first commit

discord-ipc.rkt

@@ -0,0 +1,67 @@
+#lang racket/base
+(require racket/unix-socket
+         json
+         racket/list
+         racket/os)
+
+(provide connect-discord update-presence)
+
+(define ipc-out #f)
+
+(define (get-socket-path)
+  (define base-dirs
+    (list (getenv "XDG_RUNTIME_DIR")
+          (getenv "TMPDIR")
+          "/tmp"
+          (build-path "/run/user" (number->string (getpid)))))
+
+  (for/first ([dir base-dirs]
+              #:when dir
+              [i (in-range 10)]
+              #:do [(define p (build-path dir (format "discord-ipc-~a" i)))]
+              #:when (file-exists? p))
+    p))
+
+(define (write-packet opcode payload)
+  (when ipc-out
+    (define json-bytes (string->bytes/utf-8 (jsexpr->string payload)))
+    (define len (bytes-length json-bytes))
+
+    (write-bytes (integer->integer-bytes opcode 4 #f #f) ipc-out) ; Opcode
+    (write-bytes (integer->integer-bytes len 4 #f #f) ipc-out)    ; Length
+    (write-bytes json-bytes ipc-out)
+    (flush-output ipc-out)))
+
+(define (connect-discord client-id)
+  (define path (get-socket-path))
+  (if path
+      (with-handlers ([exn:fail? (lambda (e) (printf "Discord connection failed.\n"))])
+        (define-values (in out) (unix-socket-connect path))
+        (set! ipc-out out)
+        (write-packet 0 (hash 'v 1 'client_id client-id))
+        (printf "Connected to Discord at ~a\n" path))
+      (printf "Discord not found.\n")))
+
+(define (update-presence details state
+                         #:start [start-timestamp #f]
+                         #:small-text [small-text #f])
+
+  (define activity
+    (hash 'details details
+          'state state
+          'assets (hash
+                   'large_image "racket-logo-ezgif_com-svg-to-png-converter"
+                   'large_text "DrRacket"
+
+                   'small_image (if small-text "lambda" #f)
+                   'small_text small-text)
+
+          'timestamps (if start-timestamp
+                          (hash 'start start-timestamp)
+                          #f)))
+
+  (write-packet 1
+                (hash 'cmd "SET_ACTIVITY"
+                      'nonce (number->string (current-milliseconds))
+                      'args (hash 'pid (getpid)
+                                  'activity activity))))