Rewrite nijie html view page to image url

app/logical/downloads/rewrite_strategies/base.rb

@@ -6,7 +6,7 @@ module Downloads
       end
 
       def self.strategies
-        [Downloads::RewriteStrategies::Pixiv, Downloads::RewriteStrategies::NicoSeiga, Downloads::RewriteStrategies::Twitpic, Downloads::RewriteStrategies::DeviantArt, Downloads::RewriteStrategies::Tumblr, Downloads::RewriteStrategies::Moebooru, Downloads::RewriteStrategies::Twitter]
+        [Downloads::RewriteStrategies::Pixiv, Downloads::RewriteStrategies::NicoSeiga, Downloads::RewriteStrategies::Twitpic, Downloads::RewriteStrategies::DeviantArt, Downloads::RewriteStrategies::Tumblr, Downloads::RewriteStrategies::Moebooru, Downloads::RewriteStrategies::Twitter, Downloads::RewriteStrategies::Nijie]
       end
 
       def rewrite(url, headers, data = {})

app/logical/downloads/rewrite_strategies/nijie.rb

@@ -0,0 +1,40 @@
+module Downloads
+  module RewriteStrategies
+    class Nijie < Base
+      attr_accessor :url, :source
+
+      def initialize(url)
+        @url  = url
+      end
+
+      def rewrite(url, headers, data = {})
+        if url =~ %r{https?://nijie\.info\/view\.php.+id=\d+}
+          url, headers = rewrite_html_pages(url, headers)
+        end
+
+        return [url, headers, data]
+      end
+
+    protected
+      def rewrite_html_pages(url, headers)
+        # example: http://nijie.info/view.php?id=151126
+
+        if url =~ %r{https?://nijie\.info\/view\.php.+id=\d+}
+          return [source.image_url, headers]
+        else
+          return [url, headers]
+        end
+      end
+
+      # Cache the source data so it gets fetched at most once.
+      def source
+        @source ||= begin
+          source = ::Sources::Strategies::Nijie.new(url)
+          source.get
+
+          source
+        end
+      end
+    end
+  end
+end