git.rb

require 'active_support/core_ext/hash/keys'

class Git
  PATHNAME = File.expand_path('output', '.')
  REPOSITORY = ENV['REPOSITORY'] || 'https://github.com/alphagov/govuk-rfcs.git'
  AUTHOR = ENV['AUTHOR'] || 'govuk-tech-members'

  class << self
    def init
      FileUtils.rm_rf PATHNAME
      FileUtils.mkdir_p PATHNAME
      git 'init'
    end

    def checkout(name)
      if git 'rev-parse', name
        git 'checkout', name
      else
        git 'checkout', '-b', name
      end
    end

    def add(old_name: nil, new_name:, contents:, message: nil, author: AUTHOR, date: Time.now.to_s, page_id: nil)
      if old_name && old_name != new_name
        git 'mv', old_name, new_name
      end

      File.write(new_name, contents)
      git 'add', new_name

      message = nil if message == ''
      message ||= "Update #{new_name}"

      message << "\n\nOriginal url: https://gov-uk.atlassian.net/wiki/pages/viewpage.action?pageId=#{page_id}" if page_id

      t = Tempfile.new('message')
      t.write(message)
      t.close

      author_name = author.sub('.', ' ').titleize
      author_email = "#{author}@digital.cabinet-office.gov.uk"
      author_line = "'#{author_name} <#{author_email}>'"

      git 'commit',
        '-F', t.path,
        '--author', author_line,
        '--date', "'#{date}'",
        GIT_COMMITTER_NAME: author_name,
        GIT_COMMITTER_EMAIL: author_email

      t.unlink
    end

    def add_remote
      git 'remote', 'add', 'origin', REPOSITORY
    end

    def push_all
      git "push origin --all --force"
    end

    private
    def git(*args, **env)
      FileUtils.cd PATHNAME
      cmd = (['git'] + args.flatten).join(' ')
      system env.stringify_keys, cmd
      $?.exitstatus == 0
    end
  end
end