<?php
$piwigo_root = realpath(dirname(__DIR__, 2));
if ($piwigo_root === false)
{
  http_response_code(500);
  exit;
}
define('PHPWG_ROOT_PATH', rtrim($piwigo_root, DIRECTORY_SEPARATOR).DIRECTORY_SEPARATOR);
include_once(PHPWG_ROOT_PATH.'include/common.inc.php');

if (!defined('BRATONIEN_TOOLS_PATH'))
{
  http_response_code(500);
  exit;
}

require_once(BRATONIEN_TOOLS_PATH.'include/watermark_runtime.inc.php');
require_once(PHPWG_ROOT_PATH.'admin/include/image.class.php');

function bratonien_tools_runtime_b64url_decode($value)
{
  $value = strtr((string)$value, '-_', '+/');
  $padding = strlen($value) % 4;
  if ($padding)
  {
    $value .= str_repeat('=', 4 - $padding);
  }
  return base64_decode($value, true);
}

function bratonien_tools_watermark_fail($code, $message)
{
  http_response_code($code);
  header('Content-Type: text/plain; charset=utf-8');
  echo $message;
  exit;
}

function bratonien_tools_output_image($path)
{
  $ext = strtolower(pathinfo($path, PATHINFO_EXTENSION));
  $types = array('jpg'=>'image/jpeg','jpeg'=>'image/jpeg','png'=>'image/png','gif'=>'image/gif','webp'=>'image/webp');
  $mtime = @filemtime($path) ?: time();
  $etag = '"'.sha1($path.'|'.$mtime.'|'.filesize($path)).'"';
  if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) && trim($_SERVER['HTTP_IF_NONE_MATCH']) === $etag)
  {
    header('ETag: '.$etag, true, 304);
    header('Cache-Control: public, max-age=31536000, immutable');
    exit;
  }
  header('Content-Type: '.($types[$ext] ?? 'application/octet-stream'));
  header('Content-Length: '.filesize($path));
  header('Last-Modified: '.gmdate('D, d M Y H:i:s', $mtime).' GMT');
  header('ETag: '.$etag);
  header('Cache-Control: public, max-age=31536000, immutable');
  readfile($path);
  exit;
}

function bratonien_tools_url_to_size($value)
{
  $parts = explode('x', (string)$value, 2);
  if (count($parts) === 1)
  {
    $size = max(1, (int)$parts[0]);
    return array($size, $size);
  }
  return array(max(1, (int)$parts[0]), max(1, (int)$parts[1]));
}

function bratonien_tools_custom_params(array $tokens)
{
  if (empty($tokens)) return null;
  $token = array_shift($tokens);
  $crop = 0;
  $min_size = null;
  if (isset($token[0]) && $token[0] === 's')
  {
    $size = bratonien_tools_url_to_size(substr($token, 1));
  }
  elseif (isset($token[0]) && $token[0] === 'e')
  {
    $crop = 1;
    $size = $min_size = bratonien_tools_url_to_size(substr($token, 1));
  }
  else
  {
    if (count($tokens) < 2) return null;
    $size = bratonien_tools_url_to_size($token);
    $crop_token = array_shift($tokens);
    $min_size = bratonien_tools_url_to_size(array_shift($tokens));
    $crop = function_exists('char_to_fraction') ? char_to_fraction($crop_token) : 0;
  }
  return new DerivativeParams(new SizingParams($size, $crop, $min_size));
}

function bratonien_tools_parse_derivative($rel_url)
{
  $location = null;
  if (strpos($rel_url, PWG_DERIVATIVE_DIR) === 0)
  {
    $location = substr($rel_url, strlen(PWG_DERIVATIVE_DIR));
  }
  elseif (preg_match('#^i(?:\.php)?\?/(.+)$#', $rel_url, $match) || preg_match('#^i(?:\.php)?/(.+)$#', $rel_url, $match))
  {
    $location = $match[1];
  }
  if ($location === null) return null;
  $location = ltrim(rawurldecode($location), '/');
  if ($location === '' || strpos($location, "\0") !== false || strpos($location, '..') !== false) return null;
  $dot = strrpos($location, '.');
  if ($dot === false) return null;
  $ext = strtolower(substr($location, $dot + 1));
  if (!in_array($ext, array('jpg','jpeg','png','gif','webp'), true)) return null;
  $without_ext = substr($location, 0, $dot);
  $dash = strrpos($without_ext, '-');
  if ($dash === false) return null;
  $source_rel = substr($without_ext, 0, $dash).'.'.$ext;
  $derivative = substr($without_ext, $dash + 1);
  $tokens = explode('_', $derivative);
  $type_token = array_shift($tokens);
  $params = null;
  foreach (ImageStdParams::get_defined_type_map() as $type => $candidate)
  {
    if (function_exists('derivative_to_url') && derivative_to_url($type) === $type_token)
    {
      $params = $candidate;
      break;
    }
  }
  if ($params === null && defined('IMG_CUSTOM') && function_exists('derivative_to_url') && derivative_to_url(IMG_CUSTOM) === $type_token)
  {
    $params = bratonien_tools_custom_params($tokens);
  }
  if (!$params) return null;
  $source_path = PHPWG_ROOT_PATH.$source_rel;
  if (!is_file($source_path) || !is_readable($source_path)) return null;
  return array('source_rel'=>$source_rel,'source_path'=>$source_path,'extension'=>$ext,'params'=>$params);
}

function bratonien_tools_source_metadata($source_rel, $source_path)
{
  $rotation = 0;
  $coi = null;
  $escaped = array();
  foreach (array($source_rel, './'.$source_rel) as $candidate)
  {
    $escaped[] = "'".pwg_db_real_escape_string($candidate)."'";
  }
  $query = 'SELECT rotation, coi FROM '.IMAGES_TABLE.' WHERE path IN ('.implode(',', $escaped).') LIMIT 1';
  $row = pwg_db_fetch_assoc(pwg_query($query));
  if ($row)
  {
    $rotation = isset($row['rotation']) ? pwg_image::get_rotation_angle_from_code($row['rotation']) : pwg_image::get_rotation_angle($source_path);
    $coi = $row['coi'] ?? null;
  }
  return array('rotation'=>$rotation,'coi'=>$coi);
}

if (!bratonien_tools_watermark_engine_enabled()) bratonien_tools_watermark_fail(404, 'Watermark engine disabled');

$profile_id = (int)($_GET['p'] ?? 0);
$profile_version = (string)($_GET['v'] ?? '');
$encoded_url = (string)($_GET['u'] ?? '');
$signature = (string)($_GET['s'] ?? '');
$rel_url = bratonien_tools_runtime_b64url_decode($encoded_url);
if ($profile_id <= 0 || $profile_version === '' || $rel_url === false || $rel_url === '') bratonien_tools_watermark_fail(400, 'Invalid request');

$profile = bratonien_tools_runtime_get_profile($profile_id);
if (!$profile || empty($profile['active'])) bratonien_tools_watermark_fail(404, 'Watermark profile unavailable');
$current_profile_version = bratonien_tools_runtime_profile_version($profile);
if (!hash_equals($current_profile_version, $profile_version)) bratonien_tools_watermark_fail(410, 'Watermark profile changed');
$expected = bratonien_tools_runtime_sign($rel_url, $profile_id, $profile_version);
if (!hash_equals($expected, $signature)) bratonien_tools_watermark_fail(403, 'Invalid signature');
$watermark_path = bratonien_tools_profile_watermark_path($profile);
if (!$watermark_path) bratonien_tools_watermark_fail(404, 'Watermark file unavailable');
$derivative = bratonien_tools_parse_derivative($rel_url);
if (!$derivative) bratonien_tools_watermark_fail(404, 'Derivative description unavailable');

$params = $derivative['params'];
$source_path = $derivative['source_path'];
$source_mtime = @filemtime($source_path) ?: 0;
$scale_percent = isset($profile['scale_percent']) ? max(1.0, min(1000.0, (float)$profile['scale_percent'])) : 100.0;
$cache_dir = PHPWG_ROOT_PATH.PWG_DERIVATIVE_DIR.'bratonien-watermark/'.$profile_id;
if (!is_dir($cache_dir) && !mkdir($cache_dir, 0755, true) && !is_dir($cache_dir)) bratonien_tools_watermark_fail(500, 'Cache directory unavailable');
$min_size = is_array($params->sizing->min_size) ? implode('x', $params->sizing->min_size) : '';
$cache_fingerprint = array(
  bratonien_tools_runtime_canonical_derivative_url($rel_url), $profile_version, $source_mtime,
  $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),
);
$cache_path = $cache_dir.'/'.sha1(implode('|', $cache_fingerprint)).'.'.$derivative['extension'];
if (is_file($cache_path) && is_readable($cache_path)) bratonien_tools_output_image($cache_path);

$lock_path = $cache_path.'.lock';
$lock = @fopen($lock_path, 'c');
if (!$lock || !flock($lock, LOCK_EX))
{
  if (is_resource($lock)) fclose($lock);
  bratonien_tools_watermark_fail(500, 'Watermark cache lock unavailable');
}
if (is_file($cache_path) && is_readable($cache_path))
{
  flock($lock, LOCK_UN); fclose($lock); @unlink($lock_path); bratonien_tools_output_image($cache_path);
}

$metadata = bratonien_tools_source_metadata($derivative['source_rel'], $source_path);
$image = new pwg_image($source_path);
if (!empty($metadata['rotation'])) $image->rotate($metadata['rotation']);
$original_size = array($image->get_width(), $image->get_height());
$params->sizing->compute($original_size, $metadata['coi'], $crop_rect, $scaled_size);
if ($crop_rect) $image->crop($crop_rect->width(), $crop_rect->height(), $crop_rect->l, $crop_rect->t);
if ($scaled_size) $image->resize($scaled_size[0], $scaled_size[1]);
if ($params->sharpen) $image->sharpen($params->sharpen);
$width = $image->get_width();
$height = $image->get_height();

if ($width >= (int)$profile['min_width'] && $height >= (int)$profile['min_height'])
{
  $wm = new pwg_image($watermark_path);
  $original_wm_width = $wm->get_width();
  $original_wm_height = $wm->get_height();
  $wm_width = max(1, (int)round($original_wm_width * $scale_percent / 100));
  $wm_height = max(1, (int)round($original_wm_height * $scale_percent / 100));
  if ($wm_width !== $original_wm_width || $wm_height !== $original_wm_height) $wm->resize($wm_width, $wm_height);
  if ($width < $wm_width || $height < $wm_height)
  {
    $fit = min($width / $wm_width, $height / $wm_height);
    $wm_width = max(1, (int)floor($wm_width * $fit));
    $wm_height = max(1, (int)floor($wm_height * $fit));
    $wm->resize($wm_width, $wm_height);
  }
  $x = (int)round(((int)$profile['xpos'] / 100) * ($width - $wm_width));
  $y = (int)round(((int)$profile['ypos'] / 100) * ($height - $wm_height));
  $opacity = (int)$profile['opacity'];
  $image->compose($wm, $x, $y, $opacity);
  $xrepeat = max(0, (int)$profile['xrepeat']);
  $yrepeat = max(0, (int)$profile['yrepeat']);
  if ($xrepeat || $yrepeat)
  {
    $xpad = $wm_width + max(30, (int)round($wm_width / 4));
    $ypad = $wm_height + max(30, (int)round($wm_height / 4));
    for ($i=-$xrepeat; $i<=$xrepeat; $i++)
    {
      for ($j=-$yrepeat; $j<=$yrepeat; $j++)
      {
        if ($i === 0 && $j === 0) continue;
        $x2 = $x + $i * $xpad;
        $y2 = $y + $j * $ypad;
        if ($x2 >= 0 && $x2 + $wm_width <= $width && $y2 >= 0 && $y2 + $wm_height <= $height) $image->compose($wm, $x2, $y2, $opacity);
      }
    }
  }
  $wm->destroy();
}
$image->write($cache_path);
$image->destroy();
@chmod($cache_path, 0644);
flock($lock, LOCK_UN);
fclose($lock);
@unlink($lock_path);
bratonien_tools_output_image($cache_path);