class KPM::Sha1Checker

def self.from_file(sha1_file, logger=nil)
  Sha1Checker.new(sha1_file, logger)
end

def add_or_modify_entry!(coordinates, sha1)
  @sha1_config['sha1'][coordinates] = sha1
  save!
end

def init!
  if !File.exists?(@sha1_file)
    init_config = {}
    init_config['sha1'] = {}
    File.open(@sha1_file, 'w') do |file|
      file.write(init_config.to_yaml)
    end
  end
  reload!
end

def initialize(sha1_file, logger=nil)
  @sha1_file = sha1_file
  init!
  if logger.nil?
    @logger       = Logger.new(STDOUT)
    @logger.level = Logger::INFO
  else
    @logger = logger
  end
end

def reload!
  @sha1_config = YAML::load_file(@sha1_file)
end

def save!
  Dir.mktmpdir do |tmp_destination_dir|
    tmp_file = File.join(tmp_destination_dir, File.basename(@sha1_file))
    File.open(tmp_file, 'w') do |file|
      file.write(@sha1_config.to_yaml)
    end
    FileUtils.copy(tmp_file, @sha1_file)
  end
  reload!
end

def sha1(coordinates)
  @sha1_config['sha1'][coordinates]
end