#!/usr/bin/env ruby

require "optparse"
require "asciidoctor/cli"

supported_backends = [
  {
    short: :rfc2,
    load_path: "asciidoctor/rfc/v2/converter",
    asciidoctor_backend: "rfc2"
  },

  {
    short: :rfc3,
    load_path: "asciidoctor/rfc/v3/converter",
    asciidoctor_backend: "rfc3"
  },

  {
    short: :iso,
    load_path: "asciidoctor/iso/converter",
    asciidoctor_backend: "iso"
  },

  {
    short: :gb,
    load_path: "asciidoctor/gb/converter",
    asciidoctor_backend: "gb"
  },

  {
    short: :csd,
    load_path: "asciidoctor/csd/converter",
    asciidoctor_backend: "csd"
  },

  # {
  #   short: :rsd,
  #   load_path: "asciidoctor/rsd/converter",
  #   asciidoctor_backend: "rsd"
  # },
]

print "[metanorma] detecting backends: "
backends_enabled, backends_disabled = supported_backends.partition do |backend|
  begin
    print "#{backend[:short]} "
    require backend[:load_path]
    true
  rescue LoadError
    # puts "[metanorma] backend #{backend[:short]} not present"
    false
  end
end
puts

options = {
  format: "asciidoc"
}

backend_keys = backends_enabled.map {|b| b[:short].to_s }

opt_parser = OptionParser.new do |opts|
  opts.banner += " <file>"
  opts.on(
    '-t',
    '--type TYPE',
    "Type of standard to generate: #{backend_keys.join(", ")}"
  ) { |v| options[:type] = v }

  opts.on(
    '-f',
    '--format FORMAT',
    'Format of source file: asciidoc (current default, only format supported)'
  ) { |v| options[:format] = v }

  opts.on_tail("-h", "--help", "Show this message") do
    puts opts
    exit
  end

end

opt_parser.parse!(ARGV)
options[:filename] = ARGV.pop

unless options[:type]
  puts "[metanorma] Error: Please specify a standard type."
  puts opt_parser.help
  exit 0
end

unless backend_keys.include? options[:type]
  puts "[metanorma] Error: #{options[:type]} is not a supported standard type."
  exit 0
end

unless options[:format] == "asciidoc"
  puts "[metanorma] Error: Only source file format currently supported is 'asciidoc'."
  exit 0
end

unless options[:filename]
  puts "[metanorma] Error: Need to specify a file to process."
  exit 0
end

asciidoc_options = Asciidoctor::Cli::Options.new(
  backend: options[:type],
  header_footer: true
)
if asciidoc_options.parse!([options[:filename]]) == 0
  puts "[metanorma] Error: Backend process error."
  exit 0
end

invoker = Asciidoctor::Cli::Invoker.new asciidoc_options
GC.start
invoker.invoke!
exit invoker.code