require_relative '../dencli'

class DenCli::CMD
	attr_reader :parent, :name, :description, :exe, :completion, :options

	def initialize parent, name, description, exe
		raise "Proc expected, instead of: #{exe.inspect}"  unless Proc === exe
		@parent, @name, @description, @exe = parent, name, description, lambda( &exe)
		@options = []
		completion {|*a| [] }
	end

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

	def parameters() @exe.parameters end
	def required() @exe.parameters.select{|e|:req == e[0]}.map{|e|e[1]} end
	def additional() @exe.parameters.select{|e|:opt == e[0]}.map{|e|e[1]} end

	def call( *as)
		if @options.empty?
			@exe.call *as
		else
			os = {}
			options = OptionParser.new
			options.banner = "#{full_cmd.join ' '}"
			@options.each do |(aname, aas, aos, aexe)|
				os[aname] = aos[aname]  if aos.has_key? :default
				options.on( *aas) {|val| os[aname] = aexe[val] }
			end
			as = options.parse! as
			if @exe.lambda?
				pars = required
				if as.length < pars.length
					raise DenCli::UsageError, "Missing parameter(s): #{pars[as.length..-1].join " "}"
				end
				if parameters.select{|e|:rest == e[0]}.empty?
					pars = pars + additional
					if as.length > pars.length
						raise DenCli::UsageError, "Unused parameter(s): #{as[-pars.length..-1].shelljoin}"
					end
				end
			end
			@exe.call *as, **os
		end
	end

	def usage
		"#{parent.full_cmd.join ' '} #{name} "+
			@options.map{|(_,(o,_,_,_),_)|"[#{o}] "}.join( '')+
			(@exe.lambda? ? (
				required.join( " ")+
				(additional.empty? ? "" : " [#{additional.join " "}]")
			) : '...')
	end

	def help
		"#{usage}\n#{description}"
	end

	def complete( *pre, str) @completion.call *pre, str end

	def completion &exe
		@completion = exe
		self
	end

	def opt name, *as, **os, &exe
		@options.push [name.to_s.to_sym, as, os, exe || lambda{|val|val} ]
		self
	end

	def inspect
		"#<%s:0x%x %s @name=%p @description=%p @parent=<%s:0x%x %s> @exe=<arity=%d>>" % [
			self.class.name, self.object_id, self.full_cmd,
			@name, @description, @parent.class.name, @parent.class.object_id, @parent.full_cmd,
			@exe.arity
		]
	end
end