Reduce distribution value totals by item category filter on distribution index page

app/controllers/distributions_controller.rb

@@ -52,13 +52,13 @@ def index
     @storage_locations = current_organization.storage_locations.active_locations.alphabetized.select(:id, :name)
     @partners = current_organization.partners.active.alphabetized.select(:id, :name)
     @selected_item = filter_params[:by_item_id].presence
-    @distribution_totals = DistributionTotalsService.new(current_organization.distributions, scope_filters)
-    @total_value_all_distributions = @distribution_totals.total_value
-    @total_items_all_distributions = @distribution_totals.total_quantity
+    @distribution_totals = DistributionTotalsService.call(current_organization.distributions.class_filter(scope_filters))
+    @total_value_all_distributions = @distribution_totals.values.sum(&:value)
+    @total_items_all_distributions = @distribution_totals.values.sum(&:quantity)
     paginated_ids = @paginated_distributions.ids
-    @total_value_paginated_distributions = @distribution_totals.total_value(paginated_ids)
-    @total_items_paginated_distributions = @distribution_totals.total_quantity(paginated_ids)
-    @selected_item_category = filter_params[:by_item_category_id]
+    @total_value_paginated_distributions = @distribution_totals.slice(*paginated_ids).values.sum(&:value)
+    @total_items_paginated_distributions = @distribution_totals.slice(*paginated_ids).values.sum(&:quantity)
+    @selected_item_category = filter_params[:by_item_category_id].presence
     @selected_partner = filter_params[:by_partner]
     @selected_status = filter_params[:by_state]
     @selected_location = filter_params[:by_location]
@@ -69,7 +69,11 @@ def index
     respond_to do |format|
       format.html
       format.csv do
-        send_data Exports::ExportDistributionsCSVService.new(distributions: @distributions, organization: current_organization, filters: scope_filters).generate_csv, filename: "Distributions-#{Time.zone.today}.csv"
+        send_data Exports::ExportDistributionsCSVService.new(
+          distributions: @distributions,
+          organization: current_organization,
+          filters: scope_filters
+        ).generate_csv, filename: "Distributions-#{Time.zone.today}.csv"
       end
     end
   end

app/services/distribution_totals_service.rb

@@ -1,65 +1,31 @@
 class DistributionTotalsService
-  def initialize(distributions, filter_params)
-    @filter_params = filter_params
-    @distribution_quantities = calculate_quantities(distributions)
-    @distribution_values = calculate_values(distributions)
-  end
-
-  def total_quantity(filter_ids = [])
-    totals = filter_ids.present? ? @distribution_quantities.slice(*filter_ids) : @distribution_quantities
-    totals.sum { |_, quantity| quantity }
-  end
-
-  def total_value(filter_ids = [])
-    totals = filter_ids.present? ? @distribution_values.slice(*filter_ids) : @distribution_values
-    totals.sum { |_, value| value }
-  end
-
-  def fetch_value(id)
-    @distribution_values.fetch(id)
-  end
-
-  def fetch_quantity(id)
-    @distribution_quantities.fetch(id)
-  end
-
-  private
-
-  attr_reader :filter_params
-
-  # Returns hash of total quantity of items per distribution
-  # Quantity of items after item filtering (id/category)
-  #
-  # @return [Hash<Integer, Integer>]
-  def calculate_quantities(distributions)
-    distributions
-      .class_filter(filter_params)
-      .left_joins(line_items: [:item])
-      .group("distributions.id, line_items.id, items.id")
-      .pluck(
-        Arel.sql(
-          "distributions.id,
-          COALESCE(SUM(line_items.quantity) OVER (PARTITION BY distributions.id), 0) AS quantity"
-        )
-      )
-      .to_h
-  end
-
-  # Returns hash of total value of items per distribution WITHOUT item id/category filter
-  # Value of entire distribution (not reduced by filtered items)
-  #
-  # @return [Hash<Integer, Integer>]
-  def calculate_values(distributions)
-    Distribution
-      .where(id: distributions.class_filter(filter_params))
-      .left_joins(line_items: [:item])
-      .group("distributions.id, line_items.id, items.id")
-      .pluck(
-        Arel.sql(
-          "distributions.id,
-          COALESCE(SUM(COALESCE(items.value_in_cents, 0) * line_items.quantity) OVER (PARTITION BY distributions.id), 0) AS value"
+  DistributionTotal = Data.define(:quantity, :value)
+
+  class << self
+    def call(distributions)
+      calculate_totals(distributions)
+    end
+
+    private
+
+    # Returns hash with quantity/value totals for each distribution.
+    # Quantity and value of items are reduced if item filtering present (id/category)
+    #
+    # @return [Hash<Integer, DistributionTotal>]
+    def calculate_totals(distributions)
+      distributions
+        .left_joins(line_items: [:item])
+        .group("distributions.id, line_items.id, items.id")
+        .pluck(
+          Arel.sql(
+            "distributions.id,
+            COALESCE(SUM(line_items.quantity) OVER (PARTITION BY distributions.id), 0) AS quantity,
+            COALESCE(SUM(COALESCE(items.value_in_cents, 0) * line_items.quantity) OVER (PARTITION BY distributions.id), 0) AS value"
+          )
         )
-      )
-      .to_h
+        .to_h do |(id, quantity, value)|
+          [id, DistributionTotal.new(quantity:, value:)]
+        end
+    end
   end
 end

app/services/exports/export_distributions_csv_service.rb

@@ -1,6 +1,8 @@
 module Exports
   class ExportDistributionsCSVService
     include DistributionHelper
+    include ItemsHelper
+
     def initialize(distributions:, organization:, filters: [])
       # Currently, the @distributions are already loaded by the controllers that are delegating exporting
       # to this service object; this is happening within the same request/response cycle, so it's already
@@ -11,6 +13,7 @@ def initialize(distributions:, organization:, filters: [])
       @distributions = distributions
       @filters = filters
       @organization = organization
+      @distribution_totals = DistributionTotalsService.call(Distribution.where(organization:).class_filter(filters))
     end
 
     def generate_csv
@@ -72,17 +75,11 @@ def base_table
         "Source Inventory" => ->(distribution) {
           distribution.storage_location.name
         },
-        base_item_header_col_name => ->(distribution) {
-          # filter the line items by item id (for selected item filter) to
-          # get the number of items
-          if @filters[:by_item_id].present?
-            distribution.line_items.where(item_id: @filters[:by_item_id].to_i).total
-          else
-            distribution.line_items.total
-          end
+        item_quantity_header_col_name => ->(distribution) {
+          @distribution_totals[distribution.id]&.quantity || 0
         },
-        "Total Value" => ->(distribution) {
-          distribution.cents_to_dollar(distribution.line_items.total_value)
+        item_value_header_col_name => ->(distribution) {
+          cents_to_dollar(@distribution_totals[distribution.id]&.value || 0)
         },
         "Delivery Method" => ->(distribution) {
           distribution.delivery_method
@@ -103,12 +100,32 @@ def base_table
     end
 
     # if filtered based on an item, change the column accordingly
-    def base_item_header_col_name
-      @filters[:by_item_id].present? ? "Total Number of #{filtered_item.name}" : "Total Items"
+    def item_quantity_header_col_name
+      if @filters[:by_item_id].present?
+        "Total Number of #{filtered_item_name}"
+      elsif @filters[:by_item_category_id].present?
+        "Total Number of #{filtered_item_category_name}"
+      else
+        "Total Items"
+      end
+    end
+
+    def item_value_header_col_name
+      if @filters[:by_item_id].present?
+        "Total Value of #{filtered_item_name}"
+      elsif @filters[:by_item_category_id].present?
+        "Total Value of #{filtered_item_category_name}"
+      else
+        "Total Value"
+      end
+    end
+
+    def filtered_item_name
+      @filtered_item ||= Item.find(@filters[:by_item_id].to_i).name
     end
 
-    def filtered_item
-      @filtered_item ||= Item.find(@filters[:by_item_id].to_i)
+    def filtered_item_category_name
+      @filtered_item_category ||= ItemCategory.find(@filters[:by_item_category_id].to_i).name
     end
 
     def base_headers

app/views/distributions/_distribution_row.html.erb

@@ -5,8 +5,8 @@
   <td class="date"><%= (distribution_row.issued_at.presence || distribution_row.created_at).strftime("%m/%d/%Y") %></td>
   <td><%= distribution_row.storage_location.name %></td>
 
-  <td class="numeric"><%= @distribution_totals.fetch_quantity(distribution_row.id) %></td>
-  <td class="numeric"><%= dollar_value(@distribution_totals.fetch_value(distribution_row.id)) %></td>
+  <td class="numeric"><%= @distribution_totals[distribution_row.id].quantity %></td>
+  <td class="numeric"><%= dollar_value(@distribution_totals[distribution_row.id].value) %></td>
   <td><%= distribution_row.delivery_method.humanize %></td>
   <td><%= distribution_shipping_cost(distribution_row.shipping_cost) %></td>
   <td><%= distribution_row.comment %></td>

app/views/distributions/index.html.erb

@@ -103,17 +103,28 @@
                 <th class="date">Date of Distribution</th>
                 <th>Source Inventory</th>
 
+                <% filtered_item_name = @selected_item ? @items.find { |i| i.id == filter_params[:by_item_id].to_i }&.name : nil %>
+                <% filtered_category_name = @selected_item_category ? @item_categories.find { |ic| ic.id == filter_params[:by_item_category_id].to_i }&.name : nil %>
+
                 <!-- Quantity -->
-                <% if filter_params[:by_item_id].present? %>
-                  <th class="numeric">Total <%= @items.find { |i| i.id == filter_params[:by_item_id].to_i }&.name %></th>
-                <% elsif filter_params[:by_item_category_id].present? %>
-                  <th class="numeric">Total in <%= @item_categories.find { |ic| ic.id == filter_params[:by_item_category_id].to_i }&.name %></th>
+                <% if filtered_item_name %>
+                  <th class="numeric">Total <%= filtered_item_name %></th>
+                <% elsif filtered_category_name %>
+                  <th class="numeric">Total in <%= filtered_category_name %></th>
                 <% else %>
                   <th class="numeric">Total Items</th>
                 <% end %>
                 <!-- End Quantity -->
 
-                <th class="numeric">Total Value</th>
+                <!-- Value -->
+                <% if filtered_item_name %>
+                  <th class="numeric">Value of <%= filtered_item_name %></th>
+                <% elsif filtered_category_name %>
+                  <th class="numeric">Value of <%= filtered_category_name %></th>
+                <% else %>
+                  <th class="numeric">Total Value</th>
+                <% end %>
+                <!-- End Value -->
 
                 <th>Delivery Method</th>
                 <th>Shipping Cost</th>

spec/requests/distributions_requests_spec.rb

@@ -140,20 +140,19 @@
           expect(distribution.total_quantity).to eq(20)
           expect(distribution.value_per_itemizable).to eq(2000)
 
-          # displays quantity of filtered item in distribution
-          # displays total value of distribution
+          # displays quantity and value of filtered item in distribution
           expect(item_quantity.text).to eq("10")
-          expect(item_value.text).to eq("$20.00")
+          expect(item_value.text).to eq("$10.00")
         end
 
-        it "changes the total quantity header" do
+        it "changes the total quantity and value headers" do
           get distributions_path, params: params
 
           page = Nokogiri::HTML(response.body)
           item_total_header, item_value_header = page.css("table thead tr th.numeric")
 
           expect(item_total_header.text).to eq("Total #{item.name}")
-          expect(item_value_header.text).to eq("Total Value")
+          expect(item_value_header.text).to eq("Value of #{item.name}")
         end
       end
 
@@ -178,20 +177,19 @@
           expect(distribution.total_quantity).to eq(20)
           expect(distribution.value_per_itemizable).to eq(2000)
 
-          # displays quantity of filtered item in distribution
-          # displays total value of distribution
+          # displays quantity and value of filtered item in distribution
           expect(item_quantity.text).to eq("10")
-          expect(item_value.text).to eq("$20.00")
+          expect(item_value.text).to eq("$10.00")
         end
 
-        it "changes the total quantity header" do
+        it "changes the total quantity and value headers" do
           get distributions_path, params: params
 
           page = Nokogiri::HTML(response.body)
           item_total_header, item_value_header = page.css("table thead tr th.numeric")
 
           expect(item_total_header.text).to eq("Total in #{item_category.name}")
-          expect(item_value_header.text).to eq("Total Value")
+          expect(item_value_header.text).to eq("Value of #{item_category.name}")
         end
 
         it "doesn't show duplicate distributions" do

spec/services/exports/export_distributions_csv_service_spec.rb

@@ -28,7 +28,8 @@
       items_lists.each_with_index.map do |items, i|
         distribution = create(
           :distribution,
-          issued_at: start_time - i.days, delivery_method: "shipped", shipping_cost: "12.09"
+          issued_at: start_time - i.days, delivery_method: "shipped", shipping_cost: "12.09",
+          organization: organization
         )
 
         items.each do |(item, quantity)|
@@ -65,7 +66,7 @@
         "Scheduled for",
         "Source Inventory",
         "Total Number of #{item_name}",
-        "Total Value",
+        "Total Value of #{item_name}",
         "Delivery Method",
         "Shipping Cost",
         "Status",