get_average_historical.rb

get_average_historical.rb

require 'csv'
require 'httparty'
require 'byebug'

OANDA_URL = 'https://www.oanda.com/rates/api/v1/rates/'
OANDA_KEY = ENV['OANDA_API_KEY']
OUTPUT_FILE = './rates.json' 
year = { 
          month_1: [],
          month_2: [],
          month_3: [],
          month_4: [],
          month_5: [],
          month_6: [],
          month_7: [],
          month_8: [],
          month_9: [],
          month_10: [],
          month_11: [],
          month_12: []
        }
average_rates = {
          month_1: {},
          month_2: {},
          month_3: {},
          month_4: {},
          month_5: {},
          month_6: {},
          month_7: {},
          month_8: {},
          month_9: {},
          month_10: {},
          month_11: {},
          month_12: {}
}

csv = CSV.parse( File.open('./exchanges.csv') { |f| f.read } )

csv.each do |exchange|
  year["month_#{exchange[2]}".to_sym] << exchange[0..1]
end

iteration = 0

year.each do |month, exchanges|
  exchanges.each do |exchange|
    month_number = month.to_s.gsub('month_', '').to_i
    start_date = Date.new(2014, month_number, 1).to_s
    end_date = month_number == 12 ? (Date.today - 1).to_s : Date.civil(2014, month_number, -1).to_s 

    response = HTTParty.get("#{OANDA_URL}#{exchange[0]}.json?quote=#{exchange[1]}&start=#{start_date}&end=#{end_date}&api_key=#{OANDA_KEY}").parsed_response
    iteration += 1
    key = "#{exchange[0]}_to_#{exchange[1]}"
    
    puts "#{iteration} - #{key}"

    average_rates[month][key.to_sym] = response['quotes'][exchange[1]]['ask'].to_f
  end
end

output = File.open(OUTPUT_FILE, 'w+') { |f| f.write average_rates.to_json }