Add: PlayerId class

Refs #52

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/game/PlayerId.java

@@ -0,0 +1,70 @@
+package ch.unibas.dmi.dbis.cs108.casono.client.game;
+
+import java.util.Objects;
+
+/**
+ * Represents a unique identifier for a player in the client domain.
+ */
+public record PlayerId(String value) {
+
+    /**
+     * Constructs a PlayerId with the given string value, ensuring it is not null or empty.
+     *
+     * @param value the string value representing the player's unique identifier.
+     */
+    public PlayerId {
+        Objects.requireNonNull(value, "PlayerId cannot be null");
+        value = value.trim();
+
+        if (value.isEmpty()) {
+            throw new IllegalArgumentException("PlayerId cannot be empty");
+        }
+    }
+
+    /**
+     * Factory method to create a PlayerId.
+     */
+    public static PlayerId of(String value) {
+        return new PlayerId(value);
+    }
+
+    /**
+     * Returns the string representation of the PlayerId, which is the encapsulated value.
+     *
+     * @return the string value of the PlayerId.
+     */
+    @Override
+    public String toString() {
+        return value;
+    }
+
+    /**
+     * Compares this PlayerId with another object for equality.
+     *
+     * @param o the object to compare to.
+     * @return true if this PlayerId is equal to the given object, false otherwise.
+     */
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        PlayerId playerId = (PlayerId) o;
+        return Objects.equals(value, playerId.value);
+    }
+
+    /**
+     * Returns the hash code for this PlayerId.
+     *
+     * @return the hash code of the PlayerId.
+     */
+    @Override
+    public int hashCode() {
+        return Objects.hash(value);
+    }
+}