/**
 *
 * 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.jivesoftware.smackx.xdata.Form;
import org.jivesoftware.smackx.xdata.FormField;
import org.jivesoftware.smackx.xdata.packet.DataForm;

import org.jxmpp.util.XmppDateTime;

/**
 * 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<>(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<>(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);
        }
    }
}