Fix stats calculation performance

.app_version

@@ -1 +1 @@
-0.30.1
+0.30.2

CHANGELOG.md

@@ -4,6 +4,13 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+# [0.30.2] - 2025-07-22
+
+## Fixed
+
+- Stats calculation is now significantly faster.
+
+
 # [0.30.1] - 2025-07-22
 
 ## Fixed

app/controllers/stats_controller.rb

@@ -13,6 +13,7 @@ class StatsController < ApplicationController
   def show
     @year = params[:year].to_i
     @stats = current_user.stats.where(year: @year).order(:month)
+    @year_distances = { @year => Stat.year_distance(@year, current_user) }
   end
 
   def update

app/models/stat.rb

@@ -37,12 +37,7 @@ class Stat < ApplicationRecord
   end
 
   def calculate_daily_distances(monthly_points)
-    timespan.to_a.map.with_index(1) do |day, index|
-      daily_points = filter_points_for_day(monthly_points, day)
-      # Calculate distance in meters for consistent storage
-      distance_meters = Point.total_distance(daily_points, :m)
-      [index, distance_meters.round]
-    end
+    Stats::DailyDistanceQuery.new(monthly_points, timespan).call
   end
 
   def filter_points_for_day(points, day)

app/queries/stats/daily_distance_query.rb

@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+class Stats::DailyDistanceQuery
+  def initialize(monthly_points, timespan)
+    @monthly_points = monthly_points
+    @timespan = timespan
+  end
+
+  def call
+    daily_distances = daily_distances(monthly_points)
+    distance_by_day_map = distance_by_day_map(daily_distances)
+
+    convert_to_daily_distances(distance_by_day_map)
+  end
+
+  private
+
+  attr_reader :monthly_points, :timespan
+
+  def daily_distances(monthly_points)
+    Stat.connection.select_all(<<-SQL.squish)
+      WITH points_with_distances AS (
+        SELECT
+          EXTRACT(day FROM to_timestamp(timestamp)) as day_of_month,
+          CASE
+            WHEN LAG(lonlat) OVER (
+              PARTITION BY EXTRACT(day FROM to_timestamp(timestamp))
+              ORDER BY timestamp
+            ) IS NOT NULL THEN
+              ST_Distance(
+                lonlat::geography,
+                LAG(lonlat) OVER (
+                  PARTITION BY EXTRACT(day FROM to_timestamp(timestamp))
+                  ORDER BY timestamp
+                )::geography
+              )
+            ELSE 0
+          END as segment_distance
+        FROM (#{monthly_points.to_sql}) as points
+      )
+      SELECT
+        day_of_month,
+        ROUND(COALESCE(SUM(segment_distance), 0)) as distance_meters
+      FROM points_with_distances
+      GROUP BY day_of_month
+      ORDER BY day_of_month
+    SQL
+  end
+
+  def distance_by_day_map(daily_distances)
+    daily_distances.index_by do |row|
+      row['day_of_month'].to_i
+    end
+  end
+
+  def convert_to_daily_distances(distance_by_day_map)
+    timespan.to_a.map.with_index(1) do |day, index|
+      distance_meters =
+        distance_by_day_map[day.day]&.fetch('distance_meters', 0) || 0
+
+      [index, distance_meters.to_i]
+    end
+  end
+end

app/services/stats/bulk_calculator.rb

@@ -21,7 +21,7 @@ module Stats
       last_calculated_at ||= DateTime.new(1970, 1, 1)
 
       time_diff = last_calculated_at.to_i..Time.current.to_i
-      Point.where(user_id:, timestamp: time_diff).pluck(:timestamp)
+      Point.where(user_id:, timestamp: time_diff).pluck(:timestamp).uniq
     end
 
     def extract_months(timestamps)

app/services/stats/calculate_month.rb

@@ -50,7 +50,7 @@ class Stats::CalculateMonth
               .tracked_points
               .without_raw_data
               .where(timestamp: start_timestamp..end_timestamp)
-              .select(:lonlat, :timestamp, :city, :country)
+              .select(:lonlat, :timestamp)
               .order(timestamp: :asc)
   end
 
@@ -59,7 +59,13 @@ class Stats::CalculateMonth
   end
 
   def toponyms
-    CountriesAndCities.new(points).call
+    toponym_points = user
+                      .tracked_points
+                      .without_raw_data
+                      .where(timestamp: start_timestamp..end_timestamp)
+                      .select(:city, :country)
+                      .distinct
+    CountriesAndCities.new(toponym_points).call
   end
 
   def create_stats_update_failed_notification(user, error)

app/views/stats/_stat.html.erb

@@ -20,7 +20,7 @@
 
   <%= area_chart(
     stat.daily_distance.map { |day, distance_meters|
-      [day, Stat.convert_distance(distance_meters, current_user.safe_settings.distance_unit).round(2)]
+      [day, Stat.convert_distance(distance_meters, current_user.safe_settings.distance_unit).round]
     },
     height: '200px',
     suffix: " #{current_user.safe_settings.distance_unit}",

app/views/stats/index.html.erb

@@ -83,7 +83,7 @@
           <% end %>
           <%= column_chart(
             @year_distances[year].map { |month_name, distance_meters|
-              [month_name, Stat.convert_distance(distance_meters, current_user.safe_settings.distance_unit).round(2)]
+              [month_name, Stat.convert_distance(distance_meters, current_user.safe_settings.distance_unit).round]
             },
             height: '200px',
             suffix: " #{current_user.safe_settings.distance_unit}",