From baa96f47d832d3d0b6564b1eeebd7b5e7b2ad384 Mon Sep 17 00:00:00 2001
From: Diogo Xavier <diogoxavierpinto@gmail.com>
Date: Mon, 30 Aug 2021 19:15:10 +0100
Subject: [PATCH] Add NixOS support

---
 cmd/linux.go     | 16 +++++++++++
 cmd/linuxdb.yaml | 72 +++++++++++++++++++++++++++++++-----------------
 cmd/system.go    |  2 ++
 3 files changed, 64 insertions(+), 26 deletions(-)

diff --git a/cmd/linux.go b/cmd/linux.go
index 81dcd6fc0..8ef7836ac 100644
--- a/cmd/linux.go
+++ b/cmd/linux.go
@@ -71,6 +71,8 @@ const (
 	Crux
 	// RHEL distribution
 	RHEL
+	// NixOS distribution
+	NixOS
 )
 
 // DistroInfo contains all the information relating to a linux distribution
@@ -183,6 +185,8 @@ func parseOsRelease(osRelease string) *DistroInfo {
 		result.Distribution = EndeavourOS
 	case "crux":
 		result.Distribution = Crux
+	case "nixos":
+		result.Distribution = NixOS
 	default:
 		result.Distribution = Unknown
 	}
@@ -274,6 +278,18 @@ func PrtGetInstalled(packageName string) (bool, error) {
 	return exitCode == 0, nil
 }
 
+// NixEnvInstalled uses nix-env to see if a package is installed
+func NixEnvInstalled(packageName string) (bool, error) {
+	program := NewProgramHelper()
+	nixEnv := program.FindProgram("nix-env")
+	if nixEnv == nil {
+		return false, fmt.Errorf("cannot check dependencies: nix-env not found")
+	}
+	packageName = strings.ReplaceAll(packageName, "+", `\+`)
+	_, _, exitCode, _ := nixEnv.Run("-q", packageName)
+	return exitCode == 0, nil
+}
+
 // RequestSupportForDistribution promts the user to submit a request to support their
 // currently unsupported distribution
 func RequestSupportForDistribution(distroInfo *DistroInfo) error {
diff --git a/cmd/linuxdb.yaml b/cmd/linuxdb.yaml
index 04db56c5e..52f6a57cd 100644
--- a/cmd/linuxdb.yaml
+++ b/cmd/linuxdb.yaml
@@ -318,30 +318,50 @@ distributions:
           - name: webkit2gtk3-devel
             help: Please install with `sudo zypper in webkit2gtk3-devel` and try again
   opensuse-leap:
-      id: opensuse-leap
-      releases:
-        default:
-          version: default
-          name: openSUSE Leap
-          gccversioncommand: *gccdumpfullversion
-          programs: *opensusedefaultprograms
-          libraries: *opensusedefaultlibraries
+    id: opensuse-leap
+    releases:
+      default:
+        version: default
+        name: openSUSE Leap
+        gccversioncommand: *gccdumpfullversion
+        programs: *opensusedefaultprograms
+        libraries: *opensusedefaultlibraries
   crux:
-      id: crux
-      releases:
-        default:
-          version: default
-          name: Crux Linux
-          gccversioncommand: *gccdumpversion
-          programs:
-            - name: gcc
-              help: Please install with `sudo prt-get depinst gcc-c++ make` and try again
-            - name: pkg-config
-              help: Please install with `sudo prt-get depinst pkg-config` and try again
-            - name: npm
-              help: Please install with `sudo prt-get depinst nodejs` and try again
-          libraries:
-            - name: gtk3
-              help: Please install with `sudo prt-get depinst gtk3` and try again
-            - name: webkitgtk
-              help: Please install with `sudo prt-get depinst webkitgtk` and try again
+    id: crux
+    releases:
+      default:
+        version: default
+        name: Crux Linux
+        gccversioncommand: *gccdumpversion
+        programs:
+          - name: gcc
+            help: Please install with `sudo prt-get depinst gcc-c++ make` and try again
+          - name: pkg-config
+            help: Please install with `sudo prt-get depinst pkg-config` and try again
+          - name: npm
+            help: Please install with `sudo prt-get depinst nodejs` and try again
+        libraries:
+          - name: gtk3
+            help: Please install with `sudo prt-get depinst gtk3` and try again
+          - name: webkitgtk
+            help: Please install with `sudo prt-get depinst webkitgtk` and try again
+  nixos:
+    id: nixos
+    releases:
+      default:
+        version: default
+        name: NixOS
+        gccversioncommand: *gccdumpversion
+        programs:
+          - name: gcc
+            help: Please install with `nix-env -iA nixos.gcc`
+          - name: pkg-config
+            help: Please install with `nix-env -iA nixos.pkg-config`
+          - name: npm
+            help: Please install with `nix-env -iA nixos.nodejs`
+        libraries:
+          - name: gtk+3
+            help: Please install with `nix-env -iA nixos.gtk3`
+          - name: webkitgtk
+            help: Please install with `nix-env -iA nixos.nodePackages.webkitgtk`
+
diff --git a/cmd/system.go b/cmd/system.go
index 76ab0b23c..5c2aa6f3c 100644
--- a/cmd/system.go
+++ b/cmd/system.go
@@ -293,6 +293,8 @@ func CheckDependencies(logger *Logger) (bool, error) {
 			libraryChecker = EOpkgInstalled
 		case Crux:
 			libraryChecker = PrtGetInstalled
+		case NixOS:
+			libraryChecker = NixEnvInstalled
 		default:
 			return false, RequestSupportForDistribution(distroInfo)
 		}