require 'ib-ruby/models/contract'

module IB
  module Models
    class Option < Contract

      validates_numericality_of :strike, :greater_than => 0
      validates_format_of :sec_type, :with => /^option$/,
                          :message => "should be an option"
      validates_format_of :local_symbol, :with => /^\w+\s*\d{15}$|^$/,
                          :message => "invalid OSI code"
      validates_format_of :right, :with => /^put$|^call$/,
                          :message => "should be put or call"

      # For Options, this is contract's OSI (Option Symbology Initiative) name/code
      alias osi local_symbol

      def osi= value
        # Normalize to 21 char
        self.local_symbol = value.sub(/ /, ' '*(22-value.size))
      end

      # Make valid IB Contract definition from OSI (Option Symbology Initiative) code.
      # NB: Simply making a new Contract with *local_symbol* (osi) property set to a
      # valid OSI code works just as well, just do NOT set *expiry*, *right* or
      # *strike* properties in this case.
      # This class method provided as a backup and shows how to analyse OSI codes.
      def self.from_osi osi

        # Parse contract's OSI (OCC Option Symbology Initiative) code
        args = osi.match(/(\w+)\s?(\d\d)(\d\d)(\d\d)([pcPC])(\d+)/).to_a.drop(1)
        symbol = args.shift
        year = 2000 + args.shift.to_i
        month = args.shift.to_i
        day = args.shift.to_i
        right = args.shift.upcase
        strike = args.shift.to_i/1000.0

        # Set correct expiry date - IB expiry date differs from OSI if expiry date
        # falls on Saturday (see https://github.com/arvicco/option_mower/issues/4)
        expiry_date = Time.utc(year, month, day)
        expiry_date = Time.utc(year, month, day-1) if expiry_date.wday == 6

        new :symbol => symbol,
            :exchange => "SMART",
            :expiry => expiry_date.to_ib[2..7], # YYMMDD
            :right => right,
            :strike => strike
      end

      def default_attributes
        super.merge :sec_type => :option
        #self[:description] ||= osi ? osi : "#{symbol} #{strike} #{right} #{expiry}"
      end

      def to_human
        "<Option: " + [symbol, expiry, right, strike, exchange, currency].join(" ") + ">"
      end

    end # class Option
  end # module Models
end # module IB