API sorting improvements:

- Add endpoints for getting/updating sorting methods
- Results from library and title endpoints are now sorted

src/library/library.cr

@@ -139,14 +139,21 @@ class Library
     titles.flat_map &.deep_entries
   end
 
-  def build_json(*, slim = false, depth = -1)
+  def build_json(*, slim = false, depth = -1, sort_context = nil)
     JSON.build do |json|
       json.object do
         json.field "dir", @dir
         json.field "titles" do
           json.array do
-            self.titles.each do |title|
-              json.raw title.build_json(slim: slim, depth: depth)
+            _titles = if sort_context
+                        sorted_titles sort_context[:username],
+                          sort_context[:opt]
+                      else
+                        self.titles
+                      end
+            _titles.each do |title|
+              json.raw title.build_json(slim: slim, depth: depth,
+                sort_context: sort_context)
             end
           end
         end

src/library/title.cr

@@ -218,9 +218,16 @@ class Title
         unless depth == 0
           json.field "titles" do
             json.array do
-              self.titles.each do |title|
+              _titles = if sort_context
+                          sorted_titles sort_context[:username],
+                            sort_context[:opt]
+                        else
+                          self.titles
+                        end
+              _titles.each do |title|
                 json.raw title.build_json(slim: slim,
-                  depth: depth > 0 ? depth - 1 : depth)
+                  depth: depth > 0 ? depth - 1 : depth,
+                  sort_context: sort_context)
               end
             end
           end

src/library/types.cr

@@ -55,6 +55,13 @@ class SortOptions
   def to_tuple
     {@method.to_s.underscore, ascend}
   end
+
+  def to_json
+    {
+      "method" => method.to_s.underscore,
+      "ascend" => ascend,
+    }.to_json
+  end
 end
 
 struct Image