<?php
if (!defined('PHPWG_ROOT_PATH'))
{
  die('Hacking attempt!');
}

function bratonien_tools_nc_connector_command_run(array $command)
{
  $result = array('exit'=>-1, 'stdout'=>'', 'stderr'=>'');
  if (!function_exists('proc_open'))
  {
    $result['stderr'] = 'proc_open ist in PHP nicht verfügbar.';
    return $result;
  }

  $spec = array(
    0=>array('file','/dev/null','r'),
    1=>array('pipe','w'),
    2=>array('pipe','w'),
  );
  $environment = array_merge($_ENV, array('LC_ALL'=>'C','LANG'=>'C'));
  $process = @proc_open($command, $spec, $pipes, null, $environment);
  if (!is_resource($process))
  {
    $result['stderr'] = 'Prozess konnte nicht gestartet werden.';
    return $result;
  }

  $result['stdout'] = trim((string)stream_get_contents($pipes[1]));
  $result['stderr'] = trim((string)stream_get_contents($pipes[2]));
  fclose($pipes[1]);
  fclose($pipes[2]);
  $result['exit'] = (int)proc_close($process);
  return $result;
}

function bratonien_tools_nc_connector_systemctl_run(array $args)
{
  return bratonien_tools_nc_connector_command_run(array_merge(array('/usr/bin/systemctl'), $args));
}

function bratonien_tools_nc_connector_systemctl_value(array $args)
{
  $result = bratonien_tools_nc_connector_systemctl_run($args);
  return $result['exit'] === 0 ? $result['stdout'] : '';
}

function bratonien_tools_nc_connector_run_now()
{
  $service = 'bratonien-nc-connector.service';
  $load_state = bratonien_tools_nc_connector_systemctl_value(array('show',$service,'--property=LoadState','--value'));
  if ($load_state !== 'loaded')
  {
    throw new RuntimeException('WebDAV-Abgleich konnte nicht gestartet werden: der privilegierte Connector-Dienst '.$service.' ist nicht geladen.');
  }

  // Der Connector verwaltet bewusst geschützte Runtime-Daten unter /etc und
  // /var/lib. Er darf deshalb niemals direkt als Webserver-Benutzer laufen.
  // Der manuelle Admin-Button startet denselben privilegierten systemd-Dienst,
  // den auch der Timer verwendet.
  $result = bratonien_tools_nc_connector_systemctl_run(array('start',$service));

  // Auf Installationen ohne passende polkit-Regel darf ausschließlich die
  // eng begrenzte, vom Betreiber eingerichtete sudo-Freigabe für genau diesen
  // systemd-Dienst verwendet werden. Es gibt absichtlich keinen Fallback auf
  // runtime/run-all.sh als www-data.
  if ($result['exit'] !== 0 && is_file('/usr/bin/sudo') && is_executable('/usr/bin/sudo'))
  {
    $result = bratonien_tools_nc_connector_command_run(array(
      '/usr/bin/sudo',
      '-n',
      '/usr/bin/systemctl',
      'start',
      $service,
    ));
  }

  if ($result['exit'] !== 0)
  {
    $detail = $result['stderr'] !== '' ? $result['stderr'] : $result['stdout'];
    if ($detail === '') $detail = 'Exit-Code '.$result['exit'];
    throw new RuntimeException(
      'WebDAV-Abgleich konnte den privilegierten Connector-Dienst nicht starten. '
      .'Der Connector wird aus Sicherheitsgründen nicht als Webserver-Benutzer direkt ausgeführt. '.$detail
    );
  }

  $service_result = bratonien_tools_nc_connector_systemctl_value(array('show',$service,'--property=Result','--value'));
  if ($service_result !== '' && $service_result !== 'success')
  {
    throw new RuntimeException('WebDAV-Abgleich wurde gestartet, der Connector-Dienst endete aber mit Ergebnis '.$service_result.'.');
  }

  return array('message'=>'WebDAV-Abgleich wurde über den privilegierten Connector-Dienst ausgeführt.');
}

function bratonien_tools_nc_connector_parse_systemd_time($value)
{
  $value = trim((string)$value);
  if ($value === '' || strtolower($value) === 'n/a') return 0;
  $parsed = strtotime($value);
  return $parsed === false ? 0 : (int)$parsed;
}

function bratonien_tools_nc_connector_monotonic_to_timestamp($value)
{
  $value = trim((string)$value);
  if ($value === '' || $value === '0' || strtolower($value) === 'n/a') return 0;
  if (!preg_match('/^([0-9]+)(?:us)?$/', $value, $matches)) return 0;

  $next_boot_seconds = ((float)$matches[1]) / 1000000;
  $uptime_raw = @file_get_contents('/proc/uptime');
  if (!is_string($uptime_raw) || !preg_match('/^([0-9]+(?:\.[0-9]+)?)/', trim($uptime_raw), $uptime_match)) return 0;

  $remaining = $next_boot_seconds - (float)$uptime_match[1];
  if ($remaining < -1) return 0;
  return (int)round(time() + max(0, $remaining));
}

function bratonien_tools_nc_connector_next_from_timer_list($timer)
{
  $line = bratonien_tools_nc_connector_systemctl_value(array('list-timers','--all','--no-pager','--no-legend',$timer));
  if ($line === '') return 0;
  $first_line = trim((string)strtok($line, "\n"));
  if (!preg_match('/^(\S+\s+\d{4}-\d{2}-\d{2}\s+\d{2}:\d{2}:\d{2}\s+\S+)/', $first_line, $matches)) return 0;
  $parsed = strtotime($matches[1]);
  return $parsed === false ? 0 : (int)$parsed;
}

function bratonien_tools_nc_connector_connection_last_status(array $connection)
{
  $empty = array(
    'timestamp'=>0,'label'=>'Nicht verfügbar','state'=>'','message'=>'','auth_mode'=>'',
    'api_state'=>'','api_message'=>'','fallback_state'=>'','fallback_message'=>'','error_detail'=>'',
  );

  $connection_id = (int)($connection['id'] ?? 0);
  $candidates = array();
  if ($connection_id > 0) $candidates[] = rtrim(PHPWG_ROOT_PATH, '/').'/_data/bratonien-tools/nc-connector-status/connection-'.$connection_id.'.json';

  $config = isset($connection['config']) && is_array($connection['config']) ? $connection['config'] : array();
  $state_dir = rtrim((string)($config['state_dir'] ?? ''), '/');
  if ($state_dir === '' && $connection_id > 0) $state_dir = '/var/lib/bratonien-tools/nc-connector/connection-'.$connection_id;
  if ($state_dir !== '') $candidates[] = $state_dir.'/connector-status.json';

  $decoded = null;
  foreach ($candidates as $candidate)
  {
    if (!is_readable($candidate)) continue;
    $value = json_decode((string)@file_get_contents($candidate), true);
    if (is_array($value)) { $decoded = $value; break; }
  }
  if (!is_array($decoded)) return $empty;

  $timestamp = (int)($decoded['timestamp'] ?? 0);
  $api = isset($decoded['api']) && is_array($decoded['api']) ? $decoded['api'] : array();
  $fallback = isset($decoded['fallback']) && is_array($decoded['fallback']) ? $decoded['fallback'] : array();

  return array(
    'timestamp'=>$timestamp,
    'label'=>$timestamp > 0 ? date('d.m.Y H:i:s', $timestamp) : 'Nicht verfügbar',
    'state'=>(string)($decoded['state'] ?? ''),
    'message'=>(string)($decoded['message'] ?? ''),
    'auth_mode'=>(string)($decoded['auth_mode'] ?? ''),
    'api_state'=>(string)($api['state'] ?? ''),
    'api_message'=>(string)($api['message'] ?? ''),
    'fallback_state'=>(string)($fallback['state'] ?? ''),
    'fallback_message'=>(string)($fallback['message'] ?? ''),
    'error_detail'=>(string)($decoded['error_detail'] ?? ''),
  );
}

function bratonien_tools_nc_connector_last_status(array $connections)
{
  $latest = array('timestamp'=>0,'state'=>'','message'=>'','auth_mode'=>'','api_state'=>'','api_message'=>'','fallback_state'=>'','fallback_message'=>'','error_detail'=>'');
  foreach ($connections as $connection)
  {
    $status = bratonien_tools_nc_connector_connection_last_status($connection);
    if ((int)$status['timestamp'] >= (int)$latest['timestamp']) $latest = $status;
  }
  return $latest;
}

function bratonien_tools_nc_connector_status_message(array $last)
{
  if ((string)($last['state'] ?? '') === 'ok')
  {
    return 'WebDAV eingelesen und Piwigo synchronisiert';
  }
  return (string)($last['message'] ?? '');
}

function bratonien_tools_nc_connector_system_status(array $connections = array())
{
  $timer = 'bratonien-nc-connector.timer';
  $service = 'bratonien-nc-connector.service';

  $next_realtime_raw = bratonien_tools_nc_connector_systemctl_value(array('show',$timer,'--property=NextElapseUSecRealtime','--value'));
  $next_timestamp = bratonien_tools_nc_connector_parse_systemd_time($next_realtime_raw);
  if ($next_timestamp <= 0)
  {
    $next_monotonic_raw = bratonien_tools_nc_connector_systemctl_value(array('show',$timer,'--property=NextElapseUSecMonotonic','--value'));
    $next_timestamp = bratonien_tools_nc_connector_monotonic_to_timestamp($next_monotonic_raw);
  }
  if ($next_timestamp <= 0) $next_timestamp = bratonien_tools_nc_connector_next_from_timer_list($timer);

  $active = bratonien_tools_nc_connector_systemctl_value(array('is-active',$timer));
  $enabled = bratonien_tools_nc_connector_systemctl_value(array('is-enabled',$timer));

  $last = bratonien_tools_nc_connector_last_status($connections);
  if ($last['timestamp'] <= 0)
  {
    $last_raw = bratonien_tools_nc_connector_systemctl_value(array('show',$service,'--property=ExecMainExitTimestamp','--value'));
    $last['timestamp'] = bratonien_tools_nc_connector_parse_systemd_time($last_raw);
  }

  return array(
    'timer_name'=>$timer,
    'timer_active'=>$active === 'active',
    'timer_enabled'=>$enabled === 'enabled',
    'last_run_timestamp'=>(int)$last['timestamp'],
    'last_run_label'=>$last['timestamp'] > 0 ? date('d.m.Y H:i:s', (int)$last['timestamp']) : 'Nicht verfügbar',
    'last_run_state'=>(string)$last['state'],
    'last_run_message'=>bratonien_tools_nc_connector_status_message($last),
    'last_run_auth_mode'=>(string)$last['auth_mode'],
    'last_run_api_state'=>(string)$last['api_state'],
    'last_run_api_message'=>(string)$last['api_message'],
    'last_run_fallback_state'=>(string)$last['fallback_state'],
    'last_run_fallback_message'=>(string)$last['fallback_message'],
    'last_run_error_detail'=>(string)$last['error_detail'],
    'next_run_timestamp'=>$next_timestamp,
    'next_run_label'=>$next_timestamp > 0 ? date('d.m.Y H:i:s', $next_timestamp) : 'Nicht verfügbar',
  );
}