feat: make a complete nix module

assets/pkg/nix/lidm.nix

@@ -1,4 +1,4 @@
-{ config, pkgs, ...}: pkgs.stdenv.mkDerivation rec {
+{ config, pkgs, lib, ...}: pkgs.stdenv.mkDerivation rec {
     pname = "lidm";
     version = config.version;
     src = config.src;
@@ -12,13 +12,11 @@
     makeFlags = [
         "DESTDIR=$(out)"
         "PREFIX="
-    ];
-
-    installPhase = ''
-        make install DESTDIR=$out PREFIX=
-        mkdir -p $out/etc/systemd/system/
-        make install-service-systemd DESTDIR=$out PREFIX=
-    '';
+    ]
+    ++ lib.optional (config.xsessions != null)
+        "CPPFLAGS+=-DSESSIONS_XSESSIONS=\\\"${config.xsessions}\\\""
+    ++ lib.optional (config.wayland-sessions != null)
+        "CPPFLAGS+=-DSESSIONS_WAYLAND=\\\"${config.wayland-sessions}\\\"";
 
     fixupPhase = ''
         rm -rf $out/etc

assets/pkg/nix/module.nix

@@ -0,0 +1,47 @@
+{ config, lib, pkgs, ... }:
+
+let
+    dmcfg = config.services.displayManager;
+    desktops = dmcfg.sessionData.desktops;
+
+    version = "1.2.1";
+    lidmPkg = pkgs.callPackage ./lidm.nix {
+        inherit pkgs;
+        config = {
+            inherit version lib;
+            src = pkgs.fetchFromGitHub {
+              owner = "javalsai";
+              repo = "lidm";
+              rev = "v${version}";
+              sha256 = "sha256-3CgUI8PUs4c1bfBrykPw87SSa4lzrh4E4Hug7cGRKFk=";
+            };
+
+            xsessions = "${desktops}/share/xsessions";
+            wayland-sessions = "${desktops}/share/wayland-sessions";
+        };
+    };
+in
+{
+    config = {
+        services.displayManager.defaultSession = "lidm";
+
+        systemd.services.lidm = {
+            description = "TUI display manager";
+            aliases = [ "display-manager.service" ];
+            after = [
+                "systemd-user-sessions.service"
+                "plymouth-quit-wait.service"
+            ];
+            serviceConfig = {
+                Type = "idle";
+                ExecStart = "${lidmPkg}/bin/lidm 7";
+                StandardInput = "tty";
+                StandardOutput = "tty";
+                StandardError = "tty";
+                TTYPath = "/dev/tty7";
+                TTYReset = "yes";
+                TTYVHangup = "yes";
+            };
+        };
+    };
+}

assets/services/systemd.service

@@ -5,9 +5,9 @@ After=systemd-user-sessions.service plymouth-quit-wait.service
 [Service]
 Type=idle
 ExecStart=/usr/bin/lidm 7
-StandardError=journal
 StandardInput=tty
 StandardOutput=tty
+StandardError=tty
 TTYPath=/dev/tty7
 TTYReset=yes
 TTYVHangup=yes