tagversions

#!/usr/bin/env ruby -w

class TagVersions
  def initialize(args)
    print_help if args.empty?
    @regexp = nil
    @preview = false
    args.each do |argument|
      case argument
      when '-a', '--all' then @regexp = ".*"
      when '-p', '--preview' then @preview = true
      when '-h', '--help' then print_help
      else @regexp = argument
      end
    end
  end

  def print_help
    puts <<-HELP
Usage: tagversions [OPTIONS] [REGEXP]
  Look through the git commits for messages with the given regular expression and tag what looks like verisons.

  Options:
    -a, --all     Search all commits, not just the ones matching the regular expression.
    -p, --preview Don't do actual branching, instead print out what will be tagged.
    -h, --help    Display this help page.
HELP
    exit
  end

  def run
    tags = `git tag`.split("\n")
    `git log --pretty="%H %s" | grep "#{@regexp}"`.split("\n").each do |line|
      version = line[/\bv?(\d\.[\d\.]*)\b/, 1]
      sha = line[/^\w+/]
      if version && !version.empty? && !tags.include?(version)
        puts "Tagging #{version} on #{sha}"
        tags << version
        `git tag -a "#{version}" -m "version #{version}" "#{sha}"` unless @preview
      end
    end
  end
end

TagVersions.new($*).run