() {
        return "Enter an Email Address and Email Delivery Format below and select the channels for which you would like email delivery " +
               "notifications. Select \"None\" in the channel list to remove a delivery type for all channels.  " +
               "Only one Email Address and Email Delivery Format may be specified. Any data entered and " +
               "saved will override prior Delivery Type selections.";
    }

    /**
     * @see org.kuali.rice.kcb.deliverer.MessageDeliverer#getName()
     */
    public String getName() {
        return NAME;
    }

    /**
     * @see org.kuali.rice.kcb.deliverer.MessageDeliverer#getTitle()
     */
    public String getTitle() {
        return "Email Message Delivery";
    }

    /**
     * This implementation returns an address field.
     * @see org.kuali.rice.kcb.deliverer.MessageDeliverer#getPreferenceKeys()
     */
    public LinkedHashMap<String, String> getPreferenceKeys() {
        LinkedHashMap<String, String> prefKeys = new LinkedHashMap<String, String>();
        prefKeys.put(EMAIL_ADDR_PREF_KEY, "Email Address (\"abc@def.edu\")");
        prefKeys.put(EMAIL_DELIV_FRMT_PREF_KEY, "Email Delivery Format (text or html)");
        return prefKeys;
    }

    /**
     * @see org.kuali.rice.kcb.deliverer.MessageDeliverer#validatePreferenceValues(java.util.HashMap)
     */
    public void validatePreferenceValues(HashMap<String, String> prefs) throws ErrorList {
        boolean error = false;
        ErrorList errorList = new ErrorList();
        String[] validformats = {"text","html"};

        if (!prefs.containsKey(getName()+"."+EMAIL_ADDR_PREF_KEY)) {
            errorList.addError("Email Address is a required field.");
            error = true;
        } else {
            String addressValue = (String) prefs.get(getName()+"."+EMAIL_ADDR_PREF_KEY);
            EmailValidator validator = EmailValidator.getInstance();
            if (!validator.isValid(addressValue)) {
                errorList.addError("Email Address is required and must be properly formatted - \"abc@def.edu\".");
                error = true;
            }
        }

        // validate format
        if (!prefs.containsKey(getName()+"."+EMAIL_DELIV_FRMT_PREF_KEY)) {
            errorList.addError("Email Delivery Format is required.");
            error = true;
        } else {
            String formatValue = (String) prefs.get(getName()+"."+EMAIL_DELIV_FRMT_PREF_KEY);
            Set<String> formats = new HashSet<String>();
            for (int i=0; i < validformats.length ; i++) {
                formats.add(validformats[i]);
            }

            if (!formats.contains(formatValue)) {
                errorList.addError("Email Delivery Format is required and must be entered as \"text\" or \"html\".");
                error = true;
            }
        }

        if (error) throw errorList;
    }
}
