Net worth calculation (#508)

* Add classification generated column to account

* Add basic net worth calculation

* Add net worth tests

* Fix lint errors

app/helpers/application_helper.rb

@@ -52,9 +52,9 @@ module ApplicationHelper
   def trend_styles(trend)
     bg_class, text_class, symbol, icon = case trend.direction
     when "up"
-      trend.type == :liability ? [ "bg-red-500/5", "text-red-500", "+", "arrow-up" ] : [ "bg-green-500/5", "text-green-500", "+", "arrow-up" ]
+      trend.type == "liability" ? [ "bg-red-500/5", "text-red-500", "+", "arrow-up" ] : [ "bg-green-500/5", "text-green-500", "+", "arrow-up" ]
     when "down"
-      trend.type == :liability ? [ "bg-green-500/5", "text-green-500", "-", "arrow-down" ] : [ "bg-red-500/5", "text-red-500", "-", "arrow-down" ]
+      trend.type == "liability" ? [ "bg-green-500/5", "text-green-500", "-", "arrow-down" ] : [ "bg-red-500/5", "text-red-500", "-", "arrow-down" ]
     when "flat"
       [ "bg-gray-500/5", "text-gray-500", "", "minus" ]
     else

app/models/account.rb

@@ -9,24 +9,8 @@ class Account < ApplicationRecord
 
   delegated_type :accountable, types: Accountable::TYPES, dependent: :destroy
 
-  delegate :type_name, to: :accountable
   before_create :check_currency
 
-  def classification
-    classifications = {
-      "Account::Depository" => :asset,
-      "Account::Investment" => :asset,
-      "Account::Property" => :asset,
-      "Account::Vehicle" => :asset,
-      "Account::OtherAsset" => :asset,
-      "Account::Loan" => :liability,
-      "Account::Credit" => :liability,
-      "Account::OtherLiability" => :liability
-    }
-
-    classifications[accountable_type]
-  end
-
   def balance_series(period)
     MoneySeries.new(
       balances.in_period(period).order(:date),

app/models/account/balance_calculator.rb

@@ -11,7 +11,7 @@ class Account::BalanceCalculator
       oldest_entry = [ valuations.first, transactions.first ].compact.min_by(&:date)
 
       net_transaction_flows = transactions.sum(&:amount)
-      net_transaction_flows *= -1 if @account.classification == :liability
+      net_transaction_flows *= -1 if @account.classification == "liability"
       implied_start_balance = oldest_entry.is_a?(Valuation) ? oldest_entry.value : @account.balance + net_transaction_flows
 
       prior_balance = implied_start_balance
@@ -22,7 +22,7 @@ class Account::BalanceCalculator
             current_balance = valuation.value
         else
             current_day_net_transaction_flows = transactions.select { |t| t.date == date }.sum(&:amount)
-            current_day_net_transaction_flows *= -1 if @account.classification == :liability
+            current_day_net_transaction_flows *= -1 if @account.classification == "liability"
             current_balance = prior_balance - current_day_net_transaction_flows
         end
 

app/models/family.rb

@@ -2,4 +2,66 @@ class Family < ApplicationRecord
   has_many :users, dependent: :destroy
   has_many :accounts, dependent: :destroy
   has_many :transactions, through: :accounts
+
+  def net_worth
+    accounts.sum("CASE WHEN classification = 'asset' THEN balance ELSE -balance END")
+  end
+
+  def assets
+    accounts.where(classification: "asset").sum(:balance)
+  end
+
+  def liabilities
+    accounts.where(classification: "liability").sum(:balance)
+  end
+
+  def net_worth_series(period = nil)
+    query = accounts.joins(:balances)
+      .select("account_balances.date, SUM(CASE WHEN accounts.classification = 'asset' THEN account_balances.balance ELSE -account_balances.balance END) AS balance, 'USD' as currency")
+      .group("account_balances.date")
+      .order("account_balances.date ASC")
+
+    if period && period.date_range
+      query = query.where("account_balances.date BETWEEN ? AND ?", period.date_range.begin, period.date_range.end)
+    end
+
+    MoneySeries.new(
+      query,
+      { trend_type: "asset" }
+    )
+  end
+
+  def asset_series(period = nil)
+    query = accounts.joins(:balances)
+      .select("account_balances.date, SUM(account_balances.balance) AS balance, 'asset' AS classification, 'USD' AS currency")
+      .group("account_balances.date")
+      .order("account_balances.date ASC")
+      .where(classification: "asset")
+
+    if period && period.date_range
+      query = query.where("account_balances.date BETWEEN ? AND ?", period.date_range.begin, period.date_range.end)
+    end
+
+    MoneySeries.new(
+      query,
+      { trend_type: "asset" }
+    )
+  end
+
+  def liability_series(period = nil)
+    query = accounts.joins(:balances)
+      .select("account_balances.date, SUM(account_balances.balance) AS balance, 'liability' AS classification, 'USD' AS currency")
+      .group("account_balances.date")
+      .order("account_balances.date ASC")
+      .where(classification: "liability")
+
+    if period && period.date_range
+      query = query.where("account_balances.date BETWEEN ? AND ?", period.date_range.begin, period.date_range.end)
+    end
+
+    MoneySeries.new(
+      query,
+      { trend_type: "liability" }
+    )
+  end
 end

app/models/money_series.rb

@@ -1,6 +1,6 @@
 class MoneySeries
     def initialize(series, options = {})
-        @trend_type = options[:trend_type] || :asset # Defines whether a positive trend is good or bad
+        @trend_type = options[:trend_type] || "asset" # Defines whether a positive trend is good or bad
         @accessor = options[:amount_accessor] || :balance
         @series = series
     end

app/models/trend.rb

@@ -1,10 +1,10 @@
 class Trend
   attr_reader :current, :previous, :type
 
-  def initialize(current:, previous: nil, type: :asset)
+  def initialize(current:, previous: nil, type: "asset")
     @current = current
     @previous = previous
-    @type = type # :asset means positive trend is good, :liability means negative trend is good
+    @type = type # asset means positive trend is good, liability means negative trend is good
   end
 
   def direction

db/migrate/20240302145715_add_classification_to_accounts.rb

@@ -0,0 +1,18 @@
+class AddClassificationToAccounts < ActiveRecord::Migration[7.2]
+  def change
+    change_table :accounts do |t|
+      t.virtual(
+        :classification,
+        type: :string,
+        stored: true,
+        as: <<-SQL
+          CASE
+            WHEN accountable_type IN ('Account::Loan', 'Account::Credit', 'Account::OtherLiability')
+            THEN 'liability'
+            ELSE 'asset'
+          END
+        SQL
+      )
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.2].define(version: 2024_02_27_142457) do
+ActiveRecord::Schema[7.2].define(version: 2024_03_02_145715) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pgcrypto"
   enable_extension "plpgsql"
@@ -79,6 +79,7 @@ ActiveRecord::Schema[7.2].define(version: 2024_02_27_142457) do
     t.decimal "converted_balance", precision: 19, scale: 4, default: "0.0"
     t.string "converted_currency", default: "USD"
     t.string "status", default: "OK"
+    t.virtual "classification", type: :string, as: "\nCASE\n    WHEN ((accountable_type)::text = ANY ((ARRAY['Account::Loan'::character varying, 'Account::Credit'::character varying, 'Account::OtherLiability'::character varying])::text[])) THEN 'liability'::text\n    ELSE 'asset'::text\nEND", stored: true
     t.index ["accountable_type"], name: "index_accounts_on_accountable_type"
     t.index ["family_id"], name: "index_accounts_on_family_id"
   end

test/controllers/accounts_controller_test.rb

@@ -3,7 +3,7 @@ require "test_helper"
 class AccountsControllerTest < ActionDispatch::IntegrationTest
   setup do
     sign_in @user = users(:family_admin)
-    @account = accounts(:generic)
+    @account = accounts(:checking)
   end
 
   test "new" do

test/controllers/valuations_controller_test.rb

@@ -3,7 +3,7 @@ require "test_helper"
 class ValuationsControllerTest < ActionDispatch::IntegrationTest
   setup do
     sign_in @user = users(:family_admin)
-    @account = accounts(:generic)
+    @account = accounts(:checking)
   end
 
   test "new" do

test/fixtures/accounts.yml

@@ -1,29 +1,27 @@
-# No transactions, no valuations, just a generic account
-generic:
-  family: dylan_family
-  name: No history, generic account
-  balance: 1200
-
 # Account with only valuations
 collectable:
   family: dylan_family
   name: Collectable Account
   balance: 550
+  accountable_type: Account::OtherAsset
 
 # Account with only transactions
 checking:
   family: dylan_family
   name: Checking Account
   balance: 5000
+  accountable_type: Account::Depository
 
 # Account with both transactions and valuations
 savings_with_valuation_overrides:
   family: dylan_family
   name: Savings account with valuation overrides
   balance: 20000
+  accountable_type: Account::Depository
 
 # Liability account
 credit_card:
   family: dylan_family
   name: Credit Card
   balance: 1000
+  accountable_type: Account::Credit

test/models/family_test.rb

@@ -2,27 +2,80 @@ require "test_helper"
 
 class FamilyTest < ActiveSupport::TestCase
   def setup
-    @dylan_family = families(:dylan_family)
+    @family = families(:dylan_family)
+
+    @family.accounts.each do |account|
+      account.accountable = account.classification == "asset" ? account_other_assets(:one) : account_other_liabilities(:one)
+      account.sync
+    end
   end
 
   test "should have many users" do
-    assert @dylan_family.users.size > 0
-    assert @dylan_family.users.include?(users(:family_admin))
+    assert @family.users.size > 0
+    assert @family.users.include?(users(:family_admin))
   end
 
   test "should have many accounts" do
-    assert @dylan_family.accounts.size > 0
+    assert @family.accounts.size > 0
   end
 
   test "should destroy dependent users" do
-    assert_difference("User.count", -@dylan_family.users.count) do
-      @dylan_family.destroy
+    assert_difference("User.count", -@family.users.count) do
+      @family.destroy
     end
   end
 
   test "should destroy dependent accounts" do
-    assert_difference("Account.count", -@dylan_family.accounts.count) do
-      @dylan_family.destroy
+    assert_difference("Account.count", -@family.accounts.count) do
+      @family.destroy
     end
   end
+
+  test "should calculate total assets" do
+    assert_equal BigDecimal("25550"), @family.assets
+  end
+
+  test "should calculate total liabilities" do
+    assert_equal BigDecimal("1000"), @family.liabilities
+  end
+
+  test "should calculate net worth" do
+    assert_equal BigDecimal("24550"), @family.net_worth
+  end
+
+  test "calculates asset series" do
+    # Sum of expected balances for all asset accounts in balance_calculator_test.rb
+    expected_balances = [
+      25650, 26135, 26135, 26135, 26135, 25385, 25385, 25385, 26460, 26460,
+      26460, 26460, 24460, 24460, 24460, 24440, 24440, 24440, 25210, 25210,
+      25210, 25210, 25210, 25210, 25210, 25400, 25250, 26050, 26050, 26050,
+      25550
+    ].map(&:to_d)
+
+    assert_equal expected_balances, @family.asset_series.data.map { |b| b[:value].amount }
+  end
+
+  test "calculates liability series" do
+    # Sum of expected balances for all liability accounts in balance_calculator_test.rb
+    expected_balances = [
+      1040, 940, 940, 940, 940, 940, 940, 940, 940, 940,
+      940, 940, 940, 940, 940, 960, 960, 960, 990, 990,
+      990, 990, 990, 990, 990, 1000, 1000, 1000, 1000, 1000,
+      1000
+    ].map(&:to_d)
+
+    assert_equal expected_balances, @family.liability_series.data.map { |b| b[:value].amount }
+  end
+
+  test "calculates net worth" do
+    # Net difference between asset and liability series above
+    expected_balances = [
+      24610, 25195, 25195, 25195, 25195, 24445, 24445, 24445, 25520, 25520,
+      25520, 25520, 23520, 23520, 23520, 23480, 23480, 23480, 24220, 24220,
+      24220, 24220, 24220, 24220, 24220, 24400, 24250, 25050, 25050, 25050,
+      24550
+    ].map(&:to_d)
+
+    assert_equal expected_balances, @family.net_worth_series.data.map { |b| b[:value].amount }
+  end
 end