Starting to fill in tournament ranking bits

rails/map-mash/app/controllers/mashes_controller.rb

@@ -8,7 +8,7 @@ class MashesController < ApplicationController
   alias_method :show, :redirect_to_new
 
   def new
-    @map_a, @map_b = Map.rand(2)
+    @map_a, @map_b = Map.pair
 
     @mash = Mash.new(
       :requester => request.remote_ip,

rails/map-mash/app/models/map.rb

@@ -6,8 +6,39 @@ class Map < ActiveRecord::Base
     self.find_or_initialize_by_name(city_name).save!
   end
 
-  def self.rand(count = 2)
+  def self.pair
-    self.find(:all, :order => 'RANDOM()', :limit => count)
+    if Mash.count == 0
+      self.all(:order => 'RANDOM()', :limit => count)
+    else
+      first_conditions = <<-SQL
+      NOT EXISTS (
+          SELECT * FROM `mashes`
+          WHERE `winner` = `maps`.`id`
+      )
+      SQL
+      second_conditions = <<-SQL
+      `maps`.`id` != :first_id
+          AND (
+              SELECT COUNT(*) FROM `mashes`
+              WHERE `winner` = :first_id
+          ) = (
+              SELECT COUNT(*) FROM `mashes`
+              WHERE `winner` = `maps`.`id`
+          )
+      SQL
+
+      first = self.all(
+          :order => 'RANDOM()',
+          :limit => 1,
+          :conditions => [first_conditions]
+      ).first
+      second = self.all(
+          :order => 'RANDOM()',
+          :limit => 1,
+          :conditions => [second_conditions, {:first_id => first.id}]
+      ).first
+      [first, second]
+    end
   end
 
   def self.import(csv_filename)
@@ -22,4 +53,24 @@ class Map < ActiveRecord::Base
       end
     end
   end
+
+  def >(other)
+    self.points > other.points
+  end
+
+  def <(other)
+    self.points < other.points
+  end
+
+  def ==(other)
+    self.points == other.points
+  end
+
+  def rounds
+    Mash.count(:conditions => ['map_a = :id OR map_b = :id', {:id => self.id}])
+  end
+
+  def points
+    Mash.count(:conditions => ['winner = ?', self.id])
+  end
 end

rails/map-mash/db/migrate/20120304151123_create_maps.rb

@@ -5,9 +5,12 @@ class CreateMaps < ActiveRecord::Migration
 
       t.timestamps
     end
+
+    add_index :maps, :name
   end
 
   def self.down
     drop_table :maps
+    remove_index :maps, :name
   end
 end

rails/map-mash/db/migrate/20120304164625_create_mashes.rb

@@ -8,9 +8,12 @@ class CreateMashes < ActiveRecord::Migration
 
       t.timestamps
     end
+
+    add_index :mashes, :winner
   end
 
   def self.down
     drop_table :mashes
+    remove_index :mashes, :winner
   end
 end

rails/map-mash/db/schema.rb

@@ -17,6 +17,8 @@ ActiveRecord::Schema.define(:version => 20120304164625) do
     t.datetime "updated_at"
   end
 
+  add_index "maps", ["name"], :name => "index_maps_on_name"
+
   create_table "mashes", :force => true do |t|
     t.string   "requester",  :null => false
     t.integer  "map_a",      :null => false
@@ -26,4 +28,6 @@ ActiveRecord::Schema.define(:version => 20120304164625) do
     t.datetime "updated_at"
   end
 
+  add_index "mashes", ["winner"], :name => "index_mashes_on_winner"
+
 end