add variable kilometergeld

app/controllers/mileage_rates_controller.rb

@@ -0,0 +1,47 @@
+class MileageRatesController < ApplicationController
+	before_action :authenticate_user!
+	# Optional: nur Admins erlauben
+	# before_action :require_admin!
+	
+	before_action :set_mileage_rate, only: [:edit, :update]
+	
+	def index
+		@mileage_rates = MileageRate.order(year: :desc)
+	end
+	
+	def new
+		@mileage_rate = MileageRate.new
+	end
+	
+	def create
+		@mileage_rate = MileageRate.new(mileage_rate_params)
+		if @mileage_rate.save
+			redirect_to mileage_rates_path, notice: "Kilometersatz für #{@mileage_rate.year} gespeichert."
+		else
+			flash.now[:alert] = "Speichern fehlgeschlagen"
+			render :new, status: :unprocessable_entity
+		end
+	end
+	
+	def edit
+	end
+	
+	def update
+		if @mileage_rate.update(mileage_rate_params)
+			redirect_to mileage_rates_path, notice: "Kilometersatz für #{@mileage_rate.year} aktualisiert."
+		else
+			flash.now[:alert] = "Aktualisierung fehlgeschlagen"
+			render :edit, status: :unprocessable_entity
+		end
+	end
+	
+	private
+	
+	def set_mileage_rate
+		@mileage_rate = MileageRate.find(params[:id])
+	end
+	
+	def mileage_rate_params
+		params.require(:mileage_rate).permit(:year, :rate_per_km)
+	end
+end

app/helpers/entries_helper.rb

@@ -1,2 +1,22 @@
 module EntriesHelper
+	# Berechnet Kilometerpauschale für eine Entry anhand der gespeicherten MileageRate
+	# entry: muss attribute `distance_km` und `date` haben
+	def kilometrergeld_for(entry)
+		rate = MileageRate.for_year(entry.date.year)
+		if rate
+			(entry.distance_km.to_f * rate).round(2)
+		else
+			# Fallback: z. B. Standardrate 0.42
+			(entry.distance_km.to_f * 0.05).round(2)
+		end
+	end
+	
+	# Für Summen: sum_meilen ist Summe der km oder Array von entries
+	def total_km_cost_for_year(user, year)
+		rate = MileageRate.for_year(year) || 0.42
+		total_km = user.entries
+		           .where("EXTRACT(YEAR FROM date) = ?", year)
+		           .sum(:distance_km).to_f
+		(total_km * rate).round(2)
+	end
 end

app/models/entry.rb

@@ -29,14 +29,17 @@ class Entry < ApplicationRecord
 	end
 	
 	def self.total_kilometer_cost_by_year(user)
-		where(user: user)
-			.where.not(distance_km: nil)
-			.group(Arel.sql("DATE_PART('year', date)"))
-			.order(Arel.sql("DATE_PART('year', date) DESC"))
-			.pluck(
-				Arel.sql("DATE_PART('year', date)::int"),
-				Arel.sql("SUM(distance_km * 0.42)")
-			).to_h
+		yearly_distances = where(user: user)
+			                   .where.not(distance_km: nil)
+			                   .group("EXTRACT(YEAR FROM date)::int")
+			                   .sum(:distance_km)
+		
+		# Für jedes Jahr die Pauschale holen und multiplizieren
+		yearly_distances.transform_keys(&:to_i).transform_values do |km_sum|
+			year = yearly_distances.key(km_sum).to_i
+			rate = MileageRate.find_by(year: year)&.rate_per_km || 0.42
+			(km_sum * rate).round(2)
+		end
 	end
 	
 	def self.total_fortbildungskosten_by_year(user)

app/models/mileage_rate.rb

@@ -0,0 +1,14 @@
+class MileageRate < ApplicationRecord
+	validates :year, presence: true, uniqueness: true
+	validates :rate_per_km, presence: true, numericality: { greater_than_or_equal_to: 0 }
+	
+	# Gibt die Rate für ein gegebenes Jahr — oder nil
+	def self.for_year(year)
+		find_by(year: year)&.rate_per_km
+	end
+	
+	# Gibt die Rate für heute bzw. aktuelles Jahr
+	def self.current
+		for_year(Date.today.year)
+	end
+end

app/views/entries/index.html.erb

@@ -7,8 +7,11 @@
     <div class="col rounded border shadow-sm p-3">
       <h5>🚗 Fahrtkosten (Kilometergeld)</h5>
       <% @total_kilometer_costs_by_year.each do |year, sum| %>
+        <% rate = MileageRate.find_by(year: year)&.rate_per_km || 0.42 %>
+        <% km = rate > 0 ? (sum.to_f / rate).round(1) : "?" %>
         <p><strong><%= year %>:</strong>
           <%= number_to_currency(sum, unit: "€", separator: ",", delimiter: ".", precision: 2) %>
+          <i>(<%= km %> km bei <%= number_to_currency(rate, unit: "€", separator: ",", delimiter: ".", precision: 2) %>/km)</i>
         </p>
       <% end %>
     </div>

app/views/mileage_rates/_form.html.erb

@@ -0,0 +1,27 @@
+<%= form_with(model: mileage_rate, local: true) do |form| %>
+  <% if mileage_rate.errors.any? %>
+    <div class="alert alert-danger">
+      <h4><%= pluralize(mileage_rate.errors.count, "Fehler") %> verhinderten das Speichern:</h4>
+      <ul>
+        <% mileage_rate.errors.full_messages.each do |msg| %>
+          <li><%= msg %></li>
+        <% end %>
+      </ul>
+    </div>
+  <% end %>
+
+  <div class="mb-3">
+    <%= form.label :year, "Jahr", class: "form-label" %>
+    <%= form.number_field :year, class: "form-control", min: 2000 %>
+  </div>
+
+  <div class="mb-3">
+    <%= form.label :rate_per_km, "Kilometersatz (€/km)", class: "form-label" %>
+    <%= form.number_field :rate_per_km, class: "form-control", step: 0.01, min: 0 %>
+  </div>
+
+  <div class="mb-3">
+    <%= form.submit class: "btn btn-success" %>
+    <%= link_to "Abbrechen", mileage_rates_path, class: "btn btn-secondary ms-2" %>
+  </div>
+<% end %>

app/views/mileage_rates/edit.html.erb

@@ -0,0 +1,2 @@
+<h1>Satz für Jahr <%= @mileage_rate.year %> bearbeiten</h1>
+<%= render "form", mileage_rate: @mileage_rate %>

app/views/mileage_rates/index.html.erb

@@ -0,0 +1,24 @@
+<h1>Kilometersätze je Jahr</h1>
+
+<%= link_to "Neuen Satz anlegen", new_mileage_rate_path, class: "btn btn-primary mb-3" %>
+
+<table class="table table-striped table-bordered">
+  <thead>
+  <tr>
+    <th>Jahr</th>
+    <th>Satz (€/km)</th>
+    <th>Aktionen</th>
+  </tr>
+  </thead>
+  <tbody>
+  <% @mileage_rates.each do |rate| %>
+    <tr>
+      <td><%= rate.year %></td>
+      <td><%= number_to_currency(rate.rate_per_km, unit: "€", separator: ",", delimiter: ".", precision: 2) %></td>
+      <td>
+        <%= link_to "Bearbeiten", edit_mileage_rate_path(rate), class: "btn btn-sm btn-outline-secondary" %>
+      </td>
+    </tr>
+  <% end %>
+  </tbody>
+</table>

app/views/mileage_rates/new.html.erb

@@ -0,0 +1,2 @@
+<h1>Neuen Kilometersatz anlegen</h1>
+<%= render "form", mileage_rate: @mileage_rate %>

config/routes.rb

@@ -14,6 +14,9 @@ Rails.application.routes.draw do
 		end
 	end
 	
+	resources :mileage_rates, only: [:index, :new, :create, :edit, :update]
+	
+	
 	resources :entries do
 		post :start_timer, on: :collection
 		member do

db/migrate/20251201050251_create_mileage_rates.rb

@@ -0,0 +1,15 @@
+class CreateMileageRates < ActiveRecord::Migration[7.1]
+  def change
+    create_table :mileage_rates do |t|
+      t.integer :year, null: false, index: { unique: true }
+      t.decimal :rate_per_km, precision: 5, scale: 2, null: false
+      t.timestamps
+    end
+    [2024, 2025, 2026].each do |year|
+      MileageRate.create_or_find_by(year: year) do |rate|
+        rate.rate_per_km = 0.42
+      end
+    end
+    
+  end
+end

db/schema.rb

@@ -10,8 +10,9 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2025_11_20_105001) do
+ActiveRecord::Schema[7.1].define(version: 2025_12_01_050251) do
   # These are extensions that must be enabled in order to support this database
+  enable_extension "pg_stat_statements"
   enable_extension "plpgsql"
 
   create_table "entries", force: :cascade do |t|
@@ -42,6 +43,14 @@ ActiveRecord::Schema[7.1].define(version: 2025_11_20_105001) do
     t.index ["user_id"], name: "index_entries_on_user_id"
   end
 
+  create_table "mileage_rates", force: :cascade do |t|
+    t.integer "year", null: false
+    t.decimal "rate_per_km", precision: 5, scale: 2, null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["year"], name: "index_mileage_rates_on_year", unique: true
+  end
+
   create_table "users", force: :cascade do |t|
     t.string "email", default: "", null: false
     t.string "encrypted_password", default: "", null: false