[BUG] Uturn faint switch bug fix (#2980)

* reordering adding switch phases for u-turn

* reverting some temp changes

* generalizing function

* adding PR suggestions

* nit indenting

src/battle-scene.ts

@@ -2084,6 +2084,24 @@ export default class BattleScene extends SceneBase {
     }
   }
 
+  /**
+   * Tries to add the input phase to index before target phase in the phaseQueue, else simply calls unshiftPhase()
+   * @param phase {@linkcode Phase} the phase to be added
+   * @param targetPhase {@linkcode Phase} the type of phase to search for in phaseQueue
+   * @returns boolean if a targetPhase was found and added
+   */
+  prependToPhase(phase: Phase, targetPhase: Constructor<Phase>): boolean {
+    const targetIndex = this.phaseQueue.findIndex(ph => ph instanceof targetPhase);
+
+    if (targetIndex !== -1) {
+      this.phaseQueue.splice(targetIndex, 0, phase);
+      return true;
+    } else {
+      this.unshiftPhase(phase);
+      return false;
+    }
+  }
+
   queueMessage(message: string, callbackDelay?: integer, prompt?: boolean, promptDelay?: integer, defer?: boolean) {
     const phase = new MessagePhase(this, message, callbackDelay, prompt, promptDelay);
     if (!defer) {

src/data/move.ts

@@ -1,5 +1,5 @@
 import { ChargeAnim, MoveChargeAnim, initMoveAnim, loadMoveAnimAssets } from "./battle-anims";
-import { BattleEndPhase, MovePhase, NewBattlePhase, PartyStatusCurePhase, PokemonHealPhase, StatChangePhase, SwitchSummonPhase } from "../phases";
+import { BattleEndPhase, MoveEndPhase, MovePhase, NewBattlePhase, PartyStatusCurePhase, PokemonHealPhase, StatChangePhase, SwitchSummonPhase } from "../phases";
 import { BattleStat, getBattleStatName } from "./battle-stat";
 import { EncoreTag, HelpingHandTag, SemiInvulnerableTag, TypeBoostTag } from "./battler-tags";
 import { getPokemonMessage, getPokemonNameWithAffix } from "../messages";
@@ -4578,10 +4578,11 @@ export class ForceSwitchOutAttr extends MoveEffectAttr {
   	// This ensures that the switch out only happens when the conditions are met
 	  const switchOutTarget = this.user ? user : target;
 	  if (switchOutTarget instanceof PlayerPokemon) {
-	  	if (switchOutTarget.hp) {
-	  	  applyPreSwitchOutAbAttrs(PreSwitchOutAbAttr, switchOutTarget);
-	  	  (switchOutTarget as PlayerPokemon).switchOut(this.batonPass, true).then(() => resolve(true));
-	  	} else {
+        if (switchOutTarget.hp > 0) {
+          applyPreSwitchOutAbAttrs(PreSwitchOutAbAttr, switchOutTarget);
+          // switchOut below sets the UI to select party(this is not a separate Phase), then adds a SwitchSummonPhase with selected 'mon
+          (switchOutTarget as PlayerPokemon).switchOut(this.batonPass, true).then(() => resolve(true));
+        } else {
           resolve(false);
         }
 	  	return;
@@ -4594,8 +4595,9 @@ export class ForceSwitchOutAttr extends MoveEffectAttr {
 	  	switchOutTarget.scene.field.remove(switchOutTarget);
 	  	user.scene.triggerPokemonFormChange(switchOutTarget, SpeciesFormChangeActiveTrigger, true);
 
-	  	if (switchOutTarget.hp) {
-          user.scene.unshiftPhase(new SwitchSummonPhase(user.scene, switchOutTarget.getFieldIndex(), user.scene.currentBattle.trainer.getNextSummonIndex((switchOutTarget as EnemyPokemon).trainerSlot), false, this.batonPass, false));
+	  	if (switchOutTarget.hp > 0) {
+        // for opponent switching out
+          user.scene.prependToPhase(new SwitchSummonPhase(user.scene, switchOutTarget.getFieldIndex(), user.scene.currentBattle.trainer.getNextSummonIndex((switchOutTarget as EnemyPokemon).trainerSlot), false, this.batonPass, false), MoveEndPhase);
         }
 	  } else {
 	    // Switch out logic for everything else

src/field/pokemon.ts

@@ -17,7 +17,7 @@ import { initMoveAnim, loadMoveAnimAssets } from "../data/battle-anims";
 import { Status, StatusEffect, getRandomStatus } from "../data/status-effect";
 import { pokemonEvolutions, pokemonPrevolutions, SpeciesFormEvolution, SpeciesEvolutionCondition, FusionSpeciesFormEvolution } from "../data/pokemon-evolutions";
 import { reverseCompatibleTms, tmSpecies, tmPoolTiers } from "../data/tms";
-import { DamagePhase, FaintPhase, LearnMovePhase, MoveEffectPhase, ObtainStatusEffectPhase, StatChangePhase, SwitchSummonPhase, ToggleDoublePositionPhase  } from "../phases";
+import { DamagePhase, FaintPhase, LearnMovePhase, MoveEffectPhase, ObtainStatusEffectPhase, StatChangePhase, SwitchSummonPhase, ToggleDoublePositionPhase, MoveEndPhase } from "../phases";
 import { BattleStat } from "../data/battle-stat";
 import { BattlerTag, BattlerTagLapseType, EncoreTag, GroundedTag, HighestStatBoostTag, TypeImmuneTag, getBattlerTag, SemiInvulnerableTag, TypeBoostTag } from "../data/battler-tags";
 import { WeatherType } from "../data/weather";
@@ -3087,7 +3087,7 @@ export class PlayerPokemon extends Pokemon {
 
       this.scene.ui.setMode(Mode.PARTY, PartyUiMode.FAINT_SWITCH, this.getFieldIndex(), (slotIndex: integer, option: PartyOption) => {
         if (slotIndex >= this.scene.currentBattle.getBattlerCount() && slotIndex < 6) {
-          this.scene.unshiftPhase(new SwitchSummonPhase(this.scene, this.getFieldIndex(), slotIndex, false, batonPass));
+          this.scene.prependToPhase(new SwitchSummonPhase(this.scene, this.getFieldIndex(), slotIndex, false, batonPass), MoveEndPhase);
         }
         if (removeFromField) {
           this.setVisible(false);

src/phases.ts

@@ -1557,6 +1557,15 @@ export class SwitchSummonPhase extends SummonPhase {
 
   private lastPokemon: Pokemon;
 
+  /**
+   * Constructor for creating a new SwitchSummonPhase
+   * @param scene {@linkcode BattleScene} the scene the phase is associated with
+   * @param fieldIndex integer representing position on the battle field
+   * @param slotIndex integer for the index of pokemon (in party of 6) to switch into
+   * @param doReturn boolean whether to render "comeback" dialogue
+   * @param batonPass boolean if the switch is from baton pass
+   * @param player boolean if the switch is from the player
+   */
   constructor(scene: BattleScene, fieldIndex: integer, slotIndex: integer, doReturn: boolean, batonPass: boolean, player?: boolean) {
     super(scene, fieldIndex, player !== undefined ? player : true);
 
@@ -1580,6 +1589,8 @@ export class SwitchSummonPhase extends SummonPhase {
       }
     }
 
+    // if doReturn === False OR slotIndex !== -1 (slotIndex is valid) and the pokemon doesn't exist/is false
+    // then switchAndSummon(), manually pick pokemon to switch into
     if (!this.doReturn || (this.slotIndex !== -1 && !(this.player ? this.scene.getParty() : this.scene.getEnemyParty())[this.slotIndex])) {
       if (this.player) {
         return this.switchAndSummon();