<?php
/** @noinspection PhpUnhandledExceptionInspection */

namespace WebAppick\FTP;

class SFTPConnection {

    private $connection;
    private $sftp;

    public function __construct( $host, $port = 22, $f_print = false ) {
	    if ( ! extension_loaded( 'ssh2' ) ) {
	        /* translators: 1: server host, 2: server port */
            throw new \Exception( sprintf( esc_html__( 'Could not connect to %1$s:%2$s. SSH2 is not enabled on this server.', 'woo-feed' ), esc_attr($host), esc_attr($port) ) );
	    }
	    $this->connection = ssh2_connect( $host, $port );

	    // Security: Man in the middle attack protection
        if ( $f_print ) {
            $fingerprint = ssh2_fingerprint($this->connection, SSH2_FINGERPRINT_MD5 | SSH2_FINGERPRINT_HEX);
            if ( $fingerprint !== $f_print ) {
                throw new \Exception(sprintf('Known host fingerprint "%s" does not match %s:%s fingerprint "%s". Possible man-in-the-middle attack ?', esc_attr($config['fingerprint']),esc_attr($config['host']), esc_attr($config['port']), esc_attr($fingerprint)));
            }
        }
    }

	public function login( $username, $password ) {
		if ( ! ssh2_auth_password( $this->connection, $username, $password ) ) {
			throw new \Exception( "Could not authenticate with username ".esc_attr($username)." " . "and password ".esc_attr($password)." ." );
		}

		$this->sftp = ssh2_sftp( $this->connection );
		if ( ! $this->sftp ) {
			throw new \Exception( 'Could not initialize SFTP subsystem.' );
		}
    }

	/**
	 * @param string $local_file    local file to upload
	 * @param string $remote_file   remote file name
	 * @param string $path          must use trailing slash. directory path to put the file on remote server.
	 *
	 * @return bool
	 * @throws Exception
	 */
	public function upload_file( $local_file, $remote_file, $path ) {

		if ( ! file_exists( $local_file ) ) {
			throw new \Exception( "Local file does't exists.: ". esc_attr($local_file)."." );
		}
		$data_to_send = file_get_contents( $local_file ); // phpcs:ignore
		if ( false === $data_to_send ) {
			throw new \Exception( "Could not open local file: ".esc_attr($local_file)."." );
		}

		$sftp = $this->sftp;
		if ( ! is_dir( "ssh2.sftp://$sftp$path" ) ) {
			throw new \Exception( "Invalid Remote Path: ".esc_attr($path)."." );
		}

		if ( ! is_writeable( "ssh2.sftp://$sftp$path" ) ) { // phpcs:ignore

		    // Not throwing an exception because only upload permission is required.
		    error_log( "CTX feed sftp upload issue: Can't write to remote. @" . $path );

		}

	    $stream = fopen( "ssh2.sftp://$sftp$path$remote_file", 'w' ); // phpcs:ignore
        if ( ! $stream ) {
            throw new \Exception( "Could not open file: ". esc_attr($path)."." );
        }

	    if ( false === fwrite( $stream, $data_to_send ) ) { // phpcs:ignore
			throw new \Exception( "Could not send data from file: ".esc_attr($local_file)."." );
		}

	    fclose( $stream ); // phpcs:ignore
		return true;

	}

	public function delete_file( $remote_file ) {
		$sftp = $this->sftp;
        unlink("ssh2.sftp://$sftp$remote_file"); // phpcs:ignore
	}
}