require 'optparse'
require 'epub/parser'

using EPUB::Parser::XMLDocument::Refinements

options = {:format => :line}
navigation_types = {
  :toc => "table of contents",
  :"page-list" => "page list",
  :landmarks => "landmarks"
}
opt = OptionParser.new do |opt|
  opt.banner = <<EOB
Show metadata of an EPUB file

Usage: epubinfo [options] EPUBFILE

EOB
  opt.version = EPUB::Parser::VERSION
  formats = [:line, :json, :yaml]
  opt.on '-f', '--format=FORMAT', formats, "format of output(#{formats[0..-2].join(', ')} or #{formats.last}), defaults to line(for console)" do |format|
    options[:format] = format
  end
  opt.on '--words', 'count words of content documents' do
    options[:words] = true
  end
  opt.on '--chars', 'count charactors of content documents' do
    options[:chars] = true
  end
  opt.on "--navigation[=TYPE]",navigation_types.keys, "show specified type of navigation(#{navigation_types.keys[0..-2].join(', ')} or #{navigation_types.keys.last})", "If TYPE is omitted, show all types of navigations.", "Can specify multiple times." do |type|
    if type
      options[type] = true
    else
      navigation_types.keys.each do |type|
        options[type] = true
      end
    end
  end
  navigation_types.each_pair do |key, name|
    opt.on "--#{key}", "show #{name} navigation(in line format only)" do
      options[key] = true
    end
  end
end
opt.parse!(ARGV)

file = ARGV.shift
unless file
  $stdout.puts "error: you must supply an EPUB file name"
  $stdout.puts opt.help
  abort
end

EPUB::OCF::PhysicalContainer.adapter = :UnpackedDirectory if File.directory? file
unless File.readable? file
  uri = URI.parse(file) rescue nil
  if uri
    EPUB::OCF::PhysicalContainer.adapter = :UnpackedURI
    file = uri
  end
end
book = EPUB::Parser.parse(file)
data = {'title' => book.title}
data.merge!(book.metadata.to_h)
data['modified'] = book.modified
data['unique identifier'] = book.metadata.unique_identifier
data['epub version'] = book.package.version
nav = book.manifest.navs.first
data["navigations"] = nav ? nav&.content_document&.navigations&.collect(&:type)&.join(", ") : []

data.each_pair do |(key, value)|
  data[key] = value.respond_to?(:join) ? value.join(", ") : value.to_s
end

counts = {:chars => 0, :words => 0}
if options[:words] or options[:chars]
  namespaces = {"xhtml" => "http://www.w3.org/1999/xhtml"}
  book.resources.select(&:xhtml?).each do |xhtml|
    begin
      doc = EPUB::Parser::XMLDocument.new(xhtml.read)
      body = doc.each_element_by_xpath('//xhtml:body', namespaces).first
      if body
        content = body.content
        counts[:words] += content.scan(/\S+/).length
        counts[:chars] += content.gsub(/\r|\n/, '').length
      end
    rescue => error
      warn "#{xhtml.href}: #{error}"
    end
  end
end
data['words'] = counts[:words] if options[:words]
data['characters'] = counts[:chars] if options[:chars]
if options[:format] == :line
  key_width = data.keys.map {|k| k.length}.max + 3
  data.each_pair do |k, v|
    puts (k.to_s.capitalize + ':').ljust(key_width) + v.to_s
  end
  navigation_types.each_pair do |key, name|
    if options[key]
      puts ""
      puts "=== #{name} ==="
      nav_item = book.manifest.nav
      if nav_item
        nav = nav_item.content_document.navigations.find {|nav| nav.type == key.to_s.sub("-", "_")}
        if nav
          nav.traverse do |item, depth|
            text = item.text || "(No heading)"
            text += "(#{item.types.sort.join(', ')})" unless item.types.empty?
            puts "#{'  ' * depth}#{text}"
          end
        else
          puts "(No #{name})"
        end
      else
        puts "(No #{name})"
      end
    end
  end
else
  require options[:format].to_s
  puts data.__send__("to_#{options[:format]}")
end