require_relative '../dencli'

class DenCli::Sub
	attr_reader :parent, :name, :description, :subs, :aliases

	def initialize parent, name, description
		@parent, @name, @description, @subs, @aliases = parent, name, "-> #{description}", {}, {}
	end

	def _full_cmd( post) parent._full_cmd [@name]+post end
	def full_cmd() _full_cmd [] end
	def []( k) @aliases[k] end

	def usage
		"#{full_cmd.join ' '} ..."
	end

	def help n = nil, *a, output: nil
		output ||= ''
		_help output, n, *a
		output
	end

	def _help output, n = nil, *a
		if n.nil?
			output << "#{full_cmd.join ' '}: #{description}\n\n"
			self.class._help_commands output, @subs
		elsif @aliases.has_key? n
			@aliases[n]._help output, *a
		else
			raise DenCli::UnknownCommand, "unknown command: #{_full_cmd( [n])[1..-1].join ' '}, available for #{full_cmd[1..-1].join' '}: #{@subs.keys.join ' '}"
		end
	end

	def commands &exe
		yield self
		@subs.each {|k, c| c.commands &exe }
	end

	def help_commands output: nil
		output ||= ''
		self.class._help_commands output, subs.map {|_,c| c}
		output
	end

	def self._help_commands output, subs
		m = subs.map {|c| x = c.usage.length; 25 < x ? 0 : x }.max
		subs.each do |c|
			if 25 < c.usage.length
				output << "% -#{m}s\n#{' ' * m} " % [c.usage]
			else
				output << "% -#{m}s " % [c.usage]
			end
			n = m+2
			prefix = nil
			c.description.split /\n/ do |l|
				c = 0
				l.split %r< > do |w|
					if prefix
						output << prefix
						prefix = nil
					end
					wl = w.length
					if 75 < c+wl
						output << "\n#{' ' * n}#{w}"
						c = n+2+wl
					else
						output << " #{w}"
						c += 1 + wl
					end
				end
				prefix = "\n#{' ' * n}"
			end
			output << "\n"
		end
		output
	end

	def goto *a
		return self  if a.empty?
		n, *a = *a
		if @aliases.has_key? n
			@aliases[n].goto *a
		else
			raise DenCli::UnknownCommand, "unknown command: #{_full_cmd( [n])[1..-1].join ' '}, available for #{full_cmd[1..-1].join' '}: #{@subs.keys.join ' '}"
		end
	end

	def call *a
		n, *a = *a
		if @aliases.has_key? n
			@aliases[n].call *a
		else
			raise DenCli::UnknownCommand, "unknown command: #{_full_cmd( [n])[1..-1].join ' '}, available for #{full_cmd[1..-1].join' '}: #{@subs.keys.join ' '}"
		end
	end

	def _add name, min, obj, aliases
		name = name.to_s  unless name.nil?
		@subs[name] = obj
		DenCli.gen_aliases( name, min) {|a| @aliases[a] = obj }
		if aliases
			[*aliases].each {|a| @aliases[a] = obj }
		end
		obj
	end
	private :_add

	def sub name, description, min: nil, aliases: nil, &exe
		r = _add name, min, DenCli::Sub.new( self, name, description), aliases
		block_given? ? yield( r) : r
	end

	def cmd name, description, min: nil, aliases: nil, &exe
		_add name, min, DenCli::CMD.new( self, name, description, exe), aliases
	end

	def complete *pre, str
		if pre.empty?
			@subs.keys.grep /\A#{Regexp.escape str}/
		elsif sub = @subs[pre[0]]
			sub.complete *pre[1..-1], str
		else
			STDOUT.print "\a"
		end
	end

	def inspect
		"#<%s:0x%x %s @name=%p @description=%p @subs={%s} @aliases={%s} @parent=<%s:0x%x %s>>" % [
			self.class.name, self.object_id, self.full_cmd,
			@name, @description, @subs.keys.join(', '), @aliases.keys.join(', '), @parent.class.name, @parent.class.object_id, @parent.full_cmd
		]
	end
end