<?php
namespace App\Rclone;

use Psr\Log\LoggerAwareTrait;
use Psr\Log\NullLogger;

use Symfony\Component\Process\Process;
use Symfony\Component\Process\Exception\ProcessFailedException;


use Exception;
/**
 * Wrapper for the rclone command line utility
 * 
 * Installation of rclone is required.
 * Configuration of the mounts must be done before use.
 * Tested using rclone v1.53.3-DEV
 */
class Rclone
{
    use LoggerAwareTrait;

    protected string $rclonePath;
    /**
     * Global options
     * 
     * @var array<string> 
     */
    protected array $globalOptions = [];

    protected string $version = "";

    /**
     * Create a new instance
     * 
     * Default it looks for "rclone" on the path.
     * But the path can be configured to be absolute.
     * 
     * @param string $rclonePath Relative or absolute path
     */
    function __construct(string $rclonePath = "rclone")
    {
        $this->rclonePath = $rclonePath;
        $this->setLogger(new NullLogger);
        try
        {
            $version = $this->exec('--version');
        }
        catch(ProcessFailedException $e)
        {
            throw new Exception("Check installation of rclone");
        }

        $this->version = explode("\n", $version)[0];
        
        if (!\str_contains($this->version, 'rclone')) {
            throw new Exception("Rclone not recognized");
        }
    }

    /**
     * Get the rclone version
     * 
     * @return string Version string
     */
    function getVersion(): string
    {
        return $this->version;
    }

    /**
     * Calculate the size of a mount/path
     * 
     * @return int Size in bytes
     */
    function getSize(string $path): int
    {
        $output = $this->exec('size', ['--json', $path]);
        return (int)json_decode($output)->bytes;
    }

    /**
     * Copy from src to dest
     * 
     * @param  $src       Source mount and path
     * @param  $dest      Destination mount and path
     * @param  $bandwidth Bandwidth limit provided as string
     * @return string     Stdout from command
     */
    function copy(string $src, string $dest, string $bandwidth = null): string
    {   
        $options = array();

        $options[] = $src;
        $options[] = $dest;
        if ($bandwidth) {
            $options[] = "--bwlimit";
            $options[] = $bandwidth;
        }

        return $this->exec('copy', $options);
    }

    /**
     * Execute a command on the rclone binary
     * 
     * @param string        $command Top level Rclone command
     * @param array<String> $options Array of additional options
     * 
     * @return string stdout data.
     */
    protected function exec(string $command, array $options = array()) : string
    {
        $process = new Process(
            array_merge(
                [$this->rclonePath],
                $this->globalOptions,
                [$command],
                $options
            )
        );
        $this->logger->info("Execute command", [$process->getCommandLine()]);
        $process->setTimeout(4*3600);
        $process->run();

        // executes after the command finishes
        if (!$process->isSuccessful()) {
            $this->logger->error("Failed execution");
            throw new ProcessFailedException($process);
        }
        $this->logger->info("Return code", [$process->getExitCode()]);
        return $process->getOutput();
    }
}