Protect against cross-session overwrites

src/system/game-data.ts

@@ -1,7 +1,7 @@
 import BattleScene, { PokeballCounts, bypassLogin } from "../battle-scene";
 import Pokemon, { EnemyPokemon, PlayerPokemon } from "../field/pokemon";
 import { pokemonEvolutions, pokemonPrevolutions } from "../data/pokemon-evolutions";
-import PokemonSpecies, { SpeciesFormKey, allSpecies, getPokemonSpecies, noStarterFormKeys, speciesStarters } from "../data/pokemon-species";
+import PokemonSpecies, { allSpecies, getPokemonSpecies, noStarterFormKeys, speciesStarters } from "../data/pokemon-species";
 import { Species, defaultStarterSpecies } from "../data/enums/species";
 import * as Utils from "../utils";
 import PokemonData from "./pokemon-data";
@@ -27,7 +27,7 @@ import { Moves } from "../data/enums/moves";
 import { speciesEggMoves } from "../data/egg-moves";
 import { allMoves } from "../data/move";
 import { TrainerVariant } from "../field/trainer";
-import { OutdatedPhase, ReloadSessionPhase, UnavailablePhase } from "#app/phases";
+import { OutdatedPhase, ReloadSessionPhase } from "#app/phases";
 import { Variant, variantData } from "#app/data/variant";
 
 const saveKey = 'x0i2O7WRiANTqPmZ'; // Temporary; secure encryption is not yet necessary
@@ -722,9 +722,19 @@ export class GameData {
         Utils.apiFetch(`savedata/delete?datatype=${GameDataType.SESSION}&slot=${slotId}`, true).then(response => {
           if (response.ok) {
             loggedInUser.lastSessionSlot = -1;
-            return resolve(true);
+            resolve(true);
           }
-          resolve(false);
+          return response.text();
+        }).then(error => {
+          if (error) {
+            if (error.startsWith('session out of date')) {
+              this.scene.clearPhaseQueue();
+              this.scene.unshiftPhase(new ReloadSessionPhase(this.scene));
+            }
+            console.error(error);
+            resolve(false);
+          }
+          resolve(true);
         });
       });
     });
@@ -742,12 +752,19 @@ export class GameData {
           return resolve([false, false]);
         const sessionData = this.getSessionSaveData(scene);
         Utils.apiPost(`savedata/clear?slot=${slotId}`, JSON.stringify(sessionData)).then(response => {
-          if (response.ok) {
+          if (response.ok)
             loggedInUser.lastSessionSlot = -1;
-            return response.json();
+          return response.json();
+        }).then(jsonResponse => {
+          if (!jsonResponse.error)
+            return resolve([true, jsonResponse.success as boolean]);
+          if (jsonResponse && jsonResponse.error.startsWith('session out of date')) {
+            this.scene.clearPhaseQueue();
+            this.scene.unshiftPhase(new ReloadSessionPhase(this.scene));
           }
+          console.error(jsonResponse);
           resolve([false, false]);
-        }).then(jsonResponse => resolve([true, jsonResponse.success as boolean]));
+        });
       });
     });
   }