CORPORATION: more granular office size upgrades (#1179)

Allows corporation.upgradeOfficeSize to increase the size of a Corporation office by a non-multiple of 3 and also be charged a corresponding amount of corporate funds. See #1166 for details of current behavior.

src/Corporation/Actions.ts

@@ -16,7 +16,13 @@ import { isRelevantMaterial } from "./ui/Helpers";
 import { CityName } from "@enums";
 import { getRandomInt } from "../utils/helpers/getRandomInt";
 import { getRecordValues } from "../Types/Record";
-import { sellSharesFailureReason, buybackSharesFailureReason, issueNewSharesFailureReason } from "./helpers";
+import {
+  calculateOfficeSizeUpgradeCost,
+  sellSharesFailureReason,
+  buybackSharesFailureReason,
+  issueNewSharesFailureReason,
+} from "./helpers";
+import { PositiveInteger } from "../types";
 
 export function NewDivision(corporation: Corporation, industry: IndustryType, name: string): void {
   if (corporation.divisions.size >= corporation.maxDivisions)
@@ -356,17 +362,10 @@ export function BuyBackShares(corporation: Corporation, numShares: number): bool
   return true;
 }
 
-export function UpgradeOfficeSize(corp: Corporation, office: OfficeSpace, size: number): void {
-  const initialPriceMult = Math.round(office.size / corpConstants.officeInitialSize);
-  const costMultiplier = 1.09;
-  // Calculate cost to upgrade size by 15 employees
-  let mult = 0;
-  for (let i = 0; i < size / corpConstants.officeInitialSize; ++i) {
-    mult += Math.pow(costMultiplier, initialPriceMult + i);
-  }
-  const cost = corpConstants.officeInitialCost * mult;
+export function UpgradeOfficeSize(corp: Corporation, office: OfficeSpace, increase: PositiveInteger): void {
+  const cost = calculateOfficeSizeUpgradeCost(office.size, increase);
   if (corp.funds < cost) return;
-  office.size += size;
+  office.size += increase;
   corp.loseFunds(cost, "office");
 }
 

src/Corporation/helpers.ts

@@ -3,6 +3,7 @@ import { PositiveInteger, isPositiveInteger } from "../types";
 import { formatShares } from "../ui/formatNumber";
 import { Corporation } from "./Corporation";
 import { CorpUpgrade } from "./data/CorporationUpgrades";
+import * as corpConstants from "./data/Constants";
 
 export function calculateUpgradeCost(corporation: Corporation, upgrade: CorpUpgrade, amount: PositiveInteger): number {
   const priceMult = upgrade.priceMult;
@@ -12,6 +13,15 @@ export function calculateUpgradeCost(corporation: Corporation, upgrade: CorpUpgr
   return cost;
 }
 
+export function calculateOfficeSizeUpgradeCost(currentSize: number, sizeIncrease: PositiveInteger): number {
+  if (sizeIncrease <= 0) throw new Error("Invalid value for sizeIncrease argument! Must be at least 0!");
+  const baseCostDivisor = 0.09;
+  const baseCostMultiplier = 1 + baseCostDivisor;
+  const currentSizeFactor = baseCostMultiplier ** (currentSize / 3);
+  const sizeIncreaseFactor = baseCostMultiplier ** (sizeIncrease / 3) - 1;
+  return (corpConstants.officeInitialCost / baseCostDivisor) * currentSizeFactor * sizeIncreaseFactor;
+}
+
 export function calculateMaxAffordableUpgrade(corp: Corporation, upgrade: CorpUpgrade): 0 | PositiveInteger {
   const Lvl = corp.upgrades[upgrade.name].level;
   const Multi = upgrade.priceMult;

src/Corporation/ui/modals/UpgradeOfficeSizeModal.tsx

@@ -10,6 +10,8 @@ import Typography from "@mui/material/Typography";
 import Button from "@mui/material/Button";
 import Tooltip from "@mui/material/Tooltip";
 import Box from "@mui/material/Box";
+import { calculateOfficeSizeUpgradeCost } from "../../helpers";
+import { PositiveInteger } from "../../../types";
 
 interface IUpgradeButton {
   cost: number;
@@ -22,19 +24,22 @@ interface IUpgradeButton {
 
 function UpgradeSizeButton(props: IUpgradeButton): React.ReactElement {
   const corp = useCorporation();
-  function upgradeSize(cost: number, size: number): void {
+  function upgradeSize(cost: number, increase: PositiveInteger): void {
     if (corp.funds < cost) {
       return;
     }
 
-    UpgradeOfficeSize(corp, props.office, size);
+    UpgradeOfficeSize(corp, props.office, increase);
     props.rerender();
     props.onClose();
   }
   return (
     <Tooltip title={formatMoney(props.cost)}>
       <span>
-        <Button disabled={corp.funds < props.cost} onClick={() => upgradeSize(props.cost, props.size)}>
+        <Button
+          disabled={corp.funds < props.cost}
+          onClick={() => upgradeSize(props.cost, props.size as PositiveInteger)}
+        >
           +{props.size}
         </Button>
       </span>
@@ -51,33 +56,23 @@ interface IProps {
 
 export function UpgradeOfficeSizeModal(props: IProps): React.ReactElement {
   const corp = useCorporation();
-  const initialPriceMult = Math.round(props.office.size / corpConstants.officeInitialSize);
-  const costMultiplier = 1.09;
-  const upgradeCost = corpConstants.officeInitialCost * Math.pow(costMultiplier, initialPriceMult);
 
-  // Calculate cost to upgrade size by 15 employees
-  let mult = 0;
-  for (let i = 0; i < 5; ++i) {
-    mult += Math.pow(costMultiplier, initialPriceMult + i);
-  }
-  const upgradeCost15 = corpConstants.officeInitialCost * mult;
+  // appears as +3 office size upgrade
+  const upgradeSizeBase = corpConstants.officeInitialSize as PositiveInteger;
+  const upgradeCostBase = calculateOfficeSizeUpgradeCost(props.office.size, upgradeSizeBase);
 
-  //Calculate max upgrade size and cost
-  const maxMult = corp.funds / corpConstants.officeInitialCost;
-  let maxNum = 1;
-  mult = Math.pow(costMultiplier, initialPriceMult);
-  while (maxNum < 50) {
-    //Hard cap of 50x (extra 150 employees)
-    if (mult >= maxMult) break;
-    const multIncrease = Math.pow(costMultiplier, initialPriceMult + maxNum);
-    if (mult + multIncrease > maxMult) {
-      break;
-    } else {
-      mult += multIncrease;
+  // appears as +15 office size upgrade
+  const upgradeSize5x = (5 * corpConstants.officeInitialSize) as PositiveInteger;
+  const upgradeCost5x = calculateOfficeSizeUpgradeCost(props.office.size, upgradeSize5x);
+
+  // optionally appears as largest affordable office size upgrade (up to +150)
+  let upgradeSizeMax = 150;
+  let upgradeCostMax = Infinity;
+  while (upgradeSizeMax > props.office.size) {
+    upgradeCostMax = calculateOfficeSizeUpgradeCost(props.office.size, upgradeSizeMax as PositiveInteger);
+    if (corp.funds > upgradeCostMax) break;
+    upgradeSizeMax -= corpConstants.officeInitialSize;
   }
-    ++maxNum;
-  }
-  const upgradeCostMax = corpConstants.officeInitialCost * mult;
 
   return (
     <Modal open={props.open} onClose={props.onClose}>
@@ -89,25 +84,28 @@ export function UpgradeOfficeSizeModal(props: IProps): React.ReactElement {
           rerender={props.rerender}
           office={props.office}
           corp={corp}
-          cost={upgradeCost}
-          size={corpConstants.officeInitialSize}
+          cost={upgradeCostBase}
+          size={upgradeSizeBase}
         />
         <UpgradeSizeButton
           onClose={props.onClose}
           rerender={props.rerender}
           office={props.office}
           corp={corp}
-          cost={upgradeCost15}
-          size={corpConstants.officeInitialSize * 5}
+          cost={upgradeCost5x}
+          size={upgradeSize5x}
         />
-        {maxNum !== 1 && maxNum !== 5 && (
+        {upgradeSizeMax > 0 &&
+          upgradeCostMax < Infinity &&
+          upgradeSizeMax !== upgradeSizeBase &&
+          upgradeSizeMax !== upgradeSize5x && (
             <UpgradeSizeButton
               onClose={props.onClose}
               rerender={props.rerender}
               office={props.office}
               corp={corp}
               cost={upgradeCostMax}
-            size={maxNum * corpConstants.officeInitialSize}
+              size={upgradeSizeMax}
             />
           )}
       </Box>

src/Documentation/doc/advanced/corporation/office.md

@@ -55,8 +55,6 @@ Maximum size with a given `MaxCost`:
 
 $$MaxUpgradeLevel = 3\ast\log_{1.09}\left( MaxCost\ast\frac{0.09}{BasePrice} + {1.09}^{\frac{CurrentSize}{3}} \right)$$
 
-When we divide office's size by 3, we need to use `Math.ceil()` to round up the value. This means upgrading from size 3 to size 4 costs the same as upgrading from size 3 to size 6. The most cost-effective size is always a multiple of 3.
-
 ## Energy and morale
 
 They are calculated in START state.

src/NetscriptFunctions/Corporation.ts

@@ -63,7 +63,7 @@ import { InternalAPI, NetscriptContext, setRemovedFunctions } from "../Netscript
 import { helpers } from "../Netscript/NetscriptHelpers";
 import { getEnumHelper } from "../utils/EnumHelper";
 import { MaterialInfo } from "../Corporation/MaterialInfo";
-import { calculateUpgradeCost } from "../Corporation/helpers";
+import { calculateOfficeSizeUpgradeCost, calculateUpgradeCost } from "../Corporation/helpers";
 import { PositiveInteger } from "../types";
 import { getRecordKeys } from "../Types/Record";
 
@@ -504,20 +504,13 @@ export function NetscriptCorporation(): InternalAPI<NSCorporation> {
       const researchName = getEnumHelper("CorpResearchName").nsGetMember(ctx, _researchName, "researchName");
       return hasResearched(getDivision(divisionName), researchName);
     },
-    getOfficeSizeUpgradeCost: (ctx) => (_divisionName, _cityName, _size) => {
+    getOfficeSizeUpgradeCost: (ctx) => (_divisionName, _cityName, _increase) => {
       checkAccess(ctx, CorpUnlockName.OfficeAPI);
       const divisionName = helpers.string(ctx, "divisionName", _divisionName);
       const cityName = getEnumHelper("CityName").nsGetMember(ctx, _cityName);
-      const size = helpers.number(ctx, "size", _size);
-      if (size < 0) throw new Error("Invalid value for size field! Must be numeric and greater than 0");
+      const increase = helpers.positiveInteger(ctx, "increase", _increase);
       const office = getOffice(divisionName, cityName);
-      const initialPriceMult = Math.round(office.size / corpConstants.officeInitialSize);
-      const costMultiplier = 1.09;
-      let mult = 0;
-      for (let i = 0; i < size / corpConstants.officeInitialSize; ++i) {
-        mult += Math.pow(costMultiplier, initialPriceMult + i);
-      }
-      return corpConstants.officeInitialCost * mult;
+      return calculateOfficeSizeUpgradeCost(office.size, increase);
     },
     setAutoJobAssignment: (ctx) => (_divisionName, _cityName, _job, _amount) => {
       checkAccess(ctx, CorpUnlockName.OfficeAPI);
@@ -558,8 +551,8 @@ export function NetscriptCorporation(): InternalAPI<NSCorporation> {
       checkAccess(ctx, CorpUnlockName.OfficeAPI);
       const divisionName = helpers.string(ctx, "divisionName", _divisionName);
       const cityName = getEnumHelper("CityName").nsGetMember(ctx, _cityName);
-      const size = helpers.number(ctx, "size", _size);
-      if (size < 0) throw new Error("Invalid value for size field! Must be numeric and greater than 0");
+      const size = helpers.positiveInteger(ctx, "size", _size);
+
       const office = getOffice(divisionName, cityName);
       const corporation = getCorporation();
       UpgradeOfficeSize(corporation, office, size);

test/jest/Corporation.test.ts

@@ -1,7 +1,11 @@
 import { PositiveInteger } from "../../src/types";
 import { Corporation } from "../../src/Corporation/Corporation";
 import { CorpUpgrades } from "../../src/Corporation/data/CorporationUpgrades";
-import { calculateMaxAffordableUpgrade, calculateUpgradeCost } from "../../src/Corporation/helpers";
+import {
+  calculateMaxAffordableUpgrade,
+  calculateUpgradeCost,
+  calculateOfficeSizeUpgradeCost,
+} from "../../src/Corporation/helpers";
 import { Player, setPlayer } from "../../src/Player";
 import { PlayerObject } from "../../src/PersonObjects/Player/PlayerObject";
 import {
@@ -112,4 +116,25 @@ describe("Corporation", () => {
       expectSharesToAddUp(corporation);
     });
   });
+
+  describe("helpers.calculateOfficeSizeUpgradeCost matches documented formula", () => {
+    // for discussion and computation of these test values, see:
+    // https://github.com/bitburner-official/bitburner-src/pull/1179#discussion_r1534948725
+    it.each([
+      { fromSize: 3, increaseBy: 3, expectedCost: 4360000000.0 },
+      { fromSize: 3, increaseBy: 15, expectedCost: 26093338259.6 },
+      { fromSize: 3, increaseBy: 150, expectedCost: 3553764305895.24902 },
+      { fromSize: 6, increaseBy: 3, expectedCost: 4752400000.0 },
+      { fromSize: 6, increaseBy: 15, expectedCost: 28441738702.964 },
+      { fromSize: 6, increaseBy: 150, expectedCost: 3873603093425.821 },
+      { fromSize: 9, increaseBy: 3, expectedCost: 5180116000.0 },
+      { fromSize: 9, increaseBy: 15, expectedCost: 31001495186.23076 },
+      { fromSize: 9, increaseBy: 150, expectedCost: 4222227371834.145 },
+    ])(
+      "should cost $expectedCost to upgrade office by $increaseBy from size $fromSize",
+      ({ fromSize, increaseBy, expectedCost }) => {
+        expect(calculateOfficeSizeUpgradeCost(fromSize, increaseBy as PositiveInteger)).toBeCloseTo(expectedCost, 1);
+      },
+    );
+  });
 });