feat: add JSON-RPC client with connection check command

2026-06-09 19:31:03 -04:00
parent 9498cbb32b
commit f71a05de79
3 changed files with 143 additions and 0 deletions
@@ -0,0 +1,92 @@
+;;; noise-rpc.el --- JSON-RPC client for signal-cli -*- lexical-binding: t; -*-
+
+;;; Commentary:
+
+;; Communicates with a signal-cli daemon over HTTP JSON-RPC.
+
+;;; Code:
+
+(require 'json)
+(require 'url)
+(require 'cl-lib)
+
+(defvar noise-signal-cli-address)
+
+(define-error 'noise-rpc-error "signal-cli JSON-RPC error")
+
+(defvar noise-rpc--next-id 0
+  "Monotonically increasing request ID for JSON-RPC.")
+
+(defun noise-rpc--plist-to-alist (plist)
+  "Convert PLIST to an alist for json-encode.
+Strips the leading colon from keyword symbols."
+  (let (alist)
+    (while plist
+      (let ((key-name (symbol-name (car plist))))
+        (when (string-prefix-p ":" key-name)
+          (setq key-name (substring key-name 1)))
+        (push (cons key-name (cadr plist)) alist))
+      (setq plist (cddr plist)))
+    (nreverse alist)))
+
+(defun noise-rpc--build-request (method &rest params)
+  "Build a JSON-RPC 2.0 request string for METHOD with PARAMS.
+PARAMS is a plist of :key value pairs."
+  (let* ((id (cl-incf noise-rpc--next-id))
+         (req `((jsonrpc . "2.0")
+                (method . ,method)
+                (id . ,id))))
+    (when params
+      (setq req (append req `((params . ,(noise-rpc--plist-to-alist params))))))
+    (json-encode req)))
+
+(defun noise-rpc-call (method &rest params)
+  "Call signal-cli JSON-RPC METHOD with PARAMS.
+PARAMS is a plist of :key value pairs.
+Returns the parsed `result` field on success.
+Signals `noise-rpc-error` on failure or connection error."
+  (let* ((url-request-method "POST")
+         (url-request-extra-headers
+          '(("Content-Type" . "application/json")))
+         (url-request-data (apply #'noise-rpc--build-request method params))
+         (url (concat noise-signal-cli-address "/api/v1/rpc"))
+         (url-show-status nil)
+         (buf (condition-case nil
+                  (url-retrieve-synchronously url t)
+                (error (signal 'noise-rpc-error
+                               (list (format "Could not connect to signal-cli at %s. Is signal-cli daemon running?"
+                                             noise-signal-cli-address)))))))
+    (if (not buf)
+        (signal 'noise-rpc-error (list (format "No response from signal-cli at %s" noise-signal-cli-address)))
+      (unwind-protect
+          (with-current-buffer buf
+            (goto-char (point-min))
+            (re-search-forward "\n\n" nil t)
+            (let* ((body (buffer-substring (point) (point-max)))
+                   (result (noise-rpc--parse-response body)))
+              result))
+        (kill-buffer buf)))))
+
+(defun noise-rpc--parse-response (raw)
+  "Parse RAW JSON-RPC response body.
+Returns the `result` on success.
+Signals `noise-rpc-error` on JSON-RPC error or malformed response."
+  (let* ((parsed (condition-case nil
+                     (json-parse-string raw)
+                   (error (signal 'noise-rpc-error (list "signal-cli returned invalid JSON response"))))))
+    (if-let ((err (gethash "error" parsed)))
+        (signal 'noise-rpc-error
+                (list (format "signal-cli error %s: %s"
+                              (gethash "code" err)
+                              (gethash "message" err))))
+      (gethash "result" parsed))))
+
+(defun noise-rpc-check ()
+  "Check connectivity to signal-cli.
+Returns the version string on success.
+Signals `noise-rpc-error` on failure."
+  (let ((result (noise-rpc-call "getVersion")))
+    (gethash "version" result)))
+
+(provide 'noise-rpc)
+;;; noise-rpc.el ends here