Refactor CLI and Twilio modules; add helper tests and comments

src/twilio/webhook.ts

@@ -0,0 +1,94 @@
+import express, { type Request, type Response } from "express";
+import bodyParser from "body-parser";
+import chalk from "chalk";
+import type { Server } from "http";
+
+import { success, logVerbose, danger } from "../globals.js";
+import { readEnv } from "../env.js";
+import { createClient } from "./client.js";
+import { normalizePath } from "../utils.js";
+import { getReplyFromConfig } from "../auto-reply/reply.js";
+import { sendTypingIndicator } from "./typing.js";
+import { logTwilioSendError } from "./utils.js";
+import { defaultRuntime, type RuntimeEnv } from "../runtime.js";
+
+/** Start the inbound webhook HTTP server and wire optional auto-replies. */
+export async function startWebhook(
+  port: number,
+  path = "/webhook/whatsapp",
+  autoReply: string | undefined,
+  verbose: boolean,
+  runtime: RuntimeEnv = defaultRuntime,
+): Promise<Server> {
+  const normalizedPath = normalizePath(path);
+  const env = readEnv(runtime);
+  const app = express();
+
+  // Twilio sends application/x-www-form-urlencoded payloads.
+  app.use(bodyParser.urlencoded({ extended: false }));
+  app.use((req, _res, next) => {
+    runtime.log(chalk.gray(`REQ ${req.method} ${req.url}`));
+    next();
+  });
+
+  app.post(normalizedPath, async (req: Request, res: Response) => {
+    const { From, To, Body, MessageSid } = req.body ?? {};
+    runtime.log(`
+[INBOUND] ${From ?? "unknown"} -> ${To ?? "unknown"} (${MessageSid ?? "no-sid"})`);
+    if (verbose) runtime.log(chalk.gray(`Body: ${Body ?? ""}`));
+
+    const client = createClient(env);
+    let replyText = autoReply;
+    if (!replyText) {
+      replyText = await getReplyFromConfig(
+        { Body, From, To, MessageSid },
+        {
+          onReplyStart: () => sendTypingIndicator(client, MessageSid, runtime),
+        },
+      );
+    }
+
+    if (replyText) {
+      try {
+        await client.messages.create({ from: To, to: From, body: replyText });
+        if (verbose) runtime.log(success(`↩️  Auto-replied to ${From}`));
+      } catch (err) {
+        logTwilioSendError(err, From ?? undefined, runtime);
+      }
+    }
+
+    // Respond 200 OK to Twilio.
+    res.type("text/xml").send("<Response></Response>");
+  });
+
+  app.use((_req, res) => {
+    if (verbose) runtime.log(chalk.yellow(`404 ${_req.method} ${_req.url}`));
+    res.status(404).send("warelay webhook: not found");
+  });
+
+  // Start server and resolve once listening; reject on bind error.
+  return await new Promise((resolve, reject) => {
+    const server = app.listen(port);
+
+    const onListening = () => {
+      cleanup();
+      runtime.log(
+        `📥 Webhook listening on http://localhost:${port}${normalizedPath}`,
+      );
+      resolve(server);
+    };
+
+    const onError = (err: NodeJS.ErrnoException) => {
+      cleanup();
+      reject(err);
+    };
+
+    const cleanup = () => {
+      server.off("listening", onListening);
+      server.off("error", onError);
+    };
+
+    server.once("listening", onListening);
+    server.once("error", onError);
+  });
+}