require 'optparse'
require 'aws/rikanjo/base'

module Aws
  module RiKanjoo
    class CLI

      def initialize
        @options = {}
        @optparse = nil
        @cost = nil
      end

      def start
        parse
        rikanjo
        output
      end

      def parse
        optparse = OptionParser.new do |opts|
          opts.banner = 'Usage: rikanjo ec2/rds [options]'

          # subcommand
          mode = ARGV.shift
          if mode == 'ec2'
          elsif mode == 'rds'
            opts.on('--multiaz', 'enable multi-az') do |value|
              @options[:multiaz] = value
            end
          else
            $stderr.puts "no such subcommand: #{mode}"
            puts opts
            exit 1
          end
          @options[:mode] = mode

          region_values = %w(us-east-1 us-west-1 us-west-2 eu-west-1 ap-southeast-1 ap-northeast-1 ap-southeast-2 sa-east-1 )
          opts.on('-r', '--region=VALUE', region_values, "specify aws-region (#{region_values.join('/')})") do |value|
            @options[:region] = value
          end

          opts.on('-t', '--instance_type=VALUE', 'specify ec2-instance-type') do |value|
            @options[:instance_type] = value
          end

          ri_util_values = %w(light medium heavy)
          opts.on('-u', '--ri_util=VALUE', ri_util_values, "specify ri-util (#{ri_util_values.join('/')})") do |value|
            @options[:ri_util] = value
          end

          opts.on('-j', '--output_json', "specify output_json flg") do |value|
            @options[:output_json] = value
          end

          opts.on('-h', '--help') do
            puts opts
            exit
          end
        end

        # validation
        begin
          optparse.parse!
          require_args = [:region, :instance_type, :ri_util]
          error_args = require_args.select { |param| @options[param].nil? }
          unless error_args.empty?
            puts "require arguments: #{error_args.join(', ')}"
            puts
            puts optparse
            exit
          end
        rescue
          puts $!.to_s
          puts
          puts optparse
          exit
        end
      end

      def rikanjo
        # rikanjo
        a = Aws::RiKanjoo::Base.new(
            mode = @options[:mode],
            region = @options[:region],
            instance_type = @options[:instance_type],
            ri_util = @options[:ri_util],
            multiaz = @options[:multiaz],
        )
        @cost = a.total_cost_year
      end

      def output
        if @options[:output_json]
          output_json()
        else
          output_text()
        end
      end

      def output_json
        puts @cost.to_json
      end

      def output_text
        @cost.keys.each do |key|
          puts "#{key}: #{@cost[key]}"
        end
      end

    end
  end
end