redef fun apply(args)
	do
		if args.not_empty then
			# Install each package
			for arg in args do
				# Parse each arg as an import string, with versions and commas
				install_packages arg
			end
		else
			# Install packages from local package.ini
			var ini_path = "package.ini"
			if not ini_path.file_exists then
				print_error "Local `package.ini` not found."
				print_local_help
				exit 1
			end

			var ini = new IniFile.from_file(ini_path)
			var import_line = ini["package.import"]
			if import_line == null then
				print_error "The local `package.ini` declares no external dependencies."
				exit 0
				abort
			end

			install_packages import_line
		end
	end

	redef fun apply(args)
	do
		if args.length != 1 then
			print_local_help
			exit 1
		end

		var name = args.first
		var target_dir = nitpm_lib_dir / name

		if not target_dir.file_exists or not target_dir.to_path.is_dir then
			print_error "Package not found"
			exit 1
		end

		check_git

		var cmd = "cd {target_dir.escape_to_sh}; git pull"
		if verbose then print "+ {cmd}"

		var proc = new Process("sh", "-c", cmd)
		proc.wait

		if proc.status != 0 then
			print_error "Upgrade failed"
			exit 1
		end
	end

	redef fun apply(args)
	do
		var opt_force = "-f"
		var force = args.has(opt_force)
		if force then args.remove(opt_force)

		if args.is_empty then
			print_local_help
			exit 1
		end

		for name in args do

			var clean_nitpm_lib_dir = nitpm_lib_dir.simplify_path
			var target_dir = clean_nitpm_lib_dir / name

			# Check validity of the package to delete
			target_dir = target_dir.simplify_path
			var within_dir = target_dir.has_prefix(clean_nitpm_lib_dir + "/") and
				target_dir.length > clean_nitpm_lib_dir.length + 1
			var valid_name = name.length > 0 and name.chars.first.is_lower
			if not valid_name or not within_dir then
				print_error "Package name '{name}' is invalid"
				continue
			end

			if not target_dir.file_exists or not target_dir.to_path.is_dir then
				print_error "Package not found"
				exit 1
			end

			# Ask confirmation
			if not force then
				var response = prompt("Delete {target_dir.escape_to_sh}? [Y/n] ")
				var accept = response != null and
					(response.to_lower == "y" or response.to_lower == "yes" or response == "")
				if not accept then return
			end

			var cmd = "rm -rf {target_dir.escape_to_sh}"
			if verbose then print "+ {cmd}"

			var proc = new Process("sh", "-c", cmd)
			proc.wait

			if proc.status != 0 then
				print_error "Uninstall failed"
				exit 1
			end
		end
	end

	redef fun apply(args)
	do
		var files = nitpm_lib_dir.files
		var name_to_desc = new Map[String, nullable String]
		var max_name_len = 0

		# Collect package info
		for file in files do
			var ini_path = nitpm_lib_dir / file / "package.ini"
			if verbose then print "- Reading ini file at {ini_path}"
			var ini = new IniFile.from_file(ini_path)
			var tags = ini["package.tags"]

			name_to_desc[file] = tags
			max_name_len = max_name_len.max(file.length)
		end

		# Sort in alphabetical order
		var sorted_names = name_to_desc.keys.to_a
		alpha_comparator.sort sorted_names

		# Print with clear columns
		for name in sorted_names do
			var col0 = name.justify(max_name_len+1, 0.0)
			var col1 = name_to_desc[name] or else ""
			var line = col0 + col1
			print line.trim
		end
	end

	redef fun apply(args)
	do
		# Try first to help about a valid action
		if args.length == 1 then
			var command = commands.get_or_null(args.first)
			if command != null then
				command.print_local_help
				return
			end
		end

		print_help
	end