MISC: Refactor favor code (#1321)

src/Faction/Faction.ts

@@ -1,6 +1,7 @@
 import { AugmentationName, FactionName, FactionDiscovery } from "@enums";
 import { FactionInfo, FactionInfos } from "./FactionInfo";
-import { favorToRep, repToFavor } from "./formulas/favor";
+import { MaxFavor, calculateFavorAfterResetting } from "./formulas/favor";
+import { clampNumber } from "../utils/helpers/clampNumber";
 
 export class Faction {
   /**
@@ -13,7 +14,7 @@ export class Faction {
   augmentations: AugmentationName[] = [];
 
   /** Amount of favor the player has with this faction. */
-  favor = 0;
+  #favor = 0;
 
   /** Flag signalling whether player has been banned from this faction */
   isBanned = false;
@@ -34,6 +35,25 @@ export class Faction {
     this.name = name;
   }
 
+  get favor() {
+    return this.#favor;
+  }
+
+  /**
+   * There is no setter for this.#favor. This is intentional. Performing arithmetic operations on `favor` may lead to
+   * the overflow error of `playerReputation`, so anything that wants to change `favor` must explicitly do that through
+   * `setFavor`.
+   *
+   * @param value
+   */
+  setFavor(value: number) {
+    if (Number.isNaN(value)) {
+      this.#favor = 0;
+      return;
+    }
+    this.#favor = clampNumber(value, 0, MaxFavor);
+  }
+
   getInfo(): FactionInfo {
     const info = FactionInfos[this.name];
     if (info == null) {
@@ -47,7 +67,7 @@ export class Faction {
 
   prestigeSourceFile() {
     // Reset favor, reputation, and flags
-    this.favor = 0;
+    this.setFavor(0);
     this.playerReputation = 0;
     this.alreadyInvited = false;
     this.isMember = false;
@@ -56,23 +76,11 @@ export class Faction {
 
   prestigeAugmentation(): void {
     // Gain favor
-    if (this.favor == null) this.favor = 0;
-    this.favor += this.getFavorGain();
+    this.setFavor(calculateFavorAfterResetting(this.favor, this.playerReputation));
     // Reset reputation and flags
     this.playerReputation = 0;
     this.alreadyInvited = false;
     this.isMember = false;
     this.isBanned = false;
   }
-
-  //Returns an array with [How much favor would be gained, how much rep would be left over]
-  getFavorGain(): number {
-    if (this.favor == null) {
-      this.favor = 0;
-    }
-    const storedRep = Math.max(0, favorToRep(this.favor));
-    const totalRep = storedRep + this.playerReputation;
-    const newFavor = repToFavor(totalRep);
-    return newFavor - this.favor;
-  }
 }

src/Faction/Factions.ts

@@ -8,6 +8,7 @@ import { assertLoadingType } from "../utils/TypeAssertion";
 import { PartialRecord, createEnumKeyedRecord, getRecordValues } from "../Types/Record";
 import { Augmentations } from "../Augmentation/Augmentations";
 import { getEnumHelper } from "../utils/EnumHelper";
+import { clampNumber } from "../utils/helpers/clampNumber";
 
 /** The static list of all factions. Initialized once and never modified. */
 export const Factions = createEnumKeyedRecord(FactionName, (name) => new Faction(name));
@@ -33,8 +34,14 @@ export function loadFactions(saveString: string, player: PlayerObject): void {
     if (typeof loadedFaction !== "object") continue;
     assertLoadingType<SavegameFaction>(loadedFaction);
     const { playerReputation: loadedRep, favor: loadedFavor, discovery: loadedDiscovery } = loadedFaction;
-    if (typeof loadedRep === "number" && loadedRep > 0) faction.playerReputation = loadedRep;
-    if (typeof loadedFavor === "number" && loadedFavor > 0) faction.favor = loadedFavor;
+    if (typeof loadedRep === "number" && loadedRep >= 0) {
+      // `playerReputation` must be in [0, Number.MAX_VALUE].
+      faction.playerReputation = clampNumber(loadedRep, 0);
+    }
+    if (typeof loadedFavor === "number" && loadedFavor >= 0) {
+      // `favor` must be in [0, MaxFavor]. This rule will be enforced in the `setFavor` function.
+      faction.setFavor(loadedFavor);
+    }
     if (getEnumHelper("FactionDiscovery").isMember(loadedDiscovery)) faction.discovery = loadedDiscovery;
   }
   // Load joined factions from player save

src/Faction/formulas/favor.ts

@@ -2,12 +2,18 @@
 // see https://en.wikipedia.org/wiki/Geometric_series#Closed-form_formula
 // for information on how to calculate this
 
+import { clampNumber } from "../../utils/helpers/clampNumber";
+
+export const MaxFavor = 35331;
+
 export function favorToRep(f: number): number {
-  const raw = 25000 * (Math.pow(1.02, f) - 1);
-  return Math.round(raw * 10000) / 10000; // round to make things easier.
+  return clampNumber(25000 * (Math.pow(1.02, f) - 1), 0);
 }
 
 export function repToFavor(r: number): number {
-  const raw = Math.log(r / 25000 + 1) / Math.log(1.02);
-  return Math.round(raw * 10000) / 10000; // round to make things easier.
+  return clampNumber(Math.log(r / 25000 + 1) / Math.log(1.02), 0, MaxFavor);
+}
+
+export function calculateFavorAfterResetting(favor: number, playerReputation: number) {
+  return repToFavor(favorToRep(favor) + playerReputation);
 }

src/Faction/ui/Info.tsx

@@ -17,6 +17,7 @@ import Typography from "@mui/material/Typography";
 import Tooltip from "@mui/material/Tooltip";
 import Box from "@mui/material/Box";
 import { useRerender } from "../../ui/React/hooks";
+import { calculateFavorAfterResetting } from "../formulas/favor";
 
 interface IProps {
   faction: Faction;
@@ -49,8 +50,6 @@ export function Info(props: IProps): React.ReactElement {
 
   const Assignment = props.factionInfo.assignment ?? DefaultAssignment;
 
-  const favorGain = props.faction.getFavorGain();
-
   return (
     <>
       <Typography classes={{ root: classes.noformat }}>{props.factionInfo.infoText}</Typography>
@@ -60,8 +59,9 @@ export function Info(props: IProps): React.ReactElement {
           title={
             <>
               <Typography>
-                You will have <Favor favor={Math.floor(props.faction.favor + favorGain)} /> faction favor after
-                installing an Augmentation.
+                You will have{" "}
+                <Favor favor={calculateFavorAfterResetting(props.faction.favor, props.faction.playerReputation)} />{" "}
+                faction favor after installing an Augmentation.
               </Typography>
               <MathJax>{"\\(\\huge{r = \\text{total faction reputation}}\\)"}</MathJax>
               <MathJax>