<?php
class CustomCategoryRepository {
  function clearCache () {
  }

  function getCategory ($id, $options=[]) {
    global $db;

    $stmt = $db->prepare("select content from customCategory where id=:id");
    $stmt->bindValue(':id', $id, PDO::PARAM_STR);
    if ($stmt->execute()) {
      $row = $stmt->fetch(PDO::FETCH_ASSOC);
      $result = $row['content'];
      $stmt->closeCursor();

      return $result;
    }
  }

  function recordAccess ($id) {
    global $db;

    if (!isset($_SESSION['customCategoryAccess'])) {
      $_SESSION['customCategoryAccess'] = [];
    }

    // update access per session only once a day
    if (array_key_exists($id, $_SESSION['customCategoryAccess']) && $_SESSION['customCategoryAccess'][$id] > time() - 86400) {
      return;
    }

    $_SESSION['customCategoryAccess'][$id] = time();

    $stmt = $db->prepare("insert into customCategoryAccess (id) values (:id)");
    $stmt->bindValue(':id', $id);
    $stmt->execute();
  }

  function saveCategory ($content) {
    global $db;

    $id = md5($content);

    switch ($db->getAttribute(PDO::ATTR_DRIVER_NAME)) {
      case 'mysql':
        $sqlAction = "insert ignore";
        break;
      case 'sqlite':
      default:
        $sqlAction = "insert or ignore";
    }

    $stmt = $db->prepare("{$sqlAction} into customCategory (id, content) values (:id, :content)");
    $stmt->bindValue(':id', $id, PDO::PARAM_STR);
    $stmt->bindValue(':content', $content, PDO::PARAM_STR);
    $result = $stmt->execute();

    return $id;
  }

  function list ($options=[]) {
    global $db;

    // $sqlCalcAge: the age of the access in days
    switch ($db->getAttribute(PDO::ATTR_DRIVER_NAME)) {
      case 'mysql':
        $sqlCalcAge = "datediff(now(), ts)";
        break;
      case 'sqlite':
        $sqlCalcAge = "julianday('now')-julianday(ts)";
    }

    // the popularity column counts every acess with declining value over time,
    // it halves every year.
    $stmt = $db->prepare("select customCategory.id, customCategory.created, customCategory.content, t.accessCount, t.popularity, t.lastAccess from customCategory left join (select id, count(id) accessCount, sum(1/(({$sqlCalcAge})/365.25+1)) popularity, max(ts) lastAccess from customCategoryAccess group by id) t on customCategory.id=t.id order by popularity desc, created desc limit 25");
    $stmt->execute();
    $data = $stmt->fetchAll(PDO::FETCH_ASSOC);
    $data = array_map(function ($d) {
      $d['popularity'] = (float)$d['popularity'];
      $d['accessCount'] = (int)$d['accessCount'];

      $content = yaml_parse($d['content']);
      if ($content && is_array($content) && array_key_exists('name', $content)) {
        $d['name'] = lang($content['name']);
      }
      else {
        $d['name'] = 'Custom ' . substr($d['id'], 0, 6);
      }

      unset($d['content']);
      return $d;
    }, $data);

    $stmt->closeCursor();
    return $data;
  }
}

$customCategoryRepository = new CustomCategoryRepository();