Add Live Data to Account Page (#464)

* Add trends, time series, seed data

* Remove test data

* Replace old view values with helpers

* Fix tooltip bugs in D3 chart

* Fix tests

* Fix smoke test

* Add CRUD actions for valuations

* Scaffold out inline editing with Turbo

app/models/account.rb

@@ -1,6 +1,7 @@
 class Account < ApplicationRecord
   belongs_to :family
-  has_many :account_balances
+  has_many :balances, class_name: "AccountBalance"
+  has_many :valuations
 
   delegated_type :accountable, types: Accountable::TYPES, dependent: :destroy
 
@@ -8,6 +9,15 @@ class Account < ApplicationRecord
 
   before_create :check_currency
 
+  # Show all valuations in history table (no date range filtering)
+  def valuations_with_trend
+    series_for(valuations, :value)
+  end
+
+  def balances_with_trend(date_range = default_date_range)
+    series_for(balances, :balance, date_range)
+  end
+
   def check_currency
     if self.original_currency == self.family.currency
       self.converted_balance = self.original_balance
@@ -17,4 +27,36 @@ class Account < ApplicationRecord
       self.converted_currency = self.family.currency
     end
   end
+
+  private
+
+    def default_date_range
+      { start: 30.days.ago.to_date, end: Date.today }
+    end
+
+    # TODO: probably a better abstraction for this in the future
+    def series_for(collection, value_attr, date_range = {})
+      collection = filtered_by_date_for(collection, date_range)
+      overall_trend = Trend.new(collection.last&.send(value_attr), collection.first&.send(value_attr))
+
+      collection_with_trends = [ nil, *collection ].each_cons(2).map do |previous, current|
+        {
+          current: current,
+          previous: previous,
+          date: current.date,
+          currency: current.currency,
+          value: current.send(value_attr),
+          trend: Trend.new(current.send(value_attr), previous&.send(value_attr))
+        }
+      end
+
+      { date_range: date_range, trend: overall_trend, series: collection_with_trends }
+    end
+
+    def filtered_by_date_for(association, date_range)
+      scope = association
+      scope = scope.where("date >= ?", date_range[:start]) if date_range[:start]
+      scope = scope.where("date <= ?", date_range[:end]) if date_range[:end]
+      scope.order(:date).to_a
+    end
 end

app/models/adjustment.rb

@@ -0,0 +1,3 @@
+# Used for manual account value adjustments (e.g. to correct for a missing transaction)
+class Adjustment < Valuation
+end

app/models/appraisal.rb

@@ -0,0 +1,3 @@
+# Used to update the value of an account based on a manual or external appraisal (i.e. Zillow)
+class Appraisal < Valuation
+end

app/models/trend.rb

@@ -0,0 +1,26 @@
+class Trend
+    attr_reader :current, :previous
+
+    def initialize(current, previous)
+        @current = current
+        @previous = previous
+    end
+
+    def direction
+        return "flat" unless @previous
+        return "up" if @current > @previous
+        return "down" if @current < @previous
+        "flat"
+    end
+
+    def amount
+      return 0 if @previous.nil?
+      @current - @previous
+    end
+
+    def percent
+      return 0 if @previous.nil?
+      return Float::INFINITY if @previous == 0
+      ((@current - @previous).abs / @previous.to_f * 100).round(1)
+    end
+end

app/models/valuation.rb

@@ -0,0 +1,5 @@
+# STI model to represent a point-in-time "valuation" of an account's value
+# Types include: Appraisal, Adjustment
+class Valuation < ApplicationRecord
+  belongs_to :account
+end