feat(mail): implement sending mail

src/main/kotlin/apply/application/MailHistoryService.kt

@@ -1,7 +1,6 @@
 package apply.application
 
 import apply.application.mail.MailData
-import apply.domain.mail.MailHistory
 import apply.domain.mail.MailHistoryRepository
 import apply.domain.mail.getById
 import org.springframework.stereotype.Service
@@ -12,18 +11,6 @@ import javax.transaction.Transactional
 class MailHistoryService(
     private val mailHistoryRepository: MailHistoryRepository
 ) {
-    fun save(request: MailData) {
-        mailHistoryRepository.save(
-            MailHistory(
-                request.subject,
-                request.body,
-                request.sender,
-                request.recipients,
-                request.sentTime
-            )
-        )
-    }
-
     fun findAll(): List<MailData> {
         return mailHistoryRepository.findAll().map { MailData(it) }
     }

src/main/kotlin/apply/application/mail/MailData.kt

@@ -1,6 +1,7 @@
 package apply.application.mail
 
 import apply.domain.mail.MailHistory
+import org.springframework.core.io.ByteArrayResource
 import java.time.LocalDateTime
 import javax.validation.constraints.NotEmpty
 import javax.validation.constraints.NotNull
@@ -24,6 +25,8 @@ data class MailData(
     @field:NotNull
     var sentTime: LocalDateTime = LocalDateTime.now(),
 
+    var attachments: Map<String, ByteArrayResource> = emptyMap(),
+
     @field:NotNull
     var id: Long = 0L
 ) {
@@ -33,6 +36,6 @@ data class MailData(
         mailHistory.sender,
         mailHistory.recipients,
         mailHistory.sentTime,
-        mailHistory.id
+        id = mailHistory.id
     )
 }

src/main/kotlin/apply/application/mail/MailSender.kt

@@ -1,5 +1,9 @@
 package apply.application.mail
 
+import org.springframework.core.io.ByteArrayResource
+
 interface MailSender {
     fun send(toAddress: String, subject: String, body: String)
+
+    fun sendBcc(toAddresses: List<String>, subject: String, body: String, attachments: Map<String, ByteArrayResource>)
 }

src/main/kotlin/apply/application/mail/MailService.kt

@@ -2,24 +2,32 @@ package apply.application.mail
 
 import apply.application.ApplicationProperties
 import apply.domain.applicationform.ApplicationFormSubmittedEvent
+import apply.domain.mail.MailHistory
+import apply.domain.mail.MailHistoryRepository
 import apply.domain.recruitment.RecruitmentRepository
 import apply.domain.recruitment.getById
 import apply.domain.user.PasswordResetEvent
 import apply.domain.user.UserRepository
 import apply.domain.user.getById
+import org.springframework.boot.autoconfigure.mail.MailProperties
+import org.springframework.core.io.ByteArrayResource
 import org.springframework.scheduling.annotation.Async
 import org.springframework.stereotype.Service
 import org.springframework.transaction.event.TransactionalEventListener
 import org.thymeleaf.context.Context
 import org.thymeleaf.spring5.ISpringTemplateEngine
 
+private const val MAIL_SENDING_UNIT: Int = 50
+
 @Service
 class MailService(
     private val userRepository: UserRepository,
     private val recruitmentRepository: RecruitmentRepository,
+    private val mailHistoryRepository: MailHistoryRepository,
     private val applicationProperties: ApplicationProperties,
     private val templateEngine: ISpringTemplateEngine,
-    private val mailSender: MailSender
+    private val mailSender: MailSender,
+    private val mailProperties: MailProperties
 ) {
     @Async
     @TransactionalEventListener
@@ -78,4 +86,37 @@ class MailService(
             templateEngine.process("mail/email-authentication.html", context)
         )
     }
+
+    @Async
+    fun sendMailsByBcc(request: MailData, files: Map<String, ByteArrayResource>) {
+        val context = Context().apply {
+            setVariables(
+                mapOf(
+                    "content" to request.body,
+                    "url" to applicationProperties.url
+                )
+            )
+        }
+        val body = templateEngine.process("mail/common", context)
+        val recipients = request.recipients + mailProperties.username
+
+        // TODO: 성공과 실패를 분리하여 히스토리 관리
+        val succeeded = mutableListOf<String>()
+        val failed = mutableListOf<String>()
+        for (addresses in recipients.chunked(MAIL_SENDING_UNIT)) {
+            runCatching { mailSender.sendBcc(addresses, request.subject, body, files) }
+                .onSuccess { succeeded.addAll(addresses) }
+                .onFailure { failed.addAll(addresses) }
+        }
+
+        mailHistoryRepository.save(
+            MailHistory(
+                request.subject,
+                request.body,
+                request.sender,
+                request.recipients,
+                request.sentTime
+            )
+        )
+    }
 }

src/main/kotlin/apply/infra/mail/AwsMailSender.kt

@@ -10,9 +10,26 @@ import com.amazonaws.services.simpleemail.model.Body
 import com.amazonaws.services.simpleemail.model.Content
 import com.amazonaws.services.simpleemail.model.Destination
 import com.amazonaws.services.simpleemail.model.Message
+import com.amazonaws.services.simpleemail.model.RawMessage
 import com.amazonaws.services.simpleemail.model.SendEmailRequest
+import com.amazonaws.services.simpleemail.model.SendRawEmailRequest
 import org.springframework.boot.autoconfigure.mail.MailProperties
+import org.springframework.core.io.ByteArrayResource
 import org.springframework.stereotype.Component
+import support.infra.RateLimiter
+import java.io.ByteArrayOutputStream
+import java.nio.ByteBuffer
+import java.util.Properties
+import javax.activation.DataHandler
+import javax.activation.DataSource
+import javax.activation.MimetypesFileTypeMap
+import javax.mail.Message.RecipientType
+import javax.mail.Session
+import javax.mail.internet.InternetAddress
+import javax.mail.internet.MimeBodyPart
+import javax.mail.internet.MimeMessage
+import javax.mail.internet.MimeMultipart
+import javax.mail.util.ByteArrayDataSource
 
 @Component
 class AwsMailSender(
@@ -32,7 +49,10 @@ class AwsMailSender(
         .withRegion(Regions.AP_NORTHEAST_2)
         .build()
 
+    private val rateLimiter = RateLimiter(14)
+
     override fun send(toAddress: String, subject: String, body: String) {
+        rateLimiter.acquire()
         val request = SendEmailRequest()
             .withSource(mailProperties.username)
             .withDestination(Destination().withToAddresses(toAddress))
@@ -44,7 +64,100 @@ class AwsMailSender(
         client.sendEmail(request)
     }
 
+    override fun sendBcc(
+        toAddresses: List<String>,
+        subject: String,
+        body: String,
+        attachments: Map<String, ByteArrayResource>
+    ) {
+        rateLimiter.acquire()
+        val multipartMimeMessage = MultipartMimeMessage(
+            subject = subject,
+            userName = mailProperties.username,
+            recipient = toAddresses,
+            body = body,
+            files = attachments
+        )
+        val rawEmailRequest = multipartMimeMessage.getRawEmailRequest()
+        // TODO: MessageRejectedException, AmazonSimpleEmailServiceException 처리
+        client.sendRawEmail(rawEmailRequest)
+    }
+
     private fun createContent(data: String): Content {
-        return Content(data).withCharset("UTF-8")
+        return Content(data).withCharset(Charsets.UTF_8.name())
+    }
+}
+
+private class MultipartMimeMessage(
+    val message: MimeMessage = MimeMessage(Session.getDefaultInstance(Properties()))
+) {
+    constructor(
+        subject: String,
+        userName: String,
+        recipient: List<String>,
+        body: String,
+        files: Map<String, ByteArrayResource>
+    ) : this() {
+        val mimeMultipart = MimeMultipart("mixed")
+        setSubject(subject)
+        setFrom(userName)
+        setRecipient(recipient)
+        addBody(body, mimeMultipart)
+        addAttachment(files, mimeMultipart)
+    }
+
+    fun setSubject(subject: String) {
+        message.setSubject(subject, Charsets.UTF_8.name())
+    }
+
+    fun setFrom(userName: String) {
+        message.setFrom(InternetAddress(userName))
+    }
+
+    fun setRecipient(recipient: List<String>) {
+        message.setRecipients(
+            RecipientType.BCC,
+            recipient.map { InternetAddress(it) }.toTypedArray()
+        )
+    }
+
+    fun addBody(body: String, mimeMixedPart: MimeMultipart) {
+        val messageBody = MimeMultipart("alternative")
+        val wrap = MimeBodyPart()
+        val htmlPart = MimeBodyPart()
+        htmlPart.setContent(body, "text/html; charset=UTF-8")
+        messageBody.addBodyPart(htmlPart)
+        wrap.setContent(messageBody)
+        message.setContent(mimeMixedPart)
+        mimeMixedPart.addBodyPart(wrap)
+    }
+
+    fun addAttachment(files: Map<String, ByteArrayResource>, mimeMixedPart: MimeMultipart) {
+        for ((fileName, fileData) in files) {
+            val bodyPart = MimeBodyPart()
+            val fds: DataSource = ByteArrayDataSource(
+                fileData.byteArray,
+                findMimeContentTypeByFileName(fileName)
+            )
+            bodyPart.dataHandler = DataHandler(fds)
+            bodyPart.fileName = fileName
+            mimeMixedPart.addBodyPart(bodyPart)
+        }
+    }
+
+    fun findMimeContentTypeByFileName(fileName: String): String {
+        return MimetypesFileTypeMap().getContentType(fileName) ?: throw IllegalArgumentException("잘못된 확장자입니다.")
+    }
+
+    fun getRawEmailRequest(): SendRawEmailRequest {
+        val rawMessage = createRawMessage(message)
+        return SendRawEmailRequest(rawMessage)
+    }
+
+    fun createRawMessage(message: MimeMessage): RawMessage {
+        ByteArrayOutputStream().use { outputStream ->
+            message.writeTo(outputStream)
+            return RawMessage(ByteBuffer.wrap(outputStream.toByteArray()))
+        }
     }
 }

src/main/kotlin/apply/infra/mail/SimpleMailSender.kt

@@ -2,6 +2,7 @@ package apply.infra.mail
 
 import apply.application.mail.MailSender
 import org.springframework.boot.autoconfigure.mail.MailProperties
+import org.springframework.core.io.ByteArrayResource
 import org.springframework.mail.javamail.JavaMailSender
 import org.springframework.mail.javamail.MimeMessageHelper
 
@@ -19,4 +20,23 @@ class SimpleMailSender(
         }
         mailSender.send(message)
     }
+
+    override fun sendBcc(
+        toAddresses: List<String>,
+        subject: String,
+        body: String,
+        attachments: Map<String, ByteArrayResource>
+    ) {
+        val message = mailSender.createMimeMessage()
+        val mimeMessageHelper = MimeMessageHelper(message, true).apply {
+            setFrom(mailProperties.username)
+            setBcc(toAddresses.toTypedArray())
+            setSubject(subject)
+            setText(body, true)
+        }
+        attachments.forEach { (fileName, data) ->
+            mimeMessageHelper.addAttachment(fileName, data)
+        }
+        mailSender.send(message)
+    }
 }

src/main/kotlin/apply/ui/admin/evaluation/EvaluationForm.kt

@@ -89,7 +89,6 @@ class EvaluationForm() : BindingIdentityFormLayout<EvaluationData>(EvaluationDat
             result?.beforeEvaluation = beforeEvaluation.value
         }
         return result?.apply {
-            recruitment
             evaluationItems = items
         }
     }

src/main/kotlin/apply/ui/admin/mail/MailForm.kt

@@ -17,7 +17,9 @@ import com.vaadin.flow.component.upload.Upload
 import com.vaadin.flow.component.upload.receivers.MultiFileMemoryBuffer
 import com.vaadin.flow.data.renderer.ComponentRenderer
 import com.vaadin.flow.data.renderer.Renderer
+import elemental.json.JsonObject
 import org.springframework.boot.autoconfigure.mail.MailProperties
+import org.springframework.core.io.ByteArrayResource
 import support.views.BindingFormLayout
 import support.views.NO_NAME
 import support.views.addSortableColumn
@@ -34,20 +36,22 @@ class MailForm(
     private val mailProperties: MailProperties
 ) : BindingFormLayout<MailData>(MailData::class) {
     private val subject: TextField = TextField("제목").apply { setWidthFull() }
+    private val sender: TextField = createSender()
     private val body: TextArea = createBody()
     private val mailTargets: MutableSet<MailTargetResponse> = mutableSetOf()
+    private val uploadFile: MutableMap<String, ByteArrayResource> = mutableMapOf()
     private val mailTargetsGrid: Grid<MailTargetResponse> = createMailTargetsGrid(mailTargets)
     private val recipientFilter: Component = createRecipientFilter()
-    private val fileUpload: Component = createFileUpload()
+    private val fileUpload: Upload = createFileUpload()
 
     init {
-        add(subject, createSender(), recipientFilter, mailTargetsGrid, body, fileUpload)
+        add(subject, sender, recipientFilter, mailTargetsGrid, body, fileUpload)
         setResponsiveSteps(ResponsiveStep("0", 1))
         drawRequired()
         refreshGridFooter()
     }
 
-    private fun createSender(): Component {
+    private fun createSender(): TextField {
         return TextField("보낸사람").apply {
             value = mailProperties.username
             isReadOnly = true
@@ -103,15 +107,17 @@ class MailForm(
     }
 
     private fun createFileUpload(): Upload {
-        return createUpload("파일첨부", MultiFileMemoryBuffer()) {
-            // TODO: 추후 업로드 된 파일을 메일로 첨부하는 로직이 추가되어야 함
-            // (uploadFiles 같은 필드를 두고 mail을 보내는 기능에 포함시키면 될 것 같음)
-            // it.files.forEach { fileName ->
-            //     val fileData = it.getFileData(fileName)
-            //     val inputStream = it.getInputStream(fileName)
-            //     val readBytes = inputStream.readBytes()
-            // }
+        val upload = createUpload("파일첨부", MultiFileMemoryBuffer()) {
+            it.files.forEach { fileName ->
+                val byteArray = it.getInputStream(fileName).readBytes()
+                uploadFile[fileName] = ByteArrayResource(byteArray)
+            }
         }
+        upload.element.addEventListener("file-remove") { event ->
+            val eventData: JsonObject = event.eventData
+            uploadFile.remove(eventData.getString("event.detail.file.name"))
+        }.addEventData("event.detail.file.name")
+        return upload
     }
 
     private fun createRemoveButton(): Renderer<MailTargetResponse> {
@@ -123,8 +129,12 @@ class MailForm(
     }
 
     override fun bindOrNull(): MailData? {
+        if (mailTargets.isEmpty()) {
+            return null
+        }
         return bindDefaultOrNull()?.apply {
             recipients = mailTargets.map { it.email }.toList()
+            attachments = uploadFile
         }
     }