<?php

class Mysql
{
    /** @var  mysqli */
    private $connection;
    protected $db_list = [];
    protected $time_limit = 200;

    public function __construct($db_name = 'location')
    {
        $this->time_limit = config('time_limit', null, 'mysql');
        $this->db_list = config('db_config');
        $this->connect($db_name);
    }

    public function connect($db_name = 'location')
    {
        if (array_key_exists($db_name, $this->db_list)) {
            if (isset($this->connection)) {
                mysqli_close($this->connection);
            }
            $db_conf = $this->db_list[$db_name];
            $conn = new mysqli(
                $db_conf['DB_HOST'],
                $db_conf['DB_USER'],
                $db_conf['DB_PWD'],
                $db_conf['DB_NAME'],
                $db_conf['DB_PORT']
            );
            $this->connection = $conn;
        }
    }

    /**
     * @param string $db_name
     * @param        $sql
     * @return object
     */
    public function select($sql, callable $callback = null, $option = MYSQLI_STORE_RESULT)
    {
        $conn = $this->connection;
        $result = $conn->query($sql, $option);
        if ($result === false) {
            throw new Exception(json_encode(['error' => $conn->error, 'sql' => $sql], JSON_UNESCAPED_UNICODE));
        } else {
            if (is_callable($callback)) {
                $response = $callback($result);
                if ($option === MYSQLI_USE_RESULT and is_a($result, 'mysqli_result')) {
                    $result->free();
                }

                return $response;
            } else {
                return $result;
            }
        }
    }

    /**
     * @param $sql
     * @param $option array {
    ’time_limit‘
     * }
     * @return array
     * @throws Exception
     */
    public function DQL($sql, array $option=[])
    {
        $time_limit = $option['time_limit'] ?? null;
        if (strpos($sql, '%TIME_LIMIT%') !== false) {
            $replace_str = '/*+ MAX_EXECUTION_TIME('.($time_limit ?? $this->time_limit).') */';
            $sql = str_replace('%TIME_LIMIT%', $replace_str, $sql);
        }
        return (array)$this->select($sql, function (mysqli_result $dbResult) {
            $result = [];
            while ($row = $dbResult->fetch_assoc()) {
                $result[] = $row;
            }
            return $result;
        },
            MYSQLI_USE_RESULT);
    }

    public function insert($table, array $fields, array $data, $fetch_sql = false)
    {
        $conn = $this->connection;
        $sql = 'insert into ' . $table . ' (' . implode(',', $fields) . ') values ';
        $value = [];
        foreach ($data as $v) {
            $s_value = [];
            foreach ($fields as $k) {
                $s_value[] = '\'' . $conn->real_escape_string($v[$k]) . '\'';
            }
            $value[] = "(" . implode(', ', $s_value) . ")";
        }
        $sql .= implode(',', $value);
        if ($fetch_sql) {
            return $sql;
        }
        if ($conn->query($sql) === true) {
            return $conn->affected_rows;
        } else {
            throw new Exception($conn->error);
        }
    }

    public function replace($table, array $fields, array $data, $fetch_sql = false)
    {
        $conn = $this->connection;
        $sql = 'replace into ' . $table . ' (' . implode(',', $fields) . ') values ';
        $value = [];
        foreach ($data as $v) {
            $s_string = '';
            foreach ($fields as $k) {
                if (array_key_exists($k, $v) and $v[$k] !== null) {
                    $s_string .= '\'' . $conn->real_escape_string($v[$k]) . '\', ';
                } else {
                    $s_string .= 'null, ';
                }
            }
            $value[] = '(' . rtrim($s_string, ', ') . ')';
        }
        $sql .= implode(',', $value);
        if ($fetch_sql) {
            return $sql;
        }
        if ($conn->query($sql) === true) {
            return $conn->affected_rows;
        } else {
            throw new Exception($conn->error);
        }
    }

    public function update($sql)
    {
        $conn = $this->connection;
        if ($conn->query($sql) === true) {
            return $conn->affected_rows;
        } else {
            throw new Exception($conn->error);
        }
    }

    public function delete($sql)
    {
        return $this->update($sql);
    }

    public function __call($name, $arguments)
    {
        if (method_exists($this->connection, $name)) {
            return call_user_func_array([$this->connection, $name], $arguments);
        } else {
            throw new Exception('method not implemented: ' . $name);
        }
    }

    public function __destruct()
    {
        $this->connection->close();
    }

    public function getLastInsID()
    {
        return $this->connection->insert_id;
    }
}