Implented Gen VII Sheer Cold Changes (#349)

* Made Sheer Cold not affect Ice Types, as well as implementing the Gen VII change of 20% for non ice types.

* Pushed accurancy change

* Updated and separated the accuracy attribute and the Ice no effect attribute

* Fixed the OHKO attribute (accidentally removed) and fixed multiplier

* Updated attribute names, as well as making the move cancelled instead of 0x multiplier

* Added TSDoc comments

* Updated accuracy logic

* Changed the text response for Sheer Cold immunity

* Added immune to the HitResult enum

src/data/move.ts

@@ -2676,6 +2676,24 @@ export class WaterSuperEffectTypeMultiplierAttr extends VariableMoveTypeMultipli
   }
 }
 
+export class IceNoEffectTypeAttr extends VariableMoveTypeMultiplierAttr {
+  /**
+   * Checks to see if the Target is Ice-Type or not. If so, the move will have no effect.
+   * @param {Pokemon} user N/A
+   * @param {Pokemon} target Pokemon that is being checked whether Ice-Type or not.
+   * @param {Move} move N/A
+   * @param {any[]} args Sets to false if the target is Ice-Type, so it should do no damage/no effect.
+   * @returns {boolean} Returns true if move is successful, false if Ice-Type.
+   */
+   apply(user: Pokemon, target: Pokemon, move: Move, args: any[]): boolean {
+    if (target.isOfType(Type.ICE)) {
+      (args[0] as Utils.BooleanHolder).value = false;
+      return false;
+    }
+    return true;
+  }
+}
+
 export class FlyingTypeMultiplierAttr extends VariableMoveTypeMultiplierAttr {
   apply(user: Pokemon, target: Pokemon, move: Move, args: any[]): boolean {
     const multiplier = args[0] as Utils.NumberHolder;
@@ -2695,6 +2713,29 @@ export class OneHitKOAccuracyAttr extends VariableAccuracyAttr {
   }
 }
 
+export class SheerColdAccuracyAttr extends OneHitKOAccuracyAttr {
+  /**
+   * Changes the normal One Hit KO Accuracy Attr to implement the Gen VII changes, 
+   * where if the user is Ice-Type, it has more accuracy.
+   * @param {Pokemon} user Pokemon that is using the move; checks the Pokemon's level.
+   * @param {Pokemon} target Pokemon that is receiving the move; checks the Pokemon's level.
+   * @param {Move} move N/A 
+   * @param {any[]} args Uses the accuracy argument, allowing to change it from either 0 if it doesn't pass
+   * the first if/else, or 30/20 depending on the type of the user Pokemon.
+   * @returns Returns true if move is successful, false if misses.
+   */
+  apply(user: Pokemon, target: Pokemon, move: Move, args: any[]): boolean {
+    const accuracy = args[0] as Utils.NumberHolder;
+      if (user.level < target.level) {
+          accuracy.value = 0;
+      } else { 
+         const baseAccuracy = user.isOfType(Type.ICE) ? 30 : 20;
+         accuracy.value = Math.min(Math.max(baseAccuracy + 100 * (1 - target.level / user.level), 0), 100);
+      }
+    return true;
+  }
+}
+
 export class MissEffectAttr extends MoveAttr {
   private missEffectFunc: UserMoveConditionFunc;
 
@@ -5095,9 +5136,10 @@ export function initMoves() {
     new AttackMove(Moves.SAND_TOMB, Type.GROUND, MoveCategory.PHYSICAL, 35, 85, 15, 100, 0, 3)
       .attr(TrapAttr, BattlerTagType.SAND_TOMB)
       .makesContact(false),
-    new AttackMove(Moves.SHEER_COLD, Type.ICE, MoveCategory.SPECIAL, 200, 30, 5, -1, 0, 3)
+    new AttackMove(Moves.SHEER_COLD, Type.ICE, MoveCategory.SPECIAL, 200, 20, 5, -1, 0, 3)
+      .attr(IceNoEffectTypeAttr)
       .attr(OneHitKOAttr)
-      .attr(OneHitKOAccuracyAttr),
+      .attr(SheerColdAccuracyAttr),
     new AttackMove(Moves.MUDDY_WATER, Type.WATER, MoveCategory.SPECIAL, 90, 85, 10, 30, 0, 3)
       .attr(StatChangeAttr, BattleStat.ACC, -1)
       .target(MoveTarget.ALL_NEAR_ENEMIES),

src/field/pokemon.ts

@@ -1563,7 +1563,7 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
           
           if (!result) {
             if (!typeMultiplier.value)
-              result = HitResult.NO_EFFECT;
+              result = move.id == Moves.SHEER_COLD ? HitResult.IMMUNE : HitResult.NO_EFFECT;
             else {
               const oneHitKo = new Utils.BooleanHolder(false);
               applyMoveAttrs(OneHitKOAttr, source, this, move, oneHitKo);
@@ -1631,6 +1631,9 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
               case HitResult.NO_EFFECT:
                 this.scene.queueMessage(i18next.t('battle:hitResultNoEffect', { pokemonName: this.name }));
                 break;
+              case HitResult.IMMUNE:
+                this.scene.queueMessage(`${this.name} is unaffected!`);
+                break;
               case HitResult.ONE_HIT_KO:  
                 this.scene.queueMessage(i18next.t('battle:hitResultOneHitKO'));
                 break;
@@ -3360,7 +3363,8 @@ export enum HitResult {
   HEAL,
   FAIL,
   MISS,
-  OTHER
+  OTHER,
+  IMMUNE
 }
 
 export type DamageResult = HitResult.EFFECTIVE | HitResult.SUPER_EFFECTIVE | HitResult.NOT_VERY_EFFECTIVE | HitResult.ONE_HIT_KO | HitResult.OTHER;