namespace woo\process;

abstract class Base{
static $DB; //pdo对象
static $stmts = array(); //sql语句句柄

function __construct (){
$dsn = \woo\base\ApplicationRegistry::getDSN();
if(is_null($dsn)){
throw new \woo\base\AppException("No DSN");
}
self::$DB = new PDO($dsn);
self::$DB->setAttribute(\PDO::ATTR_ERRMODE,\PDO::ERRMODE_EXCEPTION);
}

function prepareStatement($stmt_s){ //缓存sql语句句柄
if(isset(self::$stmts($stmt_s)){
return self::$stmts[$stmt_s];
}
$stmt_handle = self::$DB->prepare($stmt_s);
self::$stmts[$stmt_s] = $stmt_handle;
return $stmt_handle;
}

protected function doStatement($stmt_s,$values_a){ //执行sql并获取一个语句资源
$sth = $this->prepareStatement($stmt_s);
$sth->closeCursor();
$db_result = $sth->execute($values_a);
return $sth;
}
}

//这个类就是向数据库中写入一些数据，比较简单没什么好多说的
class VenueManager extends Base{
static $add_venue = "INSERT INTO venue (name) values(?)";
static $add_space = "INSERT INTO space (name,venue) values(?,?)";
static $check_slot = "SELECT id,name FROM event WHERE space = ? AND (start+duration)>? AND start <?";
static $add_event = "INSERT INTO event (name,space,start,duration) values(?,?,?)";

function addVenue($name,$space_array){
$ret = array();
$ret['venue'] = array($name);
$this->doStatement(self::$add_venue,$ret['venue']);
$v_id = self::$DB->lastInsertId();
$ret['spaces'] = array();
foreach($space_array as $space_name){
$values = array($space_name,$v_id);
$this->doStatement(self::$add_space,$values);
$s_id = self::$DB->lastInsertId();
array_unshift($values,$s_id);
$ret['spaces'][] = $values;
}
return $ret;
}

function bookEvent ($space_id,$name,$time,$duration){
$values = array($space_id,($time+$duration));
$stmt = $this->doStatement(self::$check_slot,$values,false);
if($result = $stmt->fetch()){
throw new \woo\base\AppException("double booked! try again");
}
$this->doStatement(self::$add_event,array($name,$space_id,$duration));
}
}

//客户端,使用起来还是比较简便的
$venue = new VenueManager();
$venue->addVenue('test',array('test1','test2','test3'));