first barebones project structure

src/main/java/de/pnreichmuth/timekeep_backend/entities/Team.java

@@ -0,0 +1,71 @@
+package de.pnreichmuth.timekeep_backend.entities;
+
+import jakarta.persistence.*;
+import lombok.Getter;
+import lombok.Setter;
+
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.stream.Stream;
+
+@Entity
+@Getter
+public class Team  {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private UUID id;
+
+    @Setter
+    private String teamName;
+
+    private boolean firstSemesterTeam;
+
+    @OneToMany(cascade = CascadeType.ALL)
+    private Map<String, Racer> members;
+
+    @OneToMany(cascade = CascadeType.ALL)
+    private Map<String, Station> passedStations;
+
+    public Team(){
+        this.teamName = "Team-" + UUID.randomUUID();
+        this.firstSemesterTeam = true;
+        this.members = new HashMap<>(4);
+        this.passedStations = new HashMap<>();
+    }
+
+
+
+    /**
+    * Treat this team as a team of first semester students, if at least 50% of its members are in the first semester
+     */
+    private void checkFirstSemesterTeam(){
+        long erstiCount = members.entrySet().stream()
+                .filter(
+                        e -> e.getValue().getIsFirstSemester()
+                ).count();
+        double percentFirstSemester = erstiCount /(double)members.size();
+        this.firstSemesterTeam = percentFirstSemester >= 0.5;
+    }
+
+    /**
+     * Adds a new member to the team and checks whether the team still qualifies as a first semester team
+     * @param newMember the Racer object to be added to the team
+     */
+    public void addMember(Racer newMember){
+        this.members.put(newMember.getName(), newMember);
+        this.checkFirstSemesterTeam();
+    }
+
+    /**
+     * Removes a member from the team by name
+     * @param name the name of the member to be removed
+     */
+    public void removeMember(String name){
+        this.members.remove(name);
+        this.checkFirstSemesterTeam();
+    }
+}