Generating Markov sentences from character dialog

speak.rb

# frozen_string_literal: true

require 'rubygems'
require 'bundler/setup'
require 'markovite'

# from_book: the filename (ending in .txt) of the Freddy book to read in
# character: the character's name to find dialog for (ie. Charles or Freddy)
def get_dialog(from_book, character)
  # read the entire contents of the given file (book) into memory
  book = File.read(from_book)
  # split the ebook text into paragraphs by splitting it on a double newline,
  # then trim all newlines out of each paragraph to ensure they are on a single line.
  paragraphs = book.split("\n\n").map! { |p| p.tr "\n", ' ' }

  # since the text uses Unicode smartquote characters, instead of regular "
  # store them here for convenience
  open_quote = "\u201c"
  close_quote = "\u201d"

  # This is a regular expression that matches any string between smart quotes,
  # ie. “Freddy the detective”
  dialog_matcher = /#{open_quote}(.+?)#{close_quote}/

  all_paragraphs = []

  paragraphs.each do |paragraph|
    # For each paragraph, find all the dialog in it and store it in 'dialogs'
    dialogs = paragraph.scan(dialog_matcher)
    paragraph_no_dialog = paragraph
    has_dialog = true
    
    # then for each stored dialog, remove it from the paragraph
    dialogs.each do |dialog|
      dialog = dialog[0] if dialog.is_a? Array
      begin
        paragraph_no_dialog = paragraph_no_dialog.sub dialog, ''
      rescue TypeError => e
        # do nothing
      end
    end
    
    # a paragraph does NOT have dialog if it is equal to its dialog-stripped version
    has_dialog = false if paragraph_no_dialog == paragraph

    # if the dialog-stripped version contains the given character's name,
    # assume that character is doing the talking
    has_freddy = paragraph_no_dialog.scan(character).length >= 1
    
    # push all dialogs by the character onto the main dialog stack for future reference
    all_paragraphs.push dialogs.join ' ' if has_dialog && has_freddy
  end

  all_paragraphs.join ' '
end

def generate_sentence_for(character)
  dialog_for_char = []
  Dir.entries('books/').each do |book|
    if File.file? ('books/' + book)
      dialog_for_char.push get_dialog 'books/' + book, character
    end
  end

  chain = Markovite::Chain.new
  chain << dialog_for_char.join(' ')

  chain.make_sentence_of_length 140
end