# cua-compositor: a minimal headless wlroots compositor that cua-driver spawns
# as its nested session (CUA_WAYLAND_NEST_COMPOSITOR=cua-compositor) to perform
# focus-free keyboard injection and multi-cursor pointer injection via a unix
# control socket. Built from wlroots' own upstream tinywl example (pinned to the
# same wlroots_0_19 the patch targets) transformed by cua_compositor_patch.py —
# so it tracks the exact wlroots API in nixpkgs and needs no vendored C.
{
  stdenv,
  lib,
  pkg-config,
  python3,
  wayland,
  wayland-scanner,
  wayland-protocols,
  wlroots_0_19,
  libxkbcommon,
  pixman,
}:

stdenv.mkDerivation {
  pname = "cua-compositor";
  version = "0.1.0";

  src = lib.cleanSource ./.;

  nativeBuildInputs = [
    pkg-config
    python3
    wayland-scanner
  ];
  buildInputs = [
    wayland
    wayland-protocols
    wlroots_0_19
    libxkbcommon
    pixman
  ];

  buildPhase = ''
    runHook preBuild
    cp ${wlroots_0_19.src}/tinywl/tinywl.c tinywl.c
    python3 cua_compositor_patch.py tinywl.c cua-compositor.c
    wp=${wayland-protocols}/share/wayland-protocols
    wayland-scanner server-header "$wp/stable/xdg-shell/xdg-shell.xml" xdg-shell-protocol.h
    wayland-scanner private-code  "$wp/stable/xdg-shell/xdg-shell.xml" xdg-shell-protocol.c
    $CC -DWLR_USE_UNSTABLE -I. cua-compositor.c xdg-shell-protocol.c -o cua-compositor \
      $(pkg-config --cflags --libs wlroots-0.19 wayland-server xkbcommon pixman-1)
    runHook postBuild
  '';

  installPhase = ''
    runHook preInstall
    install -Dm755 cua-compositor $out/bin/cua-compositor
    runHook postInstall
  '';

  meta = {
    description = "Headless wlroots compositor with focus-free + multi-cursor input injection for cua-driver";
    platforms = lib.platforms.linux;
    mainProgram = "cua-compositor";
  };
}