#
# Copyright (c) 2009-2017 Minero Aoki, Kenshi Muto
#               2002-2008 Minero Aoki
#
# This program is free software.
# You can distribute or modify this program under the terms of
# the GNU LGPL, Lesser General Public License version 2.1.
# For details of the GNU LGPL, see the file "COPYING".
#
require 'review/book/compilable'
require 'review/lineinput'
require 'review/preprocessor'

module ReVIEW
  module Book
    class Chapter
      include Compilable

      attr_reader :number, :book

      def initialize(book, number, name, path, io = nil)
        @book = book
        @number = number
        @name = name
        @path = path
        @io = io
        @title = nil
        if @io
          begin
            @content = @io.read
          rescue
            @content = nil
          end
        else
          @content = nil
        end
        if !@content && @path && File.exist?(@path)
          @content = File.read(@path, mode: 'r:BOM|utf-8')
          @number = nil if %w[nonum nodisp notoc].include?(find_first_header_option)
        end
        @list_index = nil
        @table_index = nil
        @footnote_index = nil
        @image_index = nil
        @icon_index = nil
        @numberless_image_index = nil
        @indepimage_index = nil
        @headline_index = nil
        @column_index = nil
        @volume = nil
      end

      def find_first_header_option
        f = LineInput.new(Preprocessor::Strip.new(StringIO.new(@content)))
        while f.next?
          case f.peek
          when /\A=+[\[\s\{]/
            m = /\A(=+)(?:\[(.+?)\])?(?:\{(.+?)\})?(.*)/.match(f.gets)
            return m[2] # tag
          when %r{/\A//[a-z]+/}
            line = f.gets
            f.until_match(%r{\A//\}}) if line.rstrip[-1, 1] == '{'
          end
          f.gets
        end
        nil
      end

      def inspect
        "#<#{self.class} #{@number} #{@path}>"
      end

      def format_number(heading = true)
        return '' unless @number
        return @number.to_s if on_predef?

        if on_appendix?
          return @number.to_s if @number < 1 || @number > 27
          raise ReVIEW::ConfigError, %Q('appendix_format:' in config.yml is obsoleted.) if @book.config['appendix_format']

          i18n_appendix = I18n.get('appendix')
          fmt = i18n_appendix.scan(/%\w{1,3}/).first || '%s'
          I18n.update('appendix_without_heading' => fmt)

          return I18n.t('appendix', @number) if heading
          return I18n.t('appendix_without_heading', @number)
        end

        if heading
          I18n.t('chapter', @number)
        else
          @number.to_s
        end
      end

      def on_chaps?
        on_file?(@book.read_chaps)
      end

      def on_predef?
        on_file?(@book.read_predef)
      end

      def on_appendix?
        on_file?(@book.read_appendix)
      end

      def on_postdef?
        on_file?(@book.read_postdef)
      end

      private

      def on_file?(contents)
        contents.lines.map(&:strip).include?("#{id}#{@book.ext}")
      end

      # backward compatibility
      alias_method :on_CHAPS?, :on_chaps?
      alias_method :on_PREDEF?, :on_predef?
      alias_method :on_APPENDIX?, :on_appendix?
      alias_method :on_POSTDEF?, :on_postdef?
      alias_method :on_FILE?, :on_file?
    end
  end
end