Build a market

coinbase.rb

# Imagine I wish to buy 5 btc. Iterate over order_book ask price and amounts. fullfill order, return lowest possible cost

order_book = {asks:[{price:2, amount:1, id:'id'},{price:2, amount:4, id:'id'}], bids:{}}
user_amount = 5

# 1000 btc for $2.5/each

def get_asks(order_book, user_amount)
	asks = order_book[:asks]
	returned_value = []
	total_price = 0
	total_sold = 0
	until user_amount == total_sold do
		asks.each_with_index do |ask, index|
		  ask_price = determine_price(ask)
		  total_sold += ask[:amount]
		  total_price += ask_price
	  end
	end
	total_price
end

def determine_price(ask)
	ask[:amount] * ask[:price]
end


def check_get_asks
  order_book = {asks:[{price:2, amount:1, id:'id'},{price:2, amount:4, id:'id'}], bids:{}}
  a = get_asks(order_book, 5)
  a == 10
end


check_get_asks()
get_asks(order_book, user_amount)