#!/usr/bin/env ruby

# encoding: UTF-8

require 'optparse'

class File
  def self.binary?(name)
    fstat = stat(name)
    return false unless fstat.file?
    open(name) do |file|
      blk = file.read(fstat.blksize)
      return blk && (
          blk.size == 0 ||
          blk.count("^ -~", "^\r\n") / blk.size > 0.3 ||
          blk.count("\x00") > 0
        )
    end
  end
end



options = {}
OptionParser.new do |opts|
  opts.banner = "Usage: git-rank-contributors [path] [options]"
  opts.on("--file-types [TYPES]", "Comma separated list of file types") do |v|
    options[:file_types] = v.split(",")
  end

  opts.on("--count-blank", "Count blank lines") do |v|
    options[:count_blank] = v
  end

  opts.on("--count-comments", "Count comments") do |v|
    options[:count_comments] = v
  end

  opts.on("--debug", "Show debugging messages") do |v|
    options[:debug] = v
  end

  opts.on("--ignore [REGEXP]", "RegExp of files to ignore") do |v|
    options[:ignore] = Regexp.new(v)
  end
end.parse!

dir = ARGV[0] || "."


COMMENTS = {
  '.js'  => { :oneline => %r{^(//.*|.\*.*\*/)$},
              :start   => %r{^/\*},
              :end     => %r{\*/} },
  '.css' => { :oneline => %r{^/\*.*\*/$},
              :start   => %r{^/\*},
              :end     => %r{\*/} }
}


cols = `tput cols`
cols = (cols =~ /^\d+$/) ? cols.to_i : 75

files = `git ls-files #{dir}`.split("\n").map(&:strip)
files.reject!{|f| File.directory?(f) } # submodules
files.reject!{|f| !options[:file_types].include?(File.extname(f)[1..-1]) } if options[:file_types]
files.reject!{|f| f =~ options[:ignore] } if options[:ignore]
files.reject!{|f| File.binary?(f) }

puts files.join("\n") if options[:debug]

contributors = {}
total_lines = 0

puts "Processing..."

files.each do |file|
  file_disp = file.length < cols-3 ? file : file[0..(cols-3)]+"..."
  print "#{file_disp.ljust(cols)}\r"
  $stdout.flush

  ext = File.extname(file)

  file_lines = 0
  is_comment = false
  File.read(file).each do |l|
    l.strip!
    next if l.empty? && !options[:count_blank]
    if !options[:count_comments] && regexp = COMMENTS[ext]
      if is_comment
        is_comment = false if l =~ regexp[:end]
        next
      else
        next if l =~ regexp[:oneline]
        if l =~ regexp[:start] && l !~ regexp[:end]
          is_comment = true
          next
        end
      end
    end
    file_lines += 1
  end
  total_lines += file_lines

  commits = {}

  is_comment = false
  next_is_comment = false

  enum = `git blame -pw #{file}`.each_line
  loop do
    begin
      l = enum.next.strip
    rescue StopIteration
      break
    end

    if l =~ /^([a-f0-9]{40}) \d+ \d+( \d+)?$/
      last_commit = $1

      l = enum.next.strip
      if l =~ /^author (.+)$/
        commits[last_commit] = { :author => $1, :lines => 0 }
        while l = enum.next
          if l.strip =~ /^filename/
            l = enum.next.strip
            break
          end
        end
      end

      if !options[:count_comments] && regexp = COMMENTS[ext]
        if is_comment
          next_is_comment = false if l =~ regexp[:end]
        else
          if l =~ regexp[:oneline]
            is_comment = true
            next_is_comment = false
          elsif l =~ regexp[:start] && l !~ regexp[:end]
            is_comment = next_is_comment = true
          end
        end
      end

      if (options[:count_blank] || !l.empty?) && (options[:count_comments] || !is_comment)
        puts l if options[:debug]
        commits[last_commit][:lines] += 1
      end

      is_comment = next_is_comment
    end
  end

  commits.values.each do |c|
    contributors[c[:author]] ||= 0
    contributors[c[:author]] += c[:lines]
  end
end

puts " " * cols


# reverse sort by lines
contributors.sort{|a,b| b[1] <=> a[1] }.each do |name, lines|
  puts "#{name[0..30].ljust(32)}: #{lines}"
end

puts "\n"
puts "#{"Total Lines".ljust(32)}: #{total_lines}"
puts "#{"Total Processed".ljust(32)}: #{contributors.values.inject{|sum,x| sum + x}}"