feat: add ahfail formula v0.1.0

Formula/ahfail.rb

@@ -0,0 +1,48 @@
+class Ahfail < Formula
+  desc "Plays 'ah ah ah, you didn't say the magic word' on failed screen lock attempts"
+  homepage "https://gitea.weircon.dk/agw/gtk-ahfail"
+  url "https://gitea.weircon.dk/agw/gtk-ahfail/archive/v0.1.0.tar.gz"
+  sha256 "d693e27933007023cfcbc1882187084e186435261c78461353457d5e765a9045"
+  license "AGPL-3.0-only"
+
+  depends_on "meson" => :build
+  depends_on "ninja" => :build
+  depends_on "rust" => :build
+  depends_on "gtk+3"
+  depends_on "gstreamer"
+  depends_on "gst-plugins-base"
+  depends_on "gst-plugins-good"
+  depends_on :macos
+
+  def install
+    # Pass libdir so the PAM module has DEFAULT_PATH baked in correctly for
+    # both Intel (/usr/local/lib) and Apple Silicon (/opt/homebrew/lib).
+    system "meson", "setup", "builddir",
+           "--buildtype=release",
+           "-Dlibdir=#{lib}"
+    system "meson", "compile", "-C", "builddir"
+    (lib/"ahfail").install "builddir/libahfail_pam.so"
+    (lib/"ahfail").install "builddir/ahfail-display"
+  end
+
+  def caveats
+    pam_file = if MacOS.version >= :ventura
+      "/etc/pam.d/screensaverui"
+    else
+      "/etc/pam.d/screensaver"
+    end
+    <<~EOS
+      Add this line to #{pam_file} after the existing auth entries (requires sudo):
+
+        auth optional #{lib}/ahfail/libahfail_pam.so
+
+      After upgrading ahfail, re-run `brew install ahfail` and update the path
+      in #{pam_file} if it changed.
+    EOS
+  end
+
+  test do
+    assert_predicate lib/"ahfail/libahfail_pam.so", :exist?
+    assert_predicate lib/"ahfail/ahfail-display", :exist?
+  end
+end