We want to build a simplified trade engine for exchanging bitcoins with euros

We have:

• users which have bitcoins (recorded in btc_balance) and euros (recorded in eur_balance)
• queued_orders which are created by the users and contain
  • a direction (buy or sell)
  • a btc_amount (which will always be 1 to simplify the algorithm)
  • a price in euros per bitcoins

the aim of the matching engine is to process the queued orders one by one. two orders match when:

• their direction are different
• if the price of both exactly match

when two orders match, the engine should execute both orders and update user balances:

• their state change to executed
• the seller btc_balance is decreased by the orders btc_amount
• the seller eur_balance is increased by btc_amount * price
• the buyer btc_balance is increased by the orders btc_amount
• the buyer eur_balance is decreased by btc_amount * price

complete the main.rb file to produce the output.js from the data.js