Implement Measurements#new

app/controllers/measurements_controller.rb

@@ -1,9 +1,31 @@
 class MeasurementsController < ApplicationController
+  before_action :find_quantity, only: [:new]
+
   def index
     @quantities = current_user.quantities.ordered
   end
 
   def new
+    readouts_params = params.permit(user: [readouts_attributes: Readout::ATTRIBUTES])
+    build_attrs = readouts_params.dig(:user, :readouts_attributes)&.values
+    prev_readouts = build_attrs ? Array(current_user.readouts.build(build_attrs)) : []
+
+    quantities =
+      case params[:scope]
+      when 'children'
+        @quantity.subquantities
+      when 'subtree'
+        @quantity.progenies
+      else
+        [@quantity]
+      end
+    quantities -= prev_readouts.map(&:quantity)
+    new_readouts = current_user.readouts.build(quantities.map { |q| {quantity: q} })
+    @readouts = prev_readouts + new_readouts
+
+    @ancestor_fullname = current_user.quantities
+      .common_ancestors(@readouts.map { |r| r.quantity.parent_id }).first&.fullname || ''
+    @units = current_user.units.ordered
   end
 
   def create
@@ -11,4 +33,10 @@ class MeasurementsController < ApplicationController
 
   def destroy
   end
+
+  private
+
+  def find_quantity
+    @quantity = current_user.quantities.find_by!(id: params[:id])
+  end
 end