Added emial to exchanges

buisnesslogic/src/main/java/com/plannaplan/services/EmailService.java

@@ -1,7 +1,13 @@
 package com.plannaplan.services;
 
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+
+import com.plannaplan.entities.Exchange;
 import com.plannaplan.entities.User;
 import com.plannaplan.models.EmailAcceptedData;
+import com.plannaplan.models.EmailExchangesData;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
@@ -18,6 +24,9 @@ public class EmailService {
     @Autowired
     private JavaMailSender emailSender;
 
+    @Autowired
+    private UserService userService;
+
     @Value("${plannaplan.email}")
     private String appEmail;
 
@@ -54,4 +63,39 @@ public class EmailService {
         mailMessage.setText(data.getEmailMessage());
         emailSender.send(mailMessage);
     }
+
+    /**
+     * method to send email for students whose groups were swaped
+     * 
+     * @param data EmailExchangesData instance that contains pair of datas user and
+     *             list of performed exhanges
+     */
+    public void sendExchangesResults(EmailExchangesData data) {
+        for (Map.Entry<Long, List<Exchange>> entry : data.getDataEntry()) {
+            final User user = this.userService.getById(entry.getKey()).get();
+            String response = "Znaleźliśmy dla Ciebie osobę, która zamieniła się z Tobą przedmiotami!!!\n Zamienione przedmioty: \n";
+
+            final Iterator<Exchange> interator = entry.getValue().iterator();
+
+            while (interator.hasNext()) {
+                final Exchange exchange = interator.next();
+                final String courseFrom = exchange.getDesiredAssignment().getCourseId() != null
+                        ? exchange.getDesiredAssignment().getCourseId().getName()
+                        : "Nieznane zajęcie";
+                final String courseTo = exchange.getOwnedAssignment().getGroup().getCourseId() != null
+                        ? exchange.getOwnedAssignment().getGroup().getCourseId().getName()
+                        : "Nieznane zajęcie";
+
+                response += (" - " + courseFrom + " za " + courseTo.toLowerCase());
+            }
+
+            SimpleMailMessage mailMessage = new SimpleMailMessage();
+            mailMessage.setFrom(appEmail);
+            mailMessage.setTo(user.getEmail());
+            mailMessage.setSubject("[PlanNaPlan] Zamiana przedmiotów");
+            mailMessage.setText(response);
+            emailSender.send(mailMessage);
+
+        }
+    }
 }