class Fetchers::Zip

def self.resolve(target)
  return nil unless File.file?(target) and target.end_with?('.zip')
  new(target)
end

def initialize(target)
  @target = target
  @contents = {}
  @files = []
  ::Zip::InputStream.open(@target) do |io|
    while (entry = io.get_next_entry)
      @files.push(entry.name.sub(%r{/+$}, ''))
    end
  end
end

def read(file)
  @contents[file] ||= read_from_zip(file)
end

def read_from_zip(file)
  return nil unless @files.include?(file)
  res = nil
  ::Zip::InputStream.open(@target) do |io|
    while (entry = io.get_next_entry)
      next unless file == entry.name
      res = io.read
      break
    end
  end
  res
end