<?php
/**
 * Google Utilities Script
 * 
 * This file contains the classes for various google utilities.
 * 
 * @author Aaron Saray
 */
 
/**
 * Google Parent class
 * 
 * Any shared google class items
 */
class google
{
}
 
/**
 * Google Search string class
 * 
 * This class helps create a google search string
 * 
 * Inspired by: http://www.our-picks.com/archives/2007/01/30/google-search-urls-revealed-or-how-to-create-your-own-search-url/
 */
class google_searchString extends google
{
 
	/**
	 * search terms
	 * @var string
	 */
	public $searchTerms = null;
 
	/**
	 * exclude search terms
	 * @var string
	 */
	public $excludeSearchTerms = null;
 
	/**
	 * or query?
	 * @var boolean
	 */
	public $isOr = false;
 
	/**
	 * same page query?
	 * 
	 * Means the search terms must be found on the same page, not necessarily next to each other
	 * @var boolean
	 */
	public $isSamePage = true;
 
	/**
	 * phrase query?
	 * @var boolean
	 */
	public $isPhrase = false;
 
	/**
	 * Number results (0 - 100)
	 * @var integer
	 */
	public $numberResults = 10;
 
	/**
	 * Safe search?
	 * @var boolean
	 */
	public $isSafeSearch = true;
 
	/**
	 * Last updated
	 * 'y' Year  'm6' 6 months 'm3' 3 months
	 * @var string
	 */
	public $lastUpdated = null;
 
 
	/**********************************************************************************************/
 
 
 
	/**
	 * constructor
	 * Does nothing currently
	 */
	public function __construct()
	{}
 
	/**
	 * Get output.
	 * 
	 * This will return the google search string.  
	 * @throws google_searchStringException
	 * @return string
	 */
	public function getString()
	{
	    /** process sanity/check for errors **/
	    $this->_sanityCheck();
 
	    /** process into an array **/
	    $values = $this->_processValues();
 
	    /** return the built get string **/
	    return "http://www.google.com/search?" . http_build_query($values);
	}
 
 
 
	/**********************************************************************************************/
 
 
	/**
	 * Checks for errors and unset items that could cause an error for the processing script
	 * @throws google_searchStringException
	 */
	protected function _sanityCheck()
	{
	    /**
	     * check for a search term.
	     */
	    if ($this->searchTerms === NULL) {
	        throw new google_searchStringException("Must enter a search term");
	    }
 
	    /**
	     * check if at least but not more than 1 search types
	     */
	    $isTypes = array('isOr', 'isPhrase', 'isSamePage');
	    $count = 0;
	    foreach ($isTypes as $type) {
	        if ($this->$type) {
	            $count++;
	        }
	    }
	    if (count($count) < 1) {
	        throw new google_searchStringException("One type of search must be true.");
	    }
	    else if (count($count) > 1) {
	        throw new google_searchStringException("Only one type of search must be true.");
	    }
 
	    /**
	     * check last updated
	     */
	    if ($this->lastUpdated !== NULL) {
    	    $upTypes = array('y', 'm6', 'm3');
    	    if (!in_array($this->lastUpdated, $upTypes)) {
    	        throw new google_searchStringException("Only the following values are allowed for last updated: " . implode(',', $upTypes));
    	    }
	    }
	}
 
	/**
	 * process values and returns them in the form of an array for a get statement
	 * 
	 * @return array
	 */
	protected function _processValues()
	{
	    $values = array();
 
	    /**
	     * get our search string into our type
	     */
	    switch (true) {
	        /** yes thats tacky ;) **/
	        case $this->isOr:
	            $values['as_oq'] = $this->searchTerms;
	            break;
 
	        case $this->isPhrase:
	            $values['as_epq'] = $this->searchTerms;
	            break;
 
	        case $this->isSamePage:
	            $values['as_q'] = $this->searchTerms;
	            break;
	    }
 
	    /**
	     * set exclusion
	     */
	    if ($this->excludeSearchTerms !== NULL) {
	        $values['as_eq'] = $this->excludeSearchTerms;
	    }
 
	    /**
	     * set number of results
	     */
	    $values['num'] = $this->numberResults;
 
	    /**
	     * set safe search
	     */
	    $values['safe'] = $this->isSafeSearch;
 
	    /**
	     * set updated
	     */
	    if ($this->lastUpdated !== NULL) {
	        $values['as_qdr'] = $this->lastUpdated;
	    }
 
	    /**
	     * send it back now
	     */
	    return $values;
	}
 
}
 
/**
 * Google Search String Exception
 */
class google_searchStringException extends exception
{}
 
 
 
 
/**
 * test
 */
$search = new google_searchString();
$search->searchTerms = 'test page';
 
print $search->getString();