smtp mail support (#7)

pom.xml

@@ -67,6 +67,10 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-security</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-mail</artifactId>
+        </dependency>
     </dependencies>
 
     <dependencyManagement>

src/main/java/org/otherband/Utils.java

@@ -1,8 +1,12 @@
 package org.otherband;
 
+import org.otherband.email.VerificationLinkEmailRequest;
 import org.otherband.exceptions.UserInputException;
+import org.otherband.letter.RecommendationLetterController;
 
 import static org.apache.commons.lang3.StringUtils.isBlank;
+import static org.springframework.hateoas.server.mvc.WebMvcLinkBuilder.linkTo;
+import static org.springframework.hateoas.server.mvc.WebMvcLinkBuilder.methodOn;
 
 public class Utils {
 
@@ -11,4 +15,11 @@ private Utils() {
     public static void validateNotBlank(String field, String fieldName) {
         if (isBlank(field)) throw UserInputException.formatted("[%s] cannot be blank", fieldName);
     }
+
+    public static String buildLetterVerificationLink(VerificationLinkEmailRequest verificationLinkEmailRequest) {
+        return linkTo(methodOn(RecommendationLetterController.class)
+                .verify(verificationLinkEmailRequest.getLetterId(),
+                        verificationLinkEmailRequest.getTokenId(),
+                        verificationLinkEmailRequest.getSecretToken())).withSelfRel().toString();
+    }
 }

src/main/java/org/otherband/email/simulation/EmailServiceSimulator.java

@@ -1,15 +1,11 @@
 package org.otherband.email.simulation;
 
+import org.otherband.Utils;
 import org.springframework.context.annotation.Profile;
 import org.springframework.stereotype.Component;
 import org.otherband.email.EmailService;
 import org.otherband.email.VerificationLinkEmailRequest;
-import org.otherband.letter.RecommendationLetterController;
-
 import java.util.UUID;
-
-import static org.springframework.hateoas.server.mvc.WebMvcLinkBuilder.linkTo;
-import static org.springframework.hateoas.server.mvc.WebMvcLinkBuilder.methodOn;
 import static org.otherband.email.simulation.SimulatedEmailsRepository.SimulatedEmail;
 
 @Component
@@ -23,23 +19,17 @@ public EmailServiceSimulator(SimulatedEmailsRepository emailsRepository) {
 
     @Override
     public void sendLetterVerificationLink(VerificationLinkEmailRequest verificationLinkEmailRequest) {
-        emailsRepository.save(buildEmail(verificationLinkEmailRequest.getLetterId(),
-                verificationLinkEmailRequest.getTokenId(),
-                verificationLinkEmailRequest.getSecretToken(),
-                verificationLinkEmailRequest.getReceiverEmail()));
+        emailsRepository.save(buildEmail(verificationLinkEmailRequest));
     }
 
-    private static SimulatedEmail buildEmail(String letterId, String tokenId, String secretToken, String receiverAddress) {
+    private static SimulatedEmail buildEmail(VerificationLinkEmailRequest verificationLinkEmailRequest) {
         SimulatedEmail simulatedEmail = new SimulatedEmail();
         simulatedEmail.setId(UUID.randomUUID().toString());
-        simulatedEmail.setEmailTitle(String.format("Verification link for recommendation letter [%s]", letterId));
-        simulatedEmail.setEmailBody(buildLink(letterId, tokenId, secretToken));
-        simulatedEmail.setReceiverAddress(receiverAddress);
+        simulatedEmail.setEmailTitle(String.format("Verification link for recommendation letter [%s]",
+                verificationLinkEmailRequest.getLetterId()));
+        simulatedEmail.setEmailBody(Utils.buildLetterVerificationLink(verificationLinkEmailRequest));
+        simulatedEmail.setReceiverAddress(verificationLinkEmailRequest.getReceiverEmail());
         return simulatedEmail;
     }
 
-    private static String buildLink(String letterId, String tokenId, String secretToken) {
-        return linkTo(methodOn(RecommendationLetterController.class)
-                .verify(letterId, tokenId, secretToken)).withSelfRel().toString();
-    }
 }

src/main/java/org/otherband/email/smtp/SMTPEmailService.java

@@ -0,0 +1,32 @@
+package org.otherband.email.smtp;
+
+import org.otherband.Utils;
+import org.otherband.email.EmailService;
+import org.otherband.email.VerificationLinkEmailRequest;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Profile;
+import org.springframework.mail.SimpleMailMessage;
+import org.springframework.mail.javamail.JavaMailSender;
+import org.springframework.stereotype.Service;
+
+@Profile("production")
+@Service
+public class SMTPEmailService implements EmailService {
+    private final String mailUserName;
+    private final JavaMailSender mailSender;
+
+    public SMTPEmailService(@Value("${spring.mail.username}") String mailUserName, JavaMailSender mailSender) {
+        this.mailUserName = mailUserName;
+        this.mailSender = mailSender;
+    }
+
+    @Override
+    public void sendLetterVerificationLink(VerificationLinkEmailRequest verificationLinkEmailRequest) {
+        SimpleMailMessage message = new SimpleMailMessage();
+        message.setFrom(mailUserName);
+        message.setTo(verificationLinkEmailRequest.getReceiverEmail());
+        message.setText(Utils.buildLetterVerificationLink(verificationLinkEmailRequest));
+        message.setSubject("Recommendation letter verification link");
+        mailSender.send(message);
+    }
+}

src/main/resources/application-mail.properties

@@ -0,0 +1,4 @@
+spring.mail.host=smtp.gmail.com
+spring.mail.port=587
+spring.mail.username=<SMTP username>
+spring.mail.password=<SMTP password>

src/test/java/org/otherband/email/smtp/SMTPEmailServiceTest.java

@@ -0,0 +1,49 @@
+package org.otherband.email.smtp;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
+import org.otherband.email.VerificationLinkEmailRequest;
+import org.springframework.mail.SimpleMailMessage;
+import org.springframework.mail.javamail.JavaMailSender;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+class SMTPEmailServiceTest  {
+    private static final String EXPECTED_ID = "LETTER_ID";
+    public static final String EXPECTED_RECEIVER_EMAIL = "[email protected]";
+    public static final String TOKEN_ID = "TOKEN_ID";
+    public static final String SECRET = "SECRET";
+    private SMTPEmailService service;
+    private final static String SENDER_EMAIL = "[email protected]";
+    private JavaMailSender mailSender;
+
+    @BeforeEach
+    void setup() {
+        mailSender = mock(JavaMailSender.class);
+        service = new SMTPEmailService(SENDER_EMAIL, mailSender);
+    }
+
+    @Test
+    void testSendVerificationEmail() {
+        VerificationLinkEmailRequest verificationLinkEmailRequest = buildRequest();
+        service.sendLetterVerificationLink(verificationLinkEmailRequest);
+        ArgumentCaptor<SimpleMailMessage> argumentCaptor = ArgumentCaptor.forClass(SimpleMailMessage.class);
+        verify(mailSender).send(argumentCaptor.capture());
+        SimpleMailMessage sentMessage = argumentCaptor.getValue();
+        assertArrayEquals(new String[]{EXPECTED_RECEIVER_EMAIL}, sentMessage.getTo());
+        assertEquals("Recommendation letter verification link", sentMessage.getSubject());
+        assertTrue(sentMessage.getText().contains("/api/v1/recommendation-letter/verify/LETTER_ID/TOKEN_ID/SECRET"));
+    }
+
+    private static VerificationLinkEmailRequest buildRequest() {
+        VerificationLinkEmailRequest request = new VerificationLinkEmailRequest();
+        request.setLetterId(EXPECTED_ID);
+        request.setTokenId(TOKEN_ID);
+        request.setSecretToken(SECRET);
+        request.setReceiverEmail(EXPECTED_RECEIVER_EMAIL);
+        return request;
+    }
+}