<?php

class Model{
	public $sConn; 
	public $conn;
	public $semester;
	public $schoolId;
	public $apiUrl;
	public $moduleUrl;
	public $moduleField;

	function __construct(){
		$this->conn = Yii::app()->businessDb;
		$this->sConn = $this->getDbConnection();
		
		$semesterId = Yii::app()->session['session_semester_id'];
		$semesterName = Yii::app()->session['session_semester_name'];
		
		$this->semester = array(
			"id" => $semesterId,
			"name" => $semesterName,
		);
		
		if(!Yii::app()->session['coachInfo']['school_id'])
			throw new CException("无法获取学校信息");
		
		$this->schoolId = Yii::app()->session['coachInfo']['school_id'];
		
		$this->apiUrl = Yii::app()->params["api"][0]["prefix"];
		$this->moduleUrl = $this->apiUrl.Yii::app()->params["topic_store"]["module_append"];
		$this->moduleField = Yii::app()->params["topic_store"]["module_field"];
	}
	
    public function getDbConnection(){
    	$db = Yii::app()->session['myDatebase'];
    	
    	if(empty($db)) {
	    	$getDbConnect = BusinessDatabase::model()->find('school_id=:sid',array(':sid'=>Yii::app()->session['coachInfo']['school_id']));
	    	if(empty($getDbConnect)){
	    		//删除session变量
				Yii::app()->session->clear();
	    		header('Location:/');
	    		exit();
	    	}
	    	
	    	Yii::app()->session['myDatebase'] = $getDbConnect;
	    	$db = $getDbConnect;
	    	
	    	unset($getDbConnect);
    	} 

    	$myDbDsn = 'mysql:host='.$db->database_host.';dbname='.$db->database_name;
    	$my_connection = new CDbConnection($myDbDsn,$db->database_user,$db->database_password);

    	$my_connection->emulatePrepare 	= true;
    	$my_connection->enableProfiling = true;
    	$my_connection->enableParamLogging = true;
    	
    	$myDbDsn = null;
		
    	return $my_connection;
    }
    
    public function isCurrentSemester($semesterId){
		$semesterId = (string)trim($semesterId);
		return $this->semester["id"] === $semesterId ? true : false;
    }
    
	//根据格式化语句返回最终SQL语句的非链式构造器
	public function orderBy($orderBy = array()){
		return $orderBy ? " order by ".implode(",", $orderBy) : "";
	}
	
	//根据格式化语句返回最终SQL语句的非链式构造器
	public function condition($condition = array()){
		return $condition ? " where ".implode(" and ", $condition) : "";
	}
	
	//根据格式化语句返回最终SQL语句的非链式构造器
	public function limit($offset, $limit){
		return $limit > 0 ? " limit {$offset}, {$limit}" : "";
	}
	
	public function paging($conn, $handle, $pageSize){
		$pager = new CPagination($handle->rowCount, $pageSize);
		$handle = $conn->createCommand($handle->queryString." limit :offset, :limit");
		$handle->bindValue(":offset", $pager->currentPage * $pager->pageSize);
		$handle->bindValue(":limit", $pager->pageSize);
		$rs = $handle->queryAll();
		
		return array("rs" => $rs, "pager" => $pager);
	}
	
	//从结果集分离出单个字段并合并成1维数组
	public function grouping($rs, $field, $unique = false){
		$group = array();
		
		if($field && $rs){
			foreach($rs as $key => $val){
				if(isset($val[$field]))
					$group[] = $val[$field];
			}
			
			if($unique === true)
				$group = array_unique($group);
		}
		
		return $group;
	}
	
	public function buildEmptyPagingStruct(){
		$rs = array(
			"rs" => array(),
			"pager" => (object)array(),
		);
		$rs["pager"]->pagesCount = 0;
		$rs["pager"]->rowsCount = 0;
		
		return $rs;
	}
}