#encoding: UTF-8
=begin
/***************************************************************************
 *   2023-2024, Michael Uplawski <michael.uplawski@uplawski.eu>            *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the WTFPL 2.0 or later, see                     * 
 *   http://www.wtfpl.net/about/                                           *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.                  *
 *                                                                         *
 ***************************************************************************/
=end

require_relative 'basic_logging'
require_relative 'configuration'
require_relative 'newsgroups'

# an object of this class represents the headers of a news-article

class Headers
  include BasicLogging

  # read the headers from the article
  def initialize(article_text)
    
    @config = Configuration.instance
    line = nil
    # transform the article to an array.
    debug('before split, article_text is : ' << article_text)
    line_array = article_text.split($LN)
    debug('after split, line_array is : ' << line_array.inspect)
    # find the first empty line
    end_index = line_array.index {|ele| ele.strip == ''}
    # keep the preceding lines.
    @lines = line_array.slice!(0, end_index)
    debug('headers: ' << @lines.to_s)

    # headername: headervalue
    @headers = {}

    # fill the headers Hash from the header-lines.
    # headers may have been line-wrapped. 

    cur_header = nil
    @lines.each do |l| 
      # has the header been wrapped?
      if !l.start_with?(/\s+/)
        # header is all before the first colon
        begin  
          cur_header = l.match(/^(.*?):/)[1].to_sym
        rescue Exception => ex
          error ("Cannot match a header in line " << l << "(" << ex.message << ")")
          exit false;
        end
        # Consider the two following fixes as preliminary until proven. 
        # Getting older, this kind of problem occupies me a lot more than
        # it should.
        #
        # value is all after the first colon
        #  BUGGY: val = l.match(/:(.*)/)[1].strip
        #  BUGFIX 3/2024, use lstrip
        val = l.match(/:(.*)/)[1].lstrip
      else # start_with?('  ')
        # a wrapped value is not devided
        # BUGGY: val = l.strip
        # BUGFIX 3/2024
        val = l
      end
      # add value to the existing 
      if cur_header && @headers[cur_header]  
        @headers[cur_header] += val
      else
        # or add a new value
        @headers[cur_header] = val
      end
      #@headers[l.match(/^(.*?):/)[1].to_sym] = l.match(/:(.*)/)[1].strip
      # h = l.split(':')
      # @headers[h[0].strip.to_sym] = h[1...h.size].join(':').strip
    end
    debug('headers are ' << @headers.to_s)
    @newsgroups = Newsgroups.new(header(:Newsgroups))
    debug('Newsgroups is ' << @newsgroups.inspect)

  end

  # returns the value of header 'name'
  def header(name)
    # name must be a symbol.
    if name.respond_to?(:to_sym)
      @headers[name]     
    else 
      error(name.to_s << ' is not a symbol!')
      nil
    end
  end

  # Modify headers, if need be.
  def update()
    no_archive = @newsgroups.no_archive
    debug('no_archive should be set now : ' << no_archive.to_s)
    if no_archive 
      @headers["X-No-Archive".to_sym] = no_archive
      @headers["Archive".to_sym] = 'no'
    end
    if @config.CUSTOM_HEADERS    
      ch = @config.CUSTOM_HEADERS
      debug('setting custom headers : ' << ch.inspect)
      @config.CUSTOM_HEADERS.each do |pair| 
        ch = pair.split(':')
        hn = ch[0].strip
        hv = ch[1].strip
        # Ensure header is ascii only
        if hv.ascii_only? && hn.ascii_only?
          # <---------- special treatment Post-Processor ---------->
          hv << ' ' << PROGVERSION.to_s if hn == 'X-Post-Processor' && hv == 'flnews_post_proc'
          #  >----------<
          @headers[hn.to_sym] = hv
        else
          warn "Custom header [#{hn}:#{hv}] should be ASCII only! Header is ignored!"
        end
      end
      @headers.compact!
    end
    debug('updated headers are ' << @headers.inspect)
  end

  # remove a header
  def remove(name)
    @headers.delete(name) if @headers[name]
  end

  # basically a replacement for header(name), above.
  # But you can call self.Newsgroups or self.From etc.
  def method_missing(method, args = nil)
    return @headers[method] if @headers[method]
    error("unknown symbol '#{method}'")
  end

  # return the headers as a String.
  def join
    htext = ''
    @headers.each_pair {|h, t| htext << h.to_s << ': ' << t << $LN }
    debug('joined headers: ' << htext)
    htext
  end

  attr_reader :lines, :newsgroups

end
# EOF