<?php

namespace Mall\Framework\Db;

class Db
{
    static $queries = 0;
    public $master = array(), $slaves = array(), $slave = array(), $slave_key, $sql,  $error, $errno;
    private $dbh, $dbh_master, $dbh_slave, $foreign_key_checks = 0;

    public function __construct($master = array(), $slaves = array())
    {
        $this->master = $master;
        $this->dbh_master = $this->connect($master);
        $this->dbh = $this->dbh_master;

        if(!empty($slaves)){
            $this->slaves = $slaves;
            $this->dbh_slave = $this->connect_slave();
            $this->dbh = $this->dbh_slave;
        }
    }

    public function __call($method, $args)
    {
        if (in_array($method, array('errorCode', 'errorInfo', 'getAttribute', 'lastInsertId', 'quote', 'setAttribute'), true)) {
            if (in_array($method, array('lastInsertId'))) {
                return $this->dbh_master()->$method();
            }
            if (isset($args[0])) {
                return isset($args[1]) ? $this->dbh()->$method($args[0], $args[1]) : $this->dbh()->$method($args[0]);
            } else {
                return $this->dbh()->$method();
            }
        }
    }

    public function beginTransaction($foreign_key_checks = false)
    {
        try{
            $result = $this->dbh_master()->beginTransaction();

            if ($result && !$foreign_key_checks) {
                $this->foreign_key_checks = intval($this->dbh_master()->query("SELECT @@FOREIGN_KEY_CHECKS")->fetchColumn(0));
                $this->foreign_key_checks && $this->dbh_master()->query("SET @@FOREIGN_KEY_CHECKS=0");
            }
            return $result;
        }catch (\PDOException $e){
            if ( isset($e->errorInfo) && ($e->errorInfo[1] == 2006 || $e->errorInfo[1] == 2013) ) {
                $this->closeConnection();
                return $this->beginTransaction($foreign_key_checks);
            }else{
                $msg = $e->getMessage();
                $err_msg = "SQL:".$msg;
                $this->errno = (int)$e->getCode();
                $this->error = $err_msg;
                return false;
            }
        }
    }

    public function commit()
    {
        try {
            $result = $this->dbh_master()->commit();
            if ($this->foreign_key_checks) {
                $this->dbh_master()->query("SET @@FOREIGN_KEY_CHECKS=1");
                $this->foreign_key_checks = 0;
            }
            return $result;
        }catch (\PDOException $e){
            if ( isset($e->errorInfo) && ($e->errorInfo[1] == 2006 || $e->errorInfo[1] == 2013) ) {
                $this->closeConnection();
                return $this->commit();
            }else{
                $msg = $e->getMessage();
                $err_msg = "SQL:".$msg;
                $this->errno = (int)$e->getCode();
                $this->error = $err_msg;
                return false;
            }
        }

    }

    public function rollBack()
    {
        try{
            $result = $this->dbh_master()->rollBack();
            if ($this->foreign_key_checks) {
                $this->dbh_master()->query("SET @@FOREIGN_KEY_CHECKS=1");
                $this->foreign_key_checks = 0;
            }
            return $result;
        }catch (\PDOException $e){
            if ($e->errorInfo[1] == 2006 || $e->errorInfo[1] == 2013) {
                $this->closeConnection();
                return $this->rollBack();
            }else{
                $msg = $e->getMessage();
                $err_msg = "SQL:".$msg;
                $this->errno = (int)$e->getCode();
                $this->error = $err_msg;
                return false;
            }
        }

    }

    public function connect($options = array())
    {
        try {
            $dbh = new \PDO($options['driver'] . ':host=' . $options['host'] . ';port=' . $options['port'] . ';dbname=' . $options['dbname'] . ';charset=' . $options['charset'], $options['username'], $options['password'], array(
                \PDO::ATTR_PERSISTENT => ($options['pconnect'] ? true : false),)
            );
            $dbh->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
            $dbh->setAttribute(\PDO::ATTR_STRINGIFY_FETCHES, false);
            $dbh->setAttribute(\PDO::ATTR_EMULATE_PREPARES, false);

        } catch (\PDOException $e) {
            $this->errno = $e->getCode();
            $this->error = $e->getMessage();
            return false;
        }
        if ($options['driver'] == 'mysql') {
            $dbh->exec("SET character_set_connection='" . $options['charset'] . "',character_set_results='" . $options['charset'] . "',character_set_client='{$options['charset']}'" . ($dbh->query("SELECT version()")->fetchColumn(0) > '5.0.1' ? ",sql_mode=''" : ''));
        }
        return $dbh;
    }

    private function connect_slave()
    {
        $this->slave_key = array_rand($this->slaves);
        $this->slave = $this->slaves[$this->slave_key];
        $this->dbh_slave = $this->connect($this->slave);
        if (!$this->dbh_slave && count($this->slaves) > 1) {
            unset($this->slaves[$this->slave_key]);
            return $this->connect_slave();
        }
        return $this->dbh_slave;
    }

    // https://github.com/walkor/mysql/blob/master/src/Connection.php
    // https://my.oschina.net/u/222608/blog/1621402
    public function closeConnection(){
        $this->dbh = null;
        $this->dbh_master = null;
        $this->dbh_slave  = null;
    }

    public function exec($statement)
    {
        try{
            return $this->dbh($statement) ? $this->dbh->exec($this->sql) : false;
        }catch (\PDOException $e){
            if ($e->errorInfo[1] == 2006 || $e->errorInfo[1] == 2013) {
                $this->closeConnection();
                return $this->exec($statement);
            }else{
                $msg = $e->getMessage();
                $err_msg = "SQL:".$this->sql." ".$msg;
                $this->errno = (int)$e->getCode();
                $this->error = $err_msg;
                return false;
            }
        }
    }

    public function prepare($statement, $driver_options = array())
    {
        try{
            return $this->dbh($statement) ? $this->dbh->prepare($this->sql, $driver_options) : false;
        }catch (\PDOException $e){
            file_put_contents('/tmp/transaction.log',date('Y-m-d H:i:s').'prepare'.var_export('prepare超时错误了',true).PHP_EOL,FILE_APPEND);
            if ($e->errorInfo[1] == 2006 || $e->errorInfo[1] == 2013) {
                $this->closeConnection();
                return $this->prepare($statement, $driver_options);
            }else{
                $msg = $e->getMessage();
                $err_msg = "SQL:".$this->sql." ".$msg;
                $this->errno = (int)$e->getCode();
                $this->error = $err_msg;

                file_put_contents('/tmp/transaction.log',date('Y-m-d H:i:s').'prepare'.var_export($e->getMessage(),true).PHP_EOL,FILE_APPEND);
                return false;
            }
        }
    }

    public function exportQuery($statement)
    {
        try {
            if($this->dbh($statement)){
                $this->dbh->setAttribute(\PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, false);
                return $this->dbh->query($this->sql,\PDO::FETCH_ASSOC)->fetchAll();
            }else{
                return false;
            }
        }catch (\PDOException $e){
            if ($e->errorInfo[1] == 2006 || $e->errorInfo[1] == 2013) {
                $this->closeConnection();
                return $this->query($statement);
            }else{
                $msg = $e->getMessage();
                $err_msg = "SQL:".$this->sql." ".$msg;
                $this->errno = (int)$e->getCode();
                $this->error = $err_msg;
                return false;
            }
        }
    }

    public function query($statement)
    {
        try {
            return $this->dbh($statement) ? $this->dbh->query($this->sql,\PDO::FETCH_ASSOC)->fetchAll() : false;
        }catch (\PDOException $e){
            if ($e->errorInfo[1] == 2006 || $e->errorInfo[1] == 2013) {
                $this->closeConnection();
                return $this->query($statement);
            }else{
                $msg = $e->getMessage();
                $err_msg = "SQL:".$this->sql." ".$msg;
                $this->errno = (int)$e->getCode();
                $this->error = $err_msg;
                return false;
            }
        }
    }

    private function dbh($sql = null)
    {
        if($sql === null){
            $this->sql = null;
        }else{
            $this->sql = $sql;
        }

        if (is_null($this->dbh)) {
            if (is_null($this->dbh_master)) $this->dbh_master = $this->connect($this->master);
            $this->dbh = $this->dbh_master;
        }
        return $this->dbh;


        self::$queries++;
        $this->sql = str_replace('#table_', $this->master['prefix'], trim($sql));
        if ($this->slaves && is_null($this->dbh_master) && stripos($this->sql, 'select') === 0) {
            if (is_null($this->dbh_slave)) $this->dbh_slave = $this->connect_slave();
            $this->dbh = $this->dbh_slave;
        } else {
            if (is_null($this->dbh_master)) $this->dbh_master = $this->connect($this->master);
            $this->dbh = $this->dbh_master;
        }
        return $this->dbh;
    }

    public function get($sql, $data = array(), $fetch_style = \PDO::FETCH_ASSOC)
    {
        $this->sql = $sql;
        try{
            $db = $this->prepare($sql);
            if (!$db) return false;
            if ($db->execute($data)) {
                return $db->fetch($fetch_style);
            } else {
                $this->errno = $db->errorCode();
                $this->error = $db->errorInfo();
                return false;
            }
        }catch (\PDOException $e){
            file_put_contents('/tmp/transaction.log',date('Y-m-d H:i:s').'get'.var_export('get超时错误了',true).PHP_EOL,FILE_APPEND);
            if ($e->errorInfo[1] == 2006 || $e->errorInfo[1] == 2013) {
                $this->closeConnection();
                return $this->get($sql, $data, $fetch_style);
            }else{
                $msg = $e->getMessage();
                $err_msg = "SQL:".$sql." ".$msg;
                $this->errno = (int)$e->getCode();
                $this->error = $err_msg;
                return false;
            }
        }
    }

    public function cursor($sth)
    {
        while($row = $sth->fetch(\PDO::FETCH_ASSOC)) {
            yield $row;
        }
    }

    public function exportSelect($sql, $data = array())
    {
        $this->sql = $sql;

        try{
            $db = $this->prepare($sql);
            if (!$db) return false;
            $this->dbh->setAttribute(\PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, false);
            if ($db->execute($data)) {
                return $this->cursor($db);
            } else {
                $this->errno = $db->errorCode();
                $this->error = $db->errorInfo();
                return false;
            }
        }catch (\PDOException $e){
            if ($e->errorInfo[1] == 2006 || $e->errorInfo[1] == 2013) {
                $this->closeConnection();
                return $this->exportSelect($sql, $data);
            }else{
                $msg = $e->getMessage();
                $err_msg = "SQL:".$sql." ".$msg;
                echo $err_msg;
                $this->errno = (int)$e->getCode();
                $this->error = $err_msg;
                return false;
            }
        }
    }

    public function select($sql, $data = array(), $fetch_style = \PDO::FETCH_ASSOC)
    {
        $this->sql = $sql;

        try{
            //V($sql);
            $db = $this->prepare($sql);
            if (!$db) return false;
            if ($db->execute($data)) {
                return $db->fetchAll($fetch_style);
            } else {
                $this->errno = $db->errorCode();
                $this->error = $db->errorInfo();
                return false;
            }
        }catch (\PDOException $e){
            file_put_contents('/tmp/transaction.log',date('Y-m-d H:i:s').'select'.var_export('select超时错误了',true).PHP_EOL,FILE_APPEND);
            if ($e->errorInfo[1] == 2006 || $e->errorInfo[1] == 2013) {
                $this->closeConnection();
                return $this->select($sql, $data, $fetch_style);
            }else{
                $msg = $e->getMessage();
                $err_msg = "SQL:".$sql." ".$msg;
                $this->errno = (int)$e->getCode();
                $this->error = $err_msg;
                return false;
            }
        }
    }

    public function insert($sql, $data = array(), $multiple = false)
    {
        $this->sql = $sql;
        try{
            $db = $this->prepare($sql);
            if (!$db) return false;
            if (empty($data)) {
                if ($db->execute()) {
                    $insertid = $this->dbh_master->lastInsertId();
                    return $insertid ? $insertid : true;
                } else {
                    $this->errno = $db->errorCode();
                    $this->error = $db->errorInfo();
                    return false;
                }
            }
            if ($multiple) {
                $insertids = [];
                foreach ($data as $r) {
                    $this->_bindValue($db, $r);
                    if ($db->execute()) {
                        $insertids[] = $this->dbh_master->lastInsertId();
                    }else{
                        $this->errno = $db->errorCode();
                        $this->error = $db->errorInfo();
                        return false;
                    }
                }
                return !empty($insertids) ? $insertids : true;
            } else {
                $this->_bindValue($db, $data);
                if ($db->execute()) {
                    $insertid = $this->dbh_master->lastInsertId();
                    return $insertid > 0 ? $insertid : true;
                } else {
                    $this->errno = $db->errorCode();
                    $this->error = $db->errorInfo();
                    return false;
                }
            }
        }catch (\PDOException $e){
            if ($e->errorInfo[1] == 2006 || $e->errorInfo[1] == 2013) {
                $this->closeConnection();
                return $this->insert($sql, $data, $multiple);
            }else{
                file_put_contents('/tmp/transaction.log',date('Y-m-d H:i:s').'insert'.var_export($data,true).PHP_EOL,FILE_APPEND);

                $msg = $e->getMessage();
                $err_msg = "SQL:".$sql." ".$msg;
                $this->sql   = $sql;
                $this->errno = (int)$e->getCode();
                $this->error = $err_msg;
                file_put_contents('/tmp/transaction.log',date('Y-m-d H:i:s').'insert'.var_export($e->getMessage(),true).PHP_EOL,FILE_APPEND);
                return false;
            }
        }
    }

    public function update($sql, $data = array(), $multiple = false)
    {
        $this->sql = $sql;
        try{
            $db = $this->prepare($sql);
            if (!$db) return false;
            if (empty($data)) {
                if ($db->execute()) {
                    $rowcount = $db->rowCount();
                    return $rowcount ? $rowcount : true;
                } else {
                    $this->errno = $db->errorCode();
                    $this->error = $db->errorInfo();
                    return false;
                }
            }
            if ($multiple) {
                foreach ($data as $r) {
                    $this->_bindValue($db, $r);
                    if (!$db->execute()) {
                        $this->errno = $db->errorCode();
                        $this->error = $db->errorInfo();
                        return false;
                    }
                }
                return true;
            } else {
                $this->_bindValue($db, $data);
                if ($db->execute()) {
                    $rowcount = $db->rowCount();
                    return $rowcount ? $rowcount : true;
                } else {
                    $this->errno = $db->errorCode();
                    $this->error = $db->errorInfo();
                    return false;
                }
            }
        }catch (\PDOException $e){
            if ($e->errorInfo[1] == 2006 || $e->errorInfo[1] == 2013) {
                $this->closeConnection();
                return $this->update($sql, $data, $multiple);
            }else{
                $msg = $e->getMessage();
                $err_msg = "SQL:".$sql." ".$msg;
                $this->errno = (int)$e->getCode();
                $this->error = $err_msg;
                return false;
            }
        }

    }

    public function replace($sql, $data = array(), $multiple = false)
    {
        return $this->update($sql, $data, $multiple);
    }

    public function delete($sql, $data = array())
    {
        $this->sql = $sql;

        try{
            $db = $this->prepare($sql);
            if (!$db) return false;
            if ($db->execute($data)) {
                $rowcount = $db->rowCount();
                return $rowcount ? $rowcount : true;
            } else {
                $this->errno = $db->errorCode();
                $this->error = $db->errorInfo();
                return false;
            }
        }catch (\PDOException $e){
            if ($e->errorInfo[1] == 2006 || $e->errorInfo[1] == 2013) {
                $this->closeConnection();
                return $this->delete($sql, $data);
            }else{
                $msg = $e->getMessage();
                $err_msg = "SQL:".$sql." ".$msg;
                $this->errno = (int)$e->getCode();
                $this->error = $err_msg;
                return false;
            }
        }
    }

    public function limit($sql, $limit = 0, $offset = 0, $data = array(), $fetch_style = \PDO::FETCH_ASSOC)
    {
        if ($limit > 0) $sql .= $offset > 0 ? " LIMIT $offset, $limit" : " LIMIT $limit";
        return $this->select($sql, $data, $fetch_style);
    }

    public function page($sql, $page = 1, $size = 20, $data = array(), $fetch_style = \PDO::FETCH_ASSOC)
    {
        $page = isset($page) ? max(intval($page), 1) : 1;
        $size = max(intval($size), 1);
        $offset = ($page - 1) * $size;
        return $this->limit($sql, $size, $offset, $data, $fetch_style);
    }

    public function select_db($dbname)
    {
        return $this->exec("USE $dbname");
    }

    public function list_fields($table, $field = null)
    {
        $sql = "SHOW COLUMNS FROM `$table`";
        if ($field) $sql .= " LIKE '$field'";
        return $this->query($sql);
    }

    public function list_tables($dbname = null)
    {
        $tables = array();
        $sql = $dbname ? "SHOW TABLES FROM `$dbname`" : "SHOW TABLES";
        $result = $this->query($sql);
        foreach ($result as $r) {
            $tables[] = array_pop($r);
        }
        return $tables;
    }

    public function list_dbs()
    {
        $dbs = array();
        $result = $this->query("SHOW DATABASES");
        foreach ($result as $r) {
            foreach ($r as $db) $dbs[] = $db;
        }
        return $dbs;
    }

    public function get_primary($table)
    {
        $primary = array();
        $result = $this->query("SHOW COLUMNS FROM `$table`");
        foreach ($result as $r) {
            if ($r['Key'] == 'PRI') $primary[] = $r['Field'];
        }
        return count($primary) == 1 ? $primary[0] : (empty($primary) ? null : $primary);
    }

    public function get_var($var = null)
    {
        $variables = array();
        $sql = is_null($var) ? '' : " LIKE '$var'";
        $result = $this->query("SHOW VARIABLES $sql");
        foreach ($result as $r) {
            if (!is_null($var) && isset($r['Value'])) return $r['Value'];
            $variables[$r['Variable_name']] = $r['Value'];
        }
        return $variables;
    }

    public function version()
    {
        $db = $this->query("SELECT version()");
        return $db ? $db->fetchColumn(0) : false;
    }

    public function prefix()
    {
        return $this->master['prefix'];
    }

    public function errno()
    {
        return is_null($this->errno) ? $this->errorCode() : $this->errno;
    }

    public function error()
    {
        if (is_null($this->error)) {
            return $this->errorInfo();
        } else {
            /*if($this->sql && $this->error){
                $this->error .= 'sql:'.$this->sql;
            }*/
            return $this->error;
        }
    }

    /**
     * 检查数据库连接,是否有效，无效则重新建立
     */
    protected function checkConnection()
    {
        if (!$this->pdo_ping())
        {
            $this->dbh_master = NULL;
        }
    }

    /**
     * 检查连接是否可用
     * @return Boolean
     */
    function pdo_ping(){
        file_put_contents('/tmp/transaction.log',date('Y-m-d H:i:s').'ping'.var_export(is_null($this->dbh),true).PHP_EOL,FILE_APPEND);
        if( is_null($this->dbh) ){
            return false;
        }

        if (!$this->dbh->getAttribute(\PDO::ATTR_SERVER_INFO)) {
            $this->errno = $this->dbh->errorCode();
            $this->error = $this->dbh->errorInfo();

            file_put_contents('/tmp/transaction.log',date('Y-m-d H:i:s').'error'.var_export($this->errno.':'.$this->error,true).PHP_EOL,FILE_APPEND);
            if($this->errno == 'HY000'){
                $this->dbh_master = null;
            }

            return false;
        }

        return true;
    }

    private function dbh_master()
    {
        //$this->checkConnection();

        if (is_null($this->dbh_master)) $this->dbh_master = $this->connect($this->master);
        $this->dbh = $this->dbh_master;
        return $this->dbh;
    }



    private function _bindValue(& $db, $data)
    {
        if (!is_array($data)) return false;
        foreach ($data as $k => $v) {
            $k = is_numeric($k) ? $k + 1 : ':' . $k;
            $db->bindValue($k, $v);
        }
        return true;
    }
}