class GivenFilesystem

# File lib/given_filesystem.rb, line 24
def initialize
  @path_elements = [ Dir.tmpdir, "given_filesystem" ]
  @base_paths = Array.new
end

# File lib/given_filesystem.rb, line 29
def cleanup
  @base_paths.each do |base_path|
    # Better safe than sorry, so do sanity check on path before removing it
    if base_path =~ /given_filesystem/
      FileUtils.rm_r base_path
    end
  end
end

# File lib/given_filesystem.rb, line 38
def directory user_provided_directory = nil
  create_random_base_path unless path_has_base?

  directory_to_create = user_provided_directory || random_name

  @path_elements.push directory_to_create

  created_path = path
  FileUtils.mkdir_p created_path
  yield if block_given?
  @path_elements.pop

  File.join path, first_segment_of_path(directory_to_create)
end

# File lib/given_filesystem.rb, line 53
def directory_from_data to, from = nil
  from ||= to

  create_random_base_path unless path_has_base?

  FileUtils.mkdir_p path
  @path_elements.push to

  created_path = path
  FileUtils.cp_r test_data_path(from), path
  @path_elements.pop
  created_path
end

# File lib/given_filesystem.rb, line 67
def file file_name = nil, options = {}
  create_random_base_path unless path_has_base?
  
  if file_name
    @path_elements.push file_name
  else
    @path_elements.push random_name
  end
 
  FileUtils.mkdir_p File.dirname(path)
 
  created_path = path
  File.open(created_path,"w") do |file|
    if options[:from]
      test_data = test_data_path(options[:from])
      if !File.exists? test_data
        raise "Test data file '#{test_data}' doesn't exist"
      end
      file.write File.read(test_data)
    else
      file.puts "GivenFilesystem was here"
    end
  end
  @path_elements.pop
  created_path
end

# File lib/given_filesystem.rb, line 96
def create_random_base_path
  @path_elements.push random_name
  @base_paths.push path
end

# File lib/given_filesystem.rb, line 117
def first_segment_of_path path
  path.split(File::SEPARATOR).reject(&:empty?).first
end

# File lib/given_filesystem.rb, line 105
def path
  @path_elements.join("/")
end

# File lib/given_filesystem.rb, line 109
def path_has_base?
  @path_elements.count > 2
end

# File lib/given_filesystem.rb, line 101
def random_name
  "#{Process.pid}-#{Time.now.strftime("%Y%m%d")}-#{rand(99999).to_s}"
end

# File lib/given_filesystem.rb, line 113
def test_data_path name
  File.expand_path('spec/data/' + name)
end