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

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

@@ -1,14 +1,27 @@
 package com.dinosaur.dinosaurexploder.achievements;
 
-public abstract class Achievement {
+import com.almasb.fxgl.dsl.FXGL;
 
-  protected boolean completed = false;
+import java.io.Serializable;
 
-  public boolean isCompleted() {
-    return completed;
-  }
+public abstract class Achievement implements Serializable {
 
-  public abstract void update(double tpf);
+	protected boolean completed = false;
+	protected int rewardCoins;
 
-  public abstract void onDinosaurKilled();
+	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 Boolean onDinosaurKilled();
 }

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

@@ -1,50 +1,82 @@
 package com.dinosaur.dinosaurexploder.achievements;
 
+import com.dinosaur.dinosaurexploder.constants.GameConstants;
+
+import java.io.*;
 import java.util.ArrayList;
 import java.util.List;
 
 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(10, 50));
-    allAchievements.add(new KillCountAchievement(20, 100));
-  }
-
-  // Called once when the game starts
-  public void init() {
-    if (allAchievements.isEmpty()) return;
-
-    activeAchievements.addAll(allAchievements);
-  }
-
-  // Called every frame
-  public void update(double tpf) {
-    for (Achievement achievement : activeAchievements) {
-      if (!achievement.isCompleted()) {
-        achievement.update(tpf);
-      }
-    }
-  }
-
-  // Called when a dinosaur is killed
-  public void notifyDinosaurKilled() {
-    for (Achievement achievement : activeAchievements) {
-      achievement.onDinosaurKilled();
-    }
-  }
-
-  public List<Achievement> getActiveAchievements() {
-    return activeAchievements;
-  }
-
-  public Achievement getActiveAchievement() {
-    if (activeAchievements.isEmpty()) {
-      return null;
-    }
-    return activeAchievements.get(0);
-  }
+	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));
+	}
+
+	// Called once when the game starts
+	public void init() {
+		if (allAchievements.isEmpty()) return;
+
+		activeAchievements.addAll(loadAchievement());
+		if (activeAchievements.isEmpty()) {
+			saveAchievement(allAchievements);
+			activeAchievements.addAll(allAchievements);
+		}
+	}
+
+	// Called every frame
+	public void update(double tpf) {
+		for (Achievement achievement : activeAchievements) {
+			if (!achievement.isCompleted()) {
+				achievement.update(tpf);
+			}
+		}
+	}
+
+	// Called when a dinosaur is killed
+	public void notifyDinosaurKilled() {
+		for (Achievement achievement : activeAchievements) {
+			Boolean complete = achievement.onDinosaurKilled();
+		}
+		saveAchievement(activeAchievements);
+	}
+
+	public List<Achievement> getActiveAchievements() {
+		return activeAchievements;
+	}
+
+	public Achievement getActiveAchievement() {
+		if (activeAchievements.isEmpty()) {
+			return null;
+		}
+		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

@@ -1,49 +1,37 @@
 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 final int targetKills;
+	private int currentKills = 0;
 
-  private int currentKills = 0;
-  private boolean completed = false;
+	public KillCountAchievement(int targetKills, int rewardCoins) {
+		this.targetKills = targetKills;
+		this.rewardCoins = rewardCoins;
+	}
 
-  public KillCountAchievement(int targetKills, int rewardCoins) {
-    this.targetKills = targetKills;
-    this.rewardCoins = rewardCoins;
-  }
+	public String getDescription() {
+		return "Kill " + targetKills + " dinosaurs";
+	}
 
-  public String getDescription() {
-    return "Kill " + targetKills + " dinosaurs";
-  }
+	public Boolean onDinosaurKilled() {
+		if (completed) return (true);
 
-  public boolean isCompleted() {
-    return completed;
-  }
+		currentKills++;
 
-  public void onDinosaurKilled() {
-    if (completed) return;
+		if (currentKills >= targetKills) {
+			completed = true;
+			onComplete(getDescription());
+			return (true);
+		}
+		return (false);
+	}
 
-    currentKills++;
+	@Override
+	public void update(double tpf) {
+		// Not needed for count-based achievement
+	}
 
-    if (currentKills >= targetKills) {
-      completed = true;
-      onComplete();
-    }
-  }
 
-  @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 +1,44 @@
+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);
+	}
+}