Filter By Item For Donations Page

app/controllers/donations_controller.rb

@@ -33,13 +33,16 @@ def index
     # Using the @donations allows drilling down instead of always starting with the total dataset
     @donations_quantity = @donations.collect(&:total_quantity).sum
     @paginated_donations_quantity = @paginated_donations.collect(&:total_quantity).sum
+    @items = current_organization.items.alphabetized.select(:id, :name)
     @total_value_all_donations = total_value(@donations)
     @paginated_in_kind_value = total_value(@paginated_donations)
     @total_money_raised = total_money_raised(@donations)
     @storage_locations = @donations.filter_map { |donation| donation.storage_location if !donation.storage_location.discarded_at }.compact.uniq.sort
     @selected_storage_location = filter_params[:at_storage_location]
     @sources = @donations.collect(&:source).uniq.sort
     @selected_source = filter_params[:by_source]
+    @selected_item = filter_params[:by_item_id]
+    @donation_totals = DonationTotalsService.call(current_organization.donations.class_filter(scope_filters))
     @selected_item_category = filter_params[:by_category]
     @donation_sites = @donations.collect(&:donation_site).compact.uniq.sort_by { |site| site.name.downcase }
     @selected_donation_site = filter_params[:from_donation_site]
@@ -157,8 +160,7 @@ def donation_item_params
   helper_method \
     def filter_params
     return {} unless params.key?(:filters)
-
-    params.require(:filters).permit(:at_storage_location, :by_source, :from_donation_site, :by_product_drive, :by_product_drive_participant, :from_manufacturer, :by_category)
+    params.require(:filters).permit(:at_storage_location, :by_source, :from_donation_site, :by_product_drive, :by_product_drive_participant, :from_manufacturer, :by_category, :by_item_id)
   end
 
   # Omits donation_site_id or product_drive_participant_id if those aren't selected as source
@@ -170,6 +172,12 @@ def strip_unnecessary_params
     params
   end
 
+  def scope_filters
+    filter_params
+      .except(:date_range)
+      .merge(during: helpers.selected_range)
+  end
+
   # If line_items have submitted with empty rows, clear those out first.
   def compact_line_items
     return params unless params[:donation].key?(:line_items_attributes)

app/models/donation.rb

@@ -51,6 +51,7 @@ class Donation < ApplicationRecord
   scope :from_manufacturer, ->(manufacturer_id) {
     where(manufacturer_id: manufacturer_id)
   }
+  scope :by_item_id, ->(item_id) { includes(:items).where(items: { id: item_id }) }
 
   scope :by_category, ->(item_category) {
     joins(line_items: {item: :item_category}).where("item_categories.name ILIKE ?", item_category)

app/services/donation_totals_service.rb

@@ -0,0 +1,32 @@
+class DonationTotalsService
+  DonationTotal = Data.define(:quantity, :value)
+
+  class << self
+    # @param donations [Donation::ActiveRecord_Relation]
+    # @return [Hash<Integer, DonationTotal>]
+    def call(donations)
+      calculate_totals(donations)
+    end
+
+    private
+
+    # Returns a hash with quantity/value totals for each donation.
+    #
+    # @return [Hash<Integer, DonationTotal>]
+    def calculate_totals(donations)
+      donations
+        .left_joins(line_items: [:item])
+        .group("donations.id, line_items.id, items.id")
+        .pluck(
+          Arel.sql(
+            "donations.id,
+            COALESCE(SUM(line_items.quantity) OVER (PARTITION BY donations.id), 0) AS quantity,
+            COALESCE(SUM(COALESCE(items.value_in_cents, 0) * line_items.quantity) OVER (PARTITION BY donations.id), 0) AS value"
+          )
+        )
+        .to_h do |(id, quantity, value)|
+          [id, DonationTotal.new(quantity:, value:)]
+        end
+    end
+  end
+end

app/views/donations/index.html.erb

@@ -71,6 +71,11 @@
                     <%= filter_select(label: "Filter by Donation Site", scope: :from_donation_site, collection: @donation_sites, key: :id, value: :name, selected: @selected_donation_site) %>
                   </div>
                 <% end %>
+                <% if @items.present? %>
+                  <div class="form-group col-lg-3 col-md-4 col-sm-6 col-xs-12">
+                    <%= filter_select(label: "Filter by Item", scope: :by_item_id, collection: @items, selected: @selected_item) %>
+                    </div>
+                <% end %>
                 <% if @item_categories.present? %>
                   <div class="form-group col-lg-3 col-md-4 col-sm-6 col-xs-12">
                     <% id = "filter_#{SecureRandom.uuid}" %>
@@ -116,9 +121,11 @@
                   <th>Date</th>
                   <th>Details</th>
                   <th>Storage Location</th>
-                  <th class="text-right">Quantity of Items</th>
-                  <th class="text-right">Money Raised</th>
-                  <th class="text-right">In-kind Value</th>
+                  <% filtered_item_name = @selected_item ? @items.find { |i| i.id == filter_params[:by_item_id].to_i }&.name : "Items" %>
+                  <th>Quantity of <%= filtered_item_name %></th>
+                  <th>Money Raised</th>
+                  <th>In Kind Value</th>
+
                   <th>Comments</th>
                   <th class="text-right">Actions</th>
                 </tr>

spec/system/donation_system_spec.rb

@@ -89,6 +89,22 @@
         expect(page).to have_css("table tbody tr", count: 1)
       end
 
+      it "Filters by Item id" do
+        category_1 = create(:item_category, name: "Category 1", organization: organization)
+        category_2 = create(:item_category, name: "Category 2", organization: organization)
+        item_1 = create(:item, item_category: category_1, name: "Item 1", value_in_cents: 100)
+        item_2 = create(:item, item_category: category_2, name: "Item 2", value_in_cents: 200)
+        create(:donation, :with_items, item_quantity: 25, item: item_1)
+        create(:donation, :with_items, item_quantity: 30, item: item_2)
+        visit subject
+        expect(page).to have_css("table tbody tr", count: 2)
+        select item_1.name, from: "filters[by_item_id]"
+        click_button "Filter"
+        expect(page).to have_css("table tbody tr", count: 1)
+        expect(page).to have_css("table thead tr th", text: "Quantity of #{item_1.name}")
+        expect(page).to have_css("table td.in-kind", text: "25")
+      end
+
       it "Filter by product drive participant sticks around" do
         x = create(:product_drive, name: 'x')
         a = create(:product_drive_participant, business_name: "A")