Added Package.best_screenshot_for_version

app/models/package.rb

@@ -47,10 +47,26 @@ class Package < ActiveRecord::Base
     self.joins(:screenshots).where(screenshots: {approved:false}).distinct(:name)
   end
 
+  # Get all screenshots and have them sorted descendingly by their version number (Debian style).
   def screenshots_sorted_by_version
-    self.screenshots.to_a.sort do |x,y|
+    self.screenshots.to_a.sort { |x,y| version_compare(x.version,y.version) }
-      version_x = DebImporter::Version.new(x.version)
+  end
-      version_y = DebImporter::Version.new(y.version)
+
+  # Return the newest screenshot that is not newer than the given version.
+  def best_screenshot_for_version(version)
+    sorted_screenshots = self.screenshots_sorted_by_version
+    sorted_screenshots.each do |ss|
+      logger.debug { "Comparing version #{version} against #{ss.version}" }
+      return ss if version_compare(version, ss.version)<=0
+    end
+    return sorted_screenshots.last
+  end
+
+  private
+
+  def version_compare(x,y)
+    version_x = DebImporter::Version.new(x)
+    version_y = DebImporter::Version.new(y)
     if version_x<version_y
       1
     elsif version_x>version_y
@@ -60,4 +76,3 @@ class Package < ActiveRecord::Base
     end
   end
 end
-end