<?php
namespace script;
/**
 * 核心Db框架
 * @author sunhaoqiang(shqdev@163.com)
 * @time: 2019年08月25日 16:38
*/
use config\Db as Conf;

class Db
{
 private $_host;
	private $_user;
	private $_pwd;
	private $_dbname;
	private $_port;
 private $_charset;
 private $_table;
 private $_where = "";
 private $_order = "";
 private $_group = "";
	private $pdo;
	private static $instance; //Db 类的单例对象
 /**
 * 构造函数私有化后,不能再使用 new 外部调用,私有方法只能类内部使用。
 */
	private function __construct(Array $option = []){
 if (empty($option)) {
 $conf = new Conf();
 $option = ENV ? $conf['env']: $conf['dev'];
 }

 $this->_host = isset($option['host'])?$option['host']:'';
 $this->_user = isset($option['user'])?$option['user']:'';
 $this->_pass = isset($option['pass'])?$option['pass']:'';
 $this->_dbname = isset($option['dbname'])?$option['dbname']:'';
 $this->_port = isset($option['port'])?$option['port']:'';
 $this->_charset = isset($option['charset'])?$option['charset']:'';
 
 $dsn = "mysql:host=$this->_host;dbname=$this->_dbname;port=$this->_port;charset=$this->_charset";
 $this->pdo = new \PDO($dsn,$this->_user,$this->_pass);
 }
 /**
 * 防止克隆的方法:私有克隆方法
 */
	private function __clone(){
	}
	//提供一个静态的方法生成对象
	public static function connect(Array $option = []){
		//如何生成单例对象(只生成一个),先判断$pdo属性是否属于当前类的实例
		if(!self::$instance instanceof self){
			self::$instance = new self($option); 
		}
		return self::$instance;
 }
 /**
 * 修改数据库
 */
 public function database($dbname)
 {
 $this->_dbname = $dbname;
 $sql = "use `". $this->_dbname."`";
 $this->pdo->query($sql);
 return $this;
 }
 /**
 * 修改数据表
 */
 public function table($table)
 {
 $this->_table = $table;
 return $this;
 }
 /**
 * 插入一行数据
 */
 public function insert($data)
 {
 $sql = $this->analysisInsert($data);
 $result = $this->pdo->exec($sql);
 if (empty($result)) {
 throw new \Exception($this->pdo->errorInfo()[2], 1);
 }

 return $result;
 }
 /**
 * 插入多行数据
 */
 public function insertAll($data)
 {
 $data = array_map([$this, 'analysisInsert'], $data);
 $sql = implode(" ", array_values($data));

 echo date('Y-m-d H:i:s')."\n";
 $result = $this->pdo->exec($sql);
 echo date('Y-m-d H:i:s')."\n";
 if (empty($result)) {
 throw new \Exception($this->pdo->errorInfo()[2], 1);
 }
 return $result;
 }
 public function addAll($data)
 {
 
 if (empty($data)) {
 return false;
 }

 $data = array_map([$this, 'analysisAdd'], array_values($data));
 $fields = array_unique(array_column($data, 'field'));
 if (count($fields) == 1) {
 $fields = $fields[0];
 }else{
 throw new \Exception('字段不能为空');
 }

 $values = array_column($data, 'value');
 $values = implode(',', $values);
 $sql = "INSERT INTO `".$this->_table."` ($fields) VALUES $values";
 echo date('Y-m-d H:i:s')."\n";
 $result = $this->pdo->exec($sql);
 echo date('Y-m-d H:i:s')."\n";
 if (empty($result)) {
 throw new \Exception($this->pdo->errorInfo()[2], 1);
 }
 return $result;
 }
 public function analysisAdd($data)
 {
 if (!is_array($data)) {
 throw new \Exception('数据不能为空');
 }
 $field = array_keys($data);
 $field = array_map(function ($data)
 {
 return "`".$data."`";
 }, $field);
 $field = implode(",", $field);

 $field_values = array_values($data);
 $field_values = array_map([$this->pdo,"quote"], $field_values);
 $value = implode(",", $field_values);

 $value = "(".$value.")";
 
 return [
 'value' => $value,
 'field' => $field
 ];
 }
 /**
 * 条件
 * 格式1(array):[['id', '=', 1]]
 * 格式2(string):'id = 1'
 */
 public function where($where)
 {
 if (is_string($where)) {
 $this->_where = $where;
 return $this;
 }
 if (is_array($where)) {
 
 $where = array_map(function ($data)
 {
 $data[0] = "`".$data[0]."`";
 $data[2] = "'".$data[2]."'";
 $data = implode(" ", $data);
 return $data;
 }, $where);

 $where = implode(" AND ", $where);
 $this->_where = " WHERE ".$where;
 return $this;
 }
 throw new \Exception('where 格式不规则');
 }

 public function order($order, $rule = "ASC")
 {
 $this->_order = " ORDER BY `".$order."` ".$rule;
 return $this;
 }

 public function group($group)
 {
 $this->_order = " GROUP BY `".$group."`";
 return $this;
 }
 /**
 * 获取单条
 * 
 */
 public function get()
 {
 echo 'get';
 }
 /**
 * 获取单条数据的单个字段
 * 
 */
 public function getFeild()
 {
 echo 'get';
 }
 /**
 * 获取多条数据
 */
 public function select($field = "*")
 {
 // SELECT * FROM p_paper WHERE `short_title` = '人教新课标地理七年级上册第一章地球与地图检测练' ORDER BY `pid`
 $sql = "SELECT ".$field." FROM `".$this->_table."`".$this->_where.$this->_order.$this->_group;

 
 echo date('Y-m-d H:i:s')."\n";
 $pdo_statement = $this->pdo->query($sql);

 echo date('Y-m-d H:i:s')."\n";

 if($pdo_statement == false){
 //说明sql语句有误。输出错误信息
 throw new \Exception($this->pdo->errorInfo()[2], 1);
 }
 //执行到这里,说明sql语句没有问题
 $result = $pdo_statement->fetchAll(\PDO::FETCH_ASSOC);
 $pdo_statement->closeCursor();
 return $result;
 }
 public function update()
 {
 # code...
 }
 public function analysisInsert($data)
 {
 
 if (empty($data)) {
 throw new \Exception('数据不能为空');
 }

 $field = array_keys($data);
 $field = array_map(function ($data)
 {
 return "`".$data."`";
 }, $field);
 $fields = implode(",", $field);

 $field_values = array_values($data);
 $field_values = array_map([$this->pdo,"quote"], $field_values);
 $values = implode(",", $field_values);

 
 if (empty($this->_table)) {
 throw new \Exception('数据表不能为空');
 }
 $sql = "INSERT INTO ".$this->_table." ($fields) VALUES ($values);";
 return $sql;
 }

 /**
 * 转换双引号和单引号
 */
 public function escape($string)
 {
 return htmlspecialchars($string, ENT_QUOTES);
 }
 
}