# frozen_string_literal: true

require_relative 'api'
autoload :OptionParser, 'optparse'

module Asciidoctor::Reducer
  class Cli
    LOG_LEVELS = (::Logger::Severity.constants false).each_with_object({}) do |level, accum|
      accum[level.to_s.downcase] = (::Logger::Severity.const_get level) unless level == :UNKNOWN
    end

    def parse args
      options = { attributes: {}, log_level: LOG_LEVELS['warn'], safe: :unsafe }

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

        Reduces a composite AsciiDoc document containing includes and conditionals to a single AsciiDoc document.

        EOS

        opts.on '-a KEY[=VALUE]', '--attribute=KEY[=VALUE]',
          'set a document attribute in the AsciiDoc document: [key, key!, key=value]' do |attr|
          key, val = attr.split '=', 2
          val ||= ''
          options[:attributes][key] = val
        end

        opts.on '--log-level LEVEL', %w(debug info warn error fatal),
          'set the minimum level of messages to log: [debug, info, warn, error, fatal] (default: warn)' do |level|
          options[:log_level] = level
        end

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

        opts.on '--preserve-conditionals', 'preserve preprocessor conditional directives in the reduced source' do
          options[:preserve_conditionals] = true
        end

        opts.on '-q', '--quiet', 'suppress all application log messages' do
          options[:log_level] = nil
        end

        opts.on '-rLIBRARY', '--require LIBRARY', 'require the specified library or libraries before running' do |path|
          (options[:requires] ||= []).concat path.split ','
        end

        opts.on '-S', '--safe-mode SAFE_MODE', ['unsafe', 'safe', 'server', 'secure'],
          'set safe mode level: [unsafe, safe, server, secure] (default: unsafe)' do |name|
          options[:safe] = ::Asciidoctor::SafeMode.value_for_name name
        end

        opts.on '--trace', 'trace the cause of application errors (default: false)' do
          options[:trace] = true
        end

        opts.on '-v', '--version', 'display the version information and exit' do
          print_version opts
          return 0
        end

        opts.on '-h', '--help', 'display this help text and exit' do
          print_help opts
          return 0
        end
      end

      args = opt_parser.parse args

      if args.empty?
        opt_parser.warn 'Please specify an AsciiDoc file to reduce.'
        print_help opt_parser
        1
      elsif args.size == 1
        if (requires = options.delete :requires)
          requires.uniq.each do |path|
            require path
          rescue ::LoadError
            $stderr.puts %(#{opt_parser.program_name}: '#{path}' could not be required (reason: #{$!.message}))
            return 1
          end
        end
        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 ' '}))
        print_help opt_parser
        1
      end
    rescue ::OptionParser::InvalidOption
      $stderr.puts %(#{opt_parser.program_name}: #{$!.message})
      print_help opt_parser
      1
    end

    def self.run args = ARGV
      code, options = new.parse (Array args)
      return code unless code == 0 && options
      trace = options.delete :trace
      old_logger = ::Asciidoctor::LoggerManager.logger
      if (log_level = options.delete :log_level)
        (options[:logger] = ::Asciidoctor::Logger.new $stderr).level = log_level
      else
        options[:logger] = nil
      end
      options[:to] = (output_file = options.delete :output_file) == '-' ? $stdout : (::Pathname.new output_file)
      input = (input_file = options.delete :input_file) == '-' ? $stdin : (::Pathname.new input_file)
      ::Asciidoctor::Reducer.reduce input, options
      0
    rescue ::SignalException
      $stderr.puts if ::Interrupt === $!
      $!.signo
    rescue
      raise $! if trace
      $stderr.puts %(asciidoctor-reducer: #{$!.message.delete_prefix 'asciidoctor: '})
      $stderr.puts '  Use --trace to show backtrace'
      1
    ensure
      ::Asciidoctor::LoggerManager.logger = old_logger if old_logger
    end

    private

    def print_help opt_parser
      $stdout.puts opt_parser.help.chomp
    end

    def print_version opt_parser
      $stdout.puts %(#{opt_parser.program_name} #{VERSION})
    end
  end
end