support dark mode for images with alpha channel

3 files changed, 11 insertions, 4 deletions

diff --git a/lib/MyParsedown.php b/lib/MyParsedown.php
index c2c0112..11e86d6 100644
--- a/lib/MyParsedown.php
+++ b/lib/MyParsedown.php
@@ -99,6 +99,7 @@ class MyParsedown extends ParsedownHighlight {
                 nolabel: $opts['nolabel'],
                 align: $opts['align'],
                 padding_top: round($h / $w * 100, 4),
+                may_have_alpha: $image->imageMayHaveAlphaChannel(),
 
                 url: $image_url,
                 direct_url: $image->getDirectUrl(),
diff --git a/lib/markup.php b/lib/markup.php
index 52ccf24..2f25c6c 100644
--- a/lib/markup.php
+++ b/lib/markup.php
@@ -16,12 +16,15 @@ class markup {
         return $text;
     }
 
-    public static function htmlRetinaFix(string $html): string {
+    public static function htmlImagesFix(string $html, bool $is_retina, string $user_theme): string {
         global $config;
+        $is_dark_theme = $user_theme === 'dark';
         return preg_replace_callback(
-            '/('.preg_quote($config['uploads_host'], '/').'\/\w{8}\/p)(\d+)x(\d+)(\.jpg)/',
-            function($match) {
-                return $match[1].(intval($match[2])*2).'x'.(intval($match[3])*2).$match[4];
+            '/('.preg_quote($config['uploads_host'], '/').'\/\w{8}\/)([ap])(\d+)x(\d+)(\.jpg)/',
+            function($match) use ($is_retina, $is_dark_theme) {
+                $mult = $is_retina ? 2 : 1;
+                $is_alpha = $match[2] == 'a';
+                return $match[1].$match[2].(intval($match[3])*$mult).'x'.(intval($match[4])*$mult).($is_alpha && $is_dark_theme ? '_dark' : '').$match[5];
             },
             $html
         );
diff --git a/lib/posts.php b/lib/posts.php
index bf8d149..1537749 100644
--- a/lib/posts.php
+++ b/lib/posts.php
@@ -23,6 +23,9 @@ class posts {
         return (int)$db->result($db->query($sql, $tag_id));
     }
 
+    /**
+     * @return Post[]
+     */
     public static function getPosts(int $offset = 0, int $count = -1, bool $include_hidden = false): array {
         $db = getDb();
         $sql = "SELECT * FROM posts";