Add gains by tax treatment to investment report with grouped subtype dropdown (#701)

* Add tax treatment metrics to reports, forms, and models

- Implement `build_gains_by_tax_treatment` for grouping gains by tax treatment
- Update investment performance view with tax treatment breakdown
- Add tax treatment field to crypto and investments forms
- Introduce `realized_gain_loss` calculation in the Trade model
- Group investment subtypes by region for improved dropdown organization

* Optimize investment performance report by reducing N+1 queries

- Eager-load associations in `build_gains_by_tax_treatment` to minimize database queries
- Preload holdings for realized gain/loss calculations in trades
- Refactor views to standardize "no data" placeholder using translations
- Adjust styling in tax treatment breakdown for improved layout

* Enhance investment performance translations and optimize holdings lookup logic

- Update `holdings_count` and `sells_count` translations to handle pluralization
- Refactor views to use pluralized translation keys with count interpolation
- Optimize preloaded holdings lookup in `Trade` to ensure deterministic selection using `select` and `max_by`

* Refine preloaded holdings logic in `Trade` model

- Treat empty preloaded holdings as authoritative to prevent unnecessary DB queries
- Add explicit fallback behavior for database query when holdings are not preloaded

---------

Co-authored-by: luckyPipewrench <luckypipewrench@proton.me>

app/controllers/cryptos_controller.rb

@@ -1,3 +1,5 @@
 class CryptosController < ApplicationController
   include AccountableResource
+
+  permitted_accountable_attributes :id, :tax_treatment
 end

app/controllers/reports_controller.rb

@@ -415,10 +415,75 @@ class ReportsController < ApplicationController
         period_contributions: period_totals.contributions,
         period_withdrawals: period_totals.withdrawals,
         top_holdings: investment_statement.top_holdings(limit: 5),
-        accounts: investment_accounts.to_a
+        accounts: investment_accounts.to_a,
+        gains_by_tax_treatment: build_gains_by_tax_treatment(investment_statement)
       }
     end
 
+    def build_gains_by_tax_treatment(investment_statement)
+      currency = Current.family.currency
+      # Eager-load account and accountable to avoid N+1 when accessing tax_treatment
+      current_holdings = investment_statement.current_holdings
+        .includes(account: :accountable)
+        .to_a
+
+      # Group holdings by tax treatment (from account)
+      holdings_by_treatment = current_holdings.group_by { |h| h.account.tax_treatment || :taxable }
+
+      # Get sell trades in period with realized gains
+      # Eager-load security, account, and accountable to avoid N+1
+      sell_trades = Current.family.trades
+        .joins(:entry)
+        .where(entries: { date: @period.date_range })
+        .where("trades.qty < 0")
+        .includes(:security, entry: { account: :accountable })
+        .to_a
+
+      # Preload holdings for all accounts that have sell trades to avoid N+1 in realized_gain_loss
+      account_ids = sell_trades.map { |t| t.entry.account_id }.uniq
+      holdings_by_account = Holding
+        .where(account_id: account_ids)
+        .where("date <= ?", @period.date_range.end)
+        .order(date: :desc)
+        .group_by(&:account_id)
+
+      # Inject preloaded holdings into trades for realized_gain_loss calculation
+      sell_trades.each do |trade|
+        trade.instance_variable_set(:@preloaded_holdings, holdings_by_account[trade.entry.account_id] || [])
+      end
+
+      trades_by_treatment = sell_trades.group_by { |t| t.entry.account.tax_treatment || :taxable }
+
+      # Build metrics per treatment
+      %i[taxable tax_deferred tax_exempt tax_advantaged].each_with_object({}) do |treatment, hash|
+        holdings = holdings_by_treatment[treatment] || []
+        trades = trades_by_treatment[treatment] || []
+
+        # Sum unrealized gains from holdings (only those with known cost basis)
+        unrealized = holdings.sum do |h|
+          trend = h.trend
+          trend ? trend.value : 0
+        end
+
+        # Sum realized gains from sell trades
+        realized = trades.sum do |t|
+          gain = t.realized_gain_loss
+          gain ? gain.value : 0
+        end
+
+        # Only include treatment groups that have some activity
+        next if holdings.empty? && trades.empty?
+
+        hash[treatment] = {
+          holdings: holdings,
+          sell_trades: trades,
+          unrealized_gain: Money.new(unrealized, currency),
+          realized_gain: Money.new(realized, currency),
+          total_gain: Money.new(unrealized + realized, currency)
+        }
+      end
+    end
+
     def build_net_worth_metrics
       balance_sheet = Current.family.balance_sheet
       currency = Current.family.currency

app/helpers/reports_helper.rb

@@ -1,4 +1,18 @@
 module ReportsHelper
+  # Returns CSS classes for tax treatment badge styling
+  def tax_treatment_badge_classes(treatment)
+    case treatment.to_sym
+    when :tax_exempt
+      "bg-green-500/10 text-green-600 theme-dark:text-green-400"
+    when :tax_deferred
+      "bg-blue-500/10 text-blue-600 theme-dark:text-blue-400"
+    when :tax_advantaged
+      "bg-purple-500/10 text-purple-600 theme-dark:text-purple-400"
+    else
+      "bg-gray-500/10 text-secondary"
+    end
+  end
+
   # Generate SVG polyline points for a sparkline chart
   # Returns empty string if fewer than 2 data points (can't draw a line with 1 point)
   def sparkline_points(values, width: 60, height: 16)

app/models/investment.rb

@@ -74,5 +74,31 @@ class Investment < ApplicationRecord
     def region_label_for(region)
       I18n.t("accounts.subtype_regions.#{region || 'generic'}")
     end
+
+    # Maps currency codes to regions for prioritizing user's likely region
+    CURRENCY_REGION_MAP = {
+      "USD" => "us",
+      "GBP" => "uk",
+      "CAD" => "ca",
+      "AUD" => "au",
+      "EUR" => "eu",
+      "CHF" => "eu"
+    }.freeze
+
+    # Returns subtypes grouped by region for use with grouped_options_for_select
+    # Optionally accepts currency to prioritize user's region first
+    def subtypes_grouped_for_select(currency: nil)
+      user_region = CURRENCY_REGION_MAP[currency]
+      grouped = SUBTYPES.group_by { |_, v| v[:region] }
+
+      # Build region order: user's region first (if known), then Generic, then others
+      other_regions = %w[us uk ca au eu] - [ user_region ].compact
+      region_order = [ user_region, nil, *other_regions ].compact.uniq
+
+      region_order.filter_map do |region|
+        next unless grouped[region]
+        [ region_label_for(region), grouped[region].map { |k, v| [ v[:long], k ] } ]
+      end
+    end
   end
 end

app/models/trade.rb

@@ -39,9 +39,46 @@ class Trade < ApplicationRecord
     Trend.new(current: current_value, previous: cost_basis)
   end
 
+  # Calculates realized gain/loss for sell trades based on avg_cost at time of sale
+  # Returns nil for buy trades or when cost basis cannot be determined
+  def realized_gain_loss
+    return @realized_gain_loss if defined?(@realized_gain_loss)
+
+    @realized_gain_loss = calculate_realized_gain_loss
+  end
+
   # Trades are always excluded from expense budgets
   # They represent portfolio management, not living expenses
   def excluded_from_budget?
     true
   end
+
+  private
+
+    def calculate_realized_gain_loss
+      return nil unless sell?
+
+      # Use preloaded holdings if available (set by reports controller to avoid N+1)
+      # Treat defined-but-empty preload as authoritative to prevent DB fallback
+      holding = if defined?(@preloaded_holdings)
+        # Use select + max_by for deterministic selection regardless of array order
+        (@preloaded_holdings || [])
+          .select { |h| h.security_id == security_id && h.date <= entry.date }
+          .max_by(&:date)
+      else
+        # Fall back to database query only when not preloaded
+        entry.account.holdings
+          .where(security_id: security_id)
+          .where("date <= ?", entry.date)
+          .order(date: :desc)
+          .first
+      end
+
+      return nil unless holding&.avg_cost
+
+      cost_basis = holding.avg_cost * qty.abs
+      sale_proceeds = price_money * qty.abs
+
+      Trend.new(current: sale_proceeds, previous: cost_basis)
+    end
 end

app/views/cryptos/_form.html.erb

@@ -1,3 +1,11 @@
 <%# locals: (account:, url:) %>
 
-<%= render "accounts/form", account: account, url: url %>
+<%= render "accounts/form", account: account, url: url do |form| %>
+  <%= form.fields_for :accountable do |crypto_form| %>
+    <%= crypto_form.select :tax_treatment,
+                          Crypto.tax_treatments.keys.map { |k| [t("accounts.tax_treatments.#{k}"), k] },
+                          { label: t("cryptos.form.tax_treatment_label"), include_blank: false },
+                          {} %>
+    <p class="text-xs text-secondary mt-1"><%= t("cryptos.form.tax_treatment_hint") %></p>
+  <% end %>
+<% end %>

app/views/investments/_form.html.erb

@@ -2,6 +2,6 @@
 
 <%= render "accounts/form", account: account, url: url do |form| %>
   <%= form.select :subtype,
-                 Investment::SUBTYPES.map { |k, v| [v[:long], k] },
+                 grouped_options_for_select(Investment.subtypes_grouped_for_select(currency: Current.family.currency), account.subtype),
                  { label: true, prompt: t("investments.form.subtype_prompt"), include_blank: t("investments.form.none") } %>
 <% end %>

app/views/reports/_investment_performance.html.erb

@@ -29,7 +29,7 @@
             (<%= investment_metrics[:unrealized_trend].percent_formatted %>)
           </p>
         <% else %>
-          <p class="text-xl font-semibold text-secondary">-</p>
+          <p class="text-xl font-semibold text-secondary"><%= t("reports.investment_performance.no_data") %></p>
         <% end %>
       </div>
 
@@ -101,7 +101,7 @@
                         <%= holding.trend.percent_formatted %>
                       </span>
                     <% else %>
-                      <span class="text-secondary">-</span>
+                      <span class="text-secondary"><%= t("reports.investment_performance.no_data") %></span>
                     <% end %>
                   </td>
                 </tr>
@@ -112,6 +112,91 @@
       </div>
     <% end %>
 
+    <%# Gains by Tax Treatment %>
+    <% if investment_metrics[:gains_by_tax_treatment].present? %>
+      <div class="space-y-3">
+        <h4 class="text-sm font-medium text-secondary uppercase"><%= t("reports.investment_performance.gains_by_tax_treatment") %></h4>
+
+        <div class="flex flex-wrap gap-4">
+          <% investment_metrics[:gains_by_tax_treatment].each do |treatment, data| %>
+            <div class="bg-container-inset rounded-lg p-4 space-y-3 flex-1 min-w-64">
+              <div class="flex items-center justify-between">
+                <span class="inline-flex items-center rounded-full px-2 py-0.5 text-xs font-medium <%= tax_treatment_badge_classes(treatment) %>" title="<%= t("accounts.tax_treatment_descriptions.#{treatment}") %>">
+                  <%= t("accounts.tax_treatments.#{treatment}") %>
+                </span>
+                <span class="text-sm font-semibold text-primary">
+                  <%= format_money(data[:total_gain]) %>
+                </span>
+              </div>
+
+              <div class="space-y-2 text-sm">
+                <div class="flex justify-between">
+                  <span class="text-secondary"><%= t("reports.investment_performance.unrealized_gains") %></span>
+                  <span class="text-primary"><%= format_money(data[:unrealized_gain]) %></span>
+                </div>
+                <div class="flex justify-between">
+                  <span class="text-secondary"><%= t("reports.investment_performance.realized_gains") %></span>
+                  <span class="text-primary"><%= format_money(data[:realized_gain]) %></span>
+                </div>
+              </div>
+
+              <% if treatment == :taxable && data[:realized_gain].amount > 0 %>
+                <p class="text-xs text-warning flex items-center gap-1">
+                  <%= icon("alert-triangle", size: "sm") %>
+                  <%= t("reports.investment_performance.taxable_realized_note") %>
+                </p>
+              <% end %>
+
+              <details class="group">
+                <summary class="cursor-pointer text-xs text-secondary hover:text-primary flex items-center gap-1">
+                  <%= icon "chevron-right", size: "sm", class: "group-open:rotate-90 transition-transform" %>
+                  <%= t("reports.investment_performance.view_details") %>
+                  (<%= t("reports.investment_performance.holdings_count", count: data[:holdings].count) %>, <%= t("reports.investment_performance.sells_count", count: data[:sell_trades].count) %>)
+                </summary>
+
+                <div class="mt-2 space-y-2 text-xs">
+                  <% if data[:holdings].any? %>
+                    <div class="space-y-1">
+                      <p class="text-secondary font-medium"><%= t("reports.investment_performance.holdings") %></p>
+                      <% data[:holdings].first(5).each do |holding| %>
+                        <div class="flex justify-between pl-2">
+                          <span class="text-primary"><%= holding.ticker %></span>
+                          <span class="<%= holding.trend ? "" : "text-secondary" %>" style="<%= holding.trend ? "color: #{holding.trend.color}" : "" %>">
+                            <%= holding.trend ? format_money(Money.new(holding.trend.value, Current.family.currency)) : t("reports.investment_performance.no_data") %>
+                          </span>
+                        </div>
+                      <% end %>
+                      <% if data[:holdings].count > 5 %>
+                        <p class="text-secondary pl-2"><%= t("reports.investment_performance.and_more", count: data[:holdings].count - 5) %></p>
+                      <% end %>
+                    </div>
+                  <% end %>
+
+                  <% if data[:sell_trades].any? %>
+                    <div class="space-y-1">
+                      <p class="text-secondary font-medium"><%= t("reports.investment_performance.sell_trades") %></p>
+                      <% data[:sell_trades].first(5).each do |trade| %>
+                        <% gain = trade.realized_gain_loss %>
+                        <div class="flex justify-between pl-2">
+                          <span class="text-primary"><%= trade.security.ticker %></span>
+                          <span class="<%= gain ? "" : "text-secondary" %>" style="<%= gain ? "color: #{gain.color}" : "" %>">
+                            <%= gain ? format_money(Money.new(gain.value, Current.family.currency)) : t("reports.investment_performance.no_data") %>
+                          </span>
+                        </div>
+                      <% end %>
+                      <% if data[:sell_trades].count > 5 %>
+                        <p class="text-secondary pl-2"><%= t("reports.investment_performance.and_more", count: data[:sell_trades].count - 5) %></p>
+                      <% end %>
+                    </div>
+                  <% end %>
+                </div>
+              </details>
+            </div>
+          <% end %>
+        </div>
+      </div>
+    <% end %>
+
     <%# Investment Accounts Summary %>
     <% if investment_metrics[:accounts].any? %>
       <div class="space-y-3">

config/locales/views/cryptos/en.yml

@@ -3,5 +3,8 @@ en:
   cryptos:
     edit:
       edit: Edit %{account}
+    form:
+      tax_treatment_label: Tax Treatment
+      tax_treatment_hint: Most cryptocurrency is held in taxable accounts. Select a different option if held in a tax-advantaged account like a self-directed IRA.
     new:
       title: Enter account balance

config/locales/views/reports/en.yml

@@ -134,6 +134,22 @@ en:
       value: Value
       return: Return
       accounts: Investment Accounts
+      gains_by_tax_treatment: Gains by Tax Treatment
+      unrealized_gains: Unrealized Gains
+      realized_gains: Realized Gains
+      total_gains: Total Gains
+      taxable_realized_note: These gains may be subject to taxes
+      no_data: "-"
+      view_details: View details
+      holdings_count:
+        one: "%{count} holding"
+        other: "%{count} holdings"
+      sells_count:
+        one: "%{count} sell"
+        other: "%{count} sells"
+      holdings: Holdings
+      sell_trades: Sell Trades
+      and_more: "+%{count} more"
     investment_flows:
       title: Investment Flows
       description: Track money flowing into and out of your investment accounts