[xaprepare] Implement support for ArchLinux pacman (#5093)

This commit adds support for ArchLinux pacman package
manager. It also implements the InitOS function in
ConfigAndData/Dependencies/Linux.Arch.cs

Author: Freakness109

build-tools/xaprepare/xaprepare/Application/Program.ArchLinux.cs

@@ -11,19 +11,38 @@ public ArchLinuxProgram (string packageName, string? executableName = null)
 
 		protected override bool CheckWhetherInstalled ()
 		{
-			throw new NotImplementedException ();
+			return Utilities.RunCommand ("pacman", "-Q", PackageName);
 		}
 
 #pragma warning disable CS1998
 		public override async Task<bool> Install ()
 		{
-			throw new NotImplementedException ();
+			var runner = new ProcessRunner ("sudo", "pacman", "-S", "--noconfirm", PackageName) {
+				EchoStandardOutput = true,
+				EchoStandardError = true,
+				ProcessTimeout = TimeSpan.FromMinutes (30),
+			};
+
+			bool failed = await Task.Run (() => !runner.Run ());
+			if (failed) {
+				Log.Error ($"Installation of {PackageName} timed out");
+				failed = true;
+			}
+
+			if (runner.ExitCode != 0) {
+				Log.Error ($"Installation failed with error code {runner.ExitCode}");
+				failed = true;
+			}
+
+			return !failed;
 		}
 #pragma warning restore CS1998
 
 		protected override bool DeterminePackageVersion()
 		{
-			throw new NotImplementedException();
+			var output = Utilities.GetStringFromStdout ("pacman", "-Q", PackageName).Split(' ');
+			CurrentVersion = output.Length == 2 ? output[1] : null;
+			return !String.IsNullOrEmpty (CurrentVersion);
 		}
 	}
 }

build-tools/xaprepare/xaprepare/ConfigAndData/Dependencies/Linux.Arch.cs

@@ -53,8 +53,7 @@ protected override bool InitOS ()
 			if (!base.InitOS ())
 				return false;
 
-			Log.Todo ("Implement");
-			return false;
+			return true;
 		}
 	};
 }