implement logic in the TransactionArchive class

src/main/java/edu/ntnu/idi/idatt2003/gruppe42/Model/Portfolio.java

@@ -23,7 +23,11 @@ public Portfolio() {
    * @return true or false based on if the operation was successful or not.
    */
   public boolean addShare(Share share) {
-    return true;
+    if (share == null) {
+      return false;
+    } else {
+      return shares.add(share);
+    }
   }
 
   /**
@@ -32,7 +36,11 @@ public boolean addShare(Share share) {
    * @return true or false based on if the operation was successful or not.
    */
   public boolean removeShare(Share share) {
-    return false;
+    if (share == null || !shares.contains(share)) {
+      return false;
+    } else {
+      return shares.remove(share);
+    }
   }
 
   public List<Share> getShares() {
@@ -45,6 +53,6 @@ public List<Share> getShares() {
    * @return true or false based on if the share was found or not.
    */
   public boolean contains(Share share) {
-    return true;
+    return share != null && shares.contains(share);
   }
 }

src/main/java/edu/ntnu/idi/idatt2003/gruppe42/Model/Transaction/TransactionArchive.java

@@ -1,7 +1,9 @@
 package edu.ntnu.idi.idatt2003.gruppe42.Model.Transaction;
 
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 public class TransactionArchive {
   private List<Transaction> transactions;
@@ -11,26 +13,60 @@ public TransactionArchive() {
   }
 
   public boolean add(Transaction transaction) {
-    return true;
+    if (transaction == null) {
+      return false;
+    } else {
+      return transactions.add(transaction);
+    }
   }
 
   public boolean isEmpty() {
-    return true;
+    return transactions.isEmpty();
   }
 
   public List<Transaction> getTransactions(int week) {
-    return transactions;
+    List<Transaction> transactionsThisWeek = new ArrayList<>();
+
+    for (Transaction transaction : transactions) {
+      if (transaction.getWeek() == week) {
+        transactionsThisWeek.add(transaction);
+      }
+    }
+
+    return transactionsThisWeek;
   }
 
   public List<Purchase> getPurchases(int week) {
-    return null;
+    List<Purchase> purchasesThisWeek = new ArrayList<>();
+
+    for (Transaction transaction : transactions) {
+      if (transaction.getWeek() == week && transaction instanceof Purchase) {
+        purchasesThisWeek.add((Purchase) transaction);
+      }
+    }
+
+    return purchasesThisWeek;
   }
 
   public List<Sale> getSales(int week) {
-    return null;
+    List<Sale> salesThisWeek = new ArrayList<>();
+
+    for (Transaction transaction : transactions) {
+      if (transaction.getWeek() == week && transaction instanceof Sale) {
+        salesThisWeek.add((Sale) transaction);
+      }
+    }
+
+    return salesThisWeek;
   }
 
   public int countDistinctWeeks() {
-    return 0;
+    Set<Integer> distinctWeeks = new HashSet<>();
+
+    for (Transaction transaction : transactions) {
+      distinctWeeks.add(transaction.getWeek());
+    }
+
+    return distinctWeeks.size();
   }
 }