class Bake::Arguments

def self.extract(recipe, arguments, **defaults)
	# Only supply defaults that match the recipe option names:
	defaults = defaults.slice(*recipe.required_options)
	
	self.new(recipe, defaults).extract(arguments)
end

def delimiter_index(arguments)
	arguments.index{|argument| argument =~ /\A(--|;\z)/}
end

def extract(arguments)
	while argument = arguments.first
		if /^--(?<name>.*)$/ =~ argument
			# Consume the argument:
			arguments.shift
			
			if name.empty?
				break
			end
			
			name = normalize(name)
			
			# Extract the trailing arguments:
			@options[name] = extract_arguments(name, arguments)
		elsif /^(?<name>.*?)=(?<value>.*)$/ =~ argument
			# Consume the argument:
			arguments.shift
			
			name = name.to_sym
			
			# Extract the single argument:
			@options[name] = extract_argument(name, value)
		elsif @ordered.size < @arity
			_, name = @parameters.shift
			value = arguments.shift
			
			# Consume it:
			@ordered << extract_argument(name, value)
		else
			break
		end
	end
	
	return @ordered, @options
end

def extract_argument(name, value)
	if type = @types[name]
		value = type.parse(value)
	end
	
	return value
end

def extract_arguments(name, arguments)
	value = nil
	type = @types[name]
	
	# Can this named parameter accept more than one input argument?
	if type&.composite?
		if count = delimiter_index(arguments)
			value = arguments.shift(count)
			arguments.shift if arguments.first == ";"
		else
			value = arguments.dup
			arguments.clear
		end
	else
		# Otherwise we just take one item:
		value = arguments.shift
	end
	
	if type
		value = type.parse(value)
	end
	
	return value
end

def initialize(recipe, defaults)
	@recipe = recipe
	
	@types = recipe.types
	@parameters = recipe.parameters
	@arity = recipe.arity
	
	@ordered = []
	@options = defaults
end

def normalize(name)
	name.tr("-", "_").to_sym
end