simplify story finding

app/controllers/home_controller.rb

@@ -11,8 +11,7 @@ class HomeController < ApplicationController
   before_filter :find_user_from_rss_token, :only => [ :index, :newest ]
 
   def index
-    @stories = find_stories_for_user_and_tag_and_newest_and_by_user(@user,
-      nil, false, nil)
+    @stories = find_stories
 
     @rss_link ||= "<link rel=\"alternate\" type=\"application/rss+xml\" " <<
       "title=\"RSS 2.0\" href=\"/rss" <<
@@ -35,18 +34,16 @@ class HomeController < ApplicationController
   end
 
   def newest
-    @stories = find_stories_for_user_and_tag_and_newest_and_by_user(@user,
-      nil, true, nil)
+    @stories = find_stories({ :newest => true })
 
     @heading = @title = "Newest Stories"
     @cur_url = "/newest"
+    @newest = true
 
     @rss_link = "<link rel=\"alternate\" type=\"application/rss+xml\" " <<
       "title=\"RSS 2.0 - Newest Items\" href=\"/newest.rss" <<
       (@user ? "?token=#{@user.rss_token}" : "") << "\" />"
 
-    @newest = true
-
     respond_to do |format|
       format.html { render :action => "index" }
       format.rss {
@@ -61,24 +58,23 @@ class HomeController < ApplicationController
   end
 
   def newest_by_user
-    for_user = User.where(:username => params[:user]).first!
+    by_user = User.where(:username => params[:user]).first!
 
-    @stories = find_stories_for_user_and_tag_and_newest_and_by_user(@user,
-      nil, false, for_user.id)
+    @stories = find_stories({ :by_user => by_user })
 
-    @heading = @title = "Newest Stories by #{for_user.username}"
-    @cur_url = "/newest/#{for_user.username}"
+    @heading = @title = "Newest Stories by #{by_user.username}"
+    @cur_url = "/newest/#{by_user.username}"
 
     @newest = true
-    @for_user = for_user.username
+    @for_user = by_user.username
 
     render :action => "index"
   end
 
   def tagged
     @tag = Tag.where(:tag => params[:tag]).first!
-    @stories = find_stories_for_user_and_tag_and_newest_and_by_user(@user,
-      @tag, false, nil)
+
+    @stories = find_stories({ :tag => @tag })
 
     @heading = @title = @tag.description.blank?? @tag.tag : @tag.description
     @cur_url = tag_url(@tag.tag)
@@ -115,8 +111,7 @@ class HomeController < ApplicationController
   end
 
 private
-  def find_stories_for_user_and_tag_and_newest_and_by_user(user, tag = nil,
-  newest = false, by_user = nil)
+  def find_stories(how = {})
     @page = 1
     if params[:page].to_i > 0
       @page = params[:page].to_i
@@ -124,32 +119,28 @@ private
 
     # guest views have caching, but don't bother for logged-in users or dev or
     # when the user has tag filters
-    if Rails.env == "development" || user || tags_filtered_by_cookie.any?
-      stories, @show_more =
-        _find_stories_for_user_and_tag_and_newest_and_by_user(user, tag,
-        newest, by_user)
+    if Rails.env == "development" || @user || tags_filtered_by_cookie.any?
+      stories, @show_more = _find_stories(how)
     else
-      stories, @show_more = Rails.cache.fetch("stories tag:" <<
-      "#{tag ? tag.tag : ""} new:#{newest} page:#{@page.to_i} by:#{by_user}",
-      :expires_in => 45) do
-        _find_stories_for_user_and_tag_and_newest_and_by_user(user, tag,
-          newest, by_user)
+      stories, @show_more = Rails.cache.fetch("stories " <<
+      "tag:#{how[:tag].try(:tag)} new:#{how[:newest]} page:#{@page.to_i} " <<
+      "by:#{how[:by_user].try(:id)}", :expires_in => 45) do
+        _find_stories(how)
       end
     end
 
     stories
   end
 
-  def _find_stories_for_user_and_tag_and_newest_and_by_user(user, tag = nil,
-  newest = false, by_user = nil)
+  def _find_stories(how)
     stories = Story.where(:is_expired => false)
 
-    if user && !(newest || by_user)
+    if @user && !(how[:newest] || how[:by_user])
       # exclude downvoted items
       stories = stories.where(
         Story.arel_table[:id].not_in(
           Vote.arel_table.where(
-            Vote.arel_table[:user_id].eq(user.id)
+            Vote.arel_table[:user_id].eq(@user.id)
           ).where(
             Vote.arel_table[:vote].lt(0)
           ).where(
@@ -162,13 +153,13 @@ private
     end
 
     filtered_tag_ids = []
-    if user
+    if @user
       filtered_tag_ids = @user.tag_filters.map{|tf| tf.tag_id }
     else
       filtered_tag_ids = tags_filtered_by_cookie.map{|t| t.id }
     end
 
-    if tag
+    if how[:tag]
       stories = stories.where(
         Story.arel_table[:id].in(
           Tagging.arel_table.where(
@@ -178,8 +169,8 @@ private
           )
         )
       )
-    elsif by_user
-      stories = stories.where(:user_id => by_user)
+    elsif how[:by_user]
+      stories = stories.where(:user_id => how[:by_user].id)
     elsif filtered_tag_ids.any?
       stories = stories.where(
         Story.arel_table[:id].not_in(
@@ -192,7 +183,7 @@ private
       )
     end
 
-    if newest && @page == 1
+    if how[:newest] && @page == 1
       # try to help recently-submitted stories that didn't gain traction
 
       # grab the list of stories from the past n days, shifting out popular
@@ -224,7 +215,7 @@ private
     ).offset(
       (@page - 1) * STORIES_PER_PAGE
     ).order(
-      newest ? "stories.created_at DESC" : "hotness"
+      how[:newest] ? "stories.created_at DESC" : "hotness"
     ).to_a
 
     show_more = false
@@ -233,9 +224,8 @@ private
       stories.pop
     end
 
-    if user
-      votes = Vote.votes_by_user_for_stories_hash(user.id,
-        stories.map{|s| s.id })
+    if @user
+      votes = Vote.votes_by_user_for_stories_hash(@user.id, stories.map(&:id))
 
       stories.each do |s|
         if votes[s.id]