/**
 *
 * Copyright the original author or authors
 *
 * 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.
 */
package org.jivesoftware.smackx.pubsub;

import java.text.ParseException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.List;
import java.util.UnknownFormatConversionException;

import org.jxmpp.util.XmppDateTime;
import org.jivesoftware.smackx.xdata.Form;
import org.jivesoftware.smackx.xdata.FormField;
import org.jivesoftware.smackx.xdata.packet.DataForm;

/**
 * A decorator for a {@link Form} to easily enable reading and updating
 * of subscription options.  All operations read or update the underlying {@link DataForm}.
 * 
 * <p>Unlike the {@link Form}.setAnswer(XXX)} methods, which throw an exception if the field does not
 * exist, all <b>SubscribeForm.setXXX</b> methods will create the field in the wrapped form
 * if it does not already exist.
 * 
 * @author Robin Collier
 */
public class SubscribeForm extends Form
{       
        public SubscribeForm(DataForm configDataForm)
        {
                super(configDataForm);
        }
        
        public SubscribeForm(Form subscribeOptionsForm)
        {
                super(subscribeOptionsForm.getDataFormToSend());
        }
        
        public SubscribeForm(DataForm.Type formType)
        {
                super(formType);
        }
        
        /**
         * Determines if an entity wants to receive notifications.
         * 
         * @return true if want to receive, false otherwise
         */
        public boolean isDeliverOn()
        {
                return parseBoolean(getFieldValue(SubscribeOptionFields.deliver));
        }
        
        /**
         * Sets whether an entity wants to receive notifications.
         *
         * @param deliverNotifications
         */
        public void setDeliverOn(boolean deliverNotifications)
        {
                addField(SubscribeOptionFields.deliver, FormField.Type.bool);
                setAnswer(SubscribeOptionFields.deliver.getFieldName(), deliverNotifications);
        }

        /**
         * Determines if notifications should be delivered as aggregations or not.
         * 
         * @return true to aggregate, false otherwise
         */
        public boolean isDigestOn()
        {
                return parseBoolean(getFieldValue(SubscribeOptionFields.digest));
        }
        
        /**
         * Sets whether notifications should be delivered as aggregations or not.
         * 
         * @param digestOn true to aggregate, false otherwise 
         */
        public void setDigestOn(boolean digestOn)
        {
                addField(SubscribeOptionFields.deliver, FormField.Type.bool);
                setAnswer(SubscribeOptionFields.deliver.getFieldName(), digestOn);
        }

        /**
         * Gets the minimum number of milliseconds between sending notification digests
         * 
         * @return The frequency in milliseconds
         */
        public int getDigestFrequency()
        {
                return Integer.parseInt(getFieldValue(SubscribeOptionFields.digest_frequency));
        }

        /**
         * Sets the minimum number of milliseconds between sending notification digests
         * 
         * @param frequency The frequency in milliseconds
         */
        public void setDigestFrequency(int frequency)
        {
                addField(SubscribeOptionFields.digest_frequency, FormField.Type.text_single);
                setAnswer(SubscribeOptionFields.digest_frequency.getFieldName(), frequency);
        }

        /**
         * Get the time at which the leased subscription will expire, or has expired.
         * 
         * @return The expiry date
         */
        public Date getExpiry()
        {
                String dateTime = getFieldValue(SubscribeOptionFields.expire);
                try
                {
                        return XmppDateTime.parseDate(dateTime);
                }
                catch (ParseException e)
                {
                        UnknownFormatConversionException exc = new UnknownFormatConversionException(dateTime);
                        exc.initCause(e);
                        throw exc;
                }
        }
        
        /**
         * Sets the time at which the leased subscription will expire, or has expired.
         * 
         * @param expire The expiry date
         */
        public void setExpiry(Date expire)
        {
                addField(SubscribeOptionFields.expire, FormField.Type.text_single);
                setAnswer(SubscribeOptionFields.expire.getFieldName(), XmppDateTime.formatXEP0082Date(expire));
        }
        
        /**
         * Determines whether the entity wants to receive an XMPP message body in 
         * addition to the payload format.
         * 
         * @return true to receive the message body, false otherwise
         */
        public boolean isIncludeBody()
        {
                return parseBoolean(getFieldValue(SubscribeOptionFields.include_body));
        }
        
        /**
         * Sets whether the entity wants to receive an XMPP message body in 
         * addition to the payload format.
         * 
         * @param include true to receive the message body, false otherwise
         */
        public void setIncludeBody(boolean include)
        {
                addField(SubscribeOptionFields.include_body, FormField.Type.bool);
                setAnswer(SubscribeOptionFields.include_body.getFieldName(), include);
        }

        /**
         * Gets the {@link PresenceState} for which an entity wants to receive 
         * notifications.
         * 
         * @return the list of states
         */
        public List<PresenceState> getShowValues()
        {
                ArrayList<PresenceState> result = new ArrayList<PresenceState>(5);
                
                for (String state : getFieldValues(SubscribeOptionFields.show_values))
                {
                        result.add(PresenceState.valueOf(state));
                }
                return result;
        }
        
        /**
         * Sets the list of {@link PresenceState} for which an entity wants
         * to receive notifications.
         * 
         * @param stateValues The list of states
         */
        public void setShowValues(Collection<PresenceState> stateValues)
        {
                ArrayList<String> values = new ArrayList<String>(stateValues.size());
                
                for (PresenceState state : stateValues)
                {
                        values.add(state.toString());
                }
                addField(SubscribeOptionFields.show_values, FormField.Type.list_multi);
                setAnswer(SubscribeOptionFields.show_values.getFieldName(), values);
        }
        
        
        static private boolean parseBoolean(String fieldValue)
        {
                return ("1".equals(fieldValue) || "true".equals(fieldValue));
        }

        private String getFieldValue(SubscribeOptionFields field)
        {
                FormField formField = getField(field.getFieldName());
                
                return formField.getValues().get(0);
        }

        private List<String> getFieldValues(SubscribeOptionFields field)
        {
                FormField formField = getField(field.getFieldName());
                
                return formField.getValues();
        }

        private void addField(SubscribeOptionFields nodeField, FormField.Type type)
        {
                String fieldName = nodeField.getFieldName();
                
                if (getField(fieldName) == null)
                {
                        FormField field = new FormField(fieldName);
                        field.setType(type);
                        addField(field);
                }
        }
}