From 4dff7538eab1690c8271f7a7b1d9d0d17a65d564 Mon Sep 17 00:00:00 2001
From: Katrina Owen <katrina.owen@gmail.com>
Date: Fri, 1 Mar 2013 21:27:58 -0500
Subject: [PATCH] Extract duplicated query

This includes a bit of a simplification which assumes that there aren't
any orphan taggings for a user.
---
 app/controllers/stats_controller.rb | 27 +++------------------------
 app/models/stats/user_tags_query.rb | 26 ++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 24 deletions(-)
 create mode 100644 app/models/stats/user_tags_query.rb

diff --git a/app/controllers/stats_controller.rb b/app/controllers/stats_controller.rb
index 5512abad..44c7787b 100644
--- a/app/controllers/stats_controller.rb
+++ b/app/controllers/stats_controller.rb
@@ -9,8 +9,9 @@ class StatsController < ApplicationController
     @page_title = t('stats.index_title')
 
     @first_action = current_user.todos.reorder("created_at ASC").first
-    @tags_count = get_total_number_of_tags_of_user
-    @unique_tags_count = get_unique_tags_of_user.size
+    tag_ids = Stats::UserTagsQuery.new(current_user).result.map(&:id)
+    @tags_count = tag_ids.size
+    @unique_tags_count = tag_ids.uniq.size
     @hidden_contexts = current_user.contexts.hidden
 
     get_stats_actions
@@ -396,28 +397,6 @@ class StatsController < ApplicationController
     @truncate_chars = 15
   end
 
-  def get_unique_tags_of_user
-    tag_ids = current_user.todos.find_by_sql([
-        "SELECT DISTINCT tags.id as id "+
-          "FROM tags, taggings, todos "+
-          "WHERE tags.id = taggings.tag_id " +
-          "AND taggings.taggable_id = todos.id "+
-          "AND todos.user_id = #{current_user.id}"])
-    tags_ids_s = tag_ids.map(&:id).sort.join(",")
-    return {} if tags_ids_s.blank?  # return empty hash for .size to work
-    return Tag.where("id in (#{tags_ids_s})")
-  end
-
-  def get_total_number_of_tags_of_user
-    # same query as get_unique_tags_of_user except for the DISTINCT
-    return current_user.todos.find_by_sql([
-        "SELECT tags.id as id "+
-          "FROM tags, taggings, todos "+
-          "WHERE tags.id = taggings.tag_id " +
-          "AND taggings.taggable_id = todos.id " +
-          "AND todos.user_id = #{current_user.id}"]).size
-  end
-
   def init
     @me = self # for meta programming
 
diff --git a/app/models/stats/user_tags_query.rb b/app/models/stats/user_tags_query.rb
new file mode 100644
index 00000000..034e5adb
--- /dev/null
+++ b/app/models/stats/user_tags_query.rb
@@ -0,0 +1,26 @@
+module Stats
+  class UserTagsQuery
+
+    attr_reader :user
+    def initialize(user)
+      @user = user
+    end
+
+    def result
+      user.todos.find_by_sql([sql, user.id])
+    end
+
+    private
+
+    def sql
+      <<-SQL
+        SELECT tags.id as id
+        FROM tags, taggings, todos
+        WHERE tags.id = taggings.tag_id
+        AND taggings.taggable_id = todos.id
+        AND todos.user_id = ?
+      SQL
+    end
+
+  end
+end