<?php
/**
 * Implements the Histogram facet.
 *
 * @category Xodoa
 * @package Elastica
 * @author Raul Martinez Jr  <hide@address.com>
 * @link http://www.elasticsearch.org/guide/reference/api/search/facets/histogram-facet.html
 */
class Elastica_Facet_Histogram extends Elastica_Facet_Abstract
{
    /**
     * Sets the field for histogram
     *
     * @param  string                   $field The name of the field for the historgram
     * @return Elastica_Facet_Histogram
     */
    public function setField($field)
    {
        return $this->setParam('field', $field);
    }

    /**
     * Set the value for interval
     *
     * @param  string               $interval
     * @return Elastica_Facet_Range
     */
    public function setInterval($interval)
    {
        return $this->setParam('interval', $interval);
    }

    /**
     * Set the fields for key_field and value_field
     *
     * @param  string               $keyField   Key field
     * @param  string               $valueField Value field
     * @return Elastica_Facet_Range
     */
    public function setKeyValueFields($keyField, $valueField)
    {
        return $this->setParam('key_field', $keyField)->setParam('value_field', $valueField);
    }

    /**
     * Sets the key and value for this facet by script.
     *
     * @param string $keyScript   Script to check whether it falls into the range.
     * @param string $valueScript Script to use for statistical calculations.
     */
    public function setKeyValueScripts($keyScript, $valueScript)
    {
        return $this->setParam('key_script', $keyScript)
                    ->setParam('value_script', $valueScript);
    }

    /**
     * Set the "params" essential to the a script
     *
     * @param  array                    $params Associative array (key/value pair)
     * @return Elastica_Facet_Histogram Facet object
     */
    public function setScriptParams(array $params)
    {
        return $this->setParam('params', $params);
    }

    /**
     * Creates the full facet definition, which includes the basic
     * facet definition of the parent.
     *
     * @see Elastica_Facet_Abstract::toArray()
     * @throws Elastica_Exception_Invalid When the right fields haven't been set.
     * @return array
     */
    public function toArray()
    {
        /**
         * Set the range in the abstract as param.
         */
        $this->_setFacetParam('histogram', $this->_params);

        return parent::toArray();
    }
}