#!/usr/bin/env ruby

require 'net/http'
require 'uri'
require 'yajl'
require 'date'
require_relative 'rikanjo/mode/ec2'
require_relative 'rikanjo/mode/rds'

module Aws
  class RiKanjoo
    attr_reader :region, :instance_type, :ri_util

    def initialize(mode='ec2', region, instance_type, ri_util, multiaz)
      if mode == 'ec2'
        @mode_class = Aws::RiKanjoo::Mode::Ec2.new(region, instance_type, ri_util)
      elsif mode == 'rds'
        @mode_class = Aws::RiKanjoo::Mode::Rds.new(region, instance_type, ri_util, multiaz)
      end
      @region        = region
      @instance_type = instance_type
      @ri_util       = ri_util
      @om_info       = Hash.new
      @ri_info       = Hash.new
    end

    def om_get_hr_price
       # TODO: merge om and ri
      uri = URI.parse("#{@mode_class.price_url}/#{@mode_class.om_price_file}")
      contents = Net::HTTP.get(uri)

      # parse om info
      @om_info = @mode_class.om_price_from_contents(contents)
    end

    def ri_get_hr_price_and_upfront
      uri = URI.parse("#{@mode_class.price_url}/#{@mode_class.ri_price_file}")
      contents = Net::HTTP.get(uri)

      # parse ri info
      @ri_info = @mode_class.ri_price_from_contents(contents)
    end

    def calc_year_cost

      om_hr_price = @om_info[:hr_price].to_f
      ri_hr_price = @ri_info[@ri_util][:hr_price].to_f
      upfront    = @ri_info[@ri_util][:upfront].to_f

      om_day_paid = (om_hr_price * 24).to_f
      ri_day_paid = (ri_hr_price * 24).to_f

      sum_om_price = om_day_paid
      sum_ri_price = ri_day_paid + upfront
      365.times.each do |d|
        d = d + 1
        sum_om_price = sum_om_price + om_day_paid
        sum_ri_price = sum_ri_price + ri_day_paid

        if sum_ri_price < sum_om_price
          @ri_info[@ri_util].store(:sweet_spot_price, sum_ri_price.round(2))
          @ri_info[@ri_util].store(:sweet_spot_start_day, d)
          break 
        end
      end
      total_om_price = (om_day_paid * 365).round(2)
      @om_info.store(:yr_price, total_om_price)
      total_ri_price = ((ri_day_paid * 365) + upfront).round(2)
      @ri_info[@ri_util].store(:yr_price, total_ri_price)

      # exp. @om_info = {:hr_price=>"0.350", :yr_price=>3066.0}
      # exp. @ri_info = {"ri_util"=>{:upfront=>"NNN", :hr_price=>"NNN",
      #                  :sweet_spot_price=>NNN, :sweet_spot_start_day=>78, :yr_price=>2074.56}}
      return @om_info, @ri_info
    end

    def total_cost_year
       om_get_hr_price
       ri_get_hr_price_and_upfront
       calc_year_cost 

       discount_per = (100 - ((@ri_info[@ri_util][:yr_price] / @om_info[:yr_price]) * 100)).round(2)

       # If the Reserved Instance does not become cheaper than the On-demand Instance.
       if @ri_info[@ri_util][:sweet_spot_start_day].nil?
         puts "\"Price of the Reserved Instance is higher than the price of On-Demand Instances.\""
         puts "\"region\" : #{@region}"
         puts "\"instance_type\" : #{@instance_type}"
         puts "\"ri_util\" : #{@ri_util}"
         puts "\"discont percent (percent)\" : #{discount_per}"
         puts "\"ondemand hour price (doller)\" : #{@om_info[:hr_price]}"
         puts "\"reserved hour price (doller)\" : #{@ri_info[@ri_util][:hr_price]}"
         puts "\"ondemand year price (doller)\" : #{@om_info[:yr_price]}"
         puts "\"reserved year price (doller)\" : #{@ri_info[@ri_util][:yr_price]}"
         puts "\"reserved upfront (doller)\" : #{@ri_info[@ri_util][:upfront]}"

         exit 1
       end

       sweet_spot_date = Date.today + @ri_info[@ri_util][:sweet_spot_start_day]

       puts "\"region\" : #{@region}"
       puts "\"instance_type\" : #{@instance_type}"
       puts "\"ri_util\" : #{@ri_util}"
       puts "\"discont percent (percent)\" : #{discount_per}"
       puts "\"ondemand hour price (doller)\" : #{@om_info[:hr_price]}"
       puts "\"reserved hour price (doller)\" : #{@ri_info[@ri_util][:hr_price]}"
       puts "\"ondemand year price (doller)\" : #{@om_info[:yr_price]}"
       puts "\"reserved year price (doller)\" : #{@ri_info[@ri_util][:yr_price]}"
       puts "\"reserved upfront (doller)\" : #{@ri_info[@ri_util][:upfront]}"
       puts "\"sweet spot day (day)\" : #{@ri_info[@ri_util][:sweet_spot_start_day]}"
       puts "\"sweet spot date (date)\" : #{sweet_spot_date}"
       puts "\"sweet spot price (doller)\" : #{@ri_info[@ri_util][:sweet_spot_price]}"
    end

  end
end

# m = Aws::RiKanjoo.new(region = "ap-northeast-1", instance_type = "m3.large", ri_util = "medium")
# m.total_cost_year
#
#  "region" : ap-northeast-1
#  "instance_type" : m3.large
#  "ri_util" : medium
#  "discont percent (percent)" : 35.09
#  "ondemand hour price (doller)" : 0.203
#  "reserved hour price (doller)" : 0.086
#  "ondemand year price (doller)" : 1778.28
#  "reserved year price (doller)" : 1154.36
#  "reserved upfront (doller)" : 401
#  "sweet spot day (day)" : 142
#  "sweet spot date (date)" : 2014-09-19
#  "sweet spot price (doller)" : 696.15