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

require_once(BRATONIEN_TOOLS_PATH . 'include/database.class.php');
require_once(BRATONIEN_TOOLS_PATH . 'include/watermark_engine.inc.php');
require_once(BRATONIEN_TOOLS_PATH . 'tools/watermark_settings.inc.php');
require_once(BRATONIEN_TOOLS_PATH . 'tools/watermark_profiles.inc.php');
require_once(BRATONIEN_TOOLS_PATH . 'tools/album_rules.inc.php');
require_once(BRATONIEN_TOOLS_PATH . 'tools/image_cache.inc.php');

function bratonien_tools_runtime_category_id()
{
  global $page;

  if (!empty($page['category']['id']))
  {
    return (int)$page['category']['id'];
  }

  if (!empty($page['category']) && is_numeric($page['category']))
  {
    return (int)$page['category'];
  }

  return 0;
}

function bratonien_tools_runtime_effective_rule($category_id)
{
  static $categories = null;
  static $rules = null;
  static $defaults = null;

  if ($categories === null)
  {
    $categories = bratonien_tools_get_category_tree();
    $rules = bratonien_tools_get_album_rules();
    $defaults = bratonien_tools_get_watermark_defaults();
  }

  if ((int)$category_id <= 0)
  {
    if (empty($defaults['public_profile']))
    {
      return array('mode'=>'disabled','profile_id'=>null,'source'=>'global');
    }
    return array('mode'=>'profile','profile_id'=>(int)$defaults['public_profile'],'source'=>'global');
  }

  return bratonien_tools_resolve_album_rule((int)$category_id, $categories, $rules, $defaults);
}

function bratonien_tools_runtime_get_profile($profile_id)
{
  static $profiles = array();
  $profile_id = (int)$profile_id;

  if ($profile_id <= 0)
  {
    return null;
  }

  if (!array_key_exists($profile_id, $profiles))
  {
    $profiles[$profile_id] = bratonien_tools_get_watermark_profile($profile_id) ?: null;
  }

  return $profiles[$profile_id];
}

function bratonien_tools_runtime_sign($rel_url, $profile_id, $profile_version='')
{
  global $conf;
  $key = !empty($conf['secret_key']) ? $conf['secret_key'] : ($conf['db_password'] ?? 'bratonien-tools');
  return hash_hmac('sha256', $profile_id.'|'.$profile_version.'|'.$rel_url, $key);
}

function bratonien_tools_runtime_b64url_encode($value)
{
  return rtrim(strtr(base64_encode($value), '+/', '-_'), '=');
}

function bratonien_tools_profile_watermark_path(array $profile)
{
  static $paths = array();

  if (empty($profile['watermark_file']))
  {
    return null;
  }

  $relative = ltrim((string)$profile['watermark_file'], '/');
  if (array_key_exists($relative, $paths))
  {
    return $paths[$relative];
  }

  $allowed_prefix = trim(PWG_LOCAL_DIR, '/').'/watermarks/';
  if (strpos($relative, $allowed_prefix) !== 0)
  {
    $paths[$relative] = null;
    return null;
  }

  $root = realpath(PHPWG_ROOT_PATH.PWG_LOCAL_DIR.'watermarks');
  $path = realpath(PHPWG_ROOT_PATH.$relative);
  if (!$root || !$path || strpos($path, $root.DIRECTORY_SEPARATOR) !== 0 || !is_file($path))
  {
    $paths[$relative] = null;
    return null;
  }

  $paths[$relative] = $path;
  return $path;
}

function bratonien_tools_runtime_profile_version(array $profile)
{
  $watermark_path = bratonien_tools_profile_watermark_path($profile);
  $parts = array(
    $profile['id'] ?? 0,
    $profile['watermark_file'] ?? '',
    $profile['scale_percent'] ?? 100,
    $profile['xpos'] ?? 90,
    $profile['ypos'] ?? 90,
    $profile['xrepeat'] ?? 0,
    $profile['yrepeat'] ?? 0,
    $profile['opacity'] ?? 35,
    $profile['min_width'] ?? 10,
    $profile['min_height'] ?? 10,
    $profile['active'] ?? 1,
    $watermark_path ? @filemtime($watermark_path) : 0,
  );

  return substr(sha1(implode('|', $parts)), 0, 16);
}

function bratonien_tools_runtime_canonical_derivative_url($rel_url)
{
  $rel_url = (string)$rel_url;
  if (strpos($rel_url, PWG_DERIVATIVE_DIR) === 0)
  {
    return $rel_url;
  }

  if (preg_match('#^i(?:\.php)?\?/(.+)$#', $rel_url, $match) || preg_match('#^i(?:\.php)?/(.+)$#', $rel_url, $match))
  {
    return PWG_DERIVATIVE_DIR.ltrim(rawurldecode($match[1]), '/');
  }

  return $rel_url;
}

function bratonien_tools_runtime_precache_active()
{
  static $active = null;
  if ($active !== null)
  {
    return $active;
  }

  $active = false;
  $status_file = PHPWG_ROOT_PATH.PWG_LOCAL_DIR.'bratonien-tools-precache.status.json';
  if (!is_file($status_file) || !is_readable($status_file))
  {
    return false;
  }

  $raw = @file_get_contents($status_file);
  $status = $raw !== false ? json_decode($raw, true) : null;
  if (!is_array($status))
  {
    return false;
  }

  $state = (string)($status['state'] ?? '');
  $updated_at = (int)($status['updated_at'] ?? 0);
  $age = $updated_at > 0 ? max(0, time() - $updated_at) : PHP_INT_MAX;

  // running wird vom Worker waehrend der Arbeit laufend aktualisiert.
  // queued gilt nur kurz als aktiver Startvorgang; danach darf sich die
  // Galerie selbst heilen, falls der Hintergrundprozess nicht hochkam.
  if ($state === 'running' && $age <= 30)
  {
    $active = true;
  }
  elseif ($state === 'queued' && $age <= 10)
  {
    $active = true;
  }

  return $active;
}

function bratonien_tools_runtime_request_precache_if_idle()
{
  static $requested = false;

  if ($requested || bratonien_tools_runtime_precache_active())
  {
    return;
  }

  $requested = true;
  try
  {
    bratonien_tools_request_watermark_precache('Fehlende Wasserzeichenvariante beim Seitenaufruf erkannt');
  }
  catch (Throwable $e)
  {
    // Der Seiten-Fallback muss auch dann funktionieren, wenn der Hintergrund-
    // Precache nicht gestartet werden kann. Deshalb hier bewusst nicht abbrechen.
  }
}

function bratonien_tools_runtime_cache_descriptor($rel_url, array $profile, $params, $source_path, $extension='')
{
  if (!$params || !$source_path)
  {
    return null;
  }

  $watermark_path = bratonien_tools_profile_watermark_path($profile);
  if (!$watermark_path)
  {
    return null;
  }

  $canonical_rel_url = bratonien_tools_runtime_canonical_derivative_url($rel_url);
  $extension = strtolower((string)$extension);
  if ($extension === '' && preg_match('/\.(jpe?g|png|gif|webp)(?:$|\?)/i', $canonical_rel_url, $match))
  {
    $extension = strtolower($match[1]);
  }
  if (!in_array($extension, array('jpg','jpeg','png','gif','webp'), true))
  {
    $extension = 'jpg';
  }

  $profile_id = (int)($profile['id'] ?? 0);
  if ($profile_id <= 0)
  {
    return null;
  }

  $scale_percent = isset($profile['scale_percent']) ? max(1.0, min(1000.0, (float)$profile['scale_percent'])) : 100.0;
  $profile_version = bratonien_tools_runtime_profile_version($profile);
  $min_size = is_array($params->sizing->min_size) ? implode('x', $params->sizing->min_size) : '';
  $cache_fingerprint = array(
    $canonical_rel_url,
    $profile_version,
    @filemtime($source_path) ?: 0,
    $params->last_mod_time,
    $params->sharpen,
    implode('x', $params->sizing->ideal_size),
    $params->sizing->max_crop,
    $min_size,
    $profile['watermark_file'], $scale_percent, $profile['xpos'], $profile['ypos'],
    $profile['xrepeat'], $profile['yrepeat'], $profile['opacity'],
    $profile['min_width'], $profile['min_height'], $profile['active'],
    @filemtime($watermark_path),
  );

  $relative_dir = PWG_DERIVATIVE_DIR.'bratonien-watermark/'.$profile_id;
  $filename = sha1(implode('|', $cache_fingerprint)).'.'.$extension;
  $relative_path = $relative_dir.'/'.$filename;

  return array(
    'dir' => PHPWG_ROOT_PATH.$relative_dir,
    'path' => PHPWG_ROOT_PATH.$relative_path,
    'relative_path' => $relative_path,
    'url' => get_root_url().$relative_path,
    'profile_version' => $profile_version,
    'canonical_rel_url' => $canonical_rel_url,
  );
}

function bratonien_tools_filter_derivative_url($url, $params, $src_image, $rel_url)
{
  if (defined('BRATONIEN_TOOLS_PRECACHE_BUILD') && BRATONIEN_TOOLS_PRECACHE_BUILD)
  {
    return $url;
  }

  if (!bratonien_tools_watermark_engine_enabled())
  {
    return $url;
  }

  $rule = bratonien_tools_runtime_effective_rule(bratonien_tools_runtime_category_id());
  if ($rule['mode'] !== 'profile' || empty($rule['profile_id']))
  {
    return $url;
  }

  $profile = bratonien_tools_runtime_get_profile((int)$rule['profile_id']);
  if (!$profile || empty($profile['active']))
  {
    return $url;
  }

  if (!bratonien_tools_profile_watermark_path($profile))
  {
    return $url;
  }

  if (is_object($params) && is_object($src_image) && $src_image->has_size())
  {
    $size = $params->compute_final_size($src_image->get_size());
    if ($size && ($size[0] < (int)$profile['min_width'] || $size[1] < (int)$profile['min_height']))
    {
      return $url;
    }
  }

  if (is_object($params) && is_object($src_image))
  {
    $descriptor = bratonien_tools_runtime_cache_descriptor($rel_url, $profile, $params, $src_image->get_path());
    if ($descriptor && is_file($descriptor['path']) && is_readable($descriptor['path']))
    {
      return $descriptor['url'];
    }
  }

  // Cache fehlt: Der Seitenaufruf bleibt immer das Sicherheitsnetz und
  // rendert diese Variante ueber watermark.php. Falls gleichzeitig kein
  // aktiver Precache arbeitet, wird der Hintergrund-Precache einmalig neu
  // angestossen, damit weitere Varianten wieder vorab entstehen.
  bratonien_tools_runtime_request_precache_if_idle();

  $profile_id = (int)$profile['id'];
  $profile_version = bratonien_tools_runtime_profile_version($profile);
  $signature = bratonien_tools_runtime_sign($rel_url, $profile_id, $profile_version);

  return get_root_url().'plugins/'.BRATONIEN_TOOLS_ID.'/watermark.php?p='.$profile_id.'&v='.
    rawurlencode($profile_version).'&u='.rawurlencode(bratonien_tools_runtime_b64url_encode($rel_url)).'&s='.$signature;
}