feat: rough first implementation of emails in backend

backend/app/src/main/kotlin/io/tolgee/Application.kt

@@ -5,13 +5,14 @@ import org.springframework.boot.SpringApplication
 import org.springframework.boot.autoconfigure.SpringBootApplication
 import org.springframework.boot.autoconfigure.domain.EntityScan
 import org.springframework.boot.autoconfigure.ldap.LdapAutoConfiguration
+import org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration
 import org.springframework.boot.context.properties.ConfigurationPropertiesScan
 import org.springframework.data.jpa.repository.config.EnableJpaAuditing
 import org.springframework.data.jpa.repository.config.EnableJpaRepositories
 
 @SpringBootApplication(
   scanBasePackages = ["io.tolgee"],
-  exclude = [LdapAutoConfiguration::class],
+  exclude = [LdapAutoConfiguration::class, ThymeleafAutoConfiguration::class],
 )
 @EnableJpaAuditing
 @EntityScan("io.tolgee.model")

backend/data/build.gradle

@@ -52,7 +52,6 @@ apply plugin: 'org.hibernate.orm'
 
 repositories {
     mavenCentral()
-    jcenter()
 }
 
 idea {
@@ -71,6 +70,7 @@ allOpen {
     annotation("org.springframework.beans.factory.annotation.Configurable")
 }
 
+apply from: "$rootDir/gradle/email.gradle"
 apply from: "$rootDir/gradle/liquibase.gradle"
 
 configureLiquibase("public", "hibernate:spring:io.tolgee", 'src/main/resources/db/changelog/schema.xml')
@@ -98,6 +98,7 @@ dependencies {
     implementation "org.springframework.boot:spring-boot-configuration-processor"
     implementation "org.springframework.boot:spring-boot-starter-batch"
     implementation "org.springframework.boot:spring-boot-starter-websocket"
+    implementation "org.springframework.boot:spring-boot-starter-thymeleaf"
 
     /**
      * DB
@@ -170,6 +171,7 @@ dependencies {
     implementation("org.apache.commons:commons-configuration2:2.10.1")
     implementation "com.fasterxml.jackson.dataformat:jackson-dataformat-yaml:$jacksonVersion"
     implementation("com.opencsv:opencsv:5.9")
+    implementation 'ognl:ognl:3.3.4'
 
     /**
      * Google translation API
@@ -231,18 +233,14 @@ tasks.named('compileJava') {
     inputs.files(tasks.named('processResources'))
 }
 
+tasks.named('compileKotlin') {
+    dependsOn 'buildEmails'
+}
+
 ktlint {
     debug = true
     verbose = true
     filter {
         exclude("**/PluralData.kt")
     }
 }
-
-hibernate {
-    enhancement {
-        enableDirtyTracking = false
-        enableAssociationManagement = false
-        enableExtendedEnhancement = false
-    }
-}

backend/data/src/main/kotlin/io/tolgee/email/EmailService.kt

@@ -0,0 +1,81 @@
+/**
+ * Copyright (C) 2024 Tolgee s.r.o. and contributors
+ *
+ * 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 io.tolgee.email
+
+import io.tolgee.configuration.tolgee.SmtpProperties
+import io.tolgee.dtos.misc.EmailAttachment
+import org.springframework.beans.factory.annotation.Qualifier
+import org.springframework.mail.javamail.JavaMailSender
+import org.springframework.mail.javamail.MimeMessageHelper
+import org.springframework.scheduling.annotation.Async
+import org.springframework.stereotype.Service
+import org.thymeleaf.TemplateEngine
+import org.thymeleaf.context.Context
+import java.util.*
+
+@Service
+class EmailService(
+  private val smtpProperties: SmtpProperties,
+  private val mailSender: JavaMailSender,
+  @Qualifier("emailTemplateEngine") private val templateEngine: TemplateEngine,
+) {
+  private val smtpFrom
+    get() = smtpProperties.from
+      ?: throw IllegalStateException("SMTP sender is not configured. See https://docs.tolgee.io/platform/self_hosting/configuration#smtp")
+
+  @Async
+  fun sendEmailTemplate(
+    recipient: String,
+    template: String,
+    locale: Locale,
+    properties: Map<String, Any> = mapOf(),
+    attachments: List<EmailAttachment> = listOf()
+  ) {
+    val context = Context(locale, properties)
+    val html = templateEngine.process(template, context)
+    val subject = extractEmailTitle(html)
+
+    sendEmail(recipient, subject, html, attachments)
+  }
+
+  @Async
+  fun sendEmail(
+    recipient: String,
+    subject: String,
+    contents: String,
+    attachments: List<EmailAttachment> = listOf()
+  ) {
+    val message = mailSender.createMimeMessage()
+    val helper = MimeMessageHelper(message, MimeMessageHelper.MULTIPART_MODE_MIXED_RELATED,"UTF8")
+
+    helper.setFrom(smtpFrom)
+    helper.setTo(recipient)
+    helper.setSubject(subject)
+    helper.setText(contents, true)
+    attachments.forEach { helper.addAttachment(it.name, it.inputStreamSource) }
+
+    mailSender.send(message)
+  }
+
+  private fun extractEmailTitle(html: String): String {
+    return REGEX_TITLE.find(html)!!.groupValues[1]
+  }
+
+  companion object {
+    private val REGEX_TITLE = Regex("<title>(.+?)</title>")
+  }
+}

backend/data/src/main/kotlin/io/tolgee/email/EmailTemplateConfig.kt

@@ -0,0 +1,62 @@
+/**
+ * Copyright (C) 2024 Tolgee s.r.o. and contributors
+ *
+ * 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 io.tolgee.email
+
+import org.springframework.beans.factory.annotation.Qualifier
+import org.springframework.context.MessageSource
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+import org.springframework.context.support.ResourceBundleMessageSource
+import org.thymeleaf.TemplateEngine
+import org.thymeleaf.spring6.SpringTemplateEngine
+import org.thymeleaf.templateresolver.ClassLoaderTemplateResolver
+import org.thymeleaf.templateresolver.ITemplateResolver
+import java.util.*
+
+@Configuration
+class EmailTemplateConfig {
+  @Bean("emailTemplateResolver")
+  fun templateResolver(): ClassLoaderTemplateResolver {
+    val templateResolver = ClassLoaderTemplateResolver()
+    templateResolver.characterEncoding = "UTF-8"
+    templateResolver.prefix = "/email-templates/"
+    templateResolver.suffix = ".html"
+    return templateResolver
+  }
+
+  @Bean("emailMessageSource")
+  fun messageSource(): MessageSource {
+    val messageSource = ResourceBundleMessageSource()
+    messageSource.setBasename("email-i18n.messages")
+    messageSource.setDefaultEncoding("UTF-8")
+    messageSource.setDefaultLocale(Locale.ENGLISH)
+    println(messageSource.getMessage("powered-by", null, Locale.ENGLISH))
+    println(messageSource.getMessage("powered-by", null, Locale.FRENCH))
+    return messageSource
+  }
+
+  @Bean("emailTemplateEngine")
+  fun templateEngine(
+    @Qualifier("emailTemplateResolver") templateResolver: ITemplateResolver,
+    @Qualifier("emailMessageSource") messageSource: MessageSource
+  ): TemplateEngine {
+    val templateEngine = SpringTemplateEngine()
+    templateEngine.templateResolvers = setOf(templateResolver)
+    templateEngine.setTemplateEngineMessageSource(messageSource)
+    return templateEngine
+  }
+}

backend/data/src/main/resources/email-i18n

@@ -0,0 +1 @@
+../../../../../email/i18n

backend/data/src/main/resources/email-templates

@@ -0,0 +1 @@
+../../../../../email/out

backend/data/src/test/kotlin/io/tolgee/email/EmailServiceTest.kt

@@ -0,0 +1,121 @@
+/**
+ * Copyright (C) 2024 Tolgee s.r.o. and contributors
+ *
+ * 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 io.tolgee.email
+
+import io.tolgee.configuration.tolgee.SmtpProperties
+import io.tolgee.testing.assert
+import jakarta.mail.internet.MimeMessage
+import jakarta.mail.internet.MimeMultipart
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.extension.ExtendWith
+import org.mockito.ArgumentCaptor
+import org.mockito.Captor
+import org.mockito.kotlin.verify
+import org.mockito.kotlin.whenever
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.mock.mockito.MockBean
+import org.springframework.context.annotation.Import
+import org.springframework.mail.javamail.JavaMailSender
+import org.springframework.mail.javamail.JavaMailSenderImpl
+import org.springframework.stereotype.Component
+import org.springframework.test.context.junit.jupiter.SpringExtension
+import java.util.*
+
+@Component
+@ExtendWith(SpringExtension::class)
+@Import(EmailService::class, EmailTemplateConfig::class)
+class EmailServiceTest {
+  @MockBean
+  private lateinit var smtpProperties: SmtpProperties
+
+  @MockBean
+  private lateinit var mailSender: JavaMailSender
+
+  @Autowired
+  private lateinit var emailService: EmailService
+
+  @Captor
+  private lateinit var emailCaptor: ArgumentCaptor<MimeMessage>
+
+  @BeforeEach
+  fun beforeEach() {
+    val sender = JavaMailSenderImpl()
+    whenever(smtpProperties.from).thenReturn("Tolgee Test <[email protected]>")
+    whenever(mailSender.createMimeMessage()).let {
+      val msg = sender.createMimeMessage()
+      it.thenReturn(msg)
+    }
+  }
+
+  @Test
+  fun `it sends a rendered email with variables and ICU strings processed`() {
+    emailService.sendEmailTemplate("[email protected]", "zz-test-email", Locale.ENGLISH, TEST_PROPERTIES)
+    verify(mailSender).send(emailCaptor.capture())
+
+    val email = emailCaptor.value
+    email.subject.assert.isEqualTo("Test email (written with React Email)")
+    email.allRecipients.asList().assert.singleElement().asString().isEqualTo("[email protected]")
+
+    email.content
+      .let { it as MimeMultipart }
+      .let { it.getBodyPart(0).content as MimeMultipart }
+      .let { it.getBodyPart(0).content as String }
+      .assert
+      .contains("Value of `testVar` : <span>test!!</span>")
+      .contains("<span>Was `testVar` equal to &quot;meow&quot; : </span><span>no</span>")
+      .contains("Powered by")
+      .doesNotContain(" th:")
+      .doesNotContain(" data-th")
+  }
+
+  @Test
+  fun `it correctly processes conditional blocks`() {
+    // FWIW this is very close to just testing Thymeleaf itself, but it serves as a sanity check for the template itself
+    emailService.sendEmailTemplate("[email protected]", "zz-test-email", Locale.ENGLISH, TEST_PROPERTIES_MEOW)
+    verify(mailSender).send(emailCaptor.capture())
+
+    val email = emailCaptor.value
+    email.content
+      .let { it as MimeMultipart }
+      .let { it.getBodyPart(0).content as MimeMultipart }
+      .let { it.getBodyPart(0).content as String }
+      .assert
+      .contains("Value of `testVar` : <span>meow</span>")
+      .contains("<span>Was `testVar` equal to &quot;meow&quot; : </span><span>yes</span>")
+  }
+
+  companion object {
+    private val TEST_PROPERTIES = mapOf(
+      "testVar" to "test!!",
+      "testList" to listOf(
+        mapOf("name" to "Name #1"),
+        mapOf("name" to "Name #2"),
+        mapOf("name" to "Name #3"),
+      )
+    )
+
+    private val TEST_PROPERTIES_MEOW = mapOf(
+      "testVar" to "meow",
+      "testList" to listOf(
+        mapOf("name" to "Name #1"),
+        mapOf("name" to "Name #2"),
+        mapOf("name" to "Name #3"),
+      )
+    )
+  }
+}

build.gradle

@@ -57,6 +57,7 @@ project(':server-app').afterEvaluate {
         }
     }
 
+    apply from: "./gradle/email.gradle"
     apply from: "./gradle/webapp.gradle"
     apply from: "./gradle/docker.gradle"
     apply from: "./gradle/e2e.gradle"
@@ -66,6 +67,7 @@ project(':server-app').afterEvaluate {
     task packResources(type: Zip) {
         dependsOn "unpack"
         dependsOn "copyDist"
+        dependsOn "copyEmailResources"
         dependsOn "addVersionFile"
         from "${project.projectDir}/build/dependency"
         archiveFileName = "tolgee.jar"

email/.config/extractor.ts

@@ -109,8 +109,8 @@ export default async function extractor(
           code
         );
 
-        if (res.key) keys.push(res.key)
-        if (res.warning) warnings.push(res.warning)
+        if (res.key) keys.push(res.key);
+        if (res.warning) warnings.push(res.warning);
       }
 
       if (
@@ -158,8 +158,8 @@ export default async function extractor(
           code
         );
 
-        if (res.key) keys.push(res.key)
-        if (res.warning) warnings.push(res.warning)
+        if (res.key) keys.push(res.key);
+        if (res.warning) warnings.push(res.warning);
       }
     },
   });

email/.config/tolgeerc.json

@@ -1,12 +1,12 @@
 {
   "$schema": "https://docs.tolgee.io/cli-schema.json",
   "projectId": 1,
-  "format": "PROPERTIES_JAVA",
+  "format": "PROPERTIES_ICU",
   "patterns": ["./emails/**/*.ts?(x)", "./components/**/*.ts?(x)"],
   "extractor": "./.config/extractor.ts",
   "pull": {
-    "path": "./src/i18n",
-    "tags": ["email"]
+    "path": "./i18n",
+    "fileStructureTemplate": "messages_{snakeLanguageTag}.{extension}"
   },
   "push": {
     "tagNewKeys": ["email"]