require 'optparse'

class RedisStat
module Option
  DEFAULT = {
    :hosts    => ['127.0.0.1:6379'],
    :interval => 2,
    :count    => nil,
    :csv      => nil,
    :style    => :unicode
  }

  def self.parse argv
    argv = argv.dup

    options = DEFAULT.dup
    opts = ::OptionParser.new { |opts|
      opts.banner = "usage: redis-stat [HOST[:PORT] ...] [INTERVAL [COUNT]]"
      opts.separator ''

      opts.on('--auth=PASSWORD', 'Password') do |v|
        options[:auth] = v
      end

      opts.on('--csv=OUTPUT_CSV_FILE_PATH', 'Save the result in CSV format') do |v|
        options[:csv] = v
      end

      opts.on('-v', '--verbose', 'Show more info') do |v|
        options[:verbose] = v
      end

      opts.on('--style=STYLE', 'Output style: unicode|ascii') do |v|
        options[:style] = v.downcase.to_sym
      end

      opts.on('--no-color', 'Suppress ANSI color codes') do |v|
        options[:mono] = true
      end

      opts.on('--version', 'Show version') do
        puts RedisStat::VERSION
        exit 0
      end

      opts.on_tail('--help', 'Show this message') do
        puts opts
        exit 0
      end
    }
    
    begin
      opts.parse! argv

      is_number   = lambda { |str| str =~ /^([0-9]\.?[0-9]*)$|^([1-9][0-9]*)$/ }

      numbers, hosts = argv.partition { |e| is_number.call e }
      interval, count = numbers.map(&:to_f)

      options[:interval] = interval if interval
      options[:count]    = count if count
      options[:hosts]    = hosts unless hosts.empty?

      validate options

      return options
    rescue SystemExit => e
      exit e.status
    rescue Exception => e
      puts e.to_s
      puts opts
      exit 1
    end
  end

  def self.validate options
    options[:interval].tap do |interval|
      unless interval.is_a?(Numeric) && interval > 0
        raise ArgumentError.new("Invalid interval: #{interval}")
      end
    end

    options[:count].tap do |count|
      unless count.nil? || (count.is_a?(Numeric) && count > 0)
        raise ArgumentError.new("Invalid count: #{count}")
      end
    end

    options[:hosts].tap do |hosts|
      if hosts.empty?
        raise ArgumentError.new("Redis host not given")
      end

      hosts.each do |host|
        host, port = host.split(':')
        if port
          port = port.to_i
          unless port > 0 && port < 65536
            raise ArgumentError.new("Invalid port: #{port}")
          end
        end
      end
    end

    options[:style].tap do |style|
      unless [:unicode, :ascii].include?(style)
        raise ArgumentError.new("Invalid style")
      end
    end

  end
end
end