wa-cli: WhatsApp from the terminal, with a neomutt Maildir bridgeHEADmain

1 files changed, 83 insertions, 0 deletions

diff --git a/src/rpc.js b/src/rpc.js
new file mode 100644
index 0000000..d8502e9
--- /dev/null
+++ b/src/rpc.js
@@ -0,0 +1,83 @@
+// CLI <-> daemon protocol: one JSON object per line over a Unix socket.
+//
+//   -> {"id":1,"method":"messages.list","params":{...}}
+//   <- {"id":1,"result":...}                       normal reply
+//   <- {"id":1,"error":{"code":"EAUTH","message":"..."}}
+//   <- {"id":1,"event":{...}}                      stream methods (events.watch), until closed
+//
+// Simple on purpose: any language can speak it (e.g. a Python bridge with
+// socket.AF_UNIX) without going through the `wa` binary.
+
+import net from 'node:net';
+
+export class WaError extends Error {
+    constructor(code, message, data) {
+        super(message);
+        this.code = code;
+        if (data !== undefined) this.data = data;
+    }
+}
+
+export function onLines(socket, fn) {
+    let buf = '';
+    socket.setEncoding('utf8');
+    socket.on('data', (chunk) => {
+        buf += chunk;
+        let i;
+        while ((i = buf.indexOf('\n')) >= 0) {
+            const line = buf.slice(0, i);
+            buf = buf.slice(i + 1);
+            if (line.trim()) fn(line);
+        }
+    });
+}
+
+export function send(socket, obj) {
+    if (!socket.destroyed && socket.writable) socket.write(JSON.stringify(obj) + '\n');
+}
+
+// Calls a method. With onEvent(event, close), it keeps listening for events until
+// either side closes.
+export function call(socketPath, method, params = {}, { onEvent } = {}) {
+    return new Promise((resolve, reject) => {
+        const sock = net.createConnection(socketPath);
+        let settled = false;
+        const done = (fn, v) => {
+            if (settled) return;
+            settled = true;
+            fn(v);
+        };
+        sock.on('connect', () => send(sock, { id: 1, method, params }));
+        onLines(sock, (line) => {
+            let msg;
+            try {
+                msg = JSON.parse(line);
+            } catch {
+                return done(reject, new WaError('EINTERNAL', `invalid reply from the daemon: ${line.slice(0, 200)}`));
+            }
+            if (msg.event !== undefined) {
+                onEvent?.(msg.event, () => sock.end());
+            } else if (msg.error) {
+                done(reject, new WaError(msg.error.code, msg.error.message, msg.error.data));
+                sock.end();
+            } else {
+                done(resolve, msg.result);
+                sock.end();
+            }
+        });
+        sock.on('error', (e) => done(reject, e));
+        sock.on('close', () => done(onEvent ? resolve : reject,
+            onEvent ? undefined : new WaError('EDAEMON', 'the daemon closed the connection')));
+    });
+}
+
+export function ping(socketPath) {
+    return new Promise((resolve) => {
+        const sock = net.createConnection(socketPath);
+        sock.on('connect', () => {
+            sock.destroy();
+            resolve(true);
+        });
+        sock.on('error', () => resolve(false));
+    });
+}