#1866: Tumblr thumbnail rewriting

app/logical/downloads/strategies/tumblr.rb

@@ -0,0 +1,27 @@
+module Downloads
+  module Strategies
+    class Tumblr < Base
+      def rewrite(url, headers)
+        if url =~ %r{^http?://(?:(?:\d+\.)\w+\.)?tumblr\.com}
+          url, headers = rewrite_thumbnails(url, headers)
+        end
+
+        return [url, headers]
+      end
+
+    protected
+      def rewrite_thumbnails(url, headers)
+        if url =~ %r{^http?://.+\.tumblr\.com/(?:\w+/)?(?:tumblr_)?(\w+_)(250|400|500)\..+$}
+          match = $1
+          size = $2
+          big_url = url.sub(match + size, match + "1280")
+          if http_exists?(big_url, headers)
+            url = big_url
+          end
+        end
+
+        return [url, headers]
+      end
+    end
+  end
+end