require_relative "paragoz/version"
require 'json'
require 'net/http'
require 'uri'

module Paragoz

  CURRENCY_CODES = ["AUD", "BGN", "BRL", "CAD", "CHF", "CNY", "CZK", "DKK", "GBP",
                    "HKD", "HRK", "HUF", "IDR", "ILS", "INR", "JPY", "KRW", "MXN", "MYR", "NOK", "NZD",
                    "PHP", "PLN", "RON", "RUB", "SEK", "SGD", "THB", "USD", "ZAR", "EUR", "TRY"]

  private class Currency
    attr_reader :currencies_defined, :base, :date, :rates, :costs, :amount, :data

    @@currencies_defined = 0

    def initialize(code, amount, data, date)
      @data   = data || parse_data(take_response(code.upcase, date))
      @time_array = @data["date"].split('-').map {|i| i = i.to_i}
      @base   = @data["base"]
      @date   = @time_array && @time_array.is_a?(Array) ? Time.new(*@time_array) : Time.now
      @rates  = @data["rates"]
      @costs  = cost_of_other_currencies
      @amount = amount

      @@currencies_defined += 1
    end

    def amount=(value)
      if value.is_a?(Numeric) && value > 0
        @amount = value
      else
        puts "ERROR! Amount must be a Number and greater than 0."
      end
    end

    def parse_data(response)
      JSON.parse(response.body) if response.code == '200'
    end

    def take_response(base, date = nil)
      link = define_link(base, date)
      url = URI.parse(link)
      http = Net::HTTP.new(url.host, url.port)
      request = Net::HTTP::Get.new(url.request_uri)
      response = http.request(request)
      response
    end

    def define_link(base, date)
      return "http://api.fixer.io/latest?base=#{base}" if date.nil?
      "http://api.fixer.io/#{date}?base=#{base}"
    end

    private def cost_of_other_currencies
      costs = {}
      @rates.each_pair do |k, v|
        costs[k] = 1 / v
      end
      costs
    end

    def calculate_cost(currency_code ,calculate_amount = 1.0, info = false)
      cost = self.costs[currency_code.upcase] * calculate_amount || self.amount
      if amount.is_a?(Float) && amount > 0  && CURRENCY_CODES.include?(currency_code.upcase)
        puts "You need #{cost} #{@base} to buy #{amount} #{currency_code}" if info
        cost
      else
        puts "ERROR! You need to give 2 parameters >>  currency_code & calculate_amount"
        puts "Use 'Paragoz::CURRENCY_CODES' for see all defined currency codes."
        puts "Amount has to be an float and greater than 0."
      end
    end

    def currency_to_currency(other_currency_object, info = false)
      if self.base != other_currency_object.base
        exchange = self.amount * self.rates[other_currency_object.base]
        printf("%.2f %s equals to %.4f %s \n", @amount, @base, exchange, other_currency_object.base) if info
        exchange
      else
        puts "Error! Trying to conver same currency object."
      end
    end


    def exchange_to(currency_code, exchance_amount = nil, info = false)
      exchange = @rates[currency_code.upcase] * (exchance_amount || self.amount)
      printf("%.2f %s equals to %.4f", amount, @base, exchange) if info
      exchange
    end

    def take_rate(currency_code)
      @rates[currency_code.upcase]
    end

    def print_costs
      puts "at #{@date}"
      @costs.each_pair do |k, v|
        printf("1.00 %s costs %.4f %s to buy! \n", k, v, @base)
      end
    end

    def to_s
      puts "*" * 76
      puts "for #{@base} at #{@date}".upcase.center(76)
      puts "*" * 76
      @rates.each_pair do |k, v|
        puts "-" * 76
        printf("|          %.2f    >>>    %s    >>>    %03.2f    >>>   %s                 | \n", @amount, @base, v, k)
        puts "-" * 76
      end
      puts "-" * 76
    end
  end

  private class Comparation

  attr_reader :time_difference, :comparation_rates, :comparation_costs

  def initialize(currency_object, currency_object_to_compare)
  @time_difference = currency_object.date > currency_object_to_compare.date ? "Currency Object's Rates Are Newer" :
                     "Currency Object's Rates Are Older"
  @comparation_rates       = compare_rates(currency_object.rates, currency_object_to_compare.rates)
  @comparation_costs       = compare_costs(currency_object.costs, currency_object_to_compare.costs)
  end

  private def compare_rates(rates, rates_to_cmpr)
      comparation_hash = {}
      rates.each_pair do |k, v|
        comparation_hash[k] =  {difference: v - rates_to_cmpr[k], status: "#{if v > rates_to_cmpr[k]
                                                                                 'incresed'
                                                                               elsif v == rates_to_cmpr[k]
                                                                                 'same'
                                                                               else
                                                                                 'decresed'
                                                                               end}"}
      end
      comparation_hash
    end

    private def compare_costs(costs, costs_to_cmpr)
      comparation_hash = {}
      costs.each_pair do |k, v|
        comparation_hash[k] =  {difference: v - costs_to_cmpr[k], status: "#{if v > costs_to_cmpr[k]
                                                                          'incresed'
                                                                        elsif v == costs_to_cmpr[k]
                                                                          'same'
                                                                        else
                                                                          'decresed'
                                                                        end}"}
      end
      comparation_hash
    end
      def to_s
        puts "COMPARATION DATA FOR RATES".center(76)
        puts "|__Curency Code___|______Rate Difference:______|______Change Status________|"
        puts "-" * 76
        @comparation_rates.each_pair { |k, v| printf("       %s        |          %+.4f           |        %s           | \n", k, v[:difference], v[:status] )}
        puts "*" * 76
        puts "COMPARATION DATA FOR COSTS".center(76)
        puts "-" * 76
        puts "|___Curency Code__|______Cost Difference:______|______Change Status________|"
        puts "-" * 76
        @comparation_costs.each_pair { |k, v| printf("       %s        |          %+.4f           |        %s           | \n", k, v[:difference], v[:status] )}
        puts "-" * 76
      end
    end


  def self.compare_currencies(currency_object, currency_object_to_compare)
    if currency_object.is_a?(Object) && currency_object_to_compare.is_a?(Object)
      Comparation.new(currency_object, currency_object_to_compare) if currency_object.base == currency_object_to_compare.base
    else
      puts "ERROR! You can use Currency Objets as parameter!"
    end
  end

  def self.new_currency(code: "try", amount: 1.0, data: nil, date: nil)
    if code.is_a?(String) && CURRENCY_CODES.include?(code.upcase) &&
        amount.is_a?(Float) && amount > 0 && date.nil? || date =~ /^\d{4}\-(0?[1-9]|1[012])\-(0?[1-9]|[12][0-9]|3[01])$/
      Currency.new(code, amount, data, date)
    else
      puts "ERROR!"
      puts "to define a currency you have to give at least two named parameters:"
      puts "code: 'currency code as a string' & amount: 'and float greater than 0'"
      puts "Use 'Paragoz::CURRENCY_CODES' for see all defined currency codes."
      puts "date: parameter format 'YYYY-MM-DD'"
      puts "You can use customized data formated as fixer.io JSON"
    end
  end
end