<?php

class Where
{
    public $operation = 'AND';
    public $condition = '';
    public $childs    = [];
    public $params    = [];

    static private $DBH = NULL;

    /**
     * Where constructor.
     * If $condition is string, all next parameters
     * @param  $condition
     */
    public function __construct($condition)
    {
        //get DBH for escaping string
        if(empty(self::$DBH) && empty((self::$DBH = DBHandler::getHandler())))
            return NULL;

        if(is_string($condition))
        {
            $this->condition = $condition;
            $this->params    = array_slice(func_get_args(),1);
        }
        elseif(is_array($condition))
        {
            if(array_key_exists('condition',$condition) &&
                array_key_exists('values',$condition))
            {
                $this->condition = $condition['condition'];
                $this->params    = $condition['values'];
            }
            foreach ($condition as $k => $c)
                if(is_string($k))
                {
                    if ($k == 'operation')
                        $this->operation = $c;
                    else
                        $this->childs[] = new self($k, $c);
                }
                elseif(is_array($c))
                     $this->childs[] = new self($c);
        }
        else
        {
            foreach(func_get_args() as $a)
                $this->childs[] = new self($a);
        }
    }

    /**
     * Getter-setter for operation
     * @param null|string $o Operation
     * @return string|Where
     */
    public function operation($o = NULL)
    {
        if(empty($o))
            return $this->operation;
        else
        {
            $this->operation = $o;
            return $this;
        }
    }

    /**
     * Get finally condition from
     * @return string
     */
    public function get_condition()
    {
        return $this->update_condition(!empty($this->condition));
    }

    /**
     * Regenerate where-condition string with all child conditions
     * @param bool $inchilds
     * @return string
     */
    private function update_condition($inchilds=false)
    {
        if($inchilds)
        {
            return '('.implode(' '.$this->operation.' ',array_map(function(/** @var $x Where*/$x){return $x->get_condition();},$this->childs)).')';
        }
        else
        {
            $c = explode('?',$this->condition);
            $r = ''; $c1 = count($c); $c2 = count($this->params);
            for($i = 0, $j = 0; $i < $c1; $i++)
            {
                $r .= $c[$i];
                if($j < $c2 && $i < $c1-1)
                {
                    $r .= self::$DBH->_escape($this->params[$j]);
                    $j++;
                    if($j == $c2)
                        $j = 0;
                }
            }
            return $r;
        }
    }
}