Refactor ICANN reporting and billing into common package

This moves the default yearMonth logic into a common ReportingModule, rather than the coarse-scoped BackendModule, which may not want the default parameter extraction logic, as well as moving the 'yearMonth' parameter constant to the common package it's used in. This also provides a basis for future consolidation of the ReportingEmailUtils and BillingEmailUtils classes, which have modest overlap.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=183130311

java/google/registry/reporting/billing/BillingEmailUtils.java

@@ -0,0 +1,148 @@
+// Copyright 2017 The Nomulus Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.reporting.billing;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import com.google.appengine.tools.cloudstorage.GcsFilename;
+import com.google.common.collect.ImmutableList;
+import com.google.common.io.CharStreams;
+import google.registry.config.RegistryConfig.Config;
+import google.registry.gcs.GcsUtils;
+import google.registry.reporting.billing.BillingModule.InvoiceDirectoryPrefix;
+import google.registry.util.FormattingLogger;
+import google.registry.util.Retrier;
+import google.registry.util.SendEmailService;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import javax.inject.Inject;
+import javax.mail.BodyPart;
+import javax.mail.Message;
+import javax.mail.Message.RecipientType;
+import javax.mail.MessagingException;
+import javax.mail.Multipart;
+import javax.mail.internet.InternetAddress;
+import javax.mail.internet.MimeBodyPart;
+import javax.mail.internet.MimeMultipart;
+import org.joda.time.YearMonth;
+
+/** Utility functions for sending emails involving monthly invoices. */
+class BillingEmailUtils {
+
+  private final SendEmailService emailService;
+  private final YearMonth yearMonth;
+  private final String alertSenderAddress;
+  private final String alertRecipientAddress;
+  private final ImmutableList<String> invoiceEmailRecipients;
+  private final String billingBucket;
+  private final String invoiceDirectoryPrefix;
+  private final GcsUtils gcsUtils;
+  private final Retrier retrier;
+
+  @Inject
+  BillingEmailUtils(
+      SendEmailService emailService,
+      YearMonth yearMonth,
+      @Config("alertSenderEmailAddress") String alertSenderAddress,
+      @Config("alertRecipientEmailAddress") String alertRecipientAddress,
+      @Config("invoiceEmailRecipients") ImmutableList<String> invoiceEmailRecipients,
+      @Config("billingBucket") String billingBucket,
+      @InvoiceDirectoryPrefix String invoiceDirectoryPrefix,
+      GcsUtils gcsUtils,
+      Retrier retrier) {
+    this.emailService = emailService;
+    this.yearMonth = yearMonth;
+    this.alertSenderAddress = alertSenderAddress;
+    this.alertRecipientAddress = alertRecipientAddress;
+    this.invoiceEmailRecipients = invoiceEmailRecipients;
+    this.billingBucket = billingBucket;
+    this.invoiceDirectoryPrefix = invoiceDirectoryPrefix;
+    this.gcsUtils = gcsUtils;
+    this.retrier = retrier;
+  }
+
+  private static final FormattingLogger logger = FormattingLogger.getLoggerForCallerClass();
+
+  /** Sends an e-mail to all expected recipients with an attached overall invoice from GCS. */
+  void emailOverallInvoice() {
+    retrier.callWithRetry(
+        () -> {
+          String invoiceFile =
+              String.format(
+                  "%s-%s.csv", BillingModule.OVERALL_INVOICE_PREFIX, yearMonth.toString());
+          GcsFilename invoiceFilename =
+              new GcsFilename(billingBucket, invoiceDirectoryPrefix + invoiceFile);
+          try (InputStream in = gcsUtils.openInputStream(invoiceFilename)) {
+            Message msg = emailService.createMessage();
+            msg.setFrom(new InternetAddress(alertSenderAddress));
+            for (String recipient : invoiceEmailRecipients) {
+              msg.addRecipient(RecipientType.TO, new InternetAddress(recipient));
+            }
+            msg.setSubject(String.format("Domain Registry invoice data %s", yearMonth.toString()));
+            Multipart multipart = new MimeMultipart();
+            BodyPart textPart = new MimeBodyPart();
+            textPart.setText(
+                String.format(
+                    "Attached is the %s invoice for the domain registry.", yearMonth.toString()));
+            multipart.addBodyPart(textPart);
+            BodyPart invoicePart = new MimeBodyPart();
+            String invoiceData = CharStreams.toString(new InputStreamReader(in, UTF_8));
+            invoicePart.setContent(invoiceData, "text/csv; charset=utf-8");
+            invoicePart.setFileName(invoiceFile);
+            multipart.addBodyPart(invoicePart);
+            msg.setContent(multipart);
+            msg.saveChanges();
+            emailService.sendMessage(msg);
+          }
+        },
+        new Retrier.FailureReporter() {
+          @Override
+          public void beforeRetry(Throwable thrown, int failures, int maxAttempts) {}
+
+          @Override
+          public void afterFinalFailure(Throwable thrown, int failures) {
+            sendAlertEmail(
+                String.format("Emailing invoice failed due to %s", thrown.getMessage()));
+          }
+        },
+        IOException.class,
+        MessagingException.class);
+  }
+
+  /** Sends an e-mail to the provided alert e-mail address indicating a billing failure. */
+  void sendAlertEmail(String body) {
+    retrier.callWithRetry(
+        () -> {
+          Message msg = emailService.createMessage();
+          msg.setFrom(new InternetAddress(alertSenderAddress));
+          msg.addRecipient(RecipientType.TO, new InternetAddress(alertRecipientAddress));
+          msg.setSubject(String.format("Billing Pipeline Alert: %s", yearMonth.toString()));
+          msg.setText(body);
+          emailService.sendMessage(msg);
+          return null;
+        },
+        new Retrier.FailureReporter() {
+          @Override
+          public void beforeRetry(Throwable thrown, int failures, int maxAttempts) {}
+
+          @Override
+          public void afterFinalFailure(Throwable thrown, int failures) {
+            logger.severe(thrown, "The alert e-mail system failed.");
+          }
+        },
+        MessagingException.class);
+  }
+}