work on refactoring search

app/models/artist.rb

@@ -14,10 +14,8 @@ class Artist < ActiveRecord::Base
   accepts_nested_attributes_for :wiki_page
   attr_accessible :body, :name, :url_string, :other_names, :group_name, :wiki_page_attributes, :notes, :is_active, :as => [:member, :privileged, :contributor, :janitor, :moderator, :default, :admin]
   attr_accessible :is_banned, :as => :admin
-  scope :url_match, lambda {|string| where(["id in (?)", Artist.find_all_by_url(string).map(&:id)])}
-  scope :other_names_match, lambda {|string| where(["other_names_index @@ to_tsquery('danbooru', ?)", Artist.normalize_name(string)])}
-  scope :name_equals, lambda {|string| where("name = ?", string)}
-  search_methods :url_match, :other_names_match
+  scope :active, where("is_active = true")
+  scope :banned, where("is_banned = true")
   
   module UrlMethods
     extend ActiveSupport::Concern
@@ -192,6 +190,71 @@ class Artist < ActiveRecord::Base
     end
   end
   
+  module SearchMethods
+    extend ActiveSupport::Concern
+    
+    module ClassMethods
+      def url_matches(string)
+        matches = find_all_by_url(string).map(&:id)
+
+        if matches.any?
+          where("id in (?)", matches)
+        else
+          where("false")
+        end
+      end
+      
+      def other_names_match(string)
+        where("other_names_index @@ to_tsquery('danbooru', ?)", Artist.normalize_name(string))
+      end
+      
+      def group_name_matches(name)
+        stripped_name = normalize_name(name).to_escaped_for_sql_like
+        where("group_name LIKE ? ESCAPE E'\\\\'", stripped_name)
+      end
+      
+      def name_matches(name)
+        stripped_name = normalize_name(name).to_escaped_for_sql_like
+        where("name LIKE ? ESCAPE E'\\\\'", stripped_name)
+      end
+      
+      def any_name_matches(name)
+        stripped_name = normalize_name(name).to_escaped_for_sql_like
+        where("(name LIKE ? ESCAPE E'\\\\' OR other_names_index @@ to_tsquery('danbooru', ?))", stripped_name, normalize_name(name))
+      end
+      
+      def search(params)
+        q = active
+
+        case params[:name]
+        when /^http/
+          q = q.url_matches(params[:name])
+
+        when /name:(.+)/
+          q = q.name_matches($1)
+          
+        when /other:(.+)/
+          q = q.other_names_match($1)
+
+        when /group:(.+)/
+          q = q.group_name_matches($1)
+
+        when /status:banned/
+          q = q.banned
+
+        when /./
+          q = q.any_name_matches(params[:name])
+        end
+
+        if params[:id]
+          q = q.where("id = ?", params[:id])
+        end
+        
+        q
+      end
+    end
+  end
+  
   include UrlMethods
   include NameMethods
   include GroupMethods
@@ -200,6 +263,7 @@ class Artist < ActiveRecord::Base
   include NoteMethods
   include TagMethods
   include BanMethods
+  include SearchMethods
   
   def status
     if is_banned?