Added Exchange class

src/main/java/Exchange.java

@@ -0,0 +1,86 @@
+import java.math.BigDecimal;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+
+public class Exchange {
+
+    private final String name;
+    private int week;
+    private final Map<String, Stock> stockMap;
+    private final Random random;
+
+    public Exchange(String name, List<Stock> stocks) {
+        this.name = name;
+        this.week = 1;
+        this.stockMap = new HashMap<>();
+        this.random = new Random();
+
+        for (Stock stock : stocks) {
+            stockMap.put(stock.getSymbol(), stock);
+        }
+
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getWeek() {
+        return week;
+    }
+
+    public boolean hasStock(String symbol) {
+        return stockMap.containsKey(symbol);
+    }
+
+    public Stock getStock(String symbol) {
+        return stockMap.get(symbol);
+    }
+
+    public List<Stock> findStocks(String searchTerm) {
+            List<Stock> result = new ArrayList<>();
+
+        for (Stock stock : stockMap.values()) {
+            if (stock.getSymbol().contains(searchTerm)
+                    || stock.getCompany().contains(searchTerm)) {
+                result.add(stock);
+            }
+        }
+
+        return result;
+        }
+
+    // public Transaction buy(String symbol, BigDecimal quantity, Player player) {
+    //     return;
+    // }
+
+    // public Transaction sell(Share share, Player player) {
+    //     return;
+    // }
+
+    public void advance() {
+
+        week++;
+
+        for (Stock stock : stockMap.values()) { // henter stock-objektene
+
+            BigDecimal currentPrice = stock.getSalesPrice(); // henter siste pris fra Stock
+
+            double changePercent = (random.nextDouble() - 0.5) * 0.1; 
+
+            BigDecimal change = currentPrice.multiply(BigDecimal.valueOf(changePercent)); 
+
+            BigDecimal newPrice = currentPrice.add(change); 
+
+            if (newPrice.compareTo(BigDecimal.ZERO) > 0) { // unngå negativ pris
+                stock.addNewSalesPrice(newPrice);
+            }
+        }
+    }
+
+
+
+}