pack_simulator.rb

class Array; def sum; inject( nil ) { |sum,x| sum ? sum+x : x }; end; end
class Array; def mean; sum / size; end; end

class Ungoro
	
	attr_accessor :packs, :completion

	attr_accessor :nice_packs
	attr_accessor :pity_timer
	
	#est. average of 75 gold per day
	PACKS_PER_DAY = 0.75
	PITY_TIMER = 40
	
	#COMPLETION PERCENT IS A FLOAT (1.0, NOT 100)
	def self.simulate(nice_packs, completion_percent)
		data = []
		1000.times{ packs = Ungoro.new(nice_packs).get_em_all(completion_percent).packs.to_f; data << packs; p packs }
		result = data.mean
		
		puts "*"*50
		puts result
		puts "NO $$$: #{result/PACKS_PER_DAY} days"
		puts "PREORDER: #{(result-50)/PACKS_PER_DAY} days"
		puts "PREORDER+$50: #{(result-90)/PACKS_PER_DAY} days"
	end
	
	def initialize(nice_packs)

		if nice_packs
			@pity_timer = 10
		else
			@pity_timer = PITY_TIMER
		end

		@packs = 0
		@completion = {
			:common => [],
			:rare => [],
			:epic => [],
			:legend => [],
			:dust => 0
		}

		@set = {
			:common => 49,
			:rare => 36,
			:epic => 27,
			:legend => 23
		}
	end
	
	def get_em_all(completion_percent)
		total_dust = 69520 - dust_remaining + @completion[:dust]
		while total_dust < 69520*completion_percent
			open_pack
			total_dust = 69520 - dust_remaining + @completion[:dust]
		end
		self #chaining
	end

	def get_rarity(is_pitiful)
		
		if is_pitiful
			p "PITY TIMER"
			@pity_timer = PITY_TIMER
			return :legend, false, 400
		end

		#rarity source: http://www.pcgamer.com/blizzards-chinese-hearthstone-website-confirms-card-rarity-drop-rates/
		roll = rand

		#legendary : 1 in 20 (/5)
		# epic : 1 in 5 (/5)
		# rare : 1 in 5
		# common : all the rest

		#golden chance source: http://hearthstone.gamepedia.com/Card_pack_statistics#Golden_cards
		#chance to be golden
		# common: 2.06%
		# rare: 5.54%
		# epic: 4.52%
		# legendary: 7.31%

		roll = rand
		golden_roll = rand

		legendary_chance = 1.0 / 20.0 / 5.0
		golden_legendary_chance = 0.0731  #chance for a legendary to be golden, not chance to pull golden legendary
		epic_chance = 1.0 / 5.0 / 5.0
		golden_epic_chance = 0.0452
		rare_chance = 1.0 / 5.0
		golden_rare_chance = 0.0554
		golden_common_chance = 0.0206

		

		if roll < legendary_chance
			if golden_roll < golden_legendary_chance
				return :legend, true, 1600
			else
				return :legend, false, 400
			end
		elsif  roll < legendary_chance + epic_chance
			if golden_roll < golden_epic_chance
				return :epic, true, 400
			else
				return :epic, false, 100
			end
		elsif roll < legendary_chance + epic_chance + rare_chance
			if golden_roll < golden_rare_chance
				return :rare, true, 100
			else
				return :rare, false, 20
			end
		else
			if golden_roll < golden_common_chance
				return :common, true, 50
			else
				return :common, false, 5
			end
		end
	end

	def get_card(excludes, is_pitiful)
		rarity, golden, dust = get_rarity(is_pitiful)

		#guaranteed at least one rare
		if excludes[:common].length == 4 && rarity == :common
			rarity = :rare
		end

		#pool of eligible cards
		pool = (1..@set[rarity]).to_a

		if rarity == :legend
			#no duplicate legends until we get them all
			if @completion[:legend].length < pool.length
				pool = pool - @completion[:legend]
			end
			pool = pool - excludes[rarity]
		else
			excludes[rarity].each do |card_id|
				if excludes[rarity].count(card_id) >= 2
					pool = pool - [card_id]
				end
			end
		end

		#if we broke it start over
		if pool.length == 0
			pool = (1..@set[rarity]).to_a			
		end

		card_id = pool.sample

		#always dust golden cards to fill in missing cards
		if golden
			@completion[:dust] += dust
		else
			count = (rarity == :legend) ? 1 : 2
			if(@completion[rarity].count(card_id) < count)
				@completion[rarity] << card_id
			else
				@completion[:dust] += dust
			end
		end

		return rarity, card_id, golden
	end

	def open_pack
		pack = {
			:common => [],
			:rare => [],
			:epic => [],
			:legend => []
		}

		5.times do 
			rarity, card_id = get_card(pack, (@pity_timer <= 0))
			pack[rarity] << card_id
			#always dust golden cards to fill in missing cards
		end

		if pack[:legend].length == 0
			@pity_timer -= 1
		end
		
		@packs += 1
		# p pack
	end

	def dust_remaining
		common_dust = (98 - @completion[:common].count) * 40
		rare_dust = (72 - @completion[:rare].count) * 100
		epic_dust = (54 - @completion[:epic].count) * 400
		legend_dust = (23 - @completion[:legend].count) * 1600
		
		common_dust + rare_dust + epic_dust + legend_dust
	end

end