feat: adds 2 feats to BankATM: todo: remove comments

Author: Edge-J

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BankAtm.java

@@ -11,6 +11,7 @@ public class BankAtm {
 
   private final Map<UUID, Customer> customerById = new HashMap<>();
   private final Map<String, CheckingAccount> accountByNumber = new HashMap<>();
+  private final CurrencyConverter currencyConverter = new FixedRateCurrencyConverter();
 
   /**
    * Adds a checking account to the bank.
@@ -40,14 +41,20 @@ public Set<CheckingAccount> findAccountsByCustomerId(UUID customerId) {
   }
 
   /**
-   * Deposits funds into an account.
+   * Deposits funds into an account in a given currency. Non-USD is converted to USD using a
+   * fixed-rate converter. Rounds to 2 decimals, half-up. Throws AccountNotFoundException if account
+   * is missing or closed, IllegalArgumentException for non-positive amounts, and
+   * UnsupportedOperationException for unsupported currencies.
    *
    * @param accountNumber The account number.
    * @param amount The amount to deposit.
+   * @param currency The currency type.
    */
-  public void depositFunds(String accountNumber, double amount) {
+  public void depositFunds(String accountNumber, double amount, Currency currency) {
     CheckingAccount account = getAccountOrThrow(accountNumber);
-    account.deposit(amount);
+    double usdAmount =
+        (currency == Currency.USD) ? amount : currencyConverter.convertToUsd(amount, currency);
+    account.deposit(usdAmount);
   }
 
   /**

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BusinessCheckingAccount.java

@@ -0,0 +1,19 @@
+package com.codedifferently.lesson17.bank;
+
+import java.util.Set;
+
+/**
+ * A business checking account. Requires at least one business owner. Throws
+ * IllegalArgumentException if no owners are businesses.
+ */
+public class BusinessCheckingAccount extends CheckingAccount {
+  public BusinessCheckingAccount(
+      String accountNumber, Set<Customer> owners, double initialBalance) {
+    super(accountNumber, owners, initialBalance);
+    boolean hasBusiness = owners.stream().anyMatch(Customer::isBusiness);
+    if (!hasBusiness) {
+      throw new IllegalArgumentException(
+          "BusinessCheckingAccount requires at least one business owner");
+    }
+  }
+}

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Currency.java

@@ -0,0 +1,8 @@
+package com.codedifferently.lesson17.bank;
+
+/** Supported currencies for deposit. */
+public enum Currency {
+  USD,
+  EUR,
+  GBP
+}

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CurrencyConverter.java

@@ -0,0 +1,14 @@
+package com.codedifferently.lesson17.bank;
+
+/** Converts an amount in a given currency to USD. */
+public interface CurrencyConverter {
+  /**
+   * Converts the given amount in the given currency to USD.
+   *
+   * @param amount The amount in the original currency.
+   * @param currency The currency type.
+   * @return The equivalent amount in USD, rounded to 2 decimals (half-up).
+   * @throws UnsupportedOperationException if the currency is not supported.
+   */
+  double convertToUsd(double amount, Currency currency);
+}

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java

@@ -10,16 +10,29 @@ public class Customer {
   private final UUID id;
   private final String name;
   private final Set<CheckingAccount> accounts = new HashSet<>();
+  private final boolean isBusiness;
 
   /**
-   * Creates a new customer.
+   * Creates a new customer (individual).
    *
    * @param id The ID of the customer.
    * @param name The name of the customer.
    */
   public Customer(UUID id, String name) {
+    this(id, name, false);
+  }
+
+  /**
+   * Creates a new customer (individual or business).
+   *
+   * @param id The ID of the customer.
+   * @param name The name of the customer.
+   * @param isBusiness True if this customer is a business, false if an individual.
+   */
+  public Customer(UUID id, String name, boolean isBusiness) {
     this.id = id;
     this.name = name;
+    this.isBusiness = isBusiness;
   }
 
   /**
@@ -58,6 +71,11 @@ public Set<CheckingAccount> getAccounts() {
     return accounts;
   }
 
+  /** Returns true if this customer is a business. */
+  public boolean isBusiness() {
+    return isBusiness;
+  }
+
   @Override
   public int hashCode() {
     return id.hashCode();
@@ -73,6 +91,6 @@ public boolean equals(Object obj) {
 
   @Override
   public String toString() {
-    return "Customer{" + "id=" + id + ", name='" + name + '\'' + '}';
+    return "Customer{" + "id=" + id + ", name='" + name + '\'' + ", isBusiness=" + isBusiness + '}';
   }
 }

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/FixedRateCurrencyConverter.java

@@ -0,0 +1,27 @@
+package com.codedifferently.lesson17.bank;
+
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+import java.util.Map;
+
+/** Fixed-rate currency converter for supported currencies to USD. */
+public class FixedRateCurrencyConverter implements CurrencyConverter {
+  private static final Map<Currency, Double> RATES =
+      Map.of(
+          Currency.USD, 1.0,
+          Currency.EUR, 1.08,
+          Currency.GBP, 1.25);
+
+  @Override
+  public double convertToUsd(double amount, Currency currency) {
+    if (currency == null) {
+      throw new UnsupportedOperationException("Unsupported currency: null");
+    }
+    Double rate = RATES.get(currency);
+    if (rate == null) {
+      throw new UnsupportedOperationException("Unsupported currency: " + currency);
+    }
+    double usd = amount * rate;
+    return BigDecimal.valueOf(usd).setScale(2, RoundingMode.HALF_UP).doubleValue();
+  }
+}

lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BankAtmTest.java

@@ -59,7 +59,7 @@ void testFindAccountsByCustomerId() {
   @Test
   void testDepositFunds() {
     // Act
-    classUnderTest.depositFunds(account1.getAccountNumber(), 50.0);
+    classUnderTest.depositFunds(account1.getAccountNumber(), 50.0, Currency.USD);
 
     // Assert
     assertThat(account1.getBalance()).isEqualTo(150.0);
@@ -107,4 +107,24 @@ void testWithdrawFunds_AccountNotFound() {
         .isThrownBy(() -> classUnderTest.withdrawFunds(nonExistingAccountNumber, 50.0))
         .withMessage("Account not found");
   }
+
+  @Test
+  void testDepositFunds_EUR() {
+    // Arrange: 100 EUR at 1.08 = 108.00 USD
+    double eurAmount = 100.0;
+    double expectedUsd = 108.00;
+    // Act
+    classUnderTest.depositFunds(account1.getAccountNumber(), eurAmount, Currency.EUR);
+    // Assert
+    assertThat(account1.getBalance()).isEqualTo(100.0 + expectedUsd);
+  }
+
+  @Test
+  void testDepositFunds_UnsupportedCurrency() {
+    // Arrange: Use a fake currency
+    Currency unsupported = null;
+    // Act & Assert
+    assertThatExceptionOfType(UnsupportedOperationException.class)
+        .isThrownBy(() -> classUnderTest.depositFunds(account1.getAccountNumber(), 100.0, null));
+  }
 }

lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BusinessCheckingAccountTest.java

@@ -0,0 +1,26 @@
+package com.codedifferently.lesson17.bank;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+import java.util.Set;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+class BusinessCheckingAccountTest {
+  @Test
+  void testValidBusinessOwner() {
+    Customer business = new Customer(UUID.randomUUID(), "Biz LLC", true);
+    BusinessCheckingAccount acct = new BusinessCheckingAccount("BIZ123", Set.of(business), 100.0);
+    assertThat(acct.getBalance()).isEqualTo(100.0);
+  }
+
+  @Test
+  void testInvalidBusinessOwner() {
+    Customer person1 = new Customer(UUID.randomUUID(), "Alice");
+    Customer person2 = new Customer(UUID.randomUUID(), "Bob");
+    assertThatExceptionOfType(IllegalArgumentException.class)
+        .isThrownBy(() -> new BusinessCheckingAccount("BIZ124", Set.of(person1, person2), 100.0))
+        .withMessage("BusinessCheckingAccount requires at least one business owner");
+  }
+}