Add AWS SES backend to send email

crates/email/src/mailer.rs

@@ -0,0 +1,88 @@
+// Copyright 2022 The Matrix.org Foundation C.I.C.
+//
+// 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.
+
+use lettre::{
+    message::{Mailbox, MessageBuilder, MultiPart},
+    AsyncTransport, Message,
+};
+use mas_templates::{EmailVerificationContext, Templates};
+
+use crate::MailTransport;
+
+#[derive(Clone)]
+pub struct Mailer {
+    templates: Templates,
+    transport: MailTransport,
+    from: Mailbox,
+    reply_to: Mailbox,
+}
+
+impl Mailer {
+    pub fn new(
+        templates: &Templates,
+        transport: &MailTransport,
+        from: &Mailbox,
+        reply_to: &Mailbox,
+    ) -> Self {
+        Self {
+            templates: templates.clone(),
+            transport: transport.clone(),
+            from: from.clone(),
+            reply_to: reply_to.clone(),
+        }
+    }
+
+    fn base_message(&self) -> MessageBuilder {
+        Message::builder()
+            .from(self.from.clone())
+            .reply_to(self.reply_to.clone())
+    }
+
+    async fn prepare_verification_email(
+        &self,
+        to: Mailbox,
+        context: &EmailVerificationContext,
+    ) -> anyhow::Result<Message> {
+        let plain = self
+            .templates
+            .render_email_verification_txt(context)
+            .await?;
+
+        let html = self
+            .templates
+            .render_email_verification_html(context)
+            .await?;
+
+        let multipart = MultiPart::alternative_plain_html(plain, html);
+
+        let message = self
+            .base_message()
+            // TODO: template/localize this
+            .subject("Verify your email address")
+            .to(to)
+            .multipart(multipart)?;
+
+        Ok(message)
+    }
+
+    pub async fn send_verification_email(
+        &self,
+        to: Mailbox,
+        context: &EmailVerificationContext,
+    ) -> anyhow::Result<()> {
+        let message = self.prepare_verification_email(to, context).await?;
+        self.transport.send(message).await?;
+        Ok(())
+    }
+}