add user similarity report

app/assets/stylesheets/specific/reports.css.scss

@@ -0,0 +1,21 @@
+#c-reports {
+	#a-similar-users {
+    div.box {
+      h2, h3 {
+        color: #333;
+      }
+
+      margin-bottom: 2em;
+    }
+
+    /* clearfix hacks */
+    div.box:before, div.box:after {
+      content: "";
+      display: table;
+    }
+
+    div.box:after {
+      clear: both;
+    }
+  }
+}

app/controllers/reports_controller.rb

@@ -1,4 +1,7 @@
 class ReportsController < ApplicationController
+  before_filter :member_only
+  before_filter :gold_only, :only => [:similar_users]
+
   def user_promotions
     @report = Reports::UserPromotions.new
   end
@@ -14,4 +17,9 @@ class ReportsController < ApplicationController
   def uploads
     @report = Reports::Uploads.new(params[:min_date], params[:max_date], params[:queries])
   end
+
+  def similar_users
+    @report = Reports::UserSimilarity.new(CurrentUser.id)
+    @presenter = UserSimilarityPresenter.new(@report)
+  end
 end

app/logical/reports/user_similarity.rb

@@ -0,0 +1,33 @@
+module Reports
+  class UserSimilarity
+    attr_reader :user_id
+
+    def initialize(user_id)
+      @user_id = user_id
+    end
+
+    def user
+      User.find(user_id)
+    end
+
+    def fetch_similar_user_ids
+      return NotImplementedError unless Danbooru.config.report_server
+
+      params = {
+        "key" => Danbooru.config.shared_remote_key,
+        "user_id" => user_id
+      }
+      uri = URI.parse("#{Danbooru.config.listbooru_server}/reports/user_similarity")
+      uri.query = URI.encode_www_form(params)
+
+      Net::HTTP.start(uri.host, uri.port) do |http|
+        resp = http.request_get(uri.request_uri)
+        if resp.is_a?(Net::HTTPSuccess)
+          resp.body
+        else
+          raise "HTTP error code: #{resp.code} #{resp.message}"
+        end
+      end
+    end
+  end
+end

app/presenters/user_similarity_presenter.rb

@@ -0,0 +1,34 @@
+class UserSimilarityPresenter
+  attr_reader :report, :not_ready
+
+  def initialize(report)
+    @report = report
+    fetch
+  end
+
+  def not_ready?
+    not_ready
+  end
+
+  def insufficient_data?
+    report.user.favorite_count < 500
+  end
+
+  def fetch
+    user_ids = report.fetch_similar_user_ids
+
+    if user_ids = "not ready"
+      @not_ready = true
+    else
+      @user_ids = user_ids.scan(/\d+/).slice(0, 10)
+    end
+  end
+
+  def each_user(&block)
+    User.where(id: user_ids).each(&block)
+  end
+
+  def each_favorite_for(user, &block)
+    user.favorites.limit(6).joins(:post).reorder("favorites.id desc").map(&:post).each(&block)
+  end
+end

app/views/reports/similar_users.html.erb

@@ -0,0 +1,28 @@
+<div id="c-reports">
+  <div id="a-similar-users">
+    <h1>Similar Users</h1>
+
+    <% if @presenter.insufficient_data? %>
+      <p>You need at least 500 favorites before Danbooru can calculate users similar to you.</p>
+
+    <% elsif @presenter.not_ready? %>
+      <p>The report is still being generated. Check back in a few minutes.</p>
+
+    <% else %>
+      <% @presenter.each_user do |user| %>
+        <div class="box">
+          <h2><%= link_to user.pretty_name, user_path(user) %></h2>
+          <div>
+            <% @presenter.each_favorite_for(user) do |post| %>
+              <%= PostPresenter.preview(post, :tags => "fav:#{user.name}") %>
+            <% end %>
+          </div>
+        </div>
+      <% end %>
+    <% end %>
+  </div>
+</div>
+
+<% content_for(:page_title) do %>
+  Similar Users - <%= Danbooru.config.app_name %>
+<% end %>

config/routes.rb

@@ -223,6 +223,7 @@ Rails.application.routes.draw do
   get "reports/janitor_trials" => "reports#janitor_trials"
   get "reports/contributors" => "reports#contributors"
   get "reports/uploads" => "reports#uploads"
+  get "reports/similar_users" => "reports#similar_users"
   resources :saved_searches, :except => [:show] do
     collection do
       get :categories