Persists achievements when we start the game/get a new one

src/main/java/com/dinosaur/dinosaurexploder/achievements/Achievement.java

@@ -1,14 +1,29 @@
 package com.dinosaur.dinosaurexploder.achievements;
 
-public abstract class Achievement {
+import com.almasb.fxgl.dsl.FXGL;
+
+import java.io.Serializable;
+
+public abstract class Achievement implements Serializable {
 
   protected boolean completed = false;
+  protected int rewardCoins;
+
 
   public boolean isCompleted() {
     return completed;
   }
 
+
+  public void onComplete(String description) {
+    FXGL.getNotificationService().pushNotification("Achievement unlocked: " + description);
+  }
+
+  public int getRewardCoins() {
+    return rewardCoins;
+  }
+
   public abstract void update(double tpf);
 
-  public abstract void onDinosaurKilled();
+  public abstract Boolean onDinosaurKilled();
 }

src/main/java/com/dinosaur/dinosaurexploder/achievements/AchievementManager.java

@@ -1,5 +1,7 @@
 package com.dinosaur.dinosaurexploder.achievements;
 
+import com.dinosaur.dinosaurexploder.constants.GameConstants;
+import java.io.*;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -8,8 +10,11 @@ public class AchievementManager {
   private final List<Achievement> allAchievements = new ArrayList<>();
   private final List<Achievement> activeAchievements = new ArrayList<>();
 
+
   public AchievementManager() {
     // Register all available achievements here
+    allAchievements.add(new KillCountAchievement(1, 50));
+    allAchievements.add(new KillCountAchievement(2, 50));
     allAchievements.add(new KillCountAchievement(10, 50));
     allAchievements.add(new KillCountAchievement(20, 100));
   }
@@ -18,7 +23,12 @@ public AchievementManager() {
   public void init() {
     if (allAchievements.isEmpty()) return;
 
-    activeAchievements.addAll(allAchievements);
+    activeAchievements.addAll(loadAchievement());
+    if (activeAchievements.isEmpty())
+    {
+      saveAchievement(allAchievements);
+      activeAchievements.addAll(allAchievements);
+    }
   }
 
   // Called every frame
@@ -33,8 +43,10 @@ public void update(double tpf) {
   // Called when a dinosaur is killed
   public void notifyDinosaurKilled() {
     for (Achievement achievement : activeAchievements) {
-      achievement.onDinosaurKilled();
+      Boolean complete = achievement.onDinosaurKilled();
     }
+    saveAchievement(activeAchievements);
+
   }
 
   public List<Achievement> getActiveAchievements() {
@@ -45,6 +57,28 @@ public Achievement getActiveAchievement() {
     if (activeAchievements.isEmpty()) {
       return null;
     }
-    return activeAchievements.get(0);
+    return activeAchievements.getFirst();
+  }
+
+///Get the list of achievement save in the achievement.ser file
+  public List<Achievement> loadAchievement() {
+    List<Achievement> achievementFromFile = new ArrayList<>();
+	  try (ObjectInputStream in =
+				   new ObjectInputStream(new FileInputStream(GameConstants.ACHIEVEMENTS_FILE))) {
+		  achievementFromFile=   (List<Achievement>) in.readObject();
+	  } catch (IOException | ClassNotFoundException e) {
+		  System.out.println("Failed to load achievements from file");
+	  }
+      return achievementFromFile;
+  }
+
+  /// Save activeAchievement in the achievement.ser file
+  public void saveAchievement(List<Achievement> listToSave) {
+    try (ObjectOutputStream out =
+                 new ObjectOutputStream(new FileOutputStream(GameConstants.ACHIEVEMENTS_FILE))) {
+      out.writeObject(listToSave);
+    } catch (IOException e) {
+      System.err.println("Error saving achievement : " + e.getMessage());
+    }
   }
 }

src/main/java/com/dinosaur/dinosaurexploder/achievements/KillCountAchievement.java

@@ -1,14 +1,10 @@
 package com.dinosaur.dinosaurexploder.achievements;
 
-import com.almasb.fxgl.dsl.FXGL;
 
 public class KillCountAchievement extends Achievement {
 
   private final int targetKills;
-  private final int rewardCoins;
-
   private int currentKills = 0;
-  private boolean completed = false;
 
   public KillCountAchievement(int targetKills, int rewardCoins) {
     this.targetKills = targetKills;
@@ -19,31 +15,23 @@ public String getDescription() {
     return "Kill " + targetKills + " dinosaurs";
   }
 
-  public boolean isCompleted() {
-    return completed;
-  }
-
-  public void onDinosaurKilled() {
-    if (completed) return;
+	public Boolean onDinosaurKilled() {
+    if (completed) return(true);
 
     currentKills++;
 
     if (currentKills >= targetKills) {
       completed = true;
-      onComplete();
+      onComplete(getDescription());
+      return(true);
     }
+    return(false);
   }
 
   @Override
   public void update(double tpf) {
     // Not needed for count-based achievement
   }
 
-  public void onComplete() {
-    FXGL.getNotificationService().pushNotification("Achievement unlocked: " + getDescription());
-  }
 
-  public int getRewardCoins() {
-    return rewardCoins;
-  }
 }

src/main/java/com/dinosaur/dinosaurexploder/constants/GameConstants.java

@@ -60,6 +60,7 @@ private GameConstants() {}
    */
   public static final String HIGH_SCORE_FILE = "highScore.ser";
   public static final String TOTAL_COINS_FILE = "totalCoins.ser";
+  public static final String ACHIEVEMENTS_FILE = "achievements.ser";
 
   /*
    * CONSTANTS FOR TEXT

src/test/java/com/dinosaur/dinosaurexploder/achievements/AchievementTest.java

@@ -0,0 +1,43 @@
+package com.dinosaur.dinosaurexploder.achievements;
+
+import com.dinosaur.dinosaurexploder.utils.LevelManager;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import java.awt.*;
+import java.util.ArrayList;
+import java.util.List;
+
+
+public class AchievementTest {
+
+	private LevelManager levelManager;
+	private List<Achievement> currentAchievement = new ArrayList<>();
+	AchievementManager achievementManager = new AchievementManager();
+
+	@BeforeEach
+	void setUp() {
+
+		List<Achievement> emptyList = new ArrayList<>();
+		currentAchievement = achievementManager.loadAchievement();
+		achievementManager.saveAchievement(emptyList);
+		achievementManager.init();
+
+	}
+
+	@Test
+	void achievementSaveInFile() {
+		List<Achievement> listToCheck;
+
+		achievementManager.getActiveAchievement().completed = true;
+		achievementManager.saveAchievement(achievementManager.getActiveAchievements());
+		listToCheck = achievementManager.loadAchievement();
+		assert listToCheck.getFirst().isCompleted();
+	}
+
+	@AfterEach
+	void setAchievementBack() {
+
+		achievementManager.saveAchievement(currentAchievement);
+	}
+}