Ebook renamer to "title - author.epub" (and associated mobi file if present)

ascii_tic.rb

# encoding: UTF-8
# from the code dating back to 2009: https://github.com/tomash/ascii_tic

# Removes HTML tags from a string. Allows you to specify some tags to be kept.
module AsciiTic
  def strip_html( allowed = [] )
    re = if allowed.any?
      Regexp.new(
        %(<(?!(\\s|\\/)*(#{
          allowed.map {|tag| Regexp.escape( tag )}.join( "|" )
        })( |>|\\/|'|"|<|\\s*\\z))[^>]*(>+|\\s*\\z)),
        ##'
        Regexp::IGNORECASE | Regexp::MULTILINE, 'u'
      )
    else
      /<[^>]*(>+|\s*\z)/m
    end
    gsub(re,'')
  end

  def capitalize_every_word
    split(/\s+/).each{ |word| word.capitalize! }.join(' ')
  end

  def to_ascii_brutal
   #foo = self.downcase.strip
   foo = String.new(self)
   #foo = self.clone #.downcase.strip
   foo.gsub!(/[ĄÀ�?ÂÃ]/,'A')
   foo.gsub!(/[âäàãáäå�?ăąǎǟǡǻ�?ȃȧẵặ]/,'a')
   foo.gsub!(/[Ę]/,'E')
   foo.gsub!(/[ëêéèẽēĕėẻȅȇẹȩęḙḛ�?ếễểḕḗệ�?]/,'e')
   foo.gsub!(/[Ì�?ÎĨ]/,'I')
   foo.gsub!(/[�?iìíîĩīĭïỉ�?ịįȉȋḭɨḯ]/,'i')
   foo.gsub!(/[ÒÓÔÕÖ]/,'O')
   foo.gsub!(/[òóôõ�?�?ȯö�?őǒ�?�?ơǫ�?ɵøồốỗổȱȫȭ�?�?ṑṓ�?ớỡởợǭộǿ]/,'o')
   foo.gsub!(/[ÙÚÛŨÜ]/,'U')
   foo.gsub!(/[ùúûũūŭüủůűǔȕȗưụṳųṷṵṹṻǖǜǘǖǚừứữửự]/,'u')
   foo.gsub!(/[ỳýŷỹȳ�?ÿỷẙƴỵ]/,'y')
   foo.gsub!(/[œ]/,'oe')
   foo.gsub!(/[ÆǼǢæ]/,'ae')
   foo.gsub!(/[Ń]/,'N')
   foo.gsub!(/[ñǹń]/,'n')
   foo.gsub!(/[ÇĆČ]/,'C')
   foo.gsub!(/[çćč]/,'c')
   foo.gsub!(/[ß]/,'ss')
   foo.gsub!(/[œ]/,'oe')
   foo.gsub!(/[ij]/,'ij')
   foo.gsub!(/[Ł]/,'L')
   foo.gsub!(/[�?ł]/,'l')
   foo.gsub!(/[ŚŠ]/,'S')
   foo.gsub!(/[śš]/,'s')
   foo.gsub!(/[ŹŻ]/,'Z')
   foo.gsub!(/[źż]/,'z')
   #foo.sub!(/[\s\'\"\\\/\?\.\=\+\&\%]$/,'')
   #foo.gsub!(/[\s\'\"\\\/\?\.\=\+\&\%]/,'_')
   #foo.gsub!(/_+/,'_')
   foo
  end

  def to_permalink(separator = '-')
    permalink = self.to_ascii_brutal
    #permalink = string.to_ascii_brutal
    # all down
    permalink.downcase!

    # preserve alphanumerics, everything else becomes a separator
    permalink.gsub!(/[^a-z0-9]+/, separator)

    # enforce the maximum component length and return it
    #permalink = permalink.to(max_size)

    # trim any leading or trailing separators
    return permalink.gsub(/^\#{separator}+|\#{separator}+$/, '')
  end

end

Gemfile

# frozen_string_literal: true

source "https://rubygems.org"

# https://kitaitimakoto.gitlab.io/epub-parser/file.Home.html
gem "epub-parser"

renamer.rb

#!/usr/bin/env ruby

require "fileutils"
require "epub/parser"
require_relative "ascii_tic"
String.prepend(AsciiTic)

epub_path = ARGV[0]

if(epub_path.nil? || !File.exist?(epub_path) || !File.file?(epub_path))
  abort "need valid path to epub file"
else
  puts "#{epub_path} ..."
end

# 1. parse and extract metadata
book = EPUB::Parser.parse(epub_path)
# metadata:
md = book.package.metadata

title = md.titles[0].content
title_latin1 = title.to_ascii_brutal.strip

author = md.creators[0].content
author_latin1 = author.to_ascii_brutal.strip

if(title_latin1.empty?)
  abort "...title in metadata empty, aborting."
end
if(author_latin1.empty?)
  abort "...author in metadata empty, aborting."
end

# 2. rename the file
new_title = "#{title_latin1} - #{author_latin1}"
new_filename = "#{new_title}.epub"
if(File.basename(epub_path) != new_filename)
  puts "...renaming to #{new_filename}"
  new_epub_path = File.join(File.dirname(epub_path), "#{new_title}.epub")
  FileUtils.mv(epub_path, new_epub_path)
else
  puts "...file already named optimally in accordance with metadata"
end

# 3. check if there's associated mobi file, if yes then also rename
associated_mobi_name = File.basename(epub_path, File.extname(epub_path)) + ".mobi"
associated_mobi_path = File.join(File.dirname(epub_path), associated_mobi_name)

if(File.exist?(associated_mobi_path) && File.file?(associated_mobi_path))
  # mobi file found, let's rename it as well
  puts "...found associated .mobi file"
  if(File.basename(associated_mobi_name) != "#{new_title}.mobi")
    puts "...renaming associated .mobi file as well"
    new_mobi_path = File.join(File.dirname(associated_mobi_path), "#{new_title}.mobi")
    FileUtils.mv(associated_mobi_path, new_mobi_path)
  end
end