feat: use server-actions for authoring flow

This change actually makes the authoring flow work for
the most part by tying in emailing and more.

We have also done a number of quality of life updates to
simplify the codebase overall making it easier to continue
work on the refresh.

packages/email/transports/mailchannels.ts

@@ -0,0 +1,154 @@
+import { SentMessageInfo, Transport } from 'nodemailer';
+import type { Address } from 'nodemailer/lib/mailer';
+import type MailMessage from 'nodemailer/lib/mailer/mail-message';
+
+const VERSION = '1.0.0';
+
+type NodeMailerAddress = string | Address | Array<string | Address> | undefined;
+
+interface MailChannelsAddress {
+  email: string;
+  name?: string;
+}
+
+interface MailChannelsTransportOptions {
+  apiKey: string;
+  endpoint: string;
+}
+
+/**
+ * Transport for sending email through MailChannels via Cloudflare Workers.
+ *
+ * Optionally allows specifying a custom endpoint and API key so you can setup a worker
+ * to proxy requests to MailChannels with added security.
+ *
+ * @see https://blog.cloudflare.com/sending-email-from-workers-with-mailchannels/
+ */
+export class MailChannelsTransport implements Transport<SentMessageInfo> {
+  public name = 'CloudflareMailTransport';
+  public version = VERSION;
+
+  private _options: MailChannelsTransportOptions;
+
+  public static makeTransport(options: Partial<MailChannelsTransportOptions>) {
+    return new MailChannelsTransport(options);
+  }
+
+  constructor(options: Partial<MailChannelsTransportOptions>) {
+    const { apiKey = '', endpoint = 'https://api.mailchannels.net/tx/v1/send' } = options;
+
+    this._options = {
+      apiKey,
+      endpoint,
+    };
+  }
+
+  public send(mail: MailMessage, callback: (_err: Error | null, _info: SentMessageInfo) => void) {
+    if (!mail.data.to || !mail.data.from) {
+      return callback(new Error('Missing required fields "to" or "from"'), null);
+    }
+
+    const mailTo = this.toMailChannelsAddresses(mail.data.to);
+    const mailCc = this.toMailChannelsAddresses(mail.data.cc);
+    const mailBcc = this.toMailChannelsAddresses(mail.data.bcc);
+
+    const from: MailChannelsAddress =
+      typeof mail.data.from === 'string'
+        ? { email: mail.data.from }
+        : {
+            email: mail.data.from?.address,
+            name: mail.data.from?.name,
+          };
+
+    const requestHeaders: Record<string, string> = {
+      'Content-Type': 'application/json',
+    };
+
+    if (this._options.apiKey) {
+      requestHeaders['X-Auth-Token'] = this._options.apiKey;
+    }
+
+    fetch(this._options.endpoint, {
+      method: 'POST',
+      headers: requestHeaders,
+      body: JSON.stringify({
+        from: from,
+        subject: mail.data.subject,
+        personalizations: [
+          {
+            to: mailTo,
+            cc: mailCc.length > 0 ? mailCc : undefined,
+            bcc: mailBcc.length > 0 ? mailBcc : undefined,
+            dkim_domain: process.env.NEXT_PRIVATE_MAILCHANNELS_DKIM_DOMAIN || undefined,
+            dkim_selector: process.env.NEXT_PRIVATE_MAILCHANNELS_DKIM_SELECTOR || undefined,
+            dkim_private_key: process.env.NEXT_PRIVATE_MAILCHANNELS_DKIM_PRIVATE_KEY || undefined,
+          },
+        ],
+        content: [
+          {
+            type: 'text/plain',
+            value: mail.data.text?.toString('utf-8') ?? '',
+          },
+          {
+            type: 'text/html',
+            value: mail.data.html?.toString('utf-8') ?? '',
+          },
+        ],
+      }),
+    })
+      .then((res) => {
+        if (res.status >= 200 && res.status <= 299) {
+          return callback(null, {
+            messageId: '',
+            envelope: {
+              from: mail.data.from,
+              to: mail.data.to,
+            },
+            accepted: mail.data.to,
+            rejected: [],
+            pending: [],
+          });
+        }
+
+        res.json().then((data) => {
+          return callback(new Error(`MailChannels error: ${data.message}`), null);
+        });
+      })
+      .catch((err) => {
+        return callback(err, null);
+      });
+  }
+
+  /**
+   * Converts a nodemailer address(s) to an array of MailChannel compatible address.
+   */
+  private toMailChannelsAddresses(address: NodeMailerAddress): Array<MailChannelsAddress> {
+    if (!address) {
+      return [];
+    }
+
+    if (typeof address === 'string') {
+      return [{ email: address }];
+    }
+
+    if (Array.isArray(address)) {
+      return address.map((address) => {
+        if (typeof address === 'string') {
+          return { email: address };
+        }
+
+        return {
+          email: address.address,
+          name: address.name,
+        };
+      });
+    }
+
+    return [
+      {
+        email: address.address,
+        name: address.name,
+      },
+    ];
+  }
+}