From 00b65ffc71a26fba62a85aa1f90dace5fcf14645 Mon Sep 17 00:00:00 2001
From: zzhhaa <zzhhaa@protonmail.com>
Date: Wed, 27 Nov 2024 16:59:23 +0100
Subject: [PATCH] feat: calculate resale values over time

---
 app/models/Lifetime.ts | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/app/models/Lifetime.ts b/app/models/Lifetime.ts
index b906400..50390c0 100644
--- a/app/models/Lifetime.ts
+++ b/app/models/Lifetime.ts
@@ -39,6 +39,7 @@ export interface LifetimeData {
     // gasBillYearly: number;
     depreciatedHouseResaleValue: number;
     fairholdLandPurchaseResaleValue: number;
+    houseAge: number;
     [key: number]: number;
 }
 
@@ -79,6 +80,7 @@ export class Lifetime {
             params.maintenancePercentage * newBuildPriceIterative;
         let depreciatedHouseResaleValueIterative = params.property.depreciatedBuildPrice;
         let fairholdLandPurchaseResaleValueIterative = params.fairholdLandPurchase.discountedLandPrice;
+        let houseAgeIterative = params.property.age;
 
         for (let i = 0; i < params.yearsForecast - 1; i++) {
             incomeYearlyIterative = 
@@ -103,8 +105,18 @@ export class Lifetime {
                 marketRentYearlyIterative - marketRentLandYearlyIterative;
             maintenanceCostIterative =
                 newBuildPriceIterative * params.maintenancePercentage;
-            depreciatedHouseResaleValueIterative = 0// TODO
-            fairholdLandPurchaseResaleValueIterative = 0// TODO
+            
+            /* A new instance of the `Property` class is needed here in order to
+            re-calculate the depreciated house value as the house gets older*/
+                const iterativeProperty = new Property({ 
+                ...params.property,
+                age: houseAgeIterative 
+            });
+            /* Use the `calculateDepreciatedBuildPrice()` method on the new `Property` class 
+            to calculate an updated depreciated house value */
+            depreciatedHouseResaleValueIterative = iterativeProperty.calculateDepreciatedBuildPrice()            
+            fairholdLandPurchaseResaleValueIterative = (1 + params.constructionPriceGrowthPerYear) // TODO: replace variable name with cpiGrowthPerYear
+            houseAgeIterative += 1
 
             if (i < params.marketPurchase.houseMortgage.termYears - 1) {
                 newbuildHouseMortgageYearlyIterative = params.marketPurchase.houseMortgage.yearlyPaymentBreakdown[i].yearlyPayment;
@@ -138,7 +150,8 @@ export class Lifetime {
                 marketLandRentYearly: marketRentLandYearlyIterative,
                 marketHouseRentYearly: marketRentHouseYearlyIterative,
                 depreciatedHouseResaleValue: depreciatedHouseResaleValueIterative,
-                fairholdLandPurchaseResaleValue: fairholdLandPurchaseResaleValueIterative
+                fairholdLandPurchaseResaleValue: fairholdLandPurchaseResaleValueIterative,
+                houseAge: houseAgeIterative,
             });
         }
         return lifetime;