rubysolo/andrey

require 'andrey/language/american_names'
require 'andrey/language/dynamic'
require 'andrey/language/english'

module Andrey
  class Word
    def initialize(language=Language::English)
      @language = language
      @word = []
    end

    def to_s
      @word.join
    end

    def length
      @word.length
    end

    def add_letter
      @word << next_letter(@word.last || symbols.sample)
    end

    def next_letter(letter)
      index = symbols.index(letter)

      probabilities = probability_map[index]
      pointer = rand
      sum = 0

      probabilities.each_with_index do |p, index|
        if p > 0
          sum += p
          return symbols[index] if sum > pointer
        end
      end

      symbols.sample
    end

    def self.generate(options={})
      options[:length] ||= 8

      if options[:corpus]
        symbols, map = Analyzer.analyze_file(options[:corpus])
        options[:language] = Language::Dynamic.new(symbols, map)
      end

      new(options[:language] || Language::English).tap do |word|
        while word.length < options[:length]
          word.add_letter
        end
      end
    end

    private

    def symbols
      @language.symbols
    end

    def probability_map
      @language.probability_map
    end
  end
end