/lib/sql.php

<?php
class SCAR_SQL {
    public $table;
    public $columns;
    public $where;
    public $set;
    
    const ANSI_SELECT = 'SELECT %s FROM %s %s %s %s';
    const ANSI_UPDATE = 'UPDATE %s SET %s %s %s';
    const ANSI_INSERT = 'INSERT INTO %s (%s) VALUES (%s)';
    
    protected $mode;
    protected $SCAR;
    
    public function __construct($mode, $dsn, $SCAR = 'SCAR') {
        $this->mode = $mode;
        $this->dsn = $dsn;
        $this->SCAR = $SCAR;
    }
    
    public function render() {
        $table = '`'.$this->table.'`';
        
        if ($this->mode == 'update') {
            return trim(sprintf(self::ANSI_UPDATE, $table, $this->renderSet(), $this->renderWhere(), $this->renderLimit()));
        }
        
        if ($this->mode == 'insert') {
            return trim(sprintf(self::ANSI_INSERT, $table, $this->renderInsertSetColumns(), $this->renderInsertSetValues()));
        }
        
        return trim(sprintf(self::ANSI_SELECT, $this->renderColumns(), $table, $this->renderWhere(), $this->renderOrder(), $this->renderLimit()));
    }
    
    protected function renderColumns() {
        if (!isset($this->columns) || !$this->columns) {
            return '*';
        }
        
        if (is_array($this->columns)) {
            return '`'.implode('`, `', $this->columns).'`';
        }
        elseif ($this->columns == '*') {
            return '*';
        }
        else {
            return '`'.$this->columns.'`';
        }
    }
    
    protected function renderWhere() {
        if (!isset($this->where) || !$this->where) {
            return '';
        }
        
        // where
        $where = '';
        foreach ($this->where as $where_piece) {
            $where .= '`';
            $where .= call_user_func_array(array($this->SCAR, 'escape'), array($this->dsn, $where_piece['col']));
            $where .= '`';
            
            $where .= ' '.$where_piece['oper'].' ';
            
            if (is_array($where_piece['value'])) {
                $where .= '(';
                foreach ($where_piece['value'] as $value) {
                    $where .= '\'';
                    $where .= call_user_func_array(array($this->SCAR, 'escape'), array($this->dsn, $value));
                    $where .= '\', ';
                }
                $where = substr($where, 0, -2);
                $where .= ')';
            }
            else {
                $where .= '\'';
                $where .= call_user_func_array(array($this->SCAR, 'escape'), array($this->dsn, $where_piece['value']));
                $where .= '\'';
            }
            
            $where .= ' AND ';
        }
        
        if (strlen($where) > 0) {
            $where = substr($where, 0, -5);
            $where = 'WHERE '.$where;
        }
        return $where;
    }
    
    protected function renderOrder() {
        if (!isset($this->order) || !$this->order) {
            return '';
        }
        
        $order = '';
        foreach ($this->order as $order_piece) {
            $order .= '`';
            $order .= call_user_func_array(array($this->SCAR, 'escape'), array($this->dsn, $order_piece['col']));
            $order .= '` ';
            
            if ($order_piece['order'] === SORT_ASC) {
                $order .= 'ASC';
            }
            else {
                $order .= 'DESC';
            }
            
            $order .= ', ';
        }
        
        if (strlen($order) > 0) {
            $order = substr($order, 0, -2);
            $order = 'ORDER BY '.$order;
        }
        
        return $order;
    }
    
    protected function renderLimit() {
        if (!isset($this->limit) || !$this->limit) {
            return '';
        }
        
        if ($this->limit) {
            $out = 'LIMIT '.call_user_func_array(array($this->SCAR, 'escape'), array($this->dsn, $this->limit['start'])).', ';
            $out .= call_user_func_array(array($this->SCAR, 'escape'), array($this->dsn, $this->limit['count']));
            return $out;
        }
        return '';
    }
    
    protected function renderSet() {
        if (!isset($this->set) || !$this->set) {
            return '';
        }
        
        // set
        $set = '';
        foreach ($this->set as $set_piece) {
            $set .= '`';
            $set .= call_user_func_array(array($this->SCAR, 'escape'), array($this->dsn, $set_piece['col']));
            $set .= '`';
            
            $set .= ' = ';
            
            $set .= '\'';
            $set .= call_user_func_array(array($this->SCAR, 'escape'), array($this->dsn, $set_piece['value']));
            $set .= '\'';
            
            $set .= ', ';
        }
        
        if (strlen($set) > 0) {
            $set = substr($set, 0, -2);
        }
        return $set;
    }
    
    protected function renderInsertSetColumns() {
        if (!isset($this->set) || !$this->set) {
            return '';
        }
        
        $set = '';
        foreach ($this->set as $set_piece) {
            $set .= '`'.$set_piece['col'].'`';
            $set .= ', ';
        }
        $set = substr($set, 0, -2);
        return $set;
    }
    protected function renderInsertSetValues() {
        if (!isset($this->set) || !$this->set) {
            return '';
        }
        $set = '';
        foreach ($this->set as $set_piece) {
            $set .= '\''.$set_piece['value'].'\'';
            $set .= ', ';
        }
        $set = substr($set, 0, -2);
        return $set;
    }
}