<?php
/**
 * SCPHP
 *
 * An open source SmartClient library for PHP
 *
 * @package		SCPHP
 * @author		Fernando Marcelo Morgenstern <fernando@consultorpc.com> 
 * @copyright		Copyright (c) 2010, ConsultorPC
 * @license		http://www.gnu.org/licenses/lgpl-3.0-standalone.html
 * @link		http://smartclientphp.com/
 * @since		Version 0.1
 * @filesource
 */


/**
 * Smart Client Advanced Criteria to SQL converter
 *
 */
class ScAdvancedCriteriaToSql
{
	/**
	 * Array that stores all criterias
	 * 
	 * @var $_criterias 
	 */
	protected $_criterias = array();
	
	/**
	 * Operator
	 * 
	 * @var $_operator string
	 */
	protected $_operator;
	
	/**
	 * Array contaning a convert table between SC nomeclature and SQL
	 * 
	 * @var $_operatorToSql array
	 */
	protected $_operatorToSql = array(
		'iContains' => '[fieldName] LIKE "%[value]%"', 
		'iStartsWith' => '[fieldName] LIKE "[value]%"', 
		'iEndsWith' => '[fieldName] LIKE "%[value]"', 
		'iNotContains' => '[fieldName] NOT LIKE "%[value]%"', 
		'iNotStartsWith' => '[fieldName] NOT LIKE "[value]%"', 
		'iNotEndsWith' => '[fieldName] NOT LIKE "%[value]"', 
		'equals' => '[fieldName] = "[value]"', 
		'notEqual' => '[fieldName] != "[value]"', 
		'lessThan' => '[fieldName] < "[value]"', 
		'greaterThan' => '[fieldName] > "[value]"', 
		'lessOrEqual' => '[fieldName] <= "[value]"', 
		'greaterOrEqual' => '[fieldName] >= "[value]"', 
		'between' => '[fieldName] BETWEEN "[start]" AND "[end]"', 
		'isNull' => '[fieldName] IS NULL', 
		'notNull' => '[fieldName] NOT NULL'
	);
	
	/**
	 * Construct function
	 */
	public function __construct()
	{
	
	}
	
	/**
	 * Add a new criteria
	 * 
	 * @param array|string $criteria
	 * @return void
	 */
	public function addCriteria( $criteria )
	{
		if (! is_array($criteria))
		{
			$criteria = json_decode(stripslashes($criteria), true);
		}
		
		$this->_criterias[] = $criteria;
	}
	
	/**
	 * Get all criterias
	 * 
	 * @return array
	 */
	public function getCriterias()
	{
		return $this->_criterias;
	}
	
	/**
	 * Clear all criterias
	 * 
	 * @return void
	 */
	public function clearCriterias()
	{
		unset($this->_criterias);
	}
	
	/**
	 * Set operator
	 * 
	 * @param string $operator
	 * @return void
	 */
	public function setOperator( $operator )
	{
		// TODO: validate operator
		$this->_operator = $operator;
	}
	
	/**
	 * Get operator
	 * 
	 * @return string
	 */
	public function getOperator()
	{
		return $this->_operator;
	}
	
	/**
	 * Set criterias and operator from post, coming directly from SC component
	 * 
	 * @param array $post
	 * @return boolean
	 */
	public function setFromPost( $post )
	{
		// Check if constructor is advanced criteria
		if ($post['_constructor'] == 'AdvancedCriteria')
		{
			// Check if multiple criterias are coming on an array
			if (is_array($post['criteria']))
			{
				// Loop on all criterias
				foreach ($post['criteria'] as $criteria)
				{
					// Add criteria
					$this->addCriteria($criteria);
				}
			}
			else
			{
				// Single criteria, set it
				$this->addCriteria($post['criteria']);
			}
			
			// Set operator
			$this->setOperator($post['operator']);
			
			return true;
		}
		else
		{
			return false;
		}
	}
	
	/**
	 * Process criteria and operators, returning the SQL
	 * 
	 * @return string|boolean
	 */
	public function getSql()
	{
		// Check if criterias are set and is an array
		if (empty($this->_criterias) && is_array($this->_criterias))
		{
			return false;
		}
		
		// Check if we have an operator value
		if (empty($this->_operator))
		{
			$this->_operator = 'and';
		}
		
		$criteriaWhere = ' ( ';
		
		// Loop on all criterias adding them
		$totalCriterias = count($this->_criterias);
		for ($i = 0; $i < $totalCriterias; $i ++)
		{
			// Do not add operator on first criteria
			if ($i != 0)
			{
				$criteriaWhere .= ' ) ' . $this->_operator . ' ( ';
			}
			
			// Process this criteria
			$criteriaWhere .= $this->_processCriteria($this->_criterias[$i]);
		}
		
		$criteriaWhere .= ' ) ';
		
		// Return sql
		return $criteriaWhere;
	}
	
	/**
	 * Process criteria and return sql
	 * 
	 * @param mixed $criteria
	 * @return string
	 */
	protected function _processCriteria( $criteria )
	{
		// Check if criteria is an array. If it is loop on all criterias and process them
		if (is_array($criteria['criteria']))
		{
			$returnString = '';
			
			$totalCriterias = count($criteria['criteria']);
			for ($i = 0; $i < $totalCriterias; $i ++)
			{
				if ($i != 0)
				{
					$returnString .= ' ' . $criteria['operator'] . ' ';
				}
				
				$returnString .= $this->_processCriteria($criteria['criteria'][$i]);
			}
			
			return $returnString;
		}
		else
		{
			// Use operatorToSql table to convert criteria to SQL
			$returnString = str_replace('[fieldName]', $criteria['fieldName'], $this->_operatorToSql[$criteria['operator']]);
			$returnString = str_replace('[value]', $criteria['value'], $returnString);
			$returnString = str_replace('[start]', $criteria['start'], $returnString);
			$returnString = str_replace('[end]', $criteria['end'], $returnString);
			
			return $returnString;
		}
	}
}