<?php

    /**
     * Classe para fazer conexao com servidor via SSH 
     * e executar comandos como root.
     *
     * @author Lucas Awade
     * @date 25/01/2020
     */
    class SSH {

        /** @connections */
        private $connection;
        private $host;
        private $port;

        /** @streming */
        private $stream;

        /** @server */
        private $console;
        private $terminal;
        private $command;

        /** @constantes */
        const CONF_ROOT_LOGIN = "su";
        const CONF_TIME_EXEC = 2;

        function __construct($host, $port) {
            $this->host = $host;
            $this->port = $port;
            $this->connection();
        }

        ########################################################################
        #######                   CONEXAO COM SERVIDOR                   #######
        ########################################################################

        /**
         * Realiza a conexao inicial com o servidor
         * 
         * @return boolean
         */
        private function connection() {
            $this->connection = ssh2_connect($this->host, $this->port);
            if (!$this->connection) {
                return false;
            }
            return true;
        }

        /**
         * Autentica usuario e senha com a conexao criada
         * 
         * @param string $login
         * @param string $password
         * @return object
         */
        public function connectionAuth($login, $password) {
            if(ssh2_auth_password($this->connection, $login, $password)){
                return true;
            } else {
                return false;
            }
        }

        /**
         * Autentica a conexao como root no sistema.
         * @param string $passwd
         */
        public function connectionRoot($passwd) {
            $this->stream = ssh2_shell($this->connection);
            $this->command(self::CONF_ROOT_LOGIN);
            $this->command($passwd);
            $str = $this->command(PHP_EOL);
            if(strpos($str,"incorrect password") === false){
                return true;
            } else {
                return false;
            }
        }

        /**
         * Fecha a conexao com o servidor.
         */
        public function connectionClose() {
            unset($this->connection);
            fclose($this->stream);
        }

        ########################################################################
        #######                   CONEXAO COM SERVIDOR                   #######
        ########################################################################

        /**
         * Executa comando pela conexao criada.
         * @param string $command
         * @return boolean|string
         */
        public function command($command) {
            $this->command = $command;
            if ($this->stream) {
                fwrite($this->stream, $this->command . PHP_EOL);
                return $this->console();
            }
        }

        /**
         * Apresenta apenas o resultado do comando executado;
         * @return string
         */
        public function result() {
            if (!$this->terminal) {
                fwrite($this->stream, "\n");
                $console = $this->console;
                return str_replace($this->terminal($this->console()), "", $console);
            }
            return str_replace($this->terminal(), "", $this->console);
        }

        /**
         * Apresenta todas as informacoes dos comandos executados.
         * @param boolean 
         * @return string
         */
        private function console($clean = true) {
            if ($clean) {
                unset($this->console);
            }
            sleep(self::CONF_TIME_EXEC);
            $this->console = stream_get_contents($this->stream);
            return $this->console;
        }

        /**
         * Apresenta o terminal sendo executado;
         * @param string $terminal
         * @return string
         */
        private function terminal($terminal) {
            if (!$this->terminal) {
                $this->terminal = $terminal;
            }
            return $this->terminal;
        }

    }

?>