#!/usr/bin/env php
<?php

$root = dirname(dirname(dirname(__FILE__)));
require_once $root.'/scripts/__init_script__.php';

// First, figure out the authenticated user.
$args = new PhutilArgumentParser($argv);
$args->setTagline('receive SSH requests');
$args->setSynopsis(<<<EOSYNOPSIS
**ssh-exec** --phabricator-ssh-user __user__ [--ssh-command __commmand__]
    Receive SSH requests.
EOSYNOPSIS
);

$args->parse(
  array(
    array(
      'name'  => 'phabricator-ssh-user',
      'param' => 'username',
    ),
    array(
      'name' => 'ssh-command',
      'param' => 'command',
    ),
  ));

try {
  $user_name = $args->getArg('phabricator-ssh-user');
  if (!strlen($user_name)) {
    throw new Exception("No username.");
  }

  $user = id(new PhabricatorUser())->loadOneWhere(
    'userName = %s',
    $user_name);
  if (!$user) {
    throw new Exception("Invalid username.");
  }

  if ($user->getIsDisabled()) {
    throw new Exception("You have been exiled.");
  }

  if ($args->getArg('ssh-command')) {
    $original_command = $args->getArg('ssh-command');
  } else {
    $original_command = getenv('SSH_ORIGINAL_COMMAND');
  }

  // Now, rebuild the original command.
  $original_argv = id(new PhutilShellLexer())
    ->splitArguments($original_command);
  if (!$original_argv) {
    throw new Exception("No interactive logins.");
  }
  $command = head($original_argv);
  array_unshift($original_argv, 'phabricator-ssh-exec');

  $original_args = new PhutilArgumentParser($original_argv);

  $workflows = array(
    new ConduitSSHWorkflow(),

    new DiffusionSSHGitUploadPackWorkflow(),
    new DiffusionSSHGitReceivePackWorkflow(),
  );

  $workflow_names = mpull($workflows, 'getName', 'getName');
  if (empty($workflow_names[$command])) {
    throw new Exception("Invalid command.");
  }

  $workflow = $original_args->parseWorkflows($workflows);
  $workflow->setUser($user);

  $sock_stdin = fopen('php://stdin', 'r');
  if (!$sock_stdin) {
    throw new Exception("Unable to open stdin.");
  }

  $sock_stdout = fopen('php://stdout', 'w');
  if (!$sock_stdout) {
    throw new Exception("Unable to open stdout.");
  }

  $sock_stderr = fopen('php://stderr', 'w');
  if (!$sock_stderr) {
    throw new Exception("Unable to open stderr.");
  }

  $socket_channel = new PhutilSocketChannel(
    $sock_stdin,
    $sock_stdout);
  $error_channel = new PhutilSocketChannel(null, $sock_stderr);
  $metrics_channel = new PhutilMetricsChannel($socket_channel);
  $workflow->setIOChannel($metrics_channel);
  $workflow->setErrorChannel($error_channel);

  $err = $workflow->execute($original_args);

  $metrics_channel->flush();
  $error_channel->flush();
} catch (Exception $ex) {
  fwrite(STDERR, "phabricator-ssh-exec: ".$ex->getMessage()."\n");
  exit(1);
}