Update Organization.java

java/com/aa/act/interview/org/Organization.java

@@ -2,8 +2,72 @@
 
 import java.util.Optional;
 
+public abstract class Organization {package com.aa.act.interview.org;
+
+import java.util.Optional;
+import java.util.Random;
+
 public abstract class Organization {
 
+    private Position root;
+
+    public Organization() {
+        root = createOrganization();
+    }
+
+    protected abstract Position createOrganization();
+
+    /**
+     * hire the given person as an employee in the position that has that title
+     *
+     * @param person
+     * @param title
+     * @return the newly filled position or empty if no position has that title
+     */
+    public Optional<Position> hire(Name person, String title) {
+        Employee employee = new Employee(generateEmployeeId(), person);
+        return getEmployeePosition(title, root, employee);
+    }
+
+    private Optional<Position> getEmployeePosition(String title, Position position, Employee employee) {
+        if (title.equals(position.getTitle())) {
+            position.setEmployee(Optional.of(employee));
+            return Optional.of(position);
+        }
+
+        for (Position childPosition : position.getDirectReports()) {
+            if (childPosition.getTitle().equals(title)) {
+                childPosition.setEmployee(Optional.of(employee));
+                return Optional.of(childPosition);
+            } else {
+                Optional<Position> matchedPosition = getEmployeePosition(title, childPosition, employee);
+                if(matchedPosition.isPresent()) {
+                    return matchedPosition;
+                }
+            }
+        }
+        return Optional.empty();
+    }
+
+    private int generateEmployeeId() {
+        return new Random().nextInt(1001);
+    }
+
+    @Override
+    public String toString() {
+        return printOrganization(root, "");
+    }
+
+    private String printOrganization(Position pos, String prefix) {
+        StringBuffer sb = new StringBuffer(prefix + "+-" + pos.toString() + "\n");
+        for(Position p : pos.getDirectReports()) {
+            sb.append(printOrganization(p, prefix + "  "));
+        }
+        return sb.toString();
+    }
+}
+
+
     private Position root;
 
     public Organization() {