<?php


namespace fastphp\db;

use \PDOStatement;

class Sql
{
    //数据库表名
    protected $table;

    //where 和 order拼装后的条件
    private $filter = '';

    //pdo 绑定的参数集合
    private $param = array();

    private $field = '*';

    /**
     * 查询条件拼接
     *
     * @param  $where 条件
     * @return $this
     * ['id'=>1]   或者  '`id`=1' 尽量不要使用string  因为没有做防sql注入
     * 多条件查询
     * ['id'=>['<',100]]
     */
    public function where($where){
        $this->param = [];
        $this->filter = '';
        if($where){
            $this->filter .= ' WHERE ';
            if(is_string($where)){
                $this->filter .= ' '.$where;
            } else {
                $flag = true;
                foreach ($where as $key => $value){
                    if($flag){
                        $flag = false;
                        if(is_array($value)){
                            $this->filter .= ' `'.$key.'` '.$value[0].' :'.$key;
                            $this->param[$key] = $value[1];
                        } else {
                            $this->filter .= ' `'.$key.'` = :'.$key;
                            $this->param[$key] = $value;
                        }
                    } else {
                        if(is_array($value)){
                            $this->filter .= ' AND `'.$key.'` '.$value[0].' :'.$key;
                            $this->param[$key] = $value[1];
                        } else {
                            $this->filter .= ' AND `'.$key.'` = :'.$key;
                            $this->param[$key] = $value;
                        }
                    }
                }
            }
        }
        return $this;
    }

    /**
     * 拼装排序条件
     * @param array $order 排序条件
     * @return $this
     * $order='id desc'
     */
    public function order($order = 'id desc'){
        if($order){
            $this->filter .= ' ORDER BY '.$order.' ';
        }
        return $this;
    }


    /**
     * group by
     * @param array $order
     * @return $this
     * $group=['sex','name']
     */
    public function group($group = []){
        if($order){
            $this->filter .= ' GROUP BY ';
            $this->filter .= ' '.implode(' ,',$group).' ';
        }
        return $this;
    }

    /**
     * 查询limit
     * @param string 
     * @return $this
     * $limit = '100'   限制查询100条
     * $limit = '2,100' 查询第二页 100条数据
     */
    public function limit($limit = '100'){
        $this->filter .= ' LIMIT '.$limit.' ';
        return $this;
    }

    /**
     * 查询字段
     * @param string $field
     * @return $this
     * $field = 'id,count(1),sub(num)'
     */
    public function field($field = '*'){
        $this->field = $field;
        return $this;
    }

    /**
     * 查询所有
     * @return mixed
     */
    public function fetchAll(){
        $sql = sprintf('SELECT %s FROM `%s` %s',$this->field,$this->table,$this->filter);
        $this->filter = '';
        $sth = Db::pdo()->prepare($sql);
        $sth = $this->formatParam($sth,$this->param);
        $sth->execute();

        return $sth->fetchAll();
    }

    /**
     * 查询一条
     * @return mixed
     */
    public function fetch(){
        $sql = sprintf('SELECT %s FROM `%s` %s',$this->field,$this->table,$this->filter);
        $this->filter = '';
        $sth = Db::pdo()->prepare($sql);
        $sth = $this->formatParam($sth,$this->param);
        $sth->execute();

        return $sth->fetch();
    }

    /**
     * 根据条件（id）删除
     * @param $id
     * @return mixed
     */
    public function delete(){
        $sql = sprintf('DELETE FROM `%s` %s',$this->table,$this->filter);
        $this->filter = '';
        $sth = Db::pdo()->prepare($sql);
        $sth = $this->formatParam($sth,$this->param);
        $sth->execute();

        return $sth->rowCount();
    }

    /**
     * 新增数据
     * @param $data
     * @return mixed
     */
    public function add($data){
        $sql = sprintf('INSERT INTO `%s` %s',$this->table,$this->formatInsert($data));
        $sth = Db::pdo()->prepare($sql);
        $sth = $this->formatParam($sth,$data);
        $sth->execute();

        return $sth->rowCount();
    }

    /**
     * 新增多条数据
     * @param $data
     * @return int
     */
    public function addAll($data){
        $sql = sprintf('INSERT INTO `%s` %s',$this->table,$this->formatInsertAll($data));
        $sth = Db::pdo()->prepare($sql);
        $sth->execute();

        return $sth->rowCount();
    }

    /**
     * 修改数据
     * @param $data
     * @return mixed
     */
    public function update($data){
        $sql = sprintf('UPDATE `%s` SET %s %s',$this->table,$this->formatUpdate($data),$this->filter);
        $this->filter = '';
        $sth = Db::pdo()->prepare($sql);
        $sth = $this->formatParam($sth,$data);
        $sth = $this->formatParam($sth,$this->param);
        $sth->execute();

        return $sth->rowCount();
    }

    /**
     * 绑定具体变量值
     * @param PDOStatement $sth
     * @param array $params
     * @return PDOStatement
     */
    public function formatParam(PDOStatement $sth,$params = []){
        foreach ($params as $param=>&$value){
            $param = is_int($param)?$param+1:':'.ltrim($param,':');
            $sth->bindParam($param,$value);
        }
        return $sth;
    }

    /**
     * 将数组转化为插入格式的sql语句
     * @param $data
     * @return string
     */
    private function formatInsert($data){
        $fields = [];
        $names = [];
        foreach ($data as $key=>$value) {
            $fields[] = sprintf('`%s`',$key);
            $names[] = sprintf(':%s',$key);
        }
        $field = implode(',',$fields);
        $name = implode(',',$names);
        return sprintf('(%s) VALUES(%s)',$field,$name);
    }

    /**
     * 格式化插入数据
     * @param $data
     * @return string
     */
    private function formatInsertAll($data){
        $fields = [];
        $values ='';
        foreach ($data[0] as $key=>$value) {
            $fields[] = sprintf('`%s`',$key);
        }
        foreach ($data as $k=>$v){
            $values .= '(\''.implode('\',\'',$v).'\'),';
        }
        $field = implode(',',$fields);
        $values = rtrim($values,',');
        return sprintf('(%s) VALUES %s',$field,$values);
    }

    /**
     * 更新数据的格式转换
     * @param $data
     * @return string
     */
    private function formatUpdate($data){
        $fields = [];
        foreach ($data as $key=>$value){
            $fields[] = sprintf('`%s`=:%s',$key,$key);
            $this->param[$key] = $value;
        }
        return implode(',',$fields);
    }
}