require 'bigdecimal'

module Pact
  module Generator
    # RandomDecimal provides the random decimal generator which will generate a decimal value of digits length
    class RandomDecimal
      def can_generate?(hash)
        hash.key?('type') && hash['type'] == 'RandomDecimal'
      end

      def call(hash, _params = nil, _example_value = nil)
        digits = hash['digits'] || 6

        raise 'RandomDecimalGenerator digits must be > 0, got $digits' if digits < 1

        return rand(0..9) if digits == 1

        return rand(0..9) + rand(1..9) / 10 if digits == 2

        pos = rand(1..digits - 1)
        precision = digits - pos
        integers = ''
        decimals = ''
        while pos.positive?
          integers += String(rand(1..9))
          pos -= 1
        end
        while precision.positive?
          decimals += String(rand(1..9))
          precision -= 1
        end

        Float("#{integers}.#{decimals}")
      end
    end
  end
end