show moods for a year

app/controllers/moods_controller.rb

@@ -1,6 +1,6 @@
 class MoodsController < ApplicationController
   def index
     @mode = Mood.last&.mode || "croisiere"
-    @mood_log = Mood.log || []
+    @mood_log = Mood.history_for_a_year || []
   end
 end

app/models/mood.rb

@@ -1,24 +1,45 @@
 class Mood < ApplicationRecord
-  def self.log
-    return if Mood.count < 1
+  class << self
+    def history_for_a_year
+      history(Date.today - 1.year, Date.today)
+    end
 
-    first_mood = Mood.order(:recorded_at).first.recorded_at.to_date
-    first_monday = first_mood - (first_mood.wday - 1)
+    private
+    def history(from, to)
+      return [] if Mood.count < 1
+
+      first_monday = monday_of_the_week(first_mood_date(from))
 
       current_date = first_monday
-    current_mode = nil
+      current_mode = last_mode_before(current_date)
       log_mood = []
-    Mood.order(:recorded_at).all.each do |mood|
+      mood_range = Mood.order(:recorded_at).where(recorded_at: (first_monday..to))
+      mood_range.each do |mood|
         while current_date < mood.recorded_at.to_date do
           log_mood << [ current_date.to_s, current_mode ]
           current_date += 1
         end
         current_mode = mood.mode
       end
-    while current_date <= Date.today do
+
+      while current_date <= to.to_date do
         log_mood << [ current_date.to_s, current_mode ]
         current_date += 1
       end
-    log_mood.each_slice(7).to_a.last(52)
+      log_mood.each_slice(7).to_a
+    end
+
+    def first_mood_date(from)
+      Mood.order(recorded_at: :asc).where("recorded_at >= ?", from).first.recorded_at.to_date
+    end
+
+    def monday_of_the_week(date)
+      date - date.wday + 1
+    end
+
+    def last_mode_before(date)
+      mood = Mood.where("recorded_at < ?", date).last
+      mood&.mode || "croisiere"
+    end
   end
 end