remove_epub_cover

#!/usr/bin/env ruby
# frozen_string_literal: true

# HELIO-3909. Script to remove reference to covers in EPUBs.

require 'optparse'
require 'ostruct'
require 'os'

# Process the script parameters.
options = OpenStruct.new
option_parser = OptionParser.new do |opts|
  opts.banner = "Usage: #{File.basename(__FILE__)} <epub_file> [<epub_file>...]"
  opts.on_tail('-h', '--help', 'Print this help message') do
    puts opts
    exit 0
  end
end
option_parser.parse!(ARGV)
if ARGV.count < 1
  puts option_parser.help
  return
end

# Process the command line parameters.
epub_file_list = ARGV

require 'logger'
script_logger = Logger.new(STDOUT)
script_logger.formatter = proc do |severity, datetime, progname, msg|
  "#{severity}: #{msg}\n"
end

# Determine the root directory of the code base.
script_dir = File.expand_path(File.dirname(__FILE__))
root_dir = File.dirname(script_dir)

require_relative File.join(root_dir, 'lib', 'epub')

epub_file_list.each do |epub_file|
  epub_file = File.expand_path(epub_file)
  unless File.file?(epub_file)
    script_logger.fatal("Invalid EPUB \"#{epub_file}\".")
    next
  end
  script_logger.info("Using EPUB \"#{epub_file}\".")

  epub = UMPTG::EPUB::Archive.new(epub_file: epub_file)

  opf_entry = epub.opf
  opf_doc = UMPTG::XML.parse(xml_content: opf_entry.content)

=begin
  node_list = opf_doc.xpath("//*[local-name()='metadata']/*[local-name()='meta' and @name='cover']")
  if node_list.empty?
    script_logger.warn("Unable to find cover metadata.")
    next
  end
  cover_name = node_list.first["content"]
  script_logger.info("Found cover metadata \"#{cover_name}\".")
=end

  node_list = opf_doc.xpath("//*[local-name()='spine']/*[local-name()='itemref' and @idref='cover']")
  if node_list.empty?
    script_logger.warn("Unable to find cover spine reference.")
  else
    node_list.first.unlink
    script_logger.info("Removed cover spine reference.")
    epub.add(entry_name: opf_entry.name, entry_content: UMPTG::XML.doc_to_xml(opf_doc))
  end

  toc_entry = epub.entry("OEBPS/toc_flow.xhtml")
  if toc_entry.nil?
    script_logger.warn("Unable to find TOC entry.")
  else
    script_logger.info("Found TOC entry.")
    toc_doc = UMPTG::XML.parse(xml_content: toc_entry.content)
    node_list = toc_doc.xpath("//*[local-name()='li']/*[local-name()='a']/*[local-name()='h3']")
    if node_list.empty?
      script_logger.warn("Unable to find H3 within TOC entries.")
    else
      node_list.each do |node|
        text = Nokogiri::XML::Text.new(node.content, node.document)
        node.replace(text)
      end
      script_logger.info("Removed H3 within TOC entries.")
      epub.add(entry_name: toc_entry.name, entry_content: UMPTG::XML.doc_to_xml(toc_doc))
    end
  end

  fixed_epub_file = File.join(File.dirname(epub_file), File.basename(epub_file, ".*") + "_nocover.epub")
  script_logger.info("Saving #{fixed_epub_file}")
  epub.save(
        epub_file: fixed_epub_file
      )
end