Feat: Updated stock class

Added methods for getting historical prices, highest recorded price, lowest recorded price, and latest price change.

src/main/java/edu/ntnu/idi/idatt2003/g40/mappe/Stock.java

@@ -2,63 +2,132 @@
 
 import java.math.BigDecimal;
 import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.List;
 
 /**
  * Represents a stock listed on an exchange.
  */
-public class Stock {
-
-    private final String symbol;
-    private final String company;
-    private final List<BigDecimal> prices = new ArrayList<>();
-
-    /**
-     * Creates a new {@code Stock} with an initial sales price.
-     *
-     * @param symbol     the unique stock symbol
-     * @param company    the name of the company
-     * @param salesPrice the initial sales price of the stock
-     */
-    public Stock(String symbol, String company, BigDecimal salesPrice){
-        this.symbol = symbol;
-        this.company = company;
-        prices.add(salesPrice);
-    }
+public final class Stock {
 
-    /**
-     * Returns the stock symbol.
-     *
-     * @return the stock symbol
-     */
-    public String getSymbol(){
-        return symbol;
-    }
+  /**
+   * Symbol of this stock. Needs to be 4 characters.
+   * */
+  private final String symbol;
 
-    /**
-     * Returns the stock company.
-     *
-     * @return the stocks company
-     */
-    public String getCompany(){
-        return company;
-    }
+  /**
+   * Name of the company.
+   * */
+  private final String company;
+
+  /**
+   * List of prices this stock has had.
+   * */
+  private final List<BigDecimal> prices = new ArrayList<>();
 
-    /**
-     * Returns the current sales price of the stock.
-     *
-     * @return the curret sales price
-     */
-    public BigDecimal getSalesPrice() {
-        return prices.getLast();
+  /**
+   * Creates a new {@code Stock} with an initial sales price.
+   *
+   * @param symbol     the unique stock symbol
+   * @param company    the name of the company
+   * @param salesPrice the initial sales price of the stock
+   */
+  public Stock(final String symbol,
+               final String company,
+               final BigDecimal salesPrice) {
+
+    if (symbol.length() != 4) {
+      throw new IllegalArgumentException(
+              "Stock's symbol must be 4 characters!");
     }
+    this.symbol = symbol;
+    this.company = company;
+    prices.add(salesPrice);
+  }
+
+  /**
+   * Returns the stock symbol.
+   *
+   * @return the stock symbol
+   */
+  public String getSymbol() {
+    return symbol;
+  }
+
+  /**
+   * Returns the stock company.
+   *
+   * @return the stocks company
+   */
+  public String getCompany() {
+    return company;
+  }
+
+  /**
+   * Returns the current sales price of the stock.
+   *
+   * @return the current sales price
+   */
+  public BigDecimal getSalesPrice() {
+    return prices.getLast();
+  }
 
-    /**
-     * Adds a new sales price to the price history.
-     *
-     * @param price the new sales price
-     */
-    public void addNewSalesPrice(BigDecimal price) {
-        prices.add(price);
+  /**
+   * Adds a new sales price to the price history.
+   *
+   * @param price the new sales price
+   */
+  public void addNewSalesPrice(final BigDecimal price) {
+    prices.add(price);
+  }
+
+  /**
+   * Returns list of all prices for this stock.
+   *
+   * @return {@link List} object containing all prices.
+   * */
+  public List<BigDecimal> getHistoricalPrices() {
+    return prices;
+  }
+
+  /**
+   * Returns highest price this stock has been, or zero is list is empty.
+   *
+   * @return {@link BigDecimal} highest price.
+   * */
+  public BigDecimal getHighestPrice() {
+    return prices.stream()
+            .max(Comparator.naturalOrder())
+            .orElse(BigDecimal.ZERO);
+  }
+
+  /**
+   * Returns lowest price this stock has been, or zero if list is empty.
+   *
+   * @return {@link BigDecimal} lowest price.
+   * */
+  public BigDecimal getLowestPrice() {
+    return prices.stream()
+            .min(Comparator.naturalOrder())
+            .orElse(BigDecimal.ZERO);
+  }
+
+  /**
+   * Returns the latest price change of this stock.
+   *
+   * <p>Returns 0 if latest price is only price.</p>
+   *
+   * @return {@link BigDecimal} price change price.
+   * */
+  public BigDecimal getLatestPriceChange() {
+    if (prices.size() < 2) {
+      return BigDecimal.ZERO;
     }
+
+    BigDecimal currentPrice = prices.getLast();
+    BigDecimal previousPrice = prices.get(prices.size() - 2);
+
+    return currentPrice.subtract(previousPrice);
+  }
+
 }