mob: add optional speech support

This ports espeak-ng speech integration from the upstream repositories
nix package.

pkgs/applications/misc/mob/default.nix

@@ -1,9 +1,15 @@
-{ lib, buildGoPackage, fetchFromGitHub}:
+{ lib
+, buildGoPackage
+, fetchFromGitHub
+
+, withSpeech ? true
+, makeWrapper
+, espeak-ng
+}:
 
 buildGoPackage rec {
   pname = "mob";
   version = "2.1.0";
-  goPackagePath = "github.com/remotemobprogramming/mob";
 
   src = fetchFromGitHub {
     rev = "v${version}";
@@ -12,11 +18,22 @@ buildGoPackage rec {
     sha256 = "sha256-K8ID8cetzCaMc/PVRNMyIhrshtEUiD6U/jI4e0TcOO4=";
   };
 
+  nativeBuildInputs = [
+    makeWrapper
+  ];
+
+  goPackagePath = "github.com/remotemobprogramming/mob";
+
+  preFixup = lib.optionalString withSpeech ''
+    wrapProgram $out/bin/mob \
+      --set MOB_VOICE_COMMAND "${lib.getBin espeak-ng}/bin/espeak"
+  '';
+
   meta = with lib; {
-    description = "Tool for swift git handover";
+    description = "Tool for smooth git handover";
     homepage = "https://github.com/remotemobprogramming/mob";
     license = licenses.mit;
-    maintainers = [ maintainers.ericdallo ];
+    maintainers = with maintainers; [ ericdallo ];
     platforms = platforms.linux ++ platforms.darwin;
   };
 }