<?php

final class PhabricatorFilesManagementCatWorkflow
  extends PhabricatorFilesManagementWorkflow {

  protected function didConstruct() {
    $this
      ->setName('cat')
      ->setSynopsis(pht('Print the contents of a file.'))
      ->setArguments(
        array(
          array(
            'name' => 'begin',
            'param' => 'bytes',
            'help' => pht('Begin printing at a specific offset.'),
          ),
          array(
            'name' => 'end',
            'param' => 'bytes',
            'help' => pht('End printing at a specific offset.'),
          ),
          array(
            'name' => 'salvage',
            'help' => pht(
              'DANGEROUS. Attempt to salvage file content even if the '.
              'integrity check fails. If an adversary has tampered with '.
              'the file, the conent may be unsafe.'),
          ),
          array(
            'name'      => 'names',
            'wildcard'  => true,
          ),
        ));
  }

  public function execute(PhutilArgumentParser $args) {
    $console = PhutilConsole::getConsole();

    $names = $args->getArg('names');
    if (count($names) > 1) {
      throw new PhutilArgumentUsageException(
        pht('Specify exactly one file to print, like "%s".', 'F123'));
    } else if (!$names) {
      throw new PhutilArgumentUsageException(
        pht('Specify a file to print, like "%s".', 'F123'));
    }

    $file = head($this->loadFilesWithNames($names));

    $begin = $args->getArg('begin');
    $end = $args->getArg('end');

    $file->makeEphemeral();

    // If we're running in "salvage" mode, wipe out any integrity hash which
    // may be present. This makes us read file data without performing an
    // integrity check.
    $salvage = $args->getArg('salvage');
    if ($salvage) {
      $file->setIntegrityHash(null);
    }

    try {
      $iterator = $file->getFileDataIterator($begin, $end);
      foreach ($iterator as $data) {
        echo $data;
      }
    } catch (PhabricatorFileIntegrityException $ex) {
      throw new PhutilArgumentUsageException(
        pht(
          'File data integrity check failed. Use "--salvage" to bypass '.
          'integrity checks. This flag is dangerous, use it at your own '.
          'risk. Underlying error: %s',
          $ex->getMessage()));
    }

    return 0;
  }

}
