From fae2c509169bd139f1da877510d0738e2583403e Mon Sep 17 00:00:00 2001
From: Flashfyre <flashfireex@gmail.com>
Date: Thu, 7 Dec 2023 13:41:47 -0500
Subject: [PATCH] Add endless mode biome weighting

---
 src/battle-phases.ts | 40 +++++++++++++++++++++++++++++++---------
 src/data/biome.ts    | 23 +++++++++++++++++++++++
 2 files changed, 54 insertions(+), 9 deletions(-)

diff --git a/src/battle-phases.ts b/src/battle-phases.ts
index 3c702575404..bf9330f5ae0 100644
--- a/src/battle-phases.ts
+++ b/src/battle-phases.ts
@@ -15,7 +15,7 @@ import EvolutionSceneHandler from "./ui/evolution-scene-handler";
 import { EvolutionPhase } from "./evolution-phase";
 import { BattlePhase } from "./battle-phase";
 import { BattleStat, getBattleStatLevelChangeDescription, getBattleStatName } from "./data/battle-stat";
-import { Biome, biomeLinks } from "./data/biome";
+import { Biome, biomeDepths, biomeLinks } from "./data/biome";
 import { FusePokemonModifierType, ModifierPoolType, ModifierTier, ModifierType, ModifierTypeFunc, ModifierTypeOption, PokemonModifierType, PokemonMoveModifierType, RememberMoveModifierType, TmModifierType, getEnemyBuffModifierForWave, getModifierType, getPlayerModifierTypeOptionsForWave, modifierTypes, regenerateModifierPoolThresholds } from "./modifier/modifier-type";
 import SoundFade from "phaser3-rex-plugins/plugins/soundfade";
 import { BattlerTagLapseType, BattlerTagType, EncoreTag, HideSpriteTag as HiddenTag, TrappedTag } from "./data/battler-tag";
@@ -532,14 +532,9 @@ export class SelectBiomePhase extends BattlePhase {
 
     if (this.scene.gameMode === GameMode.CLASSIC && this.scene.currentBattle.waveIndex === this.scene.finalWave - 9)
       setNextBiome(Biome.END);
-    else if (this.scene.gameMode !== GameMode.CLASSIC) {
-      if (!(this.scene.currentBattle.waveIndex % 50))
-        setNextBiome(Biome.END);
-      else {
-        const allBiomes = Utils.getEnumValues(Biome);
-        setNextBiome(allBiomes[Utils.randSeedInt(allBiomes.length - 2, 1)]);
-      }
-    } else if (Array.isArray(biomeLinks[currentBiome])) {
+    else if (this.scene.gameMode !== GameMode.CLASSIC)
+      setNextBiome(this.generateNextBiome());
+    else if (Array.isArray(biomeLinks[currentBiome])) {
       const biomes = biomeLinks[currentBiome] as Biome[];
       if (this.scene.findModifier(m => m instanceof MapModifier)) {
         this.scene.ui.setMode(Mode.BIOME_SELECT, currentBiome, (biomeIndex: integer) => {
@@ -551,6 +546,33 @@ export class SelectBiomePhase extends BattlePhase {
     } else
       setNextBiome(biomeLinks[currentBiome] as Biome);
   }
+
+  generateNextBiome(): Biome {
+    if (!(this.scene.currentBattle.waveIndex % 50))
+      return Biome.END;
+    else {
+      const relWave = this.scene.currentBattle.waveIndex % 250;
+      const biomes = Utils.getEnumValues(Biome).slice(1, -1);
+      const maxDepth = biomeDepths[Biome.END] - 2;
+      const depthWeights = new Array(maxDepth + 1).fill(null)
+        .map((_, i: integer) => ((1 - Math.min(Math.abs((i / (maxDepth - 1)) - (relWave / 250)) + 0.25, 1)) / 0.75) * 250);
+      const biomeThresholds: integer[] = [];
+      let totalWeight = 0;
+      for (let biome of biomes) {
+        totalWeight += depthWeights[biomeDepths[biome] - 1];
+        biomeThresholds.push(totalWeight);
+      }
+
+      const randInt = Utils.randSeedInt(totalWeight);
+
+      for (let biome of biomes) {
+        if (randInt < biomeThresholds[biome])
+          return biome;
+      }
+
+      return biomes[Utils.randSeedInt(biomes.length)];
+    }
+  }
 }
 
 export class SwitchBiomePhase extends BattlePhase {
diff --git a/src/data/biome.ts b/src/data/biome.ts
index 7dfa3511097..31f7a962c59 100644
--- a/src/data/biome.ts
+++ b/src/data/biome.ts
@@ -60,6 +60,10 @@ interface BiomeLinks {
   [key: integer]: Biome | Biome[]
 }
 
+interface BiomeDepths {
+  [key: integer]: integer
+}
+
 export const biomeLinks: BiomeLinks = {
   [Biome.TOWN]: Biome.PLAINS,
   [Biome.PLAINS]: [ Biome.GRASS, Biome.CITY, Biome.LAKE ],
@@ -91,6 +95,8 @@ export const biomeLinks: BiomeLinks = {
   [Biome.JUNGLE]: Biome.SWAMP
 };
 
+export const biomeDepths: BiomeDepths = {}
+
 export enum BiomePoolTier {
   COMMON,
   UNCOMMON,
@@ -4561,6 +4567,23 @@ export const biomeTrainerPools: BiomeTrainerPools = {
     [ TrainerType.RIVAL, [] ]
   ];
 
+  biomeDepths[Biome.TOWN] = 0;
+
+  const traverseBiome = (biome: Biome, depth: integer) => {
+    const linkedBiomes: Biome[] = Array.isArray(biomeLinks[biome])
+      ? biomeLinks[biome] as Biome[]
+      : [ biomeLinks[biome] as Biome ];
+    for (let linkedBiome of linkedBiomes) {
+      if (!biomeDepths.hasOwnProperty(linkedBiome) || depth < biomeDepths[linkedBiome]) {
+        biomeDepths[linkedBiome] = depth + 1;
+        traverseBiome(linkedBiome, depth + 1);
+      }
+    }
+  };
+
+  traverseBiome(Biome.TOWN, 0);
+  biomeDepths[Biome.END] = Object.values(biomeDepths).reduce((max: integer, value: integer) => Math.max(max, value), 0) + 1;
+
   for (let biome of Utils.getEnumValues(Biome)) {
     biomePokemonPools[biome] = {};
     biomeTrainerPools[biome] = {};