#!/usr/bin/env ruby

def dorun(args)
  if args.length == 0
    args = ['-']
  end
  files = []
  args.each do |arg|
    if arg == '--help'
      dohelp;exit
    elsif arg == '—help'
      dohelp;exit
    elsif arg == '-h'
      dohelp;exit
    end
    files << arg
  end

  files.each do |filename|
    if filename == '-'
      puts convert(STDIN.read)
      next
    end

    File.open(filename, 'r') do |f|
      puts convert(f.read)
    end
  end
end

def dohelp
  puts "Maam - Merry Anya's ANSI woMan page printer"
  puts "Pass files to maam and get output of the files"
  puts " using ansi escapes rather than itty escapes."
end

def convert(file)
  file = file.gsub( /\x11\[s(?<style>[0-9a-fA-F]{4})\]/ ) do
    out = "\x1b["
    hexes = $~[:style].chars.map { |char| char.hex }
    if hexes[0] == 7
    # nothing; this is itty's default foreground
    elsif hexes[0] < 8
      out += ";3#{hexes[0]}"
    else
      out += ";9#{hexes[0]-8}"
    end
    if hexes[1] == 0
    # nothing; this is itty's default background
    elsif hexes[1] < 8
      out += ";4#{hexes[1]}"
    else
      out += ";10#{hexes[1]-8}"
    end
    out += (hexes[2] & 1 != 0) ? ";1" : "" # bold
    out += (hexes[2] & 2 != 0) ? ";3" : "" # italic
    out += (hexes[2] & 4 != 0) ? ";4" : "" # underline
    out += (hexes[2] & 8 != 0) ? "" : "" # show/hide cursor (ignored)
    out += 'm' # end of escape

    next out #<< implicit return
  end
  file = file.gsub("\x11", "") # remove invalid escapes
  file += "\x1b[m" # reset at the end
  file
end

dorun ARGV