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

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

function escape_name($name) {
  return preg_replace('/[^A-Za-z0-9\-]/', '_', $name);
}

function startswith($string, $prefix) {
  return substr($string, 0, strlen($prefix)) == $prefix;
}

function endswith($string, $suffix) {
  $suffix_length = strlen($suffix);
  return substr($string, strlen($string) - $suffix_length,
                $suffix_length) == $suffix;
}

function write_ini_file($array, $file) {
  $res = array();
  foreach ($array as $key => $val) {
    if (is_array($val)) {
      $res[] = "[$key]";
      foreach ($val as $skey => $sval) {
        $res[] = "$skey = $sval";
      }
      $res[] = '';
    } else {
      $res[] = "$key = $val";
    }
  }
  file_put_contents($file, implode("\n", $res));
}

// Get user's heys and put them to the configuration
function handleSingleUserPHID(
  $keydir, $viewer, $userPHID, $system_keys, &$used_keys) {
  $user = id(new PhabricatorPeopleQuery())
    ->setViewer($viewer)
    ->withPHIDs(array($userPHID))
    ->executeOne();
  if (!$user) {
    return array();
  }

  $keys = id(new PhabricatorAuthSSHKey())->loadAllWhere(
   'objectPHID = %s',
    $user->getPHID());

  $members = array();
  foreach ($keys as $key) {
      $full_key_content =
        $key->getKeyType().' '.
        $key->getKeyBody().' '.
        $key->getKeyComment()."\n";

    if (array_key_exists($full_key_content, $system_keys)) {
      $members[] = $system_keys[$full_key_content];
    } else {
      $escaped_key_name = escape_name($key->getName());
      $member = 'PHAB_'.$user->getUserName().
        '_'.$escaped_key_name.
        '_'.$key->getID();
      $members[] = $member;
      if (!array_key_exists($member, $used_keys)) {
        $used_keys[$member] = true;
        file_put_contents("$keydir/$member.pub", $full_key_content);
      }
    }
  }
  return $members;
}

function handleCustomPolicy(
  $keydir, $viewer, $policy, $system_keys, &$used_keys) {
  $members = array();
  $rules = $policy->getRules();
  foreach ($rules as $rule) {
    // Everyone is denied by default anyway
    if ($rule['action'] == 'allow') {
      if ($rule['rule'] == 'PhabricatorPolicyRuleUsers') {
        foreach ($rule['value'] as $userPHID) {
          $members = array_merge($members,
              handleSingleUserPHID($keydir, $viewer, $userPHID,
                                   $system_keys, $used_keys));
        }
      } else {
        /* pass */
      }
    }
  }
  return $members;
}

// Parse repository and put it's members to the config file
function handleSingleRepository(
  $keydir, $viewer, $repository, $all_repositories, $system_keys,
  &$new_configuration, &$used_keys) {
  $policies = PhabricatorPolicyQuery::loadPolicies(
    $viewer,
    $repository);

  $pushable = $policies[DiffusionPushCapability::CAPABILITY];
  $type = $pushable->getType();

  $members = array();

  if ($type == PhabricatorPolicyType::TYPE_PROJECT) {
    $project = id(new PhabricatorProjectQuery())
      ->setViewer($viewer)
      ->needMembers(true)
      ->withPHIDs(array($pushable->getPHID()))
      ->executeOne();

    $memberPHIDs = $project->getMemberPHIDs();
    foreach ($memberPHIDs as $memberPHID) {
      $members = array_merge($members,
        handleSingleUserPHID($keydir, $viewer, $memberPHID,
                             $system_keys, $used_keys));
    }
  } else if ($type == PhabricatorPolicyType::TYPE_USER) {
    $members = handleSingleUserPHID(
      $keydir, $viewer, $pushable->getPHID(), $system_keys, $used_keys);
  } else if ($type == PhabricatorPolicyType::TYPE_CUSTOM) {
    $members = handleCustomPolicy(
      $keydir, $viewer, $pushable, $system_keys, $used_keys);
  } else {
    /* pass */
  }

  if (count($members)) {
    $uri = $repository->getRemoteURI();
    $repository_name = basename($uri, '.git');
    $escaped_repository_name = escape_name($repository->getName());
    $group_name = "PHAB_${escaped_repository_name}";
    $values = array();
    $values['members'] = join(' ', $members);
    $values['readonly'] = join(' ', $all_repositories);
    $values['writable'] = $repository_name;
    $new_configuration["group $group_name"] = $values;
  }
}

// Remove groups from previous automated configuration built
function getCleanOldConfiguration($old_configuration) {
  $new_configuration = array();
  foreach ($old_configuration as $group => $values) {
    if (!startswith($group, 'group PHAB')) {
      $new_configuration[$group] = $values;
    }
  }
  return $new_configuration;
}

// Get non-phab keys
function getSystemPublicKeys($keydir) {
  $files = scandir($keydir);
  $system_keys = array();
  foreach ($files as $file) {
    if (!startswith($file, "PHAB") && endswith($file, '.pub')) {
      $key = file_get_contents("$keydir/$file");
      $system_keys[$key] = basename($file, '.pub');
    }
  }
  return $system_keys;
}

// Remove unused public keys
function removeUnusedPublicKeys($keydir, $used_keys) {
  $files = scandir($keydir);
  foreach ($files as $file) {
    if (startswith($file, "PHAB")) {
      $member = basename($file, '.pub');
      if (!array_key_exists($member, $used_keys)) {
        unlink("$keydir/$file");
      }
    }
  }
}

function rebuildConfiguration($gitosis_root) {
  $keydir = "$gitosis_root/keydir";
  $configuration_file = "$gitosis_root/gitosis.conf";

  if (!file_exists($configuration_file)) {
    print("Not found: $configuration_file\n");
    return false;
  }

  $viewer = id(new PhabricatorUser())
    ->loadOneWhere('username = %s', 'sergey');

  $old_configuration = parse_ini_file(
    $configuration_file, true, INI_SCANNER_RAW);

  $new_configuration = getCleanOldConfiguration(
    $old_configuration);

  // Get "system" keys to re-use if phab account uses the
  // same public key
  $system_keys = getSystemPublicKeys($keydir);

  // Get list of all repos which is awailable for read
  $all_repositories = array();
  foreach ($old_configuration as $group => $values) {
    if (startswith($group, 'repo')) {
      $repository_name = substr($group, 5, strlen($group) - 5);
      if ($repository_name == 'gitosis-admin')
        continue;
      $all_repositories[] = $repository_name;
    }
  }

  // Fill in new configuration and keys
  $used_keys = array();
  $repositories = id(new PhabricatorRepositoryQuery())
    ->setViewer($viewer)
    ->execute();

  foreach ($repositories as $repository_id => $repository) {
    $type = $repository->getVersionControlSystem();
    if ($type == PhabricatorRepositoryType::REPOSITORY_TYPE_GIT) {
      handleSingleRepository(
        $keydir, $viewer, $repository, $all_repositories, $system_keys,
        $new_configuration, $used_keys);
    }
  }

  write_ini_file($new_configuration, $configuration_file);
  removeUnusedPublicKeys($keydir, $used_keys);

  return true;
}

function getGitCommand($repository) {
  $git_dir = realpath("$repository/.git");
  $git = "git --git-dir='$git_dir'";
  $git .= ' --work-tree='.realpath($repository);
  return $git;
}

function runGitCommand($repository, $arguments,
                       &$output=null, &$return_var=null) {
  $git = getGitCommand($repository);
  $git .= " $arguments";
  exec($git, $output, $return_var);
  return $return_var == 0;
}

function runGitSshCommand($repository, $key, $arguments,
                       &$output=null, &$return_var=null) {
  $gitx_ssh = realpath(dirname(__FILE__) . "/gitx-ssh");
  $abs_key = realpath($key);
  $git = "SSH_KEYFILE=$abs_key GIT_SSH=$gitx_ssh ";
  $git .= getGitCommand($repository);
  $git .= " $arguments";
  exec($git, $output, $return_var);
  return $return_var == 0;
}

function repositoryPull($repository, $key) {
  return runGitSshCommand($repository, $key, 'pull');
}

function repositoryCommitAll($repository, $author, $message) {
  if (!runGitCommand(
    $repository, 'ls-files --other --exclude-standard', $untracked_files)) {
    return false;
  }
  if (count($untracked_files)) {
    $flat_files = join(' ', $untracked_files);
    if (!runGitCommand($repository, "add $flat_files")) {
      return false;
    }
  }
  runGitCommand($repository, "update-index -q --refresh", $output);
  runGitCommand($repository, "diff-index --name-only HEAD --", $output);
  if (count($output)) {
    return runGitCommand(
      $repository, "commit --author='$author' -a -m '$message'", $output);
  }
  return true;
}

if (count($argv) != 3) {
  print("Usage: {$argv[0]} /path/to/gitosis-admin /path/to/id_rsa.pub\n");
  exit(1);
}

$gitosis_root = $argv[1];
$key = $argv[2];

if (!repositoryPull($gitosis_root, $key)) {
  print("Failed to pull changes from server.\n");
  exit(1);
}

if (!rebuildConfiguration($gitosis_root)) {
  exit(1);
}

if (!repositoryCommitAll(
  $gitosis_root, 'Rebuild Gitadmin <null@git.blender.org>',
  'Update to correspond changes in Phabricator')) {
  print("Failed to commit changes.\n");
  exit(1);
}

runGitSshCommand($gitosis_root, $key, 'push origin master');
?>