<?php

/**
 * Collects old logs and caches to reduce the amount of data stored in the
 * database.
 *
 * @group daemon
 */
final class PhabricatorGarbageCollectorDaemon extends PhabricatorDaemon {

  public function run() {
    do {
      $n_herald = $this->collectHeraldTranscripts();
      $n_daemon = $this->collectDaemonLogs();
      $n_parse  = $this->collectParseCaches();
      $n_markup = $this->collectMarkupCaches();
      $n_tasks  = $this->collectArchivedTasks();
      $n_cache_ttl = $this->collectGeneralCacheTTL();
      $n_cache  = $this->collectGeneralCaches();

      $collected = array(
        'Herald Transcript'           => $n_herald,
        'Daemon Log'                  => $n_daemon,
        'Differential Parse Cache'    => $n_parse,
        'Markup Cache'                => $n_markup,
        'Archived Tasks'              => $n_tasks,
        'General Cache TTL'           => $n_cache_ttl,
        'General Cache Entries'       => $n_cache,
      );
      $collected = array_filter($collected);

      foreach ($collected as $thing => $count) {
        $count = number_format($count);
        $this->log("Garbage collected {$count} '{$thing}' objects.");
      }

      $total = array_sum($collected);
      if ($total < 100) {
        // We didn't max out any of the GCs so we're basically caught up. Ease
        // off the GC loop so we don't keep doing table scans just to delete
        // a handful of rows; wake up in a few hours.
        $this->sleep(4 * (60 * 60));
      } else {
        $this->stillWorking();
      }
    } while (true);

  }

  private function collectHeraldTranscripts() {
    $ttl = PhabricatorEnv::getEnvConfig('gcdaemon.ttl.herald-transcripts');
    if ($ttl <= 0) {
      return 0;
    }

    $table = new HeraldTranscript();
    $conn_w = $table->establishConnection('w');

    queryfx(
      $conn_w,
      'UPDATE %T SET
          objectTranscript     = "",
          ruleTranscripts      = "",
          conditionTranscripts = "",
          applyTranscripts     = "",
          garbageCollected     = 1
        WHERE garbageCollected = 0 AND `time` < %d
        LIMIT 100',
      $table->getTableName(),
      time() - $ttl);

    return $conn_w->getAffectedRows();
  }

  private function collectDaemonLogs() {
    $ttl = PhabricatorEnv::getEnvConfig('gcdaemon.ttl.daemon-logs');
    if ($ttl <= 0) {
      return 0;
    }

    $table = new PhabricatorDaemonLogEvent();
    $conn_w = $table->establishConnection('w');

    queryfx(
      $conn_w,
      'DELETE FROM %T WHERE epoch < %d LIMIT 100',
      $table->getTableName(),
      time() - $ttl);

    return $conn_w->getAffectedRows();
  }

  private function collectParseCaches() {
    $key = 'gcdaemon.ttl.differential-parse-cache';
    $ttl = PhabricatorEnv::getEnvConfig($key);
    if ($ttl <= 0) {
      return 0;
    }

    $table = new DifferentialChangeset();
    $conn_w = $table->establishConnection('w');

    queryfx(
      $conn_w,
      'DELETE FROM %T WHERE dateCreated < %d LIMIT 100',
      DifferentialChangeset::TABLE_CACHE,
      time() - $ttl);

    return $conn_w->getAffectedRows();
  }

  private function collectMarkupCaches() {
    $key = 'gcdaemon.ttl.markup-cache';
    $ttl = PhabricatorEnv::getEnvConfig($key);
    if ($ttl <= 0) {
      return 0;
    }

    $table = new PhabricatorMarkupCache();
    $conn_w = $table->establishConnection('w');

    queryfx(
      $conn_w,
      'DELETE FROM %T WHERE dateCreated < %d LIMIT 100',
      $table->getTableName(),
      time() - $ttl);

    return $conn_w->getAffectedRows();
  }

  private function collectArchivedTasks() {
    $key = 'gcdaemon.ttl.task-archive';
    $ttl = PhabricatorEnv::getEnvConfig($key);
    if ($ttl <= 0) {
      return 0;
    }

    $table = new PhabricatorWorkerArchiveTask();
    $data_table = new PhabricatorWorkerTaskData();
    $conn_w = $table->establishConnection('w');

    $rows = queryfx_all(
      $conn_w,
      'SELECT id, dataID FROM %T WHERE dateCreated < %d LIMIT 100',
      $table->getTableName(),
      time() - $ttl);

    if (!$rows) {
      return 0;
    }

    $data_ids = array_filter(ipull($rows, 'dataID'));
    $task_ids = ipull($rows, 'id');

    $table->openTransaction();
      if ($data_ids) {
        queryfx(
          $conn_w,
          'DELETE FROM %T WHERE id IN (%Ld)',
          $data_table->getTableName(),
          $data_ids);
      }
      queryfx(
        $conn_w,
        'DELETE FROM %T WHERE id IN (%Ld)',
        $table->getTableName(),
        $task_ids);
    $table->saveTransaction();

    return count($task_ids);
  }


  private function collectGeneralCacheTTL() {
    $cache = new PhabricatorKeyValueDatabaseCache();
    $conn_w = $cache->establishConnection('w');

    queryfx(
      $conn_w,
      'DELETE FROM %T WHERE cacheExpires < %d
        ORDER BY cacheExpires ASC LIMIT 100',
      $cache->getTableName(),
      time());

    return $conn_w->getAffectedRows();
  }


  private function collectGeneralCaches() {
    $key = 'gcdaemon.ttl.general-cache';
    $ttl = PhabricatorEnv::getEnvConfig($key);
    if ($ttl <= 0) {
      return 0;
    }

    $cache = new PhabricatorKeyValueDatabaseCache();
    $conn_w = $cache->establishConnection('w');

    queryfx(
      $conn_w,
      'DELETE FROM %T WHERE cacheCreated < %d
        ORDER BY cacheCreated ASC LIMIT 100',
      $cache->getTableName(),
      time() - $ttl);

    return $conn_w->getAffectedRows();
  }


}