#!/usr/bin/env ruby
# This script reads in a file and annotates it with 
# line number directives. Existing line annotations are updated.

require 'optparse'

@options = {}

OptionParser.new do |opts|
  opts.on("-o", "--out FILENAME", "Output FILENAME to write to.") do | v |
    @options[:out_file] = v
  end
  opts.on("-i", "--in FILENAME", "Input FILENAME to read.") do | v |
    @options[:in_file] = v
  end
  opts.on("-a", "--annotate REGEXP", "REGEXP, if matched, marker is written.") do | v |
    @options[:annotate_re] = Regexp.new(v)
  end
  opts.on("-f", "--format FORMAT", "printf FORMAT of marker, must contain %s and %d of.") do | v |
    @options[:marker_format] = v
  end
  opts.on("-m", "--marker REGEXP", "REGEXP, if matched, marker is updated.") do | v |
    @options[:marker_re] = Regexp.new(v)
  end
  opts.on("-s", "--skip", "If set skipsthe markers in the line count") do | v |
    @options[:skip] = true
  end
end.parse!

file_name = @options[:in_file] || ARGV[0]

if file_name == nil
    puts "liner: liner [options] file_to_annotate"
    exit 1
end

annotate_re      = @options[:annotate_re] || %r{^(func|type|const)}
marker_format    = @options[:marker_format] || "//line %s:%d\n"
marker_re        = @options[:marker_re] || %r{^//line [^:]+:[0-9]+$}
out_name         = @options[:out_file]

lines = nil
File.open(file_name) do |file|
    lines = file.readlines
end

marker_before    = false

out = $stdout
if out_name 
  out = File.open(out_name, "w+")
  if out == nil 
    puts "liner: cannot open output file #{out_name}"
    exit 2
  end
end

line_number = 0
lines.each do |line| 
    line_number += 1
    marker_match       = marker_re.match(line)
    if marker_match   != nil
        # Update existing marker
        out.printf(marker_format, file_name, line_number)
        marker_before  = true
        # Skip read line in output
        next        
    end
    
    if marker_before
        marker_before  = false
    else 
        annotate_match = annotate_re.match(line)
        if annotate_match
          out.printf(marker_format, file_name, line_number)
          line_number += 1 unless @options[:skip]
        end
    end
    out.puts(line)
end

if out != $stdout
  out.close
end