require "techbook"

require "asciidoctor"
require "asciidoctor-pdf"
require "asciidoctor-epub3"
require "asciidoctor-diagram"
require "listen"
require "fileutils"

module Techbook
  class Builder
    attr_accessor :basename, :pdf, :html, :epub, :mobi, :docbook, :output, :file, :path

    def self.run(pdf:, html:, epub:, mobi:, docbook:, output:, watch:)
      b = new pdf, html, epub, mobi, docbook, output
      b.build

      if watch
        Signal.trap("SIGINT") do
          puts "Bye :)".green
          exit
        end

        puts "Watching changes for #{output}".green

        listener = Listen.to(File.join(output, "book")) { b.build }
        listener.start
        sleep
      end
    end

    def initialize(pdf, html, epub, mobi, docbook, output)
      @pdf = pdf
      @html = html
      @epub = epub
      @mobi = mobi
      @docbook = docbook
      @output = output

      @basename = File.basename @output
      @book = File.join @output, "#{@basename}.asc"
      @path = File.join @output, "build"
    end

    def build
      puts "Building book...".yellow

      prepare
      generate_includes

      build_pdf
      build_html
      build_docbook
      build_epub
      build_mobi

      dist
      clean
    end

    private

    def prepare
      FileUtils.mkdir_p File.join(@path, "img")
      FileUtils.mkdir_p File.join(@path, "src")

      Dir.glob(File.join(@output, "book", "**", "img", "*")).each do |img|
        FileUtils.copy(img, File.join(@path, "img", File.basename(img)))
      end

      Dir.glob(File.join(@output, "book", "**", "src", "*")).each do |src|
        FileUtils.copy(src, File.join(@path, "src", File.basename(src)))
      end
    end

    def generate_includes
      content = File.read @book
      content = content.lines.reject { |line|
        line =~ /(include::|^\n)/
      }.join

      Dir.glob(File.join(@output, "book", "*.asc")).sort.each do |file|
        next unless file =~ /[0-9]+\-/
        content << "\ninclude::#{File.basename(file)}[]\n"
      end

      File.open(@book, "w") { |file| file.write(content) }
    end

    def build_pdf
      puts "[" + (@pdf ? "✓".green : "✕".red) + "] PDF"
      return unless @pdf

      Asciidoctor.convert_file @book, base_options.merge(backend: "pdf")
    end

    def build_html
      puts "[" + (@html ? "✓".green : "✕".red) + "] HTML"
      return unless @html

      Asciidoctor.convert_file @book, base_options.merge(backend: "html")
    end

    def build_docbook
      puts "[" + (@docbook ? "✓".green : "✕".red) + "] DOCBOOK"
      return unless @docbook

      Asciidoctor.convert_file @book, base_options.merge(backend: "docbook")
    end

    def build_epub
      puts "[" + (@epub ? "✓".green : "✕".red) + "] EPUB"
      return unless @epub

      Asciidoctor.convert_file @book, base_options.merge(backend: "epub3")
    end

    def build_mobi
      puts "[" + (@mobi ? "✓".green : "✕".red) + "] MOBI"
      return unless @mobi

      Asciidoctor.convert_file @book, base_options.merge(ebook_format: "kf8", backend: "epub3")
    end

    def base_options
      { safe: Asciidoctor::SafeMode::UNSAFE,
        base_dir: File.join(@output, "book"),
        to_dir: @path }
    end

    def dist
      FileUtils.mkdir_p File.join(@output, "dist", "img")
      FileUtils.mkdir_p File.join(@output, "dist", "src")

      FileUtils.copy_entry File.join(@path, "img"), File.join(@output, "dist", "img")
      FileUtils.copy_entry File.join(@path, "src"), File.join(@output, "dist", "src")

      FileUtils.copy File.join(@path, "#{@basename}.pdf"), File.join(@output, "dist") if @pdf
      FileUtils.copy File.join(@path, "#{@basename}.xml"), File.join(@output, "dist") if @docbook
      FileUtils.copy File.join(@path, "#{@basename}.html"), File.join(@output, "dist") if @html
      FileUtils.copy File.join(@path, "#{@basename}.epub"), File.join(@output, "dist")  if @epub
      FileUtils.copy File.join(@path, "#{@basename}.mobi"), File.join(@output, "dist")  if @mobi
    end

    def clean
      FileUtils.rm_rf @path
    end
  end
end