scm.rb

require 'rugged'

module TaskHelpers
  class SCM
    attr_reader :repo, :remote, :year, :revision, :release, :release_cutoff

    def initialize(env={})
      @repo     = Rugged::Repository.new Rails.root.to_s
      @remote   = env.fetch('REMOTE', 'origin')
      @year     = env.fetch('YEAR', Date.today.year)
      @revision = env.fetch('REVISION', 'master')
      @release  = env['RELEASE']

      @release_cutoff = -3
    end

    def branches
      repo.branches.each_name(:remote).select(&method(:match_prefix?)).sort
    end

    def next_release
      release || branches.last[prefix.length..-1].to_i + 1
    end

    def next_release_branch
      "releases/#{year}/#{next_release}"
    end

    def prefix
      "#{remote}/releases/#{year}/"
    end

    def stale_releases
      branches[0..release_cutoff]
    end

    def match_prefix?(branch)
      branch =~ /\A#{prefix}/
    end
  end
end