Add daily buddies

app/controllers/pages_controller.rb

@@ -21,6 +21,7 @@ def calendar
       }
     end
 
+    @daily_buddy = Buddy.of_the_day(current_user)
     @next_puzzle_time = Aoc.next_puzzle_time
     @now = Aoc.event_timezone.now
   end

app/jobs/buddies/generate_daily_pairs_job.rb

@@ -0,0 +1,67 @@
+# frozen_string_literal: true
+
+module Buddies
+  class GenerateDailyPairsJob < ApplicationJob
+    queue_as :default
+
+    def perform(day)
+      @day = day
+
+      if Buddy.exists?(day:)
+        Rails.logger.info "Daily pairs already exist for day #{day}"
+        return
+      end
+
+      retrieve_confirmed_users
+      handle_odd_number_of_users
+      generate_possible_pairs_of_buddies
+
+      @possible_pairs.shuffle!
+
+      pick_valid_pairs_of_buddies
+      handle_unpaired_users
+
+      insert_generated_buddies
+    end
+
+    private
+
+    def retrieve_confirmed_users
+      @user_ids = User.confirmed.order(:id).pluck(:id)
+    end
+
+    def handle_odd_number_of_users
+      @user_ids.pop if @user_ids.size.odd?
+    end
+
+    def generate_possible_pairs_of_buddies
+      all_pairs = @user_ids.combination(2).to_set
+      past_buddies = Buddy.pluck(:id_1, :id_2).to_set
+
+      @possible_pairs = (all_pairs - past_buddies).to_a
+    end
+
+    def pick_valid_pairs_of_buddies
+      @users_to_match = Set.new(@user_ids)
+      @buddies = []
+
+      # Iterate once over possible pairs to find matches
+      @possible_pairs.each do |pair|
+        # If a pair contains two available IDs, it's a match!
+        if pair.all? { |id| @users_to_match.include?(id) }
+          @buddies << pair
+          pair.each { |id| @users_to_match.delete(id) }
+        end
+      end
+    end
+
+    def handle_unpaired_users
+      @buddies += @users_to_match.to_a.shuffle.each_slice(2).to_a
+    end
+
+    def insert_generated_buddies
+      Buddy.insert_all!(@buddies.map { |a, b| { day: @day, id_1: a, id_2: b } })
+      Rails.logger.info "Buddies successfully generated for day #{@day}"
+    end
+  end
+end

app/models/buddy.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+class Buddy < ApplicationRecord
+  scope :of_today, -> { where(day: Aoc.latest_day) }
+  scope :of_user,  ->(user_id) { where("id_1 = ? OR id_2 = ?", user_id, user_id) }
+
+  def self.of_the_day(user)
+    buddy_pair = of_today.of_user(user.id).first
+    daily_buddy_id = user.id == buddy_pair.id_1 ? buddy_pair.id_2 : buddy_pair.id_1 if buddy_pair
+
+    User.find_by(id: daily_buddy_id)
+  end
+end

app/views/pages/calendar.html.erb

@@ -2,6 +2,20 @@
   Welcome, <%= link_to current_user.username, profile_path(current_user.uid), class: "strong hover:text-gold" %>
 </p>
 
+<% if @daily_buddy %>
+
+  <p class="text-center">
+    Your daily buddy is
+
+    <% if @daily_buddy.slack_id %>
+      <%= link_to "@#{@daily_buddy.slack_username}", @daily_buddy.slack_link, target: :_blank, rel: :noopener, class: "link-explicit link-slack" %>
+    <% else %>
+      <%= link_to @daily_buddy.username, profile_path(@daily_buddy.uid), class: "link-explicit" %>
+    <% end %>
+  </p>
+
+<% end %>
+
 <div class="mx-auto my-4 w-max grid grid-cols-5 gap-2 lg:gap-3">
   <%= render Calendar::AdventDayComponent.with_collection(@advent_days, now: @now) %>
 </div>

config/initializers/good_job.rb

@@ -1,22 +1,29 @@
 # frozen_string_literal: true
 
+require "aoc"
+
 Rails.application.configure do
   config.good_job = {
     execution_mode: :external,
     max_threads: 5,
     shutdown_timeout: 30,
     enable_cron: true,
     cron: {
-      refresh_completions: {
-        cron: "*/10 * 1-30 11-12 *", # every 10th minute between November 1st and December 30th
+      refresh_completions: {                      # every 10 minutes between November 1st and December 30th
+        cron: "*/10 * 1-30 11-12 *",
         class: "InsertNewCompletionsJob"
       },
-      auto_cleanup: {
-        cron: "55 5 * * *", # every day at 5:55
+      auto_cleanup: {                             # every puzzle day, just before a new puzzle
+        cron: "55 23 1-25 12 * America/New_York",
         class: "Cache::CleanupJob"
       },
-      lock_time_achievements: {
-        cron: "30 18 9 12 *", # 9th December at 18:30
+      generate_buddies: {                         # every puzzle day, just after a new puzzle
+        cron: "5 0 1-25 12 * America/New_York",
+        class: "Buddies::GenerateDailyPairsJob",
+        args: [Aoc.latest_day]
+      },
+      unlock_lock_time_achievements: {            # once at lock time
+        cron: "30 17 8 12 * Europe/Paris",
         class: "Achievements::LockTimeJob"
       }
     }

db/migrate/20231201004728_create_buddies.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+class CreateBuddies < ActiveRecord::Migration[7.1]
+  def change
+    create_table :buddies do |t|
+      t.integer :id_1
+      t.integer :id_2
+      t.integer :day
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2023_11_30_162723) do
+ActiveRecord::Schema[7.1].define(version: 2023_12_01_004728) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "citext"
   enable_extension "pgcrypto"
@@ -89,6 +89,14 @@
     t.index ["creator_id"], name: "index_blazer_queries_on_creator_id"
   end
 
+  create_table "buddies", force: :cascade do |t|
+    t.datetime "created_at", null: false
+    t.integer "day"
+    t.integer "id_1"
+    t.integer "id_2"
+    t.datetime "updated_at", null: false
+  end
+
   create_table "cities", force: :cascade do |t|
     t.datetime "created_at", null: false
     t.string "name"