# Nitx handles console queries
#
# Using `prompt`, the command line can be turned on an interactive tool.
class Nitx

	# Model that contains the informations to display
	var model: Model

	# Mainmodule for class linearization
	var mainmodule: MModule

	# ModelBuilder to access AST nodes
	var modelbuilder: ModelBuilder

	# Catalog if any
	var catalog: nullable Catalog = null is optional

	# Do not use colors in the output
	var no_color = false is optional

	# Displays the welcome message and start prompt.
	fun start do
		welcome
		prompt
	end

	# Displays the welcome message and the list of loaded modules.
	fun welcome do
		print "Welcome in the Nit Index!"
		print ""
		print "Loaded packages:\n"
		var cmd = new CmdModelEntities(model, kind = "packages")
		cmd.init_command
		for mpackage in cmd.results.as(not null) do
			print " * {mpackage.full_name}"
		end
		help
	end

	# Displays the list of available queries.
	fun help do
		# TODO automatize that
		print "\nCommands:\n"
		for usage, doc in parser.commands_usage do
			var l = usage.length / 8
			print "\t{usage}{"\t" * (3 - l)}{doc}"
		end
		print "\n"
		print "\t:h\t\t\tdisplay this help message"
		print "\t:q\t\t\tquit interactive mode"
		print ""
	end

	# Prompts the user for a query.
	fun prompt do
		var line = sys.prompt(">> ", true)
		if line != null then
			do_command(line)
		else
			# EOF
			exit 0
		end
		prompt
	end

	# Parser used to process doc commands
	var parser = new CommandParser(model, mainmodule, modelbuilder, catalog) is lazy

	# Processes the query string and performs it.
	fun do_command(str: String) do
		if str == ":q" then
			exit 0
		else if str == ":h" then
			help
			return
		end
		parser.execute(str, no_color)
	end
end