<?php
/**
 * Created by PhpStorm.
 * User: software
 * Date: 16/1/15
 * Time: 3:55 PM
 */

namespace OfficeBrain\Bundle\CoreBundle\DoctrineExtensions\Concat\Mysql;
use Doctrine\ORM\Query\AST\Functions\FunctionNode,
    Doctrine\ORM\Query\Lexer;

class ConcatWs extends FunctionNode
{
    private $values = array();
    private $notEmpty = false;
    public function parse(\Doctrine\ORM\Query\Parser $parser)
    {
        $parser->match(Lexer::T_IDENTIFIER);
        $parser->match(Lexer::T_OPEN_PARENTHESIS);
// Add the concat separator to the values array.
        $this->values[] = $parser->ArithmeticExpression();
// Add the rest of the strings to the values array. CONCAT_WS must
// be used with at least 2 strings not including the separator.
        $lexer = $parser->getLexer();
        while (count($this->values) < 3
            || $lexer->lookahead['type'] == Lexer::T_COMMA)
        {
            $parser->match(Lexer::T_COMMA);
            $peek = $lexer->glimpse();
            $this->values[] = $peek['value'] == '('
                ? $parser->FunctionDeclaration()
                : $parser->ArithmeticExpression();
        }
        while ($lexer->lookahead['type'] == Lexer::T_IDENTIFIER)
        {
            switch (strtolower($lexer->lookahead['value']))
            {
                case 'notempty':
                    $parser->match(Lexer::T_IDENTIFIER);
                    $this->notEmpty = true;
                    break;
                default: // Identifier not recognized (causes exception).
                    $parser->match(Lexer::T_CLOSE_PARENTHESIS);
                    break;
            }
        }
        $parser->match(Lexer::T_CLOSE_PARENTHESIS);
    }
    public function getSql(\Doctrine\ORM\Query\SqlWalker $sqlWalker)
    {
// Create an array to hold the query elements.
        $queryBuilder = array('CONCAT_WS(');
// Iterate over the captured expressions and add them to the query.
        for ($i = 0; $i < count($this->values); $i++)
        {
            if ($i > 0)
            {
                $queryBuilder[] = ', ';
            }
// Dispatch the walker on the current node.
            $nodeSql = $sqlWalker->walkArithmeticPrimary($this->values[$i]);
            if ($this->notEmpty)
            {
// Exclude empty strings from the concatenation.
                $nodeSql = sprintf("NULLIF(%s, '')", $nodeSql);
            }
            $queryBuilder[] = $nodeSql;
        }
// Close the query.
        $queryBuilder[] = ')';
// Return the joined query.
        return implode('', $queryBuilder);
    }
}
?>