#!/usr/bin/ruby
# Based on asciidoctor main ruby script.
# This is only meant to introspect and log which asciidoc files were used.

require 'asciidoctor'
require 'asciidoctor/cli'

class MainFileLogger < Asciidoctor::Extensions::Preprocessor
  include Asciidoctor::Logging

  def process document, reader
    main_file = document.normalize_system_path(reader.file, document.reader.dir)

    # This assumes unix-style path separator.
    if nil == main_file.match(/^.*\/rules\/S\d+\/(\w+\/)?rule.adoc$/)
      abort("Main file does not follow expected pattern: #{main_file}")
    end

    logger.info("ASCIIDOC LOGGER MAIN FILE:#{main_file}")
    reader
  end
end

class IncludeLogger < Asciidoctor::Extensions::IncludeProcessor
  include Asciidoctor::Logging

  def initialize document
    @config = {} # Defined in parent class; will be updated by the extension registry mechanism.
    @document = document

    # @document.reader.file is not defined yet at this stage.
    # Therefore we cannot compute the main file path and cache it.
    # This cannot be done once in handles? because the object is then frozen.
    # For these reasons, we end up recomputing the rule directory path each time.
  end

  def get_main_file reader
    # See how include_stack is used:
    # https://github.com/asciidoctor/asciidoctor/blob/f3800cc9c92faf8370041b2b27a61124318ed289/lib/asciidoctor/reader.rb#L669
    if reader.include_stack.empty?
      reader.file
    else
      main_frame = reader.include_stack.fetch(0)
      main_frame.fetch(1)
    end
  end

  def handles? target
    include_path = @document.normalize_system_path(target, @document.reader.dir)

    main_file = get_main_file(@document.reader)
    main_file = @document.normalize_system_path(main_file, @document.reader.dir)
    rule_dir = File.dirname(File.dirname(main_file))
    rule_id = File.basename(rule_dir)
    if rule_id == 'rules'
      # This is a language-agnostic rule description.
      rule_dir = File.dirname(main_file)
      rule_id = File.basename(rule_dir)
    end
    git_dir = File.dirname(File.dirname(rule_dir))
    shared_dir = File.join(git_dir, 'shared_content')

    rule_dir = rule_dir + '/' # Don't allow S100 to include things from S1000.
    if !include_path.start_with?(rule_dir) && !include_path.start_with?(shared_dir)
      logger.info("ASCIIDOC LOGGER CROSSREFERENCE:#{rule_id} cross-references #{include_path}")
    end

    logger.info("ASCIIDOC LOGGER INCLUDE:#{include_path}")

    false # Actually, this include processor does nothing.
  end

  # Intentionnaly no process function here.
end

Asciidoctor::Extensions.register do
  preprocessor MainFileLogger
  include_processor IncludeLogger.new @document
end

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