app.rb

require 'sinatra'
require 'json'
require './lib/eso_exercise_simulator'
require './lib/options_agreement'

get '/' do
  erb :index
end

post '/spread' do
  agreements = build_agreements
  spread = AWRY::ESOExerciseSimulator.spread(agreements, market_price, exercise_date)

  { spread: spread }.to_json
end

private

def form_params
  @param ||= JSON.parse(request.body.read)
end

def market_price
  form_params['market_price'].to_f
end

def exercise_date
  Date.parse(form_params['exercise_date'])
end

def agreement_params
  form_params['agreements']
end

def build_agreements
  agreement_params.map do |params|
    AWRY::OptionsAgreement.new(
      stock: (params['stocks']).to_f,
      strike_price: (params['strikeprice']).to_f,
      grant_date: Date.parse(params['grantdate']),
      cliff_pct: params['cliff_pct'].to_f,
      cliff_n_months: params['cliff_n_months'].to_f,
      vesting_period: params['vesting_period'].to_f
    )
  end
end