#1296 started MailJet notifications

Author: amihaiemil

self-api/src/main/java/com/selfxdsd/api/EmailNotification.java

@@ -27,6 +27,7 @@
  * @author Mihai Andronache (amihaiemil@gmail.com)
  * @version $Id$
  * @since 0.0.99
+ * @checkstyle MethodName (100 lines)
  */
 public interface EmailNotification {
 
@@ -36,6 +37,28 @@ public interface EmailNotification {
      */
     String to();
 
+    /**
+     * Name of the receiver.
+     * @return String.
+     */
+    String toName();
+
+    /**
+     * Sender e-mail address.
+     * @return String.
+     */
+    default String from() {
+        return "support@self-xdsd.com";
+    }
+
+    /**
+     * Sender name.
+     * @return String.
+     */
+    default String fromName() {
+        return "Self XDSD";
+    }
+
     /**
      * Subect text.
      * @return String.
@@ -47,4 +70,10 @@ public interface EmailNotification {
      * @return String.
      */
     String body();
+
+    /**
+     * Type of the notification.
+     * @return String.
+     */
+    String type();
 }

self-api/src/main/java/com/selfxdsd/api/EmailNotifications.java

@@ -32,7 +32,7 @@ public interface EmailNotifications {
 
     /**
      * Send a notification.
-     * @param emailNotification - Notification to send.
+     * @param emailNotification Notification to send.
      */
     void send(final EmailNotification emailNotification);
 }

self-core-impl/src/main/java/com/selfxdsd/core/MailjetEmailNotifications.java

@@ -24,15 +24,42 @@
 
 import com.selfxdsd.api.EmailNotification;
 import com.selfxdsd.api.EmailNotifications;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.json.Json;
+import javax.json.JsonObject;
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.util.Base64;
 
 /**
  * Using MailJet to send e-mail notifications.
  * @author Mihai Andronache (amihaiemil@gmail.com)
  * @version $Id$
  * @since 0.0.99
+ * @todo #1296:60min Write unit tests for this class, as well as for class
+ *  PlatformInvoiceEmailnotification.
+ * @todo #1296:60min Use this class to send e-mails as soon as a real payment
+ *  is successful. We should do it in a Wallet decorator.
  */
 public final class MailjetEmailNotifications implements EmailNotifications {
 
+    /**
+     * Logger.
+     */
+    private static final Logger LOG = LoggerFactory.getLogger(
+        MailjetEmailNotifications.class
+    );
+
+    /**
+     * MailJet Mail-Sending endpoint.
+     */
+    private static final String MAILJET = "https://api.mailjet.com/v3.1/send";
+
     /**
      * API Public Key (username).
      */
@@ -43,6 +70,11 @@ public final class MailjetEmailNotifications implements EmailNotifications {
      */
     private final String apiSecretKey;
 
+    /**
+     * HTTP Version to use.
+     */
+    private final HttpClient.Version httpVersion;
+
     /**
      * Ctor.
      * @param apiKey MailJet's API Key.
@@ -51,13 +83,130 @@ public final class MailjetEmailNotifications implements EmailNotifications {
     public MailjetEmailNotifications(
         final String apiKey,
         final String apiSecretKey
+    ) {
+        this(apiKey, apiSecretKey, HttpClient.Version.HTTP_2);
+    }
+
+    /**
+     * Ctor.
+     * @param apiKey MailJet's API Key.
+     * @param apiSecretKey MailJet's API Secret Key.
+     * @param httpVersion HTTP Version to use.
+     */
+    MailjetEmailNotifications(
+        final String apiKey,
+        final String apiSecretKey,
+        final HttpClient.Version httpVersion
     ) {
         this.apiKey = apiKey;
         this.apiSecretKey = apiSecretKey;
+        this.httpVersion = httpVersion;
     }
 
     @Override
     public void send(final EmailNotification emailNotification) {
+        try {
+            final JsonObject messages = Json.createObjectBuilder()
+                .add(
+                    "Messages",
+                    Json.createArrayBuilder()
+                        .add(this.notificationToJsonMessage(emailNotification))
+                        .build()
+                ).build();
+            LOG.debug(
+                "Sending EmailNotification [" + emailNotification.type()
+                + "] to " + emailNotification.to() + "... "
+            );
+            final HttpResponse<String> response = GlobalHttpClient.instance(
+                this.httpVersion
+            ).send(
+                this.request(
+                    URI.create(MAILJET),
+                    "POST",
+                    HttpRequest.BodyPublishers.ofString(messages.toString())
+                ),
+                HttpResponse.BodyHandlers.ofString()
+            );
+            if(response.statusCode() == 200) {
+                LOG.debug("Notification sent successfully!");
+            } else {
+                LOG.error(
+                    "Failed sending " + emailNotification.type()
+                    + "  notification! Status: "
+                    + response.statusCode()
+                );
+                LOG.error("MailJet Response: " + response.body());
+                LOG.error("MailJet Payload: " + messages);
+            }
+        } catch (final IOException | InterruptedException ex) {
+            LOG.error(
+                "Caught exception when sending " + emailNotification.type()
+                + " to " + emailNotification.toName(), ex
+            );
+        }
+    }
+
+    /**
+     * Build and return the HTTP Request.
+     * @param uri URI.
+     * @param method Method.
+     * @param body Body.
+     * @return HttpRequest.
+     * @checkstyle LineLength (100 lines)
+     */
+    private HttpRequest request(
+        final URI uri,
+        final String method,
+        final HttpRequest.BodyPublisher body
+    ) {
+        HttpRequest.Builder requestBuilder = HttpRequest.newBuilder()
+            .uri(uri)
+            .method(method, body)
+            .header("Content-Type", "application/json")
+            .header(
+                "User-Agent",
+                "Self XDSD; https://self-xdsd.com; "
+                    + "https://github.com/self-xdsd"
+            )
+            .header(
+                "Authorization",
+                "Basic " + Base64.getEncoder().encodeToString(
+                    (this.apiKey + ":" + this.apiSecretKey).getBytes()
+                )
+            );
+        return requestBuilder.build();
+    }
 
+    /**
+     * Turn an EmailNotification to a MailJet Message JSON.
+     * @param emailNotification EmailNotification.
+     * @return JsonObject.
+     */
+    private JsonObject notificationToJsonMessage(
+        final EmailNotification emailNotification
+    ) {
+        return Json.createObjectBuilder()
+            .add(
+                "From",
+                Json.createObjectBuilder()
+                    .add("Email", emailNotification.from())
+                    .add("Name", emailNotification.fromName())
+                    .build()
+            ).add(
+                "To",
+                Json.createArrayBuilder().add(
+                    Json.createObjectBuilder()
+                        .add("Email", emailNotification.to())
+                        .add("Name", emailNotification.toName())
+                        .build()
+                )
+            ).add(
+                "Subject",
+                emailNotification.subject()
+            ).add(
+                "TextPart",
+                emailNotification.body()
+            ).build();
     }
+
 }

self-core-impl/src/main/java/com/selfxdsd/core/PlatformInvoiceEmailNotification.java

@@ -11,8 +11,15 @@
  */
 final class PlatformInvoiceEmailNotification implements EmailNotification {
 
+    /**
+     * PlatformInvoice for which we send the notification.
+     */
     private final PlatformInvoice platformInvoice;
 
+    /**
+     * Ctor.
+     * @param platformInvoice PlatformInvoice in the notification.
+     */
     PlatformInvoiceEmailNotification(final PlatformInvoice platformInvoice) {
         this.platformInvoice = platformInvoice;
     }
@@ -22,15 +29,25 @@ public String to() {
         return "office@extremelydistributed.com";
     }
 
+    @Override
+    public String toName() {
+        return "Self XDSD Admin";
+    }
+
     @Override
     public String subject() {
-        return "[Self XDSD] New Platform Invoice " +
-            "(ID: " + this.platformInvoice.id() + ")";
+        return "New Platform Invoice "
+            + "(ID: " + this.platformInvoice.id() + ")";
     }
 
     @Override
     public String body() {
-        return "New platform invoice (id is " + this.platformInvoice.id() +
-            ") registered at " + this.platformInvoice.createdAt();
+        return "New platform invoice (id is " + this.platformInvoice.id()
+            + ") registered at " + this.platformInvoice.createdAt() + ".";
+    }
+
+    @Override
+    public String type() {
+        return "PlatformInvoide Mail Notification";
     }
 }