# frozen_string_literal: true

autoload :OptionParser, 'optparse'
autoload :Pathname, 'pathname'

module Asciidoctor::Reducer
  autoload :VERSION, (::File.join __dir__, 'version.rb')

  class Cli
    def parse args
      options = {}

      opt_parser = ::OptionParser.new do |opts|
        opts.program_name = 'asciidoctor-reducer'
        opts.banner = <<~EOS
        Usage: #{opts.program_name} [OPTION]... FILE

        Reduces an AsciiDoc document with includes to a single AsciiDoc document.

        EOS

        opts.on '-o FILE', '--output=FILE', 'Set the output filename or stream' do |file|
          options[:output_file] = file
        end

        opts.on '-h', '--help', 'Display this help text and exit' do
          $stdout.write opts.help
          return 0
        end

        opts.on '-v', '--version', %(Display version information and exit) do
          $stdout.write %(#{opts.program_name} #{::Asciidoctor::Reducer::VERSION}\n)
          return 0
        end
      end

      args = opt_parser.parse args

      if args.empty?
        opt_parser.warn 'Please specify an AsciiDoc file to reduce.'
        $stdout.write opt_parser.help
        1
      elsif args.size == 1
        options[:input_file] = args[0]
        options[:output_file] = '-' unless options[:output_file]
        [0, options]
      else
        opt_parser.warn %(extra arguments detected (unparsed arguments: #{(args.drop 1).join ' '}))
        $stdout.write opt_parser.help
        [1, options]
      end
    rescue ::OptionParser::InvalidOption
      $stderr.write %(#{opt_parser.program_name}: #{$!.message}\n)
      $stdout.write opt_parser.help
      1
    end

    def self.run args = ARGV
      code, options = new.parse (Array args)
      return code unless code == 0 && options
      if (output_file = options.delete :output_file) == '-'
        to = $stdout
      else
        (to = ::Pathname.new output_file).dirname.mkpath
      end
      if (input_file = options.delete :input_file) == '-'
        reduced = (Asciidoctor.load $stdin, safe: :safe).source + ?\n
      else
        reduced = (Asciidoctor.load_file input_file, safe: :safe, to_file: false).source + ?\n
      end
      Pathname === to ? (to.write reduced, encoding: ::Encoding::UTF_8) : (to.write reduced)
      0
    rescue ::IOError
      $stderr.write %(asciidoctor-reducer: #{$!.message}\n)
      1
    end
  end
end