Prevent Fusion Status Errors +Fix Double Battle Issue (#472)

* Reapply "Prevent Fusing Status Errors (#465)"

This reverts commit 18a1c152c0.

* Update phases.ts

public/manifest.webmanifest

@@ -3,7 +3,7 @@
   "short_name": "PokéRogue",
   "description": "A Pokémon fangame heavily inspired by the roguelite genre. Battle endlessly while gathering stacking items, exploring many different biomes, and reaching Pokémon stats you never thought possible.",
   "scope": "/",
-  "start_url": "https://pokerogue.net",
+  "start_url": "/",
   "display": "fullscreen",
   "background_color": "#8c8c8c",
   "theme_color": "#8c8c8c",

src/data/status-effect.ts

@@ -135,3 +135,43 @@ export function getStatusEffectCatchRateMultiplier(statusEffect: StatusEffect):
 
   return 1;
 }
+
+/**
+* Returns a random non-volatile StatusEffect
+*/
+export function generateRandomStatusEffect(): StatusEffect {
+  return Utils.randIntRange(1, 6);
+}
+
+/**
+* Returns a random non-volatile StatusEffect between the two provided
+* @param statusEffectA The first StatusEffect
+* @param statusEffectA The second StatusEffect
+*/
+export function getRandomStatusEffect(statusEffectA: StatusEffect, statusEffectB: StatusEffect): StatusEffect {
+  if (statusEffectA === StatusEffect.NONE || statusEffectA === StatusEffect.FAINT) {
+    return statusEffectB;
+  }
+  if (statusEffectB === StatusEffect.NONE || statusEffectB === StatusEffect.FAINT) {
+    return statusEffectA;
+  }
+
+  return Utils.randIntRange(0, 2) ? statusEffectA : statusEffectB;
+}
+
+/**
+* Returns a random non-volatile StatusEffect between the two provided
+* @param statusA The first Status
+* @param statusB The second Status
+*/
+export function getRandomStatus(statusA: Status, statusB: Status): Status {  
+  if (statusA === undefined || statusA.effect === StatusEffect.NONE || statusA.effect === StatusEffect.FAINT) {
+    return statusB;
+  }
+  if (statusB === undefined || statusB.effect === StatusEffect.NONE || statusB.effect === StatusEffect.FAINT) {
+    return statusA;
+  }
+  
+
+  return Utils.randIntRange(0, 2) ? statusA : statusB;
+}

src/field/pokemon.ts

@@ -14,7 +14,7 @@ import { AttackTypeBoosterModifier, DamageMoneyRewardModifier, EnemyDamageBooste
 import { PokeballType } from '../data/pokeball';
 import { Gender } from '../data/gender';
 import { initMoveAnim, loadMoveAnimAssets } from '../data/battle-anims';
-import { Status, StatusEffect } from '../data/status-effect';
+import { Status, StatusEffect, getRandomStatus } from '../data/status-effect';
 import { pokemonEvolutions, pokemonPrevolutions, SpeciesFormEvolution, SpeciesEvolutionCondition, FusionSpeciesFormEvolution } from '../data/pokemon-evolutions';
 import { reverseCompatibleTms, tmSpecies } from '../data/tms';
 import { DamagePhase, FaintPhase, LearnMovePhase, ObtainStatusEffectPhase, StatChangePhase, SwitchSummonPhase } from '../phases';
@@ -2542,6 +2542,10 @@ export class PlayerPokemon extends Pokemon {
     this.generateCompatibleTms();
   }
 
+  /**
+  * Returns a Promise to fuse two PlayerPokemon together
+  * @param pokemon The PlayerPokemon to fuse to this one
+  */
   fuse(pokemon: PlayerPokemon): Promise<void> {
     return new Promise(resolve => {
       this.fusionSpecies = pokemon.species;
@@ -2555,8 +2559,25 @@ export class PlayerPokemon extends Pokemon {
       this.scene.validateAchv(achvs.SPLICE);
       this.scene.gameData.gameStats.pokemonFused++;
 
+      // Store the average HP% that each Pokemon has
+      const newHpPercent = ((pokemon.hp / pokemon.stats[Stat.HP]) + (this.hp / this.stats[Stat.HP])) / 2;
+
       this.generateName();
       this.calculateStats();
+      
+      // Set this Pokemon's HP to the average % of both fusion components
+      this.hp = Math.round(this.stats[Stat.HP] * newHpPercent);
+      if (!this.isFainted()) {
+        // If this Pokemon hasn't fainted, make sure the HP wasn't set over the new maximum
+        this.hp = Math.min(this.hp, this.stats[Stat.HP]);
+        this.status = getRandomStatus(this.status, pokemon.status); // Get a random valid status between the two
+      }
+      else if (!pokemon.isFainted()) {
+        // If this Pokemon fainted but the other hasn't, make sure the HP wasn't set to zero
+        this.hp = Math.max(this.hp, 1);
+        this.status = pokemon.status; // Inherit the other Pokemon's status
+      }
+
       this.generateCompatibleTms();
       this.updateInfo(true);
       const fusedPartyMemberIndex = this.scene.getParty().indexOf(pokemon);

src/phases.ts

@@ -1179,14 +1179,26 @@ export class SummonPhase extends PartyMemberPokemonPhase {
     this.preSummon();
   }
 
+  /**
+  * Sends out a Pokemon before the battle begins and shows the appropriate messages
+  */
   preSummon(): void {
     const partyMember = this.getPokemon();
+    // If the Pokemon about to be sent out is fainted, switch to the first non-fainted Pokemon
     if (partyMember.isFainted()) {
+      console.warn("The Pokemon about to be sent out is fainted. Attempting to resolve...");
       const party = this.getParty();
-      const nonFaintedIndex = party.slice(this.partyMemberIndex).findIndex(p => !p.isFainted()) + this.partyMemberIndex;
-      const nonFaintedPartyMember = party[nonFaintedIndex];
-      party[nonFaintedIndex] = partyMember;
-      party[this.partyMemberIndex] = nonFaintedPartyMember;
+      
+      // Find the first non-fainted Pokemon index above the current one
+      const nonFaintedIndex = party.findIndex((p, i) => i > this.partyMemberIndex && !p.isFainted());
+      if (nonFaintedIndex === -1) {
+        console.error("Party Details:\n", party);
+        throw new Error("All available Pokemon were fainted!");
+      }
+
+      // Swaps the fainted Pokemon and the first non-fainted Pokemon in the party
+      [party[this.partyMemberIndex], party[nonFaintedIndex]] = [party[nonFaintedIndex], party[this.partyMemberIndex]]; 
+      console.warn("Swapped %s %O with %s %O", partyMember?.name, partyMember, party[0]?.name, party[0]);
     }
 
     if (this.player) {

src/utils.ts

@@ -62,6 +62,11 @@ export function padInt(value: integer, length: integer, padWith?: string): strin
   return valueStr;
 }
 
+/**
+* Returns a random integer between min and min + range
+* @param range The amount of possible numbers
+* @param min The starting number
+*/
 export function randInt(range: integer, min: integer = 0): integer {
   if (range === 1)
     return min;
@@ -74,6 +79,11 @@ export function randSeedInt(range: integer, min: integer = 0): integer {
   return Phaser.Math.RND.integerInRange(min, (range - 1) + min);
 }
 
+/**
+* Returns a random integer between min and max (non-inclusive)
+* @param min The lowest number
+* @param max The highest number
+*/
 export function randIntRange(min: integer, max: integer): integer {
   return randInt(max - min, min);
 }