Prepare email backup

.gitignore

@@ -6,6 +6,7 @@
 /.springBeans
 /*.iml
 /*.log
+/src/development
 /target
 /pom.xml.versionsBackup
 .DS_Store

pom.xml

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

src/main/java/de/perdian/flightlog/modules/backup/impl/EmailBackupConsumer.java

@@ -0,0 +1,121 @@
+package de.perdian.flightlog.modules.backup.impl;
+
+import de.perdian.flightlog.modules.authentication.User;
+import de.perdian.flightlog.modules.backup.BackupConsumer;
+import de.perdian.flightlog.modules.flights.exchange.FlightsExchangeFormat;
+import de.perdian.flightlog.modules.flights.exchange.FlightsExchangePackage;
+import jakarta.activation.DataSource;
+import jakarta.mail.internet.MimeMessage;
+import org.apache.commons.lang3.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.mail.javamail.JavaMailSender;
+import org.springframework.mail.javamail.MimeMessageHelper;
+import org.springframework.stereotype.Component;
+
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+
+@Component
+@ConditionalOnProperty(value = "flightlog.backup.email.enabled", havingValue = "true")
+public class EmailBackupConsumer implements BackupConsumer {
+
+    private static final Logger log = LoggerFactory.getLogger(EmailBackupConsumer.class);
+
+    private static DateTimeFormatter EMAIL_SUBJECT_DATE_FORMATTER = DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm:ss z");
+    private static DateTimeFormatter EMAIL_ATTACHMENT_FILENAME_DATE_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd_HHmmssX");
+
+    private String from = null;
+    private String to = null;
+    private JavaMailSender mailSender = null;
+    private FlightsExchangeFormat backupFormat = FlightsExchangeFormat.XML;
+
+    @Override
+    public void consumeBackupPackage(FlightsExchangePackage backupPackage, User user) {
+        if (this.getMailSender() == null) {
+            log.error("No MailSender available to consume email backup package for user: {}", user);
+        } else if (StringUtils.isEmpty(this.getFrom())) {
+            log.error("No email 'from' address configured' to send email backup package for user: {}", user);
+        } else {
+
+            ZonedDateTime backupTime = backupPackage.getCreationTime().atZone(ZoneId.of("UTC"));
+            String emailFrom = this.getFrom();
+            String emailTo = StringUtils.defaultIfEmpty(this.getTo(), user.getEntity().getEmail());
+            StringBuilder emailSubject = new StringBuilder();
+            emailSubject.append("[Flightlog] Flights Backup [").append(EMAIL_SUBJECT_DATE_FORMATTER.format(backupTime)).append("]");
+
+            StringBuilder attachmentFilename = new StringBuilder();
+            attachmentFilename.append("flightlog-backup-").append(user.getUsername()).append("-");
+            attachmentFilename.append(EMAIL_ATTACHMENT_FILENAME_DATE_FORMATTER.format(backupTime)).append(".").append(this.getBackupFormat().name().toLowerCase());
+
+            try {
+
+                log.info("Sending email backup package with {} flights to address '{}' for user: {}", backupPackage.getFlights().size(), emailTo, user);
+                DataSource attachmentDataSource = this.getBackupFormat().toDataSource(backupPackage);
+                MimeMessage emailMessage = this.getMailSender().createMimeMessage();
+                MimeMessageHelper emailMessageHelper = new MimeMessageHelper(emailMessage, true);
+                emailMessageHelper.setFrom(emailFrom);
+                emailMessageHelper.setTo(emailTo);
+                emailMessageHelper.setSubject(emailSubject.toString());
+                emailMessageHelper.setText(this.createEmailBody(backupPackage, user), true);
+                emailMessageHelper.addAttachment(attachmentFilename.toString(), attachmentDataSource);
+                this.getMailSender().send(emailMessage);
+
+            } catch (Exception e) {
+                log.error("Cannot send email backup package to address '{}' for user: ", emailTo, user, e);
+            }
+
+        }
+    }
+
+    private String createEmailBody(FlightsExchangePackage backupPackage, User user) {
+        return """
+                <html>
+                  <head>
+                    <style type="text/css">
+                    </style>
+                  <body>
+                    <div class="title">
+                      Flight log backup
+                    </div>
+                  </body>
+                </html>
+               """;
+    }
+
+    String getFrom() {
+        return this.from;
+    }
+    @Value("${flightlog.backup.email.from:}")
+    void setFrom(String from) {
+        this.from = from;
+    }
+
+    String getTo() {
+        return this.to;
+    }
+    @Value("${flightlog.backup.email.to:}")
+    public void setTo(String to) {
+        this.to = to;
+    }
+
+    JavaMailSender getMailSender() {
+        return this.mailSender;
+    }
+    @Autowired(required = false)
+    void setMailSender(JavaMailSender mailSender) {
+        this.mailSender = mailSender;
+    }
+
+    FlightsExchangeFormat getBackupFormat() {
+        return this.backupFormat;
+    }
+    void setBackupFormat(FlightsExchangeFormat backupFormat) {
+        this.backupFormat = backupFormat;
+    }
+
+}

src/main/java/de/perdian/flightlog/modules/flights/exchange/FlightsExchangeFormat.java

@@ -2,8 +2,13 @@
 
 import de.perdian.flightlog.modules.flights.exchange.impl.JsonExchangeHandler;
 import de.perdian.flightlog.modules.flights.exchange.impl.XmlExchangeHandler;
+import jakarta.activation.DataSource;
+import jakarta.mail.util.ByteArrayDataSource;
 import org.springframework.http.MediaType;
 
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+
 public enum FlightsExchangeFormat {
 
     XML(new XmlExchangeHandler(), MediaType.APPLICATION_XML),
@@ -17,6 +22,15 @@ public enum FlightsExchangeFormat {
         this.setMimeType(mimeType);
     }
 
+    public DataSource toDataSource(FlightsExchangePackage exchangePackage) {
+        try (ByteArrayOutputStream backupStream = new ByteArrayOutputStream()) {
+            this.getHandler().exportPackage(exchangePackage, backupStream);
+            return new ByteArrayDataSource(backupStream.toByteArray(), this.getMimeType().toString());
+        } catch (IOException e) {
+            throw new RuntimeException("Cannot encode exchange package using format: " + this.name(), e);
+        }
+    }
+
     public FlightsExchangeHandler getHandler() {
         return this.handler;
     }