require "Set"
class ModeScale

	attr_accessor :key, :mode
	attr_reader :mode_scale
	def initialize(key, mode)
		@key, @mode = key, mode
		showScale
	end


	def to_s
		"KEY:#{@key} in #{@mode} \n" +
		"Scale: #{@mode_scale.to_a}"
	end


	def showScale
		scale 	= ["C","#C/bD","D","#D/bE","E","F","#F/bG","G","#G/bA","A","#A/bB","B"]
		@mode_scale= Set.new

		mode_hash = {
			# 1 means a semitone and 2 means two semitone
			"Ionian" 	=> [0,2,2,1,2,2,2,1],
			"Dorian"	=> [0,2,1,2,2,2,1,2],
			"Phrygian"	=> [0,1,2,2,2,1,2,2],
			"Lydian"	=> [0,2,2,2,1,2,2,1],
			"Mixolydian"=> [0,2,2,1,2,2,1,2],
			"Aeolian"	=> [0,2,1,2,2,1,2,2],
			"Locrian"	=> [0,1,2,2,1,2,2,2]
		}
		# ==============================
		pos = scale.index(key)
		for i in (0..7)
			pos += (mode_hash[mode]).at(i)
			pos %= 12
			@mode_scale << scale[pos]
		end
		# ==============================
	end


end