<?php
class Core_Db_Mysql
{
	private $queries = array();
	private $link = null;

	public function connect($settings)
	{
		$this->link = new mysqli($settings['server'], $settings['username'], $settings['password'], $settings['database']);
		if($this->link->connect_error) {
			return false;
		}

		return true;
	}

	public function query($query)
	{
		$this->queries[] = $query;
		return @$this->link->query($query);
	}

	public function quote($string)
	{
		return $this->link->real_escape_string($string);
	}

	public function insert_query($table, $values)
	{
		$fields = implode('`,`', array_keys($values));
		$values = implode("','", array_map(array($this, 'quote'), $values));
		$query = "INSERT INTO ".$table." (`".$fields."`) VALUES ('".$values."')";
		if($this->query($query)) {
			return $this->insert_id();
		}
		else {
			return false;
		}
	}

	public function replace_query($table, $values)
	{
		$fields = array();
		foreach($values as $k => $v) {
			$fields[] = "`".$k."`='".$this->quote($v)."'";
		}
		$query = "UPDATE ".$table." SET ".$fields;
		return $this->query($query);
	}

	public function update_query($table, $values, $where = '')
	{
		$fields = array();
		foreach($values as $k => $v) {
			$fields[] = "`".$k."`='".$this->quote($v)."'";
		}
		$fields = implode(',', $fields);
		if($where) {
			$fields .= ' WHERE '.$where;
		}
		$query = "REPLACE INTO ".$table." SET ".$fields;
		return $this->query($query);
	}

	public function start_transaction()
	{
		$this->query('START TRANSACTION');
	}

	public function commit()
	{
		$this->query('COMMIT');
	}

	public function rollback()
	{
		$query->query('ROLLBACK');
	}

	public function delete_query($table, $where = '')
	{
		$query = 'DELETE FROM '.$table;
		if($where != '') {
			$query .= ' WHERE '.$where;
		}
		return $this->query($query);
	}

	public function insert_id()
	{
		return $this->link->insert_id;
	}

	public function affected_rows()
	{
		return $this->link->affected_rows;
	}
}