5 files changed, 243 insertions, 0 deletions
diff --git a/services/docker/mail-server/relay/aws/app.ts b/services/docker/mail-server/relay/aws/app.ts
new file mode 100644
index 0000000..e25c92c
--- /dev/null
+++ b/services/docker/mail-server/relay/aws/app.ts
@@ -0,0 +1,22 @@
+import { Hono } from "https://jsr.io/@hono/hono/4.7.9/src/hono.ts";
+import { AppBase } from "../app.ts";
+import { MailDeliverer } from "../mail.ts";
+import { AwsContext } from "./context.ts";
+import { AwsMailDeliverer } from "./deliver.ts";
+
+export class AwsRelayApp extends AppBase {
+  private readonly context = new AwsContext();
+  private readonly deliverer = new AwsMailDeliverer(this.context);
+
+  constructor() {
+    super();
+  }
+
+  protected override setupHono(_hono: Hono): Promise<void> {
+
+  }
+
+  protected override get outboundMailDeliverer(): MailDeliverer {
+    return this.deliverer;
+  }
+}
diff --git a/services/docker/mail-server/relay/aws/context.ts b/services/docker/mail-server/relay/aws/context.ts
new file mode 100644
index 0000000..65c8371
--- /dev/null
+++ b/services/docker/mail-server/relay/aws/context.ts
@@ -0,0 +1,41 @@
+import {
+  CopyObjectCommand,
+  DeleteObjectCommand,
+  S3Client,
+} from "@aws-sdk/client-s3";
+
+import { getConfig } from "../config.ts";
+
+export class AwsContext {
+  readonly region = "ap-southeast-1";
+
+  accessKeyId = getConfig().getValue("awsAccessKeyId");
+  secretAccessKey = getConfig().getValue("awsSecretAccessKey");
+
+  getCredentials() {
+    const { accessKeyId, secretAccessKey } = this;
+    return Promise.resolve({ accessKeyId, secretAccessKey });
+  }
+
+  readonly credentials = this.getCredentials.bind(this);
+}
+
+export async function s3MoveObject(
+  client: S3Client,
+  bucket: string,
+  path: string,
+  newPath: string,
+): Promise<void> {
+  const copyCommand = new CopyObjectCommand({
+    Bucket: bucket,
+    Key: newPath,
+    CopySource: path,
+  });
+  await client.send(copyCommand);
+
+  const deleteCommand = new DeleteObjectCommand({
+    Bucket: bucket,
+    Key: path,
+  });
+  await client.send(deleteCommand);
+}
diff --git a/services/docker/mail-server/relay/aws/deliver.ts b/services/docker/mail-server/relay/aws/deliver.ts
new file mode 100644
index 0000000..5982d56
--- /dev/null
+++ b/services/docker/mail-server/relay/aws/deliver.ts
@@ -0,0 +1,42 @@
+import { SendEmailCommand, SESv2Client } from "@aws-sdk/client-sesv2";
+
+import { AwsContext } from "./context.ts";
+import { Mail, MailDeliverer } from "../mail.ts";
+
+export class AwsMailDeliverer extends MailDeliverer {
+  private _ses;
+
+  constructor(readonly aws: AwsContext) {
+    super("aws");
+
+    const { region, credentials } = aws;
+
+    this._ses = new SESv2Client({ region, credentials });
+  }
+
+  protected override async doDeliver(mail: Mail): Promise<void> {
+    let awsMessageId: string | undefined;
+
+    try {
+      const sendCommand = new SendEmailCommand({
+        Content: {
+          Raw: { Data: mail.toUtf8Bytes() },
+        },
+      });
+
+      const res = await this._ses.send(sendCommand);
+      awsMessageId = res.MessageId;
+    } catch (cause) {
+      mail.throwDeliverError(
+        this,
+        "failed to call send-email api of aws.",
+        cause,
+      );
+    }
+
+    if (awsMessageId == null) {
+      mail.setDelivered(this, new Error("No message id is returned from aws."));
+    }
+    mail.awsMessageId = awsMessageId ?? null;
+  }
+}
diff --git a/services/docker/mail-server/relay/aws/retriever.ts b/services/docker/mail-server/relay/aws/retriever.ts
new file mode 100644
index 0000000..de577b0
--- /dev/null
+++ b/services/docker/mail-server/relay/aws/retriever.ts
@@ -0,0 +1,90 @@
+/// <reference types="npm:@types/node" />
+
+import {
+  GetObjectCommand,
+  ListObjectsV2Command,
+  S3Client,
+} from "@aws-sdk/client-s3";
+
+import { AwsContext, s3MoveObject } from "./context.ts";
+import { getLogger } from "../logger.ts";
+import { getConfig } from "../config.ts";
+import { Mail } from "../mail.ts";
+
+export class AwsMailRetriever {
+  readonly liveMailPrefix = "mail/live/";
+  readonly archiveMailPrefix = "mail/archive/";
+  readonly mailBucket = getConfig().getValue("awsMailBucket");
+
+  private readonly s3Client;
+
+  constructor(
+    aws: AwsContext,
+    private readonly callback: (mail: Mail) => Promise<void>,
+  ) {
+    const { region, credentials } = aws;
+    this.s3Client = new S3Client({ region, credentials });
+  }
+
+  async listLiveMails(): Promise<string[]> {
+    const listCommand = new ListObjectsV2Command({
+      Bucket: this.mailBucket,
+      Prefix: this.liveMailPrefix,
+    });
+    const res = await this.s3Client.send(listCommand);
+
+    if (res.Contents == null) {
+      getLogger().warn("Listing live mails in S3 returns null Content.");
+      return [];
+    }
+
+    const result: string[] = [];
+    for (const object of res.Contents) {
+      if (object.Key != null) {
+        // TODO: check prefix consistence here.
+        result.push(object.Key.slice(this.liveMailPrefix.length));
+      } else {
+        getLogger().warn(
+          "Listing live mails in S3 returns an object with no Key.",
+        );
+      }
+    }
+    return result;
+  }
+
+  async deliverS3MailObject(messageId: string) {
+    const mailPath = `${this.liveMailPrefix}${messageId}`;
+    const command = new GetObjectCommand({
+      Bucket: this.mailBucket,
+      Key: mailPath,
+    });
+    const res = await this.s3Client.send(command);
+
+    if (res.Body == null) {
+      // TODO: Better error.
+      throw new Error();
+    }
+
+    const rawMail = await res.Body.transformToString();
+    const mail = new Mail(rawMail);
+    mail.awsMessageId = messageId;
+    await this.callback(mail);
+
+    // TODO: Continue here.
+    await s3MoveObject(
+      this.s3Client,
+      this.mailBucket,
+      mailPath,
+      `${this.archiveMailPrefix}${
+        mail.simpleGetDateString("invalid-date")
+      }/${messageId}`,
+    );
+  }
+
+  async recycleLiveMails() {
+    const mails = await this.listLiveMails();
+    for (const messageId of mails) {
+      await this.deliverS3MailObject(messageId);
+    }
+  }
+}
diff --git a/services/docker/mail-server/relay/aws/service.ts b/services/docker/mail-server/relay/aws/service.ts
new file mode 100644
index 0000000..d0db7ae
--- /dev/null
+++ b/services/docker/mail-server/relay/aws/service.ts
@@ -0,0 +1,48 @@
+import { Mail } from "../mail.ts";
+import { AwsContext } from "./context.ts";
+import { AwsMailRetriever } from "./retriever.ts";
+
+export interface AwsServiceSetupOptions {
+  receiveCallback: (mail: Mail) => Promise<void>;
+}
+
+interface Setup {
+  receiveCallback: (mail: Mail) => Promise<void>;
+  retriever: AwsMailRetriever;
+  liveMailRecyclerAborter: AbortController;
+}
+
+export class AwsService implements Disposable {
+  private _setup: Setup | null = null;
+
+  constructor(private readonly aws: AwsContext) {}
+
+  setup(options: AwsServiceSetupOptions): Disposable {
+    if (this._setup != null) {
+      // TODO: Better error.
+      throw new Error("Aws service has already been set up.");
+    }
+    const { receiveCallback } = options;
+    const liveMailRecyclerAborter = new AbortController();
+    const retriever = new AwsMailRetriever(this.aws, receiveCallback);
+
+    Deno.cron("live-mail-recycler", "0 */6 * * *", {
+      signal: liveMailRecyclerAborter.signal,
+    }, () => {
+      retriever.recycleLiveMails();
+    });
+
+    this._setup = {
+      receiveCallback,
+      retriever,
+      liveMailRecyclerAborter,
+    };
+
+    return this;
+  }
+
+  [Symbol.dispose]() {
+    if (this._setup == null) return;
+    this._setup.liveMailRecyclerAborter.abort("Aws service is being disposed.");
+  }
+}