Rakefile

namespace :book do

    # Variables referenced for build
    version_string = `git describe --tags --abbrev=0`.chomp
    if version_string.empty?
      version_string = '0'
    else
      versions = version_string.split('.')
      version_string = versions[0] + '.' + versions[1] + '.' + versions[2].to_i.next.to_s
    end
    date_string = Time.now.strftime('%Y-%m-%d')
    params = "--attribute revnumber='#{version_string}' --attribute revdate='#{date_string}'"
    header_hash = `git rev-parse --short HEAD`.strip

    # Check contributors list
    # This checks commit hash stored in the header of list against current HEAD
    def check_contrib
      if File.exist?('book/contributors.txt')
        current_head_hash = `git rev-parse --short HEAD`.strip
        header = `head -n 1 book/contributors.txt`.strip
        # Match regex, then coerce resulting array to string by join
        header_hash = header.scan(/[a-f0-9]{7,}/).join

        if header_hash == current_head_hash
          puts "Hash on header of contributors list (#{header_hash}) matches the current HEAD (#{current_head_hash})"
        else
          puts "Hash on header of contributors list (#{header_hash}) does not match the current HEAD (#{current_head_hash}), refreshing"
          sh "rm book/contributors.txt"
          # Reenable and invoke task again
          Rake::Task['book/contributors.txt'].reenable
          Rake::Task['book/contributors.txt'].invoke
        end
      end
    end

    desc 'build basic book formats'
    task :build => [:build_html, :build_epub, :build_fb2, :build_mobi, :build_pdf] do
      begin
          # Run check
          Rake::Task['book:check'].invoke

          # Rescue to ignore checking errors
          rescue => e
          puts e.message
          puts 'Error when checking books (ignored)'
      end
    end

    desc 'build basic book formats (for ci)'
    task :ci => [:build_html, :build_epub, :build_fb2, :build_mobi, :build_pdf] do
        # Run check, but don't ignore any errors
        Rake::Task['book:check'].invoke
    end

    desc 'generate contributors list'
    file 'book/contributors.txt' do
        puts 'Generating contributors list'
        sh "echo 'Do #{header_hash} so prispevali:\n' > book/contributors.txt"
        sh "git shortlog -s HEAD | grep -v -E '(Straub|Chacon|dependabot)' | cut -f 2- | sort | column -c 80 >> book/contributors.txt"
    end

    desc 'build HTML format'
    task :build_html => 'book/contributors.txt' do
        check_contrib()

        puts 'Converting to HTML...'
        sh "bundle exec asciidoctor #{params} -a data-uri progit.asc"
        puts ' -- HTML output at progit.html'

    end

    desc 'build Epub format'
    task :build_epub => 'book/contributors.txt' do
        check_contrib()

        puts 'Converting to EPub...'
        sh "bundle exec asciidoctor-epub3 #{params} progit.asc"
        puts ' -- Epub output at progit.epub'

    end

    desc 'build FB2 format'
    task :build_fb2 => 'book/contributors.txt' do
        check_contrib()

        puts 'Converting to FB2...'
        sh "bundle exec asciidoctor-fb2 #{params} progit.asc"
        puts ' -- FB2 output at progit.fb2.zip'

    end

    desc 'build Mobi format'
    task :build_mobi => 'book/contributors.txt' do
        check_contrib()

        puts "Converting to Mobi (kf8)..."
        sh "bundle exec asciidoctor-epub3 #{params} -a ebook-format=kf8 progit.asc"
        puts " -- Mobi output at progit.mobi"
    end

    desc 'build PDF format'
    task :build_pdf => 'book/contributors.txt' do
        check_contrib()

        puts 'Converting to PDF... (this one takes a while)'
        sh "bundle exec asciidoctor-pdf #{params} progit.asc 2>/dev/null"
        puts ' -- PDF output at progit.pdf'
    end

    desc 'Check generated books'
    task :check => [:build_html, :build_epub] do
        puts 'Checking generated books'

        sh "htmlproofer progit.html"
        sh "epubcheck progit.epub"
    end

    desc 'Clean all generated files'
    task :clean do
      begin
          puts 'Removing generated files'

          FileList['book/contributors.txt', 'progit.html', 'progit-kf8.epub', 'progit.epub', 'progit.fb2.zip', 'progit.mobi', 'progit.pdf'].each do |file|
              rm file

              # Rescue if file not found
              rescue Errno::ENOENT => e
                begin
                    puts e.message
                    puts 'Error removing files (ignored)'
                end
          end
      end
    end

  end

  task :default => "book:build"